Electronics Lab Philippines

Analog and Mixed Signal => Industrial Electronics and Industrial Engineering => Topic started by: glutnix_neo on February 12, 2008, 08:19:11 AM

Title: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 12, 2008, 08:19:11 AM
Para sa lahat ng mga friendster's jan na maraming agam-agam sa technology ng SMPS free kayo magpost ng questions dito and I am willing to share what i know.

I think, this post will be my permanent tambayan.hehehe, hangout na mga dude

BTW
I am a Design Engineer working on a Power Supply Design Company
2.5 years sa Hardware and
1.5 years sa Firmware
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 12, 2008, 08:24:46 AM
plug-in ko lang website ko, nakakahiya man kasi last year pa huling update ko at kulang kulang pa, hehehe

http://badboyzgear.awardspace.com/

sana makumpleto ko na xa.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: paranz on February 12, 2008, 08:31:37 AM
nice site. Keep it up bro, sana meron din ako nyan.  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: paranz on February 12, 2008, 08:33:13 AM
btw, can you suggest other SMPS IC na available dito sa pinas maliban sa TL494. ty
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on February 12, 2008, 08:34:17 AM
first question, how do we design a switch-mode power supply?

pano nga ba?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Anna on February 12, 2008, 09:00:18 AM
btw, can you suggest other SMPS IC na available dito sa pinas maliban sa TL494. ty

as384X. more info can be found at the texas instruments site.

i hope this helps.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Anna on February 12, 2008, 09:08:45 AM
first question, how do we design a switch-mode power supply?

pano nga ba?

in essence, designing smps goes like this:

1. list down the input/output requirements
2. determine the appropriate topology accd. to 1
3. design the magnetic parts i.e. transformer, output chokes, etc.
4. prototype and test

other factors have to be considered too like thermal and mechanical requirements. but this procedure will suffice for hobbyist type projects. if its for a commercial application, compliance and reliability are also major concerns.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 12, 2008, 09:26:00 AM
UC3842 po meron sa alexan, one concern ko lang sa design ng SMPS is yung availability ng inductor core, meron ba kayong alam na mabibilhan nun locally?

regarding sa question ni sir Mars, there are steps na dapat iconsider sa design ng power supply

1st Isolated ba or non-isolated?, kung off-line or yung coming from AC, use isolated, kung baterry operated mas madali kung non-isolated

2nd, choose a topology
Non-isolated Topologies are
1. Buck               - For stepping down input voltage
2. Boost              - For stepping up
3. Buck-Boost      - Stepping up or stepping down

Isolated(with transformer) topologies are
1. Flyback           - Malimit ginagamit sa mga cellphone chargers(self-oscillating flyback) natin dahil simple ang circuit at makakamura
                        - ginagamit din sa ATX power suplly kasi madali magproduce ng multiple output
2. Forward          - Minsan ginagamit din sa ATX to
3. Full Bridge       - pang high power na to kasi complex na circuit

3rd is yung IC na gagamitin, locally limited lang tayo sa choice ng IC. Then yun na compute na mga voltages, igaguide naman tayo ng mga datasheets ng IC kung pada magdesign using the IC.


Related Links
SMPShttp://en.wikipedia.org/wiki/Switched-mode_power_supply (http://en.wikipedia.org/wiki/Switched-mode_power_supply)


Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Siramiko on February 12, 2008, 10:28:34 AM
salamat
 gusto ko talagang matutunan SMPS, marami ng akong tanong tungkol diyan.
may simple explanation ka ba kung paano gumagana yan ? 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 12, 2008, 11:10:48 AM
OK here's a short explaination, I'll try to make it as simple as possible

Para sa new sa PSU technology, there are three(main types are only two) types of power supply
1. Linear Power Supply - The transistor is operated in active region mostly in linear region, effectively para xang potentimeter na        binabago ang resistance
2. Switched Mode Power Supply - In here the transistor is operated on cutoff and saturation (switching) kaya naderive ang name na "switched Mode"
3. Others - some say a zener regulator falls under this category but it is not a real regulated PSU

The simplest SMPS topology(circuit) is the buck converter, basically what it does is it converts a higher input voltage to a lower output voltage.

(http://www.daycounter.com/LabBook/BuckConverter/BuckConverterSchematic.gif)
From the diagram above, the switch represents a MOSFET na iniswiswitch natin on and off, pag ginawa natin to alam natin na square wave pulse ang lalabas sa output but the LC combination serves as a low pass filter na pinifilter nya ang high frequency at ang natira na lang sa output eh pure DC(average ng pulse).

Alam natin from integral calculus(naks math,hehe) na ang average ng pulse is equal to the area under the curve (Vin * ton duration of switch) divide by the Period (ton + toff duration of the switch)
in short

Vout = Vin ton / (T) = Vin * Duty Cycle

usually the switching frequency is very high(70kHz up) para hindi xa magrequire ng malaking filters.

you might ask para saan ang diode sa circuit? it prevents inductive kick? Or safe to say current path ng inductor current during toff

karagdagang babasahin...
http://www.powerdesigners.com/InfoWeb/resources/pe_html/ch07s1/intro.html
http://en.wikipedia.org/wiki/Buck_converter
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: paranz on February 12, 2008, 11:20:27 AM
Bro, galing. Please teach us more
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on February 12, 2008, 11:28:27 AM
anong pinagkaiba ng voltage-mode SMPS sa current-mode SMPS ?  ???
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 12, 2008, 11:35:24 AM
medyo advanced na po yung topic na yun pero sagutin ko na rin po,
sa SMPS kasi kelangan natin ng feedback para maregulate ang output voltage.
1. Sa "voltage mode" output voltage lang ang feedback natin sa controller
2. Pero sa "current mode" eh output voltage at inductor current na.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 12, 2008, 12:46:26 PM
wala bang pwede paguploadan ng file dito? nakablock kasi office namin ang rapidshare, may ishashare sana ako powerpoint sa inyo, yung presentation ko sa school.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 12, 2008, 12:53:48 PM
Eto po share ko nice article kung paano pagpili ng inductor, capacitor, diode at fet na gagamitin sa buck converter

http://powerelectronics.com/mag/606PET25.pdf
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: alyas on February 12, 2008, 01:00:08 PM
Yung mga inductors ba na ginagamit sa mga switchmode power supplys ay commercially available for the hobbyist locally?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 12, 2008, 01:10:15 PM
Yun din ang gusto ko malaman, kung may nagtitinda ba ng inductor core/choke locally? bale sa choke iniwa-wind yung wires ng inductor, meron po ba kayo alam mga bro? As of the moment nagscavenge lang ako ng mga pyesa sa sirang charger at ballast ng mga ilaw,hehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on February 12, 2008, 02:55:26 PM
sir glutnix,pa up load din po kung merong po kayong para sa laptop adaptor or cp charger na schematic para makabuo ng smps na psu.thanks po:-)

sa motherboard po sir may toroid po dun hehe:-)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: motion55 on February 12, 2008, 10:20:05 PM
I want to reuse the cores found in ATX power supplies. Do you know of their typical specs and how to calculate the number of turns etc?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 13, 2008, 07:39:01 AM
Mahirap malaman unless may marking ng part number na pwedeng icheck sa internet, the easiest way to know is to wind some wires and test using LCR meter(L lang pala,hehe),

Gud suggestion icefire.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 13, 2008, 07:53:50 AM
Ok mga bro, i know you're going to have a lot of questions and marami din sa atin ang bago pa lang sa field ng Power Electronics so I decided to have a structured lecture sa thread para in case na may mga bagong pumapasok at may tanong na naitanong na before eh madali nating mairerefer sa past lectures natin.

I'll try my best na magprovide ng isang discussion for a topic every day, I will try to make it as simple as possible. You may ask question or we can discuss the topic on the thread para mas masaya,hehe,

Below are my initial topics na pwede kong idiscuss,

1. Introduction
   What is Power Electronics
   Some history of SMPS
   Applications


2. Why there's a need for power supply? (Can't we just use a voltage divider?)
   effects of changing input voltage
   effects of changing load resistance

3. types of power supply and operation
   zener
   linear
   SMPS

4. Category of SMPS topologies
   non-isolated
   isolated


5. Buck Converter
   operation

   issues in buck converter design
      high side switching

6. Boost Converter

7. Forward

8. Flyback
   
9. Self Oscillating Flyback

10. Control of SMPS

Please let me know if you have comments or suggestions. Or anything that you'd like to say :o
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 13, 2008, 09:03:32 AM
Lesson 1.0    Introduction to Power Electronics   20080213

Some Introduction...
Hi guys, gusto ko sana maging spontaneous sa aking mga lectures kaya I 'll just use taglish and I'll do my best to
present the topic as simple as I can that even a store keeper could understand (hopefully, hehe).

I supposed you're now thinking why I am explaining Power Electronics and what is its relation to Switched-Mode
Power Supplies(SMPS)? Well to answer that briefly, I can say that SMPS are the foundations of modern Power Electronics.
Because of the industry's demand for efficient conversion of power from source nagkaroon ng application ang SMPS
sa field ng Power Electronics and, oftentimes, the word Power Electronics could refer to SMPS through it is not
limited to it.

What is Power electronics?...
Wikipedia has a nice definition of Power Electronics, it states that...
"Power electronics is the technology associated with the efficient conversion, control and conditioning of electric
power by static means from its available input form into the desired electrical output form"

Take note of the word "efficient conversion", this is probably the main reason why Power Electronics often refer to
SMPS. SMPS are the most efficient power supply for high power applications, its efficientcy ranges from 65% - 93%
depending on the output power( the higher the output power, the greater the efficiency ) as compared to their
Linear Power supply counterpart which are only about 30%-60% on their efficiency, never technologies claimed they
can achieved higher than 80%. But, as I have said SMPS is far more superior in terms of efficiency than Linear Power Supply and
the theory of how they operate explains why.

Control and conditioning are also equally important elements of Power Electronics.

History of SMPS...
The SMPS technology is not so new technology. The theory of its operation has been around since the early 1950's
however, due to the complexity of its operation which boils down to high cost in production limited its
application. Early devices (vacuum tubes pa noon at kaiimbento pa lang ng transistors) are not sufficient to meet
the switching speed requirements of early SMPS.

As the technology of transistors matures, the SMPS technology also matured along with it. SMPS can be found on few
electronic appliances as early as 1970's  and it was extensively used on early PC during the early 80's because of
its size.

On the 90's, the age where mobile devices started to appear, the smaller the better became the trend on technology
and so SMPS became widely used for chargers/adapters for every mobile devices during the late 90's because they can comply with the size and weight demand of mobile markets.

At present, people became aware(conscious) of environmental problems especially on global warming and energy
problems that laws are passed (see "energy star") requiring a highly efficient power conversion that made SMPS the
only choice for most consumer products. The demand for industrial applications became another driving force that
encouraged the development of SMPS technologies.

Conclusion...
The two major qualities of SMPS are its efficiency and size. Application of it ranges from a small battery chargers, UPS, ATX Power Supply, Electronic Ballast, Electronic Appliances, Motor drives (washing machine and for industrial application) and many others that are too many to mention.?


Karagdagang Babasahin...
http://en.wikipedia.org/wiki/Power_electronics
http://en.wikipedia.org/wiki/Switched-mode_power_supply
www.g3src.org.uk/downloads/G4FDN-psu.pdf
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on February 13, 2008, 09:55:51 AM
sir glutnix,gagawa po ako ng proto,buck converter,gagamit ako ng UC3842 sa PWM.
Tapos po 5V output,5A,input cguro 12 to 24,ok lang po as a starter?

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 13, 2008, 10:26:48 AM
OK lang icefire, ang medyo complikado lang sa UC3842 eh current mode controller xa, try to read the application note of 3842 regarding current mode control.

Kung for experiment lang muna, pwede mo rin itry open loop using LM555 (check mo net sa configuration ng LM555 na adjustable duty).

Another difficulty na pwede mo maencounter is yung problem ng MOSFET on high side switching, common sa buck at buck-boost yun.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: motion55 on February 13, 2008, 11:04:51 AM
Quote
Another difficulty na pwede mo maencounter is yung problem ng MOSFET on high side switching, common sa buck at buck-boost yun.

I am interested in this topic specially about MOSFET driver circuits.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 13, 2008, 11:42:33 AM
Brief Explaination lang ng problem sa high side switching, common to hindi lang sa power electronics kundi sa mga VLSI na rin.

 High-side switching means the MOSFET is operated on a high side or there's a high impedance between the source and the ground(opposite: low side, source is connected to ground)

Usually the problem appears when the gate drive voltage is equal to the drain voltage with respect to ground (or (Vg - Vd)  < Vth).
Remember that there's a requied Vgs voltage(Vth) to fully turn on the MOSFET.

Let's have an example, ang gate drive voltage is 12V, supply ng buck is 12V, Vth required is 5V,
Before mag-turn on ang FET sa buck usually ang diode ay nakaforward bias, so may drop yun na -0.7 wrt ground.
Magsusupply ng 12V ang gate drive and syempre magtuturn-on ang FET because Vgs = 12-0.7 > Vth (5V),

but what happens if nagturn-on na ang FET? Drain would be shorted to Source and Vd would be equal to Vs wrt Ground.
At this point hindi na nasatisfy yung condition para magturn-on ang FET kasi Vgs would be equal to 0 that is < Vth.

Sa high side switching hindi marereach ang turn-on condition dahil magstop na magincrease bias the moment na Vgs becomes < Vth.

May mga technique para makapagswitch sa high side, (search nyo sa net ibat-ibang ways para dito)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: kamote on February 13, 2008, 03:15:42 PM
Eto po share ko nice article kung paano pagpili ng inductor, capacitor, diode at fet na gagamitin sa buck converter

http://powerelectronics.com/mag/606PET25.pdf

informative to.  salamat.

hehehe.  allergic ako sa analog design, pang digital lang talaga utak ko.  kung may tanong ako puede bang abusihin ka nang tanong in the future?  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 13, 2008, 03:36:37 PM
hehehe.  allergic ako sa analog design, pang digital lang talaga utak ko.  kung may tanong ako puede bang abusihin ka nang tanong in the future?  ;D


Well, consider mo na lang ang SMPS as digital power supply kasi switch lang  naman ang operation ng transistor,hehehe

 ???OK lang magtanong kayo, sasabihin ko naman kung di ko alam ang sagot eh, ;D ;D ;Dhehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: motion55 on February 13, 2008, 09:53:32 PM
@glutnix_neo

I design motor drivers (stepper motor drivers in particular) as part of my job. One of my projects is a high current rated type that uses an H-bridge configuration. That is, a pair of stacked N-channel MOSFETs. As you can see it needs a high side driver as well as a low side one. I think your expertise can be helpful to me.

(http://www.learn-c.com/basicmosfethbridge.gif)

How come there so many different high side drivers available from like IR or Telcom (now part of Microchip)? Do they have to be matched to the MOSFET it will be used for. What are the selection criteria? What are the typical failure modes of MOSFETs in your designs and their causes?

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 0b00000111 on February 13, 2008, 10:02:15 PM
@glutnix_neo

any recommended ebooks/reading materials for SMPS?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 0b00000111 on February 13, 2008, 10:24:11 PM
may power electronics ebook nga pala ako by Muhammad Rashid. anyone interested? upload ko bukas kung may interested...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: paranz on February 13, 2008, 10:42:37 PM
i also have "SwitchMode Power Supply Handbook" by Keith H. Billings

oki ba book na ito?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 14, 2008, 08:09:22 AM
@glutnix_neo

(http://www.learn-c.com/basicmosfethbridge.gif)

How come there so many different high side drivers available from like IR or Telcom (now part of Microchip)? Do they have to be matched to the MOSFET it will be used for. What are the selection criteria? What are the typical failure modes of MOSFETs in your designs and their causes?



Nice to know madami interested sa power electronics dito, to be honest I not much experienced on high side switching circuit, yun kasi yung iniiwasan namin sa design kasi malaking added cost kung magdadagdag ng pyesa, but there's one practical solution jan.

You can use a choke and form it like a transformer where on the primary andun yung gate drive na nakaground and on secondary nakaconnect sa Gate and Source ng FET, Yun nga lang, I dont think its applicable sa stepper kasi may time na hindi continous ang pulse, magsasaturate ang core, sa SMPS OK tong technique na to.

Would you like to consider using a stepper motor driver IC's? sa tingin ko mas makakatipid ka dun kasi wala ng FET yun, diretso na, L293 yata yung pwede.

For the criteria of selecting a driver, I think slew rate/speed is a major factor at yung driving current na rin. Although voltage driven xa may mga FET na mataas yung g-s capacitance kaya iba-iba din driver, Low side switching I dont think magkakaproblema ka dun, pwede ka gumamit ng simple transistor buffer(for high speed use a totem pole).
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 14, 2008, 08:27:00 AM
may power electronics ebook nga pala ako by Muhammad Rashid. anyone interested? upload ko bukas kung may interested...

Books? OK yung book ni sir Pranz, bilings

Kung theory yung kay Ned Mohan nakabili ako sa goodwill sa glorieta dati ok din yun at saka yung kay abraham pressman

Kung practical guide naman sa design eh yung "Power Supply Cookbook" ni Marty Brown, kaso nawawala yung book ko na to.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 14, 2008, 10:07:24 AM
Lesson 2.0    Why is There a Need for Power Supply   20080213

Introduction...

I am often asked by a question and even I asked it when I was a student, "Why do we need power supply?"...
That question is often followed by another question, "Can't we just use a voltage divider?"

Those are very good questions for beginners. Well, explaining why we can't use a voltage divider to have a stable

voltage source also explains why we need power supplies (because there's no other alternatives, hehehe).

In theory, if the voltage supplied by the input or the current drawn by the load does not vary with time,

definitely, a voltage divider computed for that specific load and input voltage is sufficient to keep the output

voltage fix on that level. But, in real applications the input voltage from battery and worst from AC line varies

with time. Switching loads such as micrcontrollers and digital circuits draws different amount of current from time

to time. Thus, the need for power supply arise.

What is a voltage divider anyway?...

It is a circuit commonly composed of two resistors in series that produces an output that is a fraction of its

input.
(http://upload.wikimedia.org/wikipedia/en/d/db/Resistive_divider.png)

the relationship of input and output becomes

Vout = vin * R2 / (R1 + R2)            eq. 2.1

I don't need to explain the derivation in detail but in case you're interested, you may refer to Mr. Wiki on the

link below

On the formula, R2 could represent a load (the effective resistance of the component supplied by the voltage

divider) or if you need to add load to it just compute the effective resistance of it and place them in parallel to

R2.


Very Simple Example...
Suppose we have a circuit that draws 5A and needs to be powered by 5V but our Vin is 10V, how are we going to have

this using a voltage divider?

Given are:
Vout = 5V
Vin = 10V
Iout = 5A

The effective resistance of the load (R2) can be calculated using Ohm's law (I = V/R) or R = V/I

R2 = 5V / 5A = 1 Ohm

Required is :
the resistance of R1 to form a voltage divider

Rearranging equation 2.1 we get

R1 = R2 * (Vin - Vout)  / Vout

R1 = 1 Ohm * ( 10V - 5V ) / 5V

R1 = 1 Ohm

Therefore 1 Ohm is the required series resistance to have a 5V output.

Effects if changing voltage on the voltage divider...

Supposed we are using the same circuit as mentioned on our "very simple example" and the voltage increased from 10V

to 20V, will our output remain the same?

Given:
Vin = 20V
R1 = 1 Ohm
R2 = 1 Ohm

Required:
V2 = ?

Again, using equation 2.1 we get

Vout = 20V * 1 Ohm / ( 1 Ohm + 1 Ohm )

Vout = 10V <<< Lumake!!!!

From the example we can conclude that in a voltage divider

1. As we increase the input voltage, the output voltage also increases
2. As we decrease the input voltage, the output voltage also decreases

Effects of loading a voltage divider...

Supposed we are using the same circuit as mentioned on our "very simple example" and two paralled 1 Ohm resistor

are used in place of R2 (same as increasing the load), will our output remain the same?

Given:
Vout = 10V
R1 = 1 Ohm
R2 = 1 Ohm // 1 Ohm = 0.5 Ohms

Required:
V2 = ?

Again, using equation 2.1 we get

Vout = 10V * 0.5 Ohms / (0.5 ohms + 1 Ohm)

Vout = 3.33333333333333333333333333333333333333333333V        <<< Lumiit!!!

From the example we can conclude that in a voltage divider

1. As we increase the input voltage, the output voltage decreases
2. As we decrease the input voltage, the output voltage increases

Conclusion...

Because of the limitations of the voltage divider on maintaining the output at a constant level on varying loads

and input voltages, the need for a better regulator became a necessity.

Karagdagang Babasahin...

http://en.wikipedia.org/wiki/Voltage_divider
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 14, 2008, 10:16:28 AM
sorry dun sa last post ko, ipinoformat ko pa lang eh napasend na, double space tuloy,hehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: motion55 on February 14, 2008, 11:27:09 AM

Nice to know madami interested sa power electronics dito, to be honest I not much experienced on high side switching circuit, yun kasi yung iniiwasan namin sa design kasi malaking added cost kung magdadagdag ng pyesa, but there's one practical solution jan.

You can use a choke and form it like a transformer where on the primary andun yung gate drive na nakaground and on secondary nakaconnect sa Gate and Source ng FET, Yun nga lang, I dont think its applicable sa stepper kasi may time na hindi continous ang pulse, magsasaturate ang core, sa SMPS OK tong technique na to.

Would you like to consider using a stepper motor driver IC's? sa tingin ko mas makakatipid ka dun kasi wala ng FET yun, diretso na, L293 yata yung pwede.

For the criteria of selecting a driver, I think slew rate/speed is a major factor at yung driving current na rin. Although voltage driven xa may mga FET na mataas yung g-s capacitance kaya iba-iba din driver, Low side switching I dont think magkakaproblema ka dun, pwede ka gumamit ng simple transistor buffer(for high speed use a totem pole).

I need to design a microstep driver that is rated 8A. I have an existing 3A rated design using the ST-Micro L6203 H-bridge. This design is already close to 10-years old. I have made minor updates but the end user is quite content with the original.

One time, I was considering using transformer to level shift the pulse. I use PWM control and duty seldom goes to 100%. That happens when the motor is running and the H-bridge is commutating anyway and so it is possible to use a transformer. I have studied lots of sample drivers from other vendors but they don't use a transformer.

I have been making prototypes of 8A rated drivers through the years but they suffer from reliability problems. Overheating isn't a problem since I use relatively over rated 25A and up MOSFET. The MOSFETs run quite cool. They MOSFET occasionaly fail on power-ON or accidental shorting of the output. I think transients cause the ratings to be exceeded and the MOSFETs suffer from catastrophic failure when this happens. Supply rail voltages range from 24V-75V.

In motor driver designs, we can afford more expensive devices compared to your business where competition is very stiff and cost is a huge factor. I have used various high-side+low-side drivers from Telcom, IR and others.

For SMPS designs, I use L4978, LM2576S or LM2676S devices for buck converters. These are used to supply +5V and other DC voltages for my controller designs. Linear regulators are seldom found in a modern appliance like a DSL modem or router.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 14, 2008, 11:59:59 AM

I have been making prototypes of 8A rated drivers through the years but they suffer from reliability problems. Overheating isn't a problem since I use relatively over rated 25A and up MOSFET. The MOSFETs run quite cool. They MOSFET occasionaly fail on power-ON or accidental shorting of the output. I think transients cause the ratings to be exceeded and the MOSFETs suffer from catastrophic failure when this happens. Supply rail voltages range from 24V-75V.


Interesting yan work nyo sir ah,

All I can say po eh, sa shorting definitely the FET will fail unless we include protection circuit na ishashut-down nya mga FETs if over current.

Problems on turn-on, hindi ako maxado familiar sa turn-on sequence ng stepper, all I know eh malaki current na nadodraw nya at start up, using soft start (min duty muna) would lessen the transient, not sure lang kung kaya nya patakbuhin motor nun,hehe,

On bridge circuit, one thing na pwede nating iwatchout is yung nagsasabay na naka-on mga FETs (hindi pa fully turn-off yung FET eh nagon na yung other rail), This problem is can be resolved using dead time sa alternation ng mga driving pulses

Sana nakatulong po sir,?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: motion55 on February 14, 2008, 02:19:57 PM
Interesting yan work nyo sir ah,

All I can say po eh, sa shorting definitely the FET will fail unless we include protection circuit na ishashut-down nya mga FETs if over current.

Problems on turn-on, hindi ako maxado familiar sa turn-on sequence ng stepper, all I know eh malaki current na nadodraw nya at start up, using soft start (min duty muna) would lessen the transient, not sure lang kung kaya nya patakbuhin motor nun,hehe,

On bridge circuit, one thing na pwede nating iwatchout is yung nagsasabay na naka-on mga FETs (hindi pa fully turn-off yung FET eh nagon na yung other rail), This problem is can be resolved using dead time sa alternation ng mga driving pulses

Sana nakatulong po sir,?


May short circuit protection na naka-designed into the circuit. It is similar to the circuit I used in the lower current devices pero it is not enough. Kaya ang nagtatanong anung possibleng mag fail sa MOSFET in case may short sa H-bridge. Karamihan ang nasisira ay yung sa high side. My theory is the short circuit causes the gate-source voltage to exceed the rating.

I use a motor control PIC like the PIC18F4431 with it's PWM control for controlling the current. With it I can also control the soft start.

I am also aware of the shoot-through problem. That is, the two stacked MOSFETs conduct at the same time when switching one ON while switching the other OFF. This is where is becomes confusing. Looking at the catalogue of half-bridge MOSFET driver devices from Telcom, ang daming klase. It gets confusing to pick which one. May built-in dead time control na ang mga motor control PICs. So that adds to the confusion too.

Putting too much dead-time will cause one MOSFET to turn completely OFF before the other one will turn ON. Ordinarily, the MOSFET's intrinsic diode will conduct the current if the MOSFET isn't ON. This is not a good thing because firstly, the diode has a greater resistance than the MOSFET's ON resistance. This will increase the power dissipation. Secondly, once the intrinsic diode conducts, it slows the MOSFET down. At least that is my theory.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 14, 2008, 03:35:52 PM
Ok sir seems like aware naman po kayo sa lahat ng pwede mangyari :D,
based from my experience sa bridge circuit (although SPMS ang application) the causes of failures are...

ndi ko alam pano magupload pic dito pero labelan na lang natin mga FET as

                  a                     b
                  |----o o o o----|
                  c                    d

1. Rating exceed, V-D or V-G voltage (peak usually when no snubbers used), Id current
2. Thermal runaway dahil hindi totally on FET dahil sa weak/slow drive or may naiiwang charge sa G-S nya, watchout sa D-S voltage nya kung fully on or off ba xa at slew rate na rin. Or thermal runaway dahil mainit talaga
3. Inductive kick kung may charge ang inductor at nag-off ang FET c but FET b is still on, may path ng current sa FET a through its body diode. With this two things can happen pwede magproduce ng malaking peak voltage sa FET c or maexceed current sa dalawang high side FET(Transients lang to at di pangmatagalan)
4. As you mentioned sir, shoot through (vin shorted to ground)
5. Lastly, kung mas ibang FET sa bridge na sira na talaga, pwede madamay iba.

Other than these, isip pa ko. ;D

Sir can i have the link ng websites?tingnan ko na rin po pag may time. Ilang FET po nasisira sa isang failure?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: paranz on February 14, 2008, 03:58:04 PM

I design motor drivers (stepper motor drivers in particular) as part of my job. One of my projects is a high current rated type that uses an H-bridge configuration. That is, a pair of stacked N-channel MOSFETs. As you can see it needs a high side driver as well as a low side one. I think your expertise can be helpful to me.

(http://www.learn-c.com/basicmosfethbridge.gif)



Sir motion55, im trying to follow sa discussion nyo dalawa ni neo. Can you please help me understand what do you mean specifically with high-side/low-side driver as based on the H-bridge diagram?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 0b00000111 on February 14, 2008, 04:10:36 PM
sir paranz,

lead-acid battery ka na pala ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: paranz on February 14, 2008, 04:41:14 PM
sir paranz,

lead-acid battery ka na pala ;D

lol i didnt notice.

Ano kaya sunod sa lead acid? muriatic?  ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 14, 2008, 05:05:32 PM

Sir motion55, im trying to follow sa discussion nyo dalawa ni neo. Can you please help me understand what do you mean specifically with high-side/low-side driver as based on the H-bridge diagram?

Sir paranz switch C and D are low side switch (FET source shorted to ground),A and B are high side (FET source is high Z wrt to ground) :)

I think nagkaron po me explaination in this thread about the problems on high side switching.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: motion55 on February 14, 2008, 05:39:18 PM
Ok sir seems like aware naman po kayo sa lahat ng pwede mangyari :D,
based from my experience sa bridge circuit (although SPMS ang application) the causes of failures are...

ndi ko alam pano magupload pic dito pero labelan na lang natin mga FET as

                  a                     b
                  |----o o o o----|
                  c                    d

1. Rating exceed, V-D or V-G voltage (peak usually when no snubbers used), Id current
2. Thermal runaway dahil hindi totally on FET dahil sa weak/slow drive or may naiiwang charge sa G-S nya, watchout sa D-S voltage nya kung fully on or off ba xa at slew rate na rin. Or thermal runaway dahil mainit talaga
3. Inductive kick kung may charge ang inductor at nag-off ang FET c but FET b is still on, may path ng current sa FET a through its body diode. With this two things can happen pwede magproduce ng malaking peak voltage sa FET c or maexceed current sa dalawang high side FET(Transients lang to at di pangmatagalan)
4. As you mentioned sir, shoot through (vin shorted to ground)
5. Lastly, kung mas ibang FET sa bridge na sira na talaga, pwede madamay iba.

Other than these, isip pa ko. ;D

Sir can i have the link ng websites?tingnan ko na rin po pag may time. Ilang FET po nasisira sa isang failure?


Thanks for the info. I really appreciate your inputs. I will use it when I get back to designing drivers. Medyo low priority siya ngayon. Bale side project lang ang status. But I keep them at the back of my mind.

Anyway, to add more info. Usually pag nag fail ang high side FET, hindi na high impedance ang gate. Occasionally nadadamay ang FET directly below the damaged one.

I figure that pag na short to ground ang output. The source pin drops close to ground while the gate is still up there. Bale momentarily na exceed ang gate to source voltage limits. Importante may short circuit protection and the driver does not die on the first short circuit. The motor is usually mounted on a moving head and sometimes over time the wire lead insulation gets worn out through constant motion. Then a short circuit happens.

Lastly, this is the first time I heard may thermal run-away problem ang MOSFET.


Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: motion55 on February 14, 2008, 05:58:27 PM
BTW, on the subject of SMPS, here is a link to the SwitcherCAD software. I have been a user of this program since the original DOS version. I don't know how good this version is but the origianl version was very useful and educational on how a switching power supply is designed.

http://www.linear.com/designtools/software/switchercad.jsp

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 14, 2008, 06:01:10 PM
Welcome po

Sorry mali word na nagamit ko, thermal problem pala,pang BJT lang usually ang runaway,hehe

Sir comment lang, ndi ko sure ano gate drive nyo sa high side FET pero normally hindi dapat ng-eexceed ang Vgs kasi ang supply ng coming from the driver should be directly connected sa g-s,
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: paranz on February 14, 2008, 06:03:56 PM
Sir paranz switch C and D are low side switch (FET source shorted to ground),A and B are high side (FET source is high Z wrt to ground) :)

I think nagkaron po me explaination in this thread about the problems on high side switching.

oki thank you po sa explanation. Im interested also even if im just following your discussions.

The most advance H-Bridge i made was for my cute rc car motors drawing 100 mA.  ;D ;D ;D All i need are 4 bjt (TO-92) and 4 resistors, kahit wala ang 4 na protection diodes ok na, kasi low power lang. And i thought thats all there is to H-bridge design hehe

Marami pa talaga ako dapat matutunan  :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 14, 2008, 06:14:06 PM
Ako lang yata AAA dito,hehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: creedcradle on February 14, 2008, 06:31:36 PM
kaya mas mabilis masira ang high side kasi dahil sa spike current flow sa high end during switching transitions... kahit nakaoff na yang low-side ung nasa high side ay may current flow pa rin. and the instance na nagswitch ON/OFF ang high end FETs ay lalo pang nagkakaroon ng additional flow of the current which goes beyond the normal current flow..


-creedcradle
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: motion55 on February 14, 2008, 06:50:34 PM
Here is a link to switchercad 2.0. It is a dos based program. No need to run install. Simply unzip and run the program "scad.exe".

http://www.electronicsoft.net/download/scad20.zip

More stuff:

http://www.electronicsoft.net/en-us/dept_5.html



Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Born2BeWired on February 14, 2008, 08:01:39 PM
Lesson 2.0    Why is There a Need for Power Supply   20080213

....
Again, using equation 2.1 we get

Vout = 10V * 0.5 Ohms / (0.5 ohms + 1 Ohm)

Vout = 3.33333333333333333333333333333333333333333333V        <<< Lumiit!!!

From the example we can conclude that in a voltage divider

1. As we increase the input voltage, the output voltage decreases
2. As we decrease the input voltage, the output voltage increases

Conclusion...



 :o :o :o
bro glutnix_neo, I believe a correction is in order here ;D ;D
I'm sure you meant "As we increase/decrease the output load..."
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Born2BeWired on February 14, 2008, 08:09:37 PM
Some of you might also be interested to know that there is a MOSFET hybrid that package a full bridge circuit using P Channel  high side and N Channel low side MOSFETs.

Part No: is MPM3002 and MPM3012

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 14, 2008, 08:15:43 PM
:o :o :o
bro glutnix_neo, I believe a correction is in order here ;D ;D
I'm sure you meant "As we increase/decrease the output load..."


Thank you pre, i stand corrected, ;D

Sabi ko nga kanina, habang ineedit ko eh aksidenteng napasend,hehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Born2BeWired on February 14, 2008, 09:05:02 PM
You are doing a great job bro! Kami ang dapat mag pa thank you sayo. ;D
Keep em coming :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 14, 2008, 09:33:33 PM
yahooo, eto na pinakamainit na thread sa analog circuit design, manalo na kaya ako ng laser pointer? ::) ??? ::)

hehehehe, joke lang, I'm not after that (ehem, pwede na rin) 8)

actually one reason why I'm posting here is para marefresh ko na rin sarili ko, matagal na rin me nabakante sa hardware design, firmware na kase ako ngayon though I still do hardware design pero as a hobby na lang.

meron po ba dito member ng pinoy electronics na yahoogroup?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 15, 2008, 02:03:48 PM
sorry mga pre, wala muna me update, busy mode pa,hehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: paranz on February 15, 2008, 02:18:39 PM
No problem, bro. This thread is very informative so far, good job  :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: mikeTech on February 15, 2008, 05:18:24 PM
just like to share this video about smps http://www.electronicrepairguide.com/pulse-width-modulation.html (http://www.electronicrepairguide.com/pulse-width-modulation.html)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 18, 2008, 09:33:46 AM
Lesson 3.0    Types of Power Supply and its operation   20080218

Introduction

Basically there are three types of power supply namely

1. Zener Type Regulator
2. Linear Regulator
3. Swtiched Mode Converter


All of them differ on their concept of operation and offers some advantages and disadvantages. Deciding which type to use for our application is not that difficult. All we need to do is to consider what range of output power our application will need and how much time is required to deliver the design.

3.1 Zener Regulator...

(http://upload.wikimedia.org/wikipedia/commons/9/92/Zener_reg.gif)
Figure 3.1

In this type of regulator, the output voltage is mainly regulated by the zener diode connected in parallel with the load that is operating on reverse bias.

From our Basic Electronics we all know that if we operate the zener diode on a reverse bias by applying a negative potential to it there will come a point that it will reach the breakdown region. At this region voltage can no longer exceed the voltage rating of the diode unless it is damaged due to over power/current.

see the 3rd quadrant of the cartesian plane...
(http://people.seas.harvard.edu/~jones/es154/lectures/lecture_2/breakdown/zener_charac_1.gif)
Figure 3.2

The resistor R1 limits the current passing through the load and the zener to prevent damage to it and at the same time it drops the excess voltage.

One requirement for this type of regulator to work is that the voltage across the zener caused by the divider network of the Load resistance (R2) and the series resistor (R1) must be greater than the zener voltage rating otherwise it wont reach the breakdown region.

Additional loading to Zener Regulator would cause its divider voltage to drop and would come to a point where the divider voltage would be less than the zener voltage rating. When this happens, zener diode is no longer operating on the breakdown region and the output voltage will be that of the divider network(similar to lesson 2, as we increase the load, the output decreases). This proves that the regulation on Zener Regulators are very poor because the voltage drops when it is heavily loaded.

Another thing to consider in the design is that the power rating of the zener diodes must not be exceeded when the regulator is unloaded/lightly loaded(because majority of the current will be dissipated by the Zener Diode). These limitations prevents us from using the regulator on higher output power.

In summary Zener Type Regulators are the easiest to design but the output power are very limited. Regulation is very poor and the performance is greatly affected by temperature.

For its applications,
   1. Can be used as Voltage Reference
   2. Voltage Clamp on IC supply
   3. Low Power Transformerless Power Supply

3.2 Linear Power Supply...
A good discussion on linear regulator can be found on National Semiconductor website www.national.com/appinfo/power/files/f4.pdf, you may want to read this..

(http://www.alw.audio.dsl.pipex.com/images/basic_reg.gif)
Figure 3.3

This type of regulator regulates the output voltage by varying the bias of the transistor(operating on active/linear region) in series with the load. The transistor acts like a variable resistor(series resistor element of a voltage divider) that reacts to changes in the output voltage so that the ouptut would remain regulated.

(http://www.steve-w.dircon.co.uk/fleadh/mphil/figures/histfig1.gif)
Figure 3.4

On figure 3.3, Part of the output is scaled in such a way that when the "actual output" is equal to the "desired output" the "scaled output"(V at R3 cause by the divider R2 and R3) should be equal to the reference voltage. R1 and D1 creates a reference voltage (usually 2.5V) where the "scaled output" voltage is being compared to and is fed on error amplifier X1. The error amplifier produces a negative feedback that biases the transistor.

Linear regulator are far superior than zener type regulators in terms of regulation because of its feedback. Wider range of load can also be suppplied by this type of regulator.

One disadvantage of this regulator is that it is lossy. As can be seen on figure 3.3, the amount of energy dissipated by the variable resistor would be P = I^2R (power loss). The same is true for the zener regulator although it has some additional loss dissipated by the zener diode. Another disadvantage would be in AC-DC application where it would require a bulky low frequency transformer. Its low efficiency requires large heatsink to remove the heat being dissipated by the transistor making the total size very huge (low power
density).

For its applications,
   1. Commonly used as a post regulator since the loss would be less when the input and output voltage difference is very small
   2. Low current application and for hobbyist since it is easy to contruct.

3.3 Switched Mode Converter...

A good reference detailing the comparison of linear and switched-mode can be found here..
http://www.steve-w.dircon.co.uk/fleadh/mphil/history.htm

(http://www.steve-w.dircon.co.uk/fleadh/mphil/figures/histfig3.gif)
Figure 3.5

On this type of regulator, the output voltage is regulated by controlling the average voltage supplied to the output by means of varying the duty of the transistor alternately operating between cut-off and saturation.

As can be seen from figure 3.5, the loss that is often dissipated by transistor on linear power supply are eliminated,

when switch is on
R = 0
P= I^2 * R = I^2 * 0 = 0

when switch is off
I = 0
P = I^2 * R = 0 * R

The pulsating output are smoothen by low pass filter placed near the load. And from integral calculus we know that the average of a waveform is the area under the curve divided by its period.

when switch is on

Area_on = Vin * Ton

when switch is off
Vin = 0
Area_off = Vin * Toff = 0 * Toff = 0

Total area = Area_on + Area_off = Area_on + 0 = Area_on

Vout_ave = Total area / T = Area_on/ T

simplifying further

Vout_ave = Vin * Ton / T = Vin * Duty Cycle


Switched-Mode offers great advantage among all type of regulators in terms of its efficiency. Switched-mode converter do not require large heatsink since in theory, its efficiency would be 100% (of course that is not true on actual application due to parasitics). The bulky low frequency transformer was also eliminated because as we operate the switch at higher frequency less filtering would be required.

One disadvantage of this type of regulator is its noise, from electromagnetics high change( high peak, small rise time) in current would produce very strong emf and rich in harmonics (sir creedcradle the physist, help me explain please, hehehe)


For its applications,
   1. high power application
   2. UPS
   3. Ac-DC



Circuit ComplexityOutput PowerEfficiencyRegulation
ZenerSimplesta few wattsdepends on the design poor, almost no regulation
LinearSimple< 100W30%-60%good
Switch ModeComplex Control>100W65%-93%good,but has greater tendency to oscillate


Mga Karagdagang Babasahin...

http://www.steve-w.dircon.co.uk/fleadh/mphil/history.htm
http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/zenereg.html
http://en.wikipedia.org/wiki/Linear_regulator
www.national.com/appinfo/power/files/f4.pdf
http://en.wikipedia.org/wiki/Switched-mode_power_supply





Title: Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 18, 2008, 09:39:37 AM
up
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 19, 2008, 08:16:38 AM
Lesson 4.0    Categories of SMPS Topologies   20080219


Introduction...

On my earlier lessons I mentioned the advantages of Switched-Mode regulators that's why it is preffered for high
power applications. But within the SMPS family there are a lot of SMPS topologies to choose(circuit arangement)
from. And, most of them can be grouped into two categories namely, the non-isolated, and the isolated.

Non-Isolated Topologies...

Non-Isolated are topologies that does not have electrical isolation (no transformer). Advantages of having it are
for simplisity and reduced cost. These topologies are often used on battery operated device that do not require
electrical isolation which is mandatory on offline PSU for safety reasons.

Topologies belonging to Non-Isolated Category are...
1. Buck
2. Boost
3. Buck-Boost
4. Sepic
5. Cuck

Isolated topologies...

Isolated Topologies are topologies characterized by having an electrical isolation in the form of high frequency
transformers. The transformer provides safe secondary side for offline applications (AC-DC) as well as allowing
multiple outputs to be implemented.

On these type of topologies, isolation must be maintained even on feedback signals coming from the output(secondary
side) and going to PWM (usually located on the primary). The use of optocoupler is often implemented on
transmitting the feedback information and other signals from the secondary to primary.

Topologies belonging to Isolated Category are...
1. Flyback
2. Forward
3. Half-Bridge
4. Full Bridge
5. Push Pull

Conclusion ...

In general, choosing between isolated and non-isolated will depend on the application of our design, for DC-DC
applications (battery operated) the common choise is non-isolated while for AC-DC (Offline) or if we want multiple
outputs the best choice would be isolated.

Mga Karagdagang Babasahin...
http://power-topics.blogspot.com/2007/10/isolated-non-isolated-dc-dc-converters.html
http://www.maxim-ic.com/appnotes.cfm/an_pk/735
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 21, 2008, 04:48:56 PM
Double A na rin pala ako,hehehe 8) 8) 8)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 21, 2008, 04:58:46 PM
Mga bro try ko magpost ulet bukas ng Buck Converter,

Let's get to the real thing, hehehe

Wla ba talaga way mag insert ng picture di to aside from linking?:-\
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: kamote on February 21, 2008, 05:05:38 PM
pare paano ba magdecide kung ilang amps ang kukunin mong voltage regulator yung 78series?  for example yung max load 300 mA, dapat ba 500 mA, 800 mA or 1A ang pipiliin? 

tapos kung magcacascade ako 7815 -> 7805 -> 783.3(3.3V)...   yung load ng 7815 300mA, 7805 500 mA, 783.3 200mA.  paano ang current rating ng mga voltage regulator.

salamat.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 22, 2008, 08:05:16 AM
pare paano ba magdecide kung ilang amps ang kukunin mong voltage regulator yung 78series?  for example yung max load 300 mA, dapat ba 500 mA, 800 mA or 1A ang pipiliin? 

Pre interesting question mo, Ciempre dapat mas mataas (usually may derating, your max load can be 80% of the rating para safe) kasi once na nareach na ng 78 series yung kanilang maximum current rating eh nagpoprotect xa (namamatay yata output, you may check the datasheet).

But if you need to draw larger amount of current pwede mo imodify circuit ng 78xx mo. Magdagdag ka ng booster transistor (PNP transistor).The book of Malvino has a good discussion of it and the circuit is below...
http://www.mitedu.freeserve.co.uk/Circuits/Power/boosti.gif

Ang poproblemahin mo na lang ngayon is yung rating ng transistor na gagamitin mo,hehehe.

Ang iba nagpaparallel ng 78xx.
http://www.instructables.com/id/Increasing-current-on-78xx-series-regulators/

Kung alin mas magnda sa dalawang technique, I'll go for the most cost effective yet simple.

Quote
tapos kung magcacascade ako 7815 -> 7805 -> 783.3(3.3V)...   yung load ng 7815 300mA, 7805 500 mA, 783.3 200mA.  paano ang current rating ng mga voltage regulator.

Kung cascaded siya at ang bawat output ay may kanya kanyang load gaya ng nasabi mo, pwede mong isispin na ang load ng 7815 ay mga constant current loads connected in parallel so ang magiging rating nya eh 300mA + 500mA + 200mA.

Ganun din sa 7805 na 500mA + 200mA, at sa 3.3V na 200mA.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: kamote on February 22, 2008, 10:55:37 AM
salamat magpaparallel na lang ako...  badtrip kasi ang mga TO-220 ang pangit sa pcb, maganda ang DPAK kaya lang ang baba ng current rating...  ibig sabihin kung dalawang parallel naga-add up yung current load rating nila? 

pang industrial kasi design ko eh, nagiinit yung 7815 at 7805, nakakapaso, although stable naman ang voltage at yung circuit, yun nga lang  baka after 1 month tustado na casing at PCB nito.  ;D
Title: Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 22, 2008, 11:03:43 AM
Yes Maga-addup po, Watchout lang kasi may possibility na hindi sila magshare ng tama, meaning masmalaking isinusupply na current nung isa against dun sa isa, kung ganun eh magpoprotect pa rin yun.

Sa init problem naman, I think you should consider adding heatsink pag maxado na mataas output current mo especially if malaki difference ng input at output
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 22, 2008, 11:16:39 AM
naisip ko lang, kung may oring diode ka naman


I think magshashare na rin siya kc nagaact siya as droop circuit (meaning habang tumataas current sa rail nya eh bumababa ng konte output voltage, in effect less current na isusuply nya against the other) tapos ang feedback naman ng mga 78xx are before the diode, I think walang prolema dun.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: kamote on February 22, 2008, 01:04:38 PM
Oring, daming resources sa net pero hinihilo ako...  paexplain naman  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 22, 2008, 02:14:11 PM
Oring Diode - from the word OR, ginagamit kung magpaparallel ng power supply para in case na magfail ang isa hindi makakaapekto sa iba. Kaya tinawag pong ORing diode kasi parang nakaOR ang power supply nyo


Sa link na nirefer ko yun yung D1 at D2
http://www.instructables.com/id/Increasing-current-on-78xx-series-regulators/

    |\   |D1
---|  >|----
    |/   |     |
                |---------- Output
                |
    |\   |D2  |
---|  >|----
    |/   |     


Some uses MOSFET para low impedance pagnakaon ang FET then kung may failure mawawala gate drive then magoopen ang FET. 8)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: fantom_mayonaise on February 22, 2008, 02:37:18 PM
Sir, can you recommend any smps-specific book na available locally?

I have this Eagle Power supply that I use in RC. 12V/18amps sya. I'm currently trying to increase the voltage up to 15V kasi bumabagsak yung voltage nya when I start drawing 10amps. I took out the ETD core for rewinding kaso nabasag ko yung isang leg.

Meron po kayong alam na mabibilhan nito? What do I need to know to also increase the amperage? Add Parallel schottkey diodes, Fet? Pwede bang magparallel nung output transformer?

Pasensya na po sa madaming tanong.  :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: kamote on February 22, 2008, 02:44:57 PM
Oring Diode - from the word OR, ginagamit kung magpaparallel ng power supply para in case na magfail ang isa hindi makakaapekto sa iba. Kaya tinawag pong ORing diode kasi parang nakaOR ang power supply nyo


Sa link na nirefer ko yun yung D1 at D2
http://www.instructables.com/id/Increasing-current-on-78xx-series-regulators/

    |\   |D1
---|  >|----
    |/   |     |
                |---------- Output
                |
    |\   |D2  |
---|  >|----
    |/   |     


Some uses MOSFET para low impedance pagnakaon ang FET then kung may failure mawawala gate drive then magoopen ang FET. 8)


ok...  pero di kaya mababawasan ang voltage niyan kasi may diode?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 22, 2008, 03:04:54 PM
ok...  pero di kaya mababawasan ang voltage niyan kasi may diode?

Good point master Kamote, talagang mababawasan ng 1 diode drop ang output nya. Yun ang reason dun sa example na inirefer ko why my diode(d3) ang ground ng mga 78xx to compensate for the diode drop ng Oring.

Kung LM317(adjustable output) ang gamit nyo, pwede nyo idetect ang feedback voltage after the diode's cathode para no need na magadd ng diode sa ground. Yun ang problem sa 78xx na nasa loob ang feedback circuit nya kaya ang nadedetect nya lang eh yung vout ng IC and not the vout ng load.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 22, 2008, 03:27:30 PM
Sir, can you recommend any smps-specific book na available locally?

Yung book ni Ne Mohan, nakabili ako one time sa glorieta sa goodwill dun less than 500 lang siguro yun, Yung kay Abraham Pressman naman nakabili yung collegue ko sale sa national bookstore sa recto 5years ago (inamag sa bookstore kasi walang may interest sa SMPS noon,hehehe), sa Alexan meron yata medyo may kamahalan nga lang kasi hardbound.

Recommended author ko eh Billings for theories at yung book ni Marty Brown kung design examples ang hanap nyo. Di ko lang sure if meron locally.


I have this Eagle Power supply that I use in RC. 12V/18amps sya. I'm currently trying to increase the voltage up to 15V kasi bumabagsak yung voltage nya when I start drawing 10amps. I took out the ETD core for rewinding kaso nabasag ko yung isang leg.

Makes me wonder why bababa ang voltage if rated xa na 18A. Malamang mali pagkakadesign or may sira and increasing the turns wont solve the problem bro.tsk tsk tsk, magrereact lang ang feedback nya as usual (BTW SMPS yan no, malamng SMPS kc ETD core tinutukoy mo po),

Gusto ko po malaman if gaano kabilis pagbaba ng voltage, below 10A ba or even at 10A eh stable pa rin sa 12V output nya (nagumpisa lang bumagsak voltage after 10A)? I'm asking the question kasi po baka power limit yung problema (pero again kung rated xa sa 18A dapat walang problema).

Meron po kayong alam na mabibilhan nito? What do I need to know to also increase the amperage? Add Parallel schottkey diodes, Fet? Pwede bang magparallel nung output transformer?

Too bad master wala po akong alam mabibilhan locally, scraps lang ng cellphone charger at PC PSU ang pinagtatyagaan ko.

To increase the ampere, dapat alam natin kung anong controller(PWM) ang ginamit nya kasi may mga controller na may power limit feature, basically ang kakailanganin mo lang gawin eh magpalit ng mga resistors. Kung parang cellphone charger lang xa, hanapin nyo yung resistor na nakaseries sa secondary winding ng power supply (current sense yun) and try decreasing its value.

Pasensya na po sa madaming tanong.  :)

OK lang bumawi naman ako ng maraming tanong din eh,hehehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 22, 2008, 03:44:41 PM
Correction "Ned Mohan" po hindi Ne Mohan


kung power limit pala problema eh pwede nyo hanaping yung resistor na nakaseries sa FET ng primary side, nakakabit yung sa source ng FET going to ground, babaan nyo rin value.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: fantom_mayonaise on February 22, 2008, 08:13:47 PM
Sir yung controller na ginamit is M51995FP. I'm rewinding the transformer to improve the voltage regulation at higher output amps. Meron syang trimmer resistor na kailangan ko pang isagad para makuha ko yung 13.8V output.

I'm beginning to think that it has no feedback from the output terminal. I'll try tracing out the schematic and post it here on tuesday.

Since kalas pa yung supply, I bought another from a different manufacturer. I tested it by charging a nicad pack at 10amps, di gumalaw sa 13.8volts yung terminal voltage the whole time na pinapalo ko ng 10amps yung nicad pack. This supply is only rated at 14amps!!!

Balak ko tuloy gawing pag-eksperimentuhan yung binaklas ko... Susubukan yung iba't ibang topology ng SMPS.



Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 26, 2008, 08:39:02 AM
Bro nadownload ko datasheet, possible na wala ngang feedback sa secondary yan kundi sa auxilliary winding xa kumuha ng voltage information, see figure 2 ng datasheet, my assumption is flyback ang pinakapossible na gagamitin nila.

http://www.alldatasheet.com/datasheet-pdf/pdf/891/MITSUBISHI/M51995FP.html

This is a common problem sa multiple winding, kung saang winding sila kumukuha ng feedback eh dun lang sila ngreregulate kaya kung medyo heavy ang loading ng iba, expected na bababa output nun,

Ang my suggestion, good ginawa mo sir na dagdagan ng winding ang secondary, you might have problem lang sa over voltage kung lightly loaded yung secondary pero I think hindi ganun kacritical kung motor lang patatakbuhin (I hope, hehehe).

Share ka pa sa mga maeexperience mo jan, gud luck.

BTW:
Auxilliary winding is an extra winding on the transformer that supplies the controller when it is already operating steady.

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: fantom_mayonaise on February 26, 2008, 09:33:53 AM
Sir eto po experiences ko. :)

Malamig ang panahon nung sunday, wala akong magawa.Makulimlim sa labas. Dahan dahan kong sinalat ang matigas na bagay na yun, kinapa ko mula puno hanggang dulo. Hinaplos haplos at hinawakan sa aking palad. Di pa nakatiis, inilabas ko na ang aking....




SOLDERING IRON.


Anyway, nirewind ko yung ETD transformer. Dati 54T:7T yung ratio nya. Ang intended rewind ko sana is 54T:8T pero nang binilang ko yung secondary ko, naging 9T. Di ko na binago since I'm shooting for better voltage regulation and sabi ko oks na yung 15V na kalalabasan nung 8T. 13.5 dati yung output pag 7T yung secondary.

Eto yung konting prob. Nabali ko yung mga outside legs nung ETD core (kaya ako naghahanap ng kapalit). Since wala akong nakitang replacement, ni-glue ko na lang ulit. Pagkatapos ko irewind bawat layer, pinapaliguan ko ng Loctite yung layer para di mag-unwind. Tapos re-assemble na.

DMM lang meron ako kaya output voltage lang na-test ko. Okay naman, kaso di nagbago yung output voltage, wala akong ginalaw sa PCB kasi di ko makita yung voltage feedback. Tama ka sir, merong 2 auxillary winding yung core. Isang 2T and isang 4T.

Kinabitan ko ng charger and nicad battery yung power supply tapos test-charge ng 1amp. Okay naman.

So using my typical testing methods, :) I increased charge amps to 5amps. From 13.8v nag-drop ng 12volts. NGEK!!!! Dito pa lang discouraged na ako.

So I bumped the charge amps to 10Amps. Merong brief flash, ayun. Sunog yung rectifier diode. hikhikhikhik. Di ko na muna sinuri agad. 1am na yun, antok na ako, walang nangyari sa pagpupuyat ko.

Good news is, I DO REALLY have a testbed for my switching supply experiments now. Mukang di nga maganda yung IC na ginamit. If you still have forthcoming lectures, mag-aabang ako hehehe...

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: fantom_mayonaise on February 26, 2008, 09:53:07 AM
TYPO error:

that should be 17volts for the new 9T. 15volts yung original intention ko with 8T
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 26, 2008, 10:26:55 AM
Anyway, nirewind ko yung ETD transformer. Dati 54T:7T yung ratio nya. Ang intended rewind ko sana is 54T:8T pero nang binilang ko yung secondary ko, naging 9T. Di ko na binago since I'm shooting for better voltage regulation and sabi ko oks na yung 15V na kalalabasan nung 8T. 13.5 dati yung output pag 7T yung secondary.
OK this is good since hindi sa kanya kinukuha ang feedback, magagawa mo ngang itaas ang output voltage by doing this. Disadvantage is gaya nga ng nabanggit ko before.

ni-glue ko na lang ulit.
:o L.O.L., usually pag-naibabagsak namin ang choke or transformer core eh considered as damaged na to even though physically whole pa xa at mukhang OK pa naman kasi a single hairline crack would change its magnetic property. ;D

Pagkatapos ko irewind bawat layer, pinapaliguan ko ng Loctite yung layer para di mag-unwind. Tapos re-assemble na.
I think loctite is ok, we use the yellow tape for that purpose, insulating material na rin xa, I dont know lang if available xa locally.

DMM lang meron ako kaya output voltage lang na-test ko.
Sa dati kong team DMM lang ginagamit ko pangtroubleshoot kahit mayoscilloscope naman ako, hehehe.

Tama ka sir, merong 2 auxillary winding yung core. Isang 2T and isang 4T.
Malamang yung 4T yung supply ng PWM, yung 2T di ko sure.

Kinabitan ko ng charger and nicad battery yung power supply tapos test-charge ng 1amp. Okay naman.
So using my typical testing methods, :) I increased charge amps to 5amps. From 13.8v nag-drop ng 12volts. NGEK!!!! Dito pa lang discouraged na ako.

So I bumped the charge amps to 10Amps. Merong brief flash, ayun. Sunog yung rectifier diode. hikhikhikhik. Di ko na muna sinuri agad. 1am na yun, antok na ako, walang nangyari sa pagpupuyat ko.
Ganito nangyari jan(parang CSI muna tayo,hehe), given na yung core mo eh nabasag ang isang leg this reduces your inductance (BTW, in flyback the transformer is acting like an inductor that stores energy) kaya during the FET's turn-on tumaas din yung peak current mo. At yung sumira ng bridge rectifier mo (tama po ba bridge rectifier yung nasira? hindi yung output rectifier?). Possible din na nasira ang FET mo due to high flyback voltage caused by the transformer.

Good news is, I DO REALLY have a testbed for my switching supply experiments now.
That is really good news po.

Mukang di nga maganda yung IC na ginamit.
Tingin ko OK lang yung IC, yung design ang hindi ganun kaganda

If you still have forthcoming lectures, mag-aabang ako hehehe...
Good to know madaming interested, this inpires me to write more about
SMPS, mejo masama lang pakiramdam ko now at busy na rin kaya di ka pa maituloy po but I will provide more lectures in the future.

For the mean time nakakapaglecture din naman me by answering your questions, ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: jaja on February 26, 2008, 11:47:03 AM
Master, sana medyo ma free-up na u para matuloy tuloy na lectures u. More power...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 26, 2008, 11:49:42 AM
ayun, dumating na resback ko, meet master Jaja.hehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: fantom_mayonaise on February 28, 2008, 01:16:03 PM
sir glutnix

based on this site http://www.hills2.u-net.com/electron/smps.htm (http://www.hills2.u-net.com/electron/smps.htm)

Okay ba na dumiretso na pag-experimenta yung full bridge converter? In your opinion, anong pinakamagandang scheme/topology para sa 15V/20amps na power supply?

Tsaka, sinisilip ko yung loob ng mga PC PSU. Tutuo kaya yung mga rating na nakalagay sa casing? parang maliit kasi yung mga output transformer para sa rating na naka-specify. Yung nirewind kong ETD core, halos 2X ang size sa mga nasa PSU pero talo pa din sya sa stated rating ng mga PSU.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 28, 2008, 03:16:39 PM
Okay ba na dumiretso na pag-experimenta yung full bridge converter?
For beginner I recommend try nyo muna basic power supply like boost (I didn't recommend buck kasi nga sa high side switching problem). Experiment muna sa mga light loads.

Or go for flyback, baklasin nyo mga cellphone chargers (mura lang naman yun,hehe)

Pero kung mejo boring sayo yung mga yun its ok lang naman to try full bridge. But still I recommend try mo muna at lighter load.

Note ko lang flyback transformers are different from other isolated topology tranformer because it has a gap on the center of the core.
 
In your opinion, anong pinakamagandang scheme/topology para sa 15V/20amps na power supply?

300W, I think flyback is OK, yun usually ginagamit sa PC PSU, at yung forward converter (two-switch forward)

Tsaka, sinisilip ko yung loob ng mga PC PSU. Tutuo kaya yung mga rating na nakalagay sa casing? parang maliit kasi yung mga output transformer para sa rating na naka-specify. Yung nirewind kong ETD core, halos 2X ang size sa mga nasa PSU pero talo pa din sya sa stated rating ng mga PSU.

Possible na hindi totoo lalo na pag local yung PSU pati dun sa mga charger na local hindi rin totoo yun, possible na totoo din kasi as I have said flyback transformer is different from others because it has a gap and acts like an inductor (stores energy) unlike others na mainly for lowering or increasing ang purpose.

BTW, malapit ko na matapos yung buck converter lesson,hehehe, baka bukas, nice site pre I would recommend it.

 8) 8) 8)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 29, 2008, 08:20:54 AM
Lesson 5.0    Buck Converter   20080222

Introduction...
Alam ko hindi na po kayo makaintay para malaman kung ano ba itong buck converter? Bakit masyado matunog ang pangalan nito?
Well, the wait is over, eto na po siya!!!

On its simplest definition a Buck Converter is a type of non-isolated switched mode power supply that is used to step-down input voltages.

It is the very basic type of SMPS that discussions about the theory of operation of SMPS often starts with a buck
converter or most likely a buck converter will be the example (just like what i did,?). Buck Converter are more
efficient than its linear type counterpart.

There are four basic components of a Buck Converter circuit that plays a vital role on its operation

These are the...
1. Transistor (main switching component)
2. Inductor
3. Capacitor
4. Diode

Theory of Operation...

(http://www.mixedmeet.co.uk/buck.gif)
Figure 5.1

As I mentioned on my previous lessons, the transistor in an SMPS operates alternately between cut-off and
saturation region, or simply as a switch. This switching action allows the current from the input to pass through
the low pass filter composed of the inductor and capacitor. The low pass filter smoothens out the squarewave,
caused by the switching action, to produce a pure DC output (average of the squarewave).

Let's take a closer look on a cylcle by cycle operation of a buck converter

When the MOSFET is on...

(http://www.ecircuitcenter.com/Circuits/smps_buck/image004.gif)
Figure 5.2

The MOSFET would allow the current to flow to the Low Pass Filter. This current produces a potential that will
reverse bias the diode (that's why we can assume it's out of the circuit).The sudden change in current will be
impeded by the inductor as it is energized (stores energy). At this point of operation, the current flowing through
the inductor (inductor current = load current + current on capacitor) will be ramping up.See m1 of the figure below...

(http://www.geocities.com/CapeCanaveral/Lab/9643/samp-ef2.gif)
Figure 5.3

We all know from Inductor's Formula that the voltage across the inductor will be equal to its inductance multiplied
by the change in current per change in time...

   Vl = L * (di/dt)   eq.5.1

From this relation we can tell that the slope of the ramp(m1 of figure 5.3) is equal on the voltage across the
inductor and the inductor's inductance...

   di/dt = Vl / L      eq.5.2

Where Vl is taken from the KVL of the current path with the assumption that the output voltage is already regulated
and is equal to...

   Vl = Vin - Vout      eq.5.3

making the equation...

   di/dt = (vin - Vout) / L   eq.5.4

Controlling the current ramp slope (di/dt) is essential in design because this would determine the maximum current
rating of the MOSFET and the Diode. The easiest way to control the di/dt is by controlling the inductance L
(because we cannot change the Vin and Vout anymore).

When the MOSFET is off...

(http://www.ecircuitcenter.com/Circuits/smps_buck/image006.gif)
Figure 5.4

There will be no current coming from the source but the inductor, after being energized during turn on of the
MOSFET, will try to maintain the current (as it is known to resist the change in current) originally flowing across
it as it de-energize (release of stored energy).

To do this, the inductor naturally negate its polarity (called the inductive kick) and voltage will increase as
high as it take to maintain the current. This could dangerously increase the inductor voltage to a very high
potential that could damage the MOSFET. Good for us we have the diode that will be forward biased the moment the
inductor reversed its polarity. This diode will allow the current to flow and this time the inductor will be the
one supplying the required by the load. Inductor current at this point of operation will be ramping down(m2 of
figure 5.3).

Using the same Inductor Formula...

di/dt = Vl / L      same as eq.5.2

Of course the L is the same during turn on and turn off but Vl now will be the KVL of the current flowing across
the output, inductor and the diode. if we assume the diode to be ideal we can say that...

Vl = Vout      eq.5.5

Thus we get...

di/dt = Vout / L   eq.5.6

The primary purpose of the capacitor is to keep the output voltage constant while the inductor is supplying a
stable average current.

Volt-Second balance...
There is a common rule that governs all inductors in the SMPS(I guess not limited to SMPS) and its called the
Volt-Second Balance. It states that in order to prevent current walk, a condition that happens when the energy
stored is greater than the energy released thus increasing the inductor current, the product of the inductor's
voltage and the time when it is energizing must be equal to the product of inductors voltage and the time when it
is de-energizing.

To prove this we can take eq.5.2

di/dt = Vl / L

rearranging it we have

Vl * dt = di * L   eq.5.7

For turn on (energizing)

Vlon * ton = di * L   eq.5.8

For turn off (de-energizing)

Vloff * toff = di * L   eq.5.9

Noticed that L is common for both conditions(on and off switch) because it will never change unless we are like
"The Flash" that can change the number of inductor's turns faster than the MOSFET is switching, hehehe. di is also
common because this is what we want to prevent the current walk(we want the current to return to its initial
value).

So equating eq.5.8 and eq.5.9 proves the volt-sec balance theory
Vlon * ton = Vloff * toff   eq.5.10

ton is the duration the MOSFET is "on", toff is the duration the MOSFET is "off", and the sum of ton + toff will
the the total period T

Knowing the volt-sec is also important in determining the transfer function of an SMPS topology. From eq.5.3 and
eq.5.5 we can replace the respective Vl to get the transfer function using the eq.5.10

(Vin - Vout) * ton = Vout * toff

Vin * ton - Vout * ton = Vout * toff

Vout * toff + Vout * ton = Vin * ton

Vout ( toff + ton ) = Vin * ton

Vout * T = Vin * ton

Vout = Vin * (ton / T)

thus we get

Vout = Vin * D.C   yehey!!!!!!!!


Continous and Discontinous...

(http://services.eng.uts.edu.au/~venkat/pe_html/ch07s1/fig17_v2.gif)
Figure 5.5

Usually we design the power supply to operate at continous mode. This is a mode where the inductor current never
reaches the 0 value, di(peak-peak ripple current) is usually set at "*%" of the full load current and is achieved
by selecting a correct value of inductance L as mentioned before.It is said that when the inductor current is
touching the zero value but never stay for long then it is operating at critically discontinous as shown on the figure above.

If the load is very light the inductor current will reach the discontinous mode where its value is zero for so long
even before the next cycle starts.


Mga Karagdagang Babasahin...
http://www.powerdesigners.com/InfoWeb/design_center/articles/DC-DC/converter.shtm
http://www.ecircuitcenter.com/Circuits/smps_buck/smps_buck.htm
http://services.eng.uts.edu.au/~venkat/pe_html/ch07s1/ch07s1p1.htm
 8) 8) 8)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 29, 2008, 08:34:50 AM
By the way mga bosing if you have questions feel free to ask po.

I'm thinking is I can extend discussion on buck converter design or should I go to other topologies na lang like boost converter,

ano po ba mas maganda? Anyway for the design may inisend na ko link before paano macompute values.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: motion55 on February 29, 2008, 09:02:08 AM
Quote
Usually we design the power supply to operate at continous mode. This is a mode where the inductor current never
reaches the 0 value, di(peak-peak ripple current) is usually set at "*%" of the full load current and is achieved
by selecting a correct value of inductance L as mentioned before.It is said that when the inductor current is
touching the zero value but never stay for long then it is operating at critically discontinous as shown on the figure above.

Hmm.. Interesting, I always thought you should design it so that it is always operates in discontinuous mode. I may have read it somewhere but maybe it was not for a buck converter.

To what % duty do you normally design it at full load? 50%?


Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 29, 2008, 11:17:41 AM
Thanks for asking that question sir,

For flyback converter usually it is designed to operate at discontinous because of control problem. Some of the PFC (Power Factor Corrector) are operating at discontinous (Most of PFC as implemented from a Boost Converte)

But for high power application, it would be too costly and I think uneccessary to operate at discontinous because this would require a semicon with high current rating (usually inductor peak current is a little less than twice the full load current: so kung 125A and requirement, 250 dapat rating ng semicon mo or more para may allowances). Unlike if continous ang ripple is a percentage of full load(   ) at ang peak is 1/2 ng ripple + full load current. Yun lang ang peak current rating na kakailanganin + some allowances ng semicon

That's the reason why continous mode ang operation natin.

Dun po sa pdf na inisend ko dati eto po link nung site...
http://powerelectronics.com/power_systems/dc_dc_converters/power_buckconverter_design_demystified/

It discuss designing a buck converter

Inductor Selection
Calculating the inductor value is most critical in designing a stepdown switching converter. First, assume the converter is in CCM, which is usually the case. CCM implies that the inductor does not fully discharge during the switch-off time. The following equations assume an ideal switch (zero on-resistance, infinite off-resistance and zero switching time) and an ideal diode:


Inassume na CCM(or continous conduction mode) ang operation at ang ginamit na percentage is 30%, see the LIR on the last statement on the page...

Hope this help sir
 ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 29, 2008, 06:08:50 PM
sir motion55 sorry naoverlooked ko yung question nyo regarding duty cycle kala ko ripple current yung percentage na tinatanong nyo,

yung mga isolated PSU eh normally less than 50%, ang alam ko flyback eh hindi dapat magexceed ng 50%,  forward is 75 - 90, for boost definitely maliit lang dapat duty.

For buck mas malaki duty. Sa design kasi dapat iconsider natin yung dynamic range so dapt makapagadjust xa if min yung input pos kailangan imax ang output. And another thing is stability ng control.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: motion55 on February 29, 2008, 06:40:45 PM
Thanks for the reply. I once designed a buck converter circuit that operated at discontinuous mode at its normal use. The sample prototype's inductor ay medyo hot to touch. I checked the current consumption and it was well below the rated value for the LM2676 regulator. This regulator operates at 260Khz frequency. Even after I specified the rated current, I figured the inductor they bought was too lossy at this frequency. Anyway, by the time the unit went into production and the engineer, who took over the conversion to production design, replaced the inductor to a higher value inductance thus it must be already operating at continuous mode. Being too busy with another project, I didn't bother to check except to ask if the inductor he had chosen was running cool. Now, I now know that by reducing the ripple current, it will reduce the core losses and it is OK to operate at continuous mode.

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 29, 2008, 06:59:30 PM
Thanks for sharing your experience sir, tama po obeservation nio dun.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: jaja on February 29, 2008, 09:47:42 PM
comment ko lang po. when you change the buck converter operation from discontinuous mode to continuous mode, the decrease in peak current reduces RMS current. the copper losses on the inductor reduces assuming the same wire gauge. Another thing, we are operating at 260kHz which is usually high. we should also consider the skin effect on the wire, maybe you used the more and thinner wire on your second choke. core property should also be consider knowing that the coreloss is proportion with frequency.

un lang po share ko.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 02, 2008, 02:32:31 PM
Thanks for that master Jaja, the more experienced one, hehehe,
actually nagulat din po ako sa frequency na 260khz( usually < 100 kHz lang kami), pero hindi inductor ang inalala ko sa frequency na yun kundi yung switching losses,hehehe,

we should also consider the skin effect on the wire, maybe you used the more and thinner wire on your second choke.

mejo nalito lang ako sa part na to, I think you mean 1st choke kasi yung 1st choke ang nagiinit po.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: motion55 on March 02, 2008, 04:19:13 PM
Thanks for that master Jaja, the more experienced one, hehehe,
actually nagulat din po ako sa frequency na 260khz( usually < 100 kHz lang kami), pero hindi inductor ang inalala ko sa frequency na yun kundi yung switching losses,hehehe,

Actually, I previously used devices that run at 80Khz. However, I just wanted to try the LM2676 which ran at 260KHz. I can afford to on that project because I was not constrained by part availability. I can always specify a different but compatible part with lower frequency. Anyway the prototype used a hand-wound toroid core. The production model used a pre-wound inductor (TDK brand) with a quality ferrite pot core probably with a small air gap.

There are newer simple switchers from National Semi that run at 500KHz. Back in the early 90's, I visited a small company in Silicon Valley which was assembling miniature DC-DC converters. The owner who also designed the devices proudly mentioned that he was operating at 1MHz to gain compact size. So no, it does not surprise me to try to use these devices.

As to issues with skin effect or swtching losses. I don't think skin effect has any bearing. Skin effect results in ohmic losses due to higher resistance in the wire. It was the core that was hot and not the wire. The core also had very few turns (less than 20-30) to have any significant resistance. The peak current was also only about 1A. The LM2676 also ran quite cool without heatsink. No significant switching loss over there. It was directly mounted to the copper foil of the PCB as recommended by the datasheet.

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 03, 2008, 08:21:46 AM
Yes sir I agree there are controllers that can handle switching that fast, what concerns me is the switching losses of the MOSFETs (the faster you switch the greater the losses are).

We'll come to think of if, the applications could be for lower power. For >2kW it would fry the FETs or efficiency could be low.


We'll I guess it's really the core loss that causing the problem. :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: motion55 on March 03, 2008, 11:17:37 AM
The claimed efficiency of the LM2676 @260KHz is 90% at rated current output. The similarly rated LM2576 @50Khz is only claiming 70-80% efficiency. I don't know how they arrived at hose figures but they are all from National Semi and so it is fair comparison.

Yesterday when I was pondering on the differences, won't the electrolytic capacitors' inductance come into play at 260KHz. Won't it require higher frequency capable caps vs. those that can operate below 100Khz?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: jaja on March 03, 2008, 12:00:44 PM
Thanks master neo.

Hi motion55, You used LM2676 on your design and I agree that you shoudn't have much problem beacause the switcher is built in and is tailored to that operation. Few components to add not to mention that the loop is also built in.

The problems that we are discussing migth not really occur for the reason stated above. The power/current is also low and is anothe factor. But when you will design hundreds and thousand of watts or high current design you might need to take a look deeper on the said problems.

High density "brick type" power supply operating at 500kHz to 1MHz do really exist, VICOR says they operate more than this frequency. These are high end PSU and most of their devices and components are custom made for their application.

For hobbyies and beginners, operationg below 100kHz is a good starting point unless you really needed to do so or to explore.

yun lang po comment ko.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 03, 2008, 12:36:12 PM
I agree with Master Jaja

I checked the datasheet of LM2676, inside the controller na rin pala yung MOSFET, it is indeed possible to have 90% efficiency by choosing lower rdson MOSFET, don't be mislead lang po, rdson losses eh walang kinalaman sa switching losses, rdson losses is mainly due to higher duty and output current (I^2 * Rdson),

switching losses naman is a function of frequency and current na rin, in the datasheet upto 3A ang capacity nya kaya po switching losses is not that significant din even a high frequency, possible din na high slew rate ang MOSFET nun kaya mas napababa pa ang switching losses.

On high power applications where it requires >100A, problems switching losses and skin effects and also MOSFET performanse vs capacity becomes a serious concern.

On the otherhand I agree with Master motion55 that operating at higher frequency would allow us to have smaller filters, though sometimes when thermals becomes a problem this will require larger heatsink this would limit the size advantage of operating at higher frequency.

still for hobbyist using uc3842, I would recommend to operate between 75kHz - 110kHz.

for electrolytic caps, we can always check the frequency characteristic curves in the datasheets, I think there is a point where the impedance of caps increases with frequency, just not sure at what frequency it will start to increase.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: jaja on March 03, 2008, 03:02:16 PM
Hi motion55, The contributor to this defference might be the built in switch characteristics. LM2676 uses DMOS with 150mohm rdson while LM2576 uses 3A BJT based on block diagram, no other data specified.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: motion55 on March 03, 2008, 03:42:26 PM
Hi motion55, The contributor to this defference might be the built in switch characteristics. LM2676 uses DMOS with 150mohm rdson while LM2576 uses 3A BJT based on block diagram, no other data specified.

There you go! All things being the same, I agree switching losses would increase with frequency. However, advances in semiconductor technology help overcome this problem.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 03, 2008, 04:32:03 PM
hmmmm, mukhang point of view ang pinagkaibaiba natin, hehehe

summary lang po, nalilito na mga beginners here :D

actually it started with the issue that 260kHz seems to be an odd frequency for an SMPS...

odd for me and jaja since we're working mostly on high power(high current) SMPS >2kW, but I failed to look at the possiblity if we implement high frequency for low power applications where there's a lot of semicon to choose from that can meet high switching requirements (lower Rdson, high slew rate), on high power the primary objective of semicon manufacturers is the current, voltage and power ratings that's why most of them have no significant difference in terms of slew rate (faster switch comes with a higher price).

High switching freq can reduce the size of the components to be used though for high power applications the heatsinks could complement the size we saved by using high freq,

Between LM2676 switching at 260kHz but 90% efficient and LM2576 switching at 50kHz and 80% efficient I think what jaja mean by what caused the difference in efficiency assuming same current in the output is that LM2676 is using a MOSFET with Rdon of  150mohms (losses is I^2 * 150mohms) while LM2576 uses a BJT (losses is 0.7V * I), let's compare

supposed current is 2A
LM2676 losses = 2^ 2 *150mOhms = 0.6W

LM2576 losses = 0.7V * 2 = 1.4W

pangita na po dun, ;D

in the example, conduction loss became more significant than switching losses

for hobbyist, we are limited to what is available in the local market, and that will specify our operating frequency ;D


Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 06, 2008, 09:05:48 AM
Source:
http://www.ee.ryerson.ca/~courses/ele754/lecture_notes/Chapter1.pdf


Very nice article on buck converter, good presentation too.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: jaja on March 07, 2008, 01:50:19 PM
master neo, sabik na kami sa next lecture mo...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 07, 2008, 03:05:05 PM
Busy pa, hehehe, pagnfree-up ulet me magpopost ako ng boost. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: paranz on March 07, 2008, 03:14:36 PM
Busy pa, hehehe, pagnfree-up ulet me magpopost ako ng boost. ;D

yeah keep posting. Very informative.

Nakagawa ako before ng SMPS using TL494 but that was way back during my college days. Its a buck converter, nakalimutan ko na halos lahat ng details but one thing i can remember was the difficulty of obtaining the appropriate inductor. Gumawa lang kami using bronze wires and we dont know ano ang value ng inductor hehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ftdc on March 10, 2008, 07:23:28 PM
wow ok ah, meron pala ganito topic dito.  sarap mag basa, nakakarelate ako. hehehe.

@glutnix_neo

uy mukhang kilala kita ah,  design engr ka pala dati tapos ngayon software ka na. ano team mo dati?  lipat din kaya ako dyan sa software. hehehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on March 10, 2008, 09:45:00 PM
wow ok ah, meron pala ganito topic dito.  sarap mag basa, nakakarelate ako. hehehe.

@glutnix_neo

uy mukhang kilala kita ah,  design engr ka pala dati tapos ngayon software ka na. ano team mo dati?  lipat din kaya ako dyan sa software. hehehe
@ ftdc
parang kilala rin kita..  ???
nats, ikaw ba yan? ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ftdc on March 10, 2008, 09:52:23 PM
@julznc

uu aku tu, hehe.  ala pa ko masyado contributions sa mga topic dito.  sana maka-contribute ako kahit konti.

so dun sa mga may tanong regarding SMPS, especially magnetics design, tanong lang kayo baka sakali masagot ko.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 11, 2008, 07:45:32 AM
naku marami na ko makakatulong magexplain, hehehe,

team1 po ako dati,

actually marami tayo dito, hehehe

@julznc
so dun sa mga may tanong regarding SMPS, especially magnetics design, tanong lang kayo baka sakali masagot ko.
tamang-tama sir madami nagtatanong dito ano daw po ba difference ng low frequency transformer sa ginagamit natin sa smps?
(kunwari di ko alam,?)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ftdc on March 11, 2008, 12:34:53 PM
Uy buena manong tanong agad,  grabe, kelangan pala mag review ako dito kung hindi baka mapahiya ako.  hehe.  search nyo na lang sa google andun sagot. hehehe, jokla.

Yung mga cores na ginagamit sa low frequency transformers are usually made of iron or laminated silicon iron/steel.  Coreloss usually comprise of hysteresys losses and eddycurrent losses which is quite similar to conduction losses I^2xR.  Usually variying magnetic fields produces eddy currents in these materials and the effects of eddy currents increases with frequency,  thus the higher the frequency the higher the eddy current losses.  That is why lamination is used instead of solid iron construction.  The benefits are easier to build/manufacture and reduces eddy current loss, but somehow reduces overall effective permeability due to reduced effective area becuase of the space occupied by insulation material.  However in very frequency applications,  this material is not suitable.  Here is where ferrites and other ferromagnetic materials come into the scene.  These are materials that are made to operate at higher frequency without too much coreloss.  However unlike pure iron and laminated steels, the ferrite materials has much lower core saturation level.  Thus there is a limited power capability, usually in a few kilowatts.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 11, 2008, 01:08:09 PM
galing ah,

one pogi points kay sir ftdc
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ftdc on March 11, 2008, 04:28:23 PM
@glutnix_neo

Uy salamat sa pogi point!  Ok pala dito pag sumasagot sa tanong eh pumopogi! hehehe.  Teka bakit di ko makita yung button para sa pogi points?  Pano ba mag bigay ng pogi points?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 11, 2008, 04:51:55 PM
pag naka 50 plus na kayo na post, may recharge na button/link sa ibaba ng pogi points, paginiclick nyo dun magiincrement pogipoints nung tao. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 14, 2008, 07:52:30 PM
Lesson 6.0    Boost Converter      20080305

Introduction...

Let's move on to boost converter. Boost converter are the oposite of buck. It is a type of SMPS that produces a higher output voltage out of a lower input.

Still the four basic components of a buck converter is present on a boost but on different locations
1. Transistor (main switching component)
2. Inductor
3. Capacitor
4. Diode


Theory of Operation...
(http://www.daycounter.com/LabBook/BoostConverter/BoostConverterSchematic.gif)

Same as with the buck converter, the transistor operates alternately between cut-off and saturation but this time the transistor is located on the low side of the circuit. The inductor is energized during turn-on of the transistor and during turn-off it is de-energized, inverting its polarity that aids the Vin potential making it possible to derive a higher output voltage from a lower input. Again, capacitor filters the inductor current and the pulsating DC voltage to a stable output.

Let's take a closer look on a cylcle by cycle operation of a boost converter

When the MOSFET is on...
(http://services.eng.uts.edu.au/~venkat/pe_html/ch07s3/fig02_v1.gif)

As mentioned, during turn-on of transistor the inductor will be energized. Current across the inductor will increase gradually (see my previous discussion on buck converter). The anode of the diode will be pulled to ground making it reverse biased. At this point of operation we can assume that the voltage across the inductor can be obtained by taking KVL of the current path when transistor is on

   Vlon = Vin      eq.6.1

When the MOSFET is off...
(http://services.eng.uts.edu.au/~venkat/pe_html/ch07s3/fig03_v1.gif)

This time the inductor will try to maintain the current originally flowing across it. To do this it will invert its potential aiding the input
voltage as it is de-energized. This current will forward bias the diode allowing current to flow to the load and output capacitor.

So, taking the KVL of the current path when transistor is off we can get

   Vloff = Vout - Vin   eq.6.2

Noticed that this time Vout is now greater than Vin.

Applying the Volt-Sec balance rule we derived from our lesson # 5, the buck converter, we get...

   Vlon * ton = Vloff * toff    eq.6.3

Substituting eq.6.1 and eq.6.2 to eq.6.3 to get the transfer function

   Vin * ton = (Vout - Vin) * toff

   Vin * ton = Vout * toff - Vin * toff

   Vin * (ton + toff) = Vout * toff

   Vout = Vin * (ton + toff) / toff

   Vout = Vin * T / toff

where toff = T - ton

   Vout = Vin * T / (T - ton)

   Vout = Vin * 1 / (1 -DC)   eq.6.4  Hay, sa wakas naderive din!!!! hehehe   


Boost converter found its application on LED drivers and other baterry supplied devices where the input voltage is usually derived from a 1.5V or lower battery. It is also the most common converter used in Power Factor Correction.


Mga Karagdagang Babasahin...
http://en.wikipedia.org/wiki/Boost_converter
http://services.eng.uts.edu.au/~venkat/pe_html/ch07s3/ch07s3p1.htm



Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 14, 2008, 07:56:09 PM
Correction lang po dun sa diagram na nakopya ko, dapat baliktad na polarity ng inductor pagnaka-off yung MOSFET that is - : + and not + : -
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hero Lou Enal on March 17, 2008, 09:40:56 PM
Anu-ano pa po ba ang iba pang types of SMPS other than Buck, Boost, Flyback, Forward and Cuk?Thanks po ng marami...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on March 17, 2008, 10:00:26 PM
Anu-ano pa po ba ang iba pang types of SMPS other than Buck, Boost, Flyback, Forward and Cuk?Thanks po ng marami...
ang pagkakaalam ko, dalawa lang ang major types ng SMPS..
kung di ako nagkakamali, forward saka flyback lang ang types (or buck and boost ?  ???) ,
and the rest are just derivation/modification of these two..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on March 17, 2008, 10:07:39 PM
yung C?k (chook) converter, invented by Dr. C?k, medyo special sya
kasi instead na inductor yung main element for transfers ng energy, gumamit sya ng capacitor
para dun makadaan yung energy from input to output..
it's almost same with sepic converter..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 18, 2008, 07:23:44 AM
tama po si sir julznc regarding cuk,

sir herolou, the converters you mentions belongs to a classification we call non-isolated(walang transformer), others that belongs to isolated are flyback(buck-boost derived) and other buck derived topologies such as forward, push-pull, bridge etc, I have a discussion on this on early part of the thread,
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 18, 2008, 07:51:10 AM
share ko sa inyo to,

pinakapaborito kong pdf related sa SMPS

http://focus.ti.com/lit/ml/sluw001a/sluw001a.pdf
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: paranz on March 18, 2008, 08:10:48 AM
bro, kindly post some simple circuits here na pwedeng ma simulate natin sa EDAs. TY
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 18, 2008, 08:20:56 AM
ano po yung EDA?

sige try ko buklatin ko ulet mga circuits ko na for pspice nga lang, pero try ko muna kung gumagana, hehehe, ang problema its either nasa note ko lang or nakatago deep somewhere in my computer, after holiweek try ko ipost,

dalawa simulator na ginagamit ko, pspice at simetrix. yung freeware eh ok lang.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: paranz on March 18, 2008, 08:25:41 AM
kahit anong simulator pwede na.

Im using multisim and proteus though.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on March 22, 2008, 03:37:26 AM
there are some methods you can do with a scope to get the hysteresis curves, etc..forgot the links..months na rin akong wala sa power electronics..simplest yung wind ng wire then measure inductance.. ;D

kung may kailangan kayong IC's na wala dito pwede humingi ng samples... :o

TI ang isa sa pinaka-generous.. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on March 22, 2008, 05:45:06 AM
here's a replacement for 7805's using a simple SMPS..no IC's needed..

http://www.romanblack.com/smps/smps.htm
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on March 22, 2008, 05:52:07 AM
to the Power Electronics guys (medyo advance question):

ano po yung simplest way to make a DC-AC Zero Volt switching? the circuit will be coming from a High Voltage DC then chopped to a Sinusoidal AC using a Full Bridge..I am currently taking a look at Philips' UcD (Universal Class-D, now licensed by Hypex) amplifier created by Bruno Putzeys and would like to create something similar to his design..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: alyas on March 23, 2008, 06:34:16 PM
Pwede ba ang variable output voltage sa smps?  Been searching the net for some info and wala ako makita.  Most smps designs now use SMPS ICs .... some chips are fixed out while some are adjustable outputs but none so far have variable output voltage.  Could the inductor  (or even capacitors?)  be the limiting factor here as the inductances need to also vary as the output voltage varies?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on March 23, 2008, 08:30:40 PM
Pwede ba ang variable output voltage sa smps?
Basically, pwede.. Like for example a Buck converter,
pwede mong i-adjust ang duty ng PWM para ma-adjust mo rin ang output voltage..
to review about Buck converter: Vo = Vi x Duty --> only true for continuous conduction mode..

Pero, HINDI sya Advisable kasi ang mga SMPS (especially yung mga high power) ini-optimize lang sa certain output voltage (i.e. highest efficiecy). Particulary yung mga magnetic components (inductors and transformers), dini-design sya para hindi sila mag-saturate, lowest core loss as possible, etc. Pati yung mga switches (i.e. FETs and Diodes), iniiwasan na ma-over strees (i.e. voltage spikes, over-current)..
(hope you get my point  ::))
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on March 23, 2008, 10:08:32 PM
doable, pero sabi nga ni julznc, not advisable...as in the case of an autovolt supply, madaming design trade off para ma-accommodate yung wide range ng input supply...

kung gagawing mong variable yung SMPS, mag-adjust ka dun sa division ng feedback mo para closed loop pa rin...this is how power inverters are done, feed ka ng AC dun sa comparison, but again maraming trade off... ;D

though merong isang class ng amps na ginagamit yan (hindi ko sure kung Class G or T)...linear pa rin yung amp pero switching yung supply...depending sa output i-adjust nung SMPS yung supply to the output voltage + 5V to achieve high efficiencies...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 24, 2008, 08:03:13 AM
Pwede ba ang variable output voltage sa smps?  Been searching the net for some info and wala ako makita.  Most smps designs now use SMPS ICs .... some chips are fixed out while some are adjustable outputs but none so far have variable output voltage.  Could the inductor  (or even capacitors?)  be the limiting factor here as the inductances need to also vary as the output voltage varies?

Tama po silang lahat, pwede, but what limits us is the cost para makabuo ng adjustable SMPS.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: alyas on March 24, 2008, 09:25:06 AM
So in otherwords inductor talaga ang limiting factor in order for you to have a consistent line and load regulation and overall flat curve efficiency. 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: fantom_mayonaise on March 24, 2008, 09:44:14 AM
Sir Glutonous Electronics  ;D:

Try nyo pala sa rsphillipines.com. Search for ETD or torroids as keyword. Meron lumabas dun sa search ng website nila. Pag may oorder, pasabay na lang ako heheh. ETD core sana para sa akin, pamalit sa nabasag dun sa Power supply ko.

Pa-post na lang dito kung meron ooder. Thanks
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on March 24, 2008, 10:17:49 AM
So in otherwords inductor talaga ang limiting factor in order for you to have a consistent line and load regulation and overall flat curve efficiency. 

for consistent line and load regulation, malaki effect nung control loop and compensation sa feedback...

trade off in designs talaga mangyayari...from V = L di/dt you can see that pag nagbago output voltage and same input voltage magbabago slopes ng current sa inductor...

then there's continuous and discontinuous modes... ;D

karamihan ng nakita kong SMPS na pwede adjust +/- 20% lang nung nominal voltage ang adjustment, for precision adjustments lang talaga...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 24, 2008, 10:51:11 AM
Sir Glutonous Electronics  ;D:

Try nyo pala sa rsphillipines.com. Search for ETD or torroids as keyword. Meron lumabas dun sa search ng website nila. Pag may oorder, pasabay na lang ako heheh. ETD core sana para sa akin, pamalit sa nabasag dun sa Power supply ko.

Pa-post na lang dito kung meron ooder. Thanks


Thank mayonaise, hehehe, for the mean time nagkaka-igi(nagkaka-ari, I don't know how to say it in a dialect na maiintindihan ng lahat, hehehe) pa naman ako sa mga scrap but I can take a look at it for the prices.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 24, 2008, 10:53:59 AM
<<<<<<<< OK tong napanalunan ko, hehehehe

By the way salamat nga pala sa mga posters ng thread na to, dahil sa inyo nanalo ang thread ng longest technical thread and still growing, hehehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on March 24, 2008, 10:25:56 PM
sir glutnix pahiram din yung napanalunan mo pag napagsawaan mo na:-)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 25, 2008, 07:29:19 AM
Off topic:

sige ba, balak ko muna gumawa nung robot na dalawang gulong na parang segway dito, hehehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 26, 2008, 08:08:12 AM
Sir Paranz nakita ko na kahapon yung notes ko ng mga SMPS. Initry ko sa pspice yung simulation at ok naman yung mga non-isolated, nagkaproblema ako sa mga isolated, nagkaron ng convergence error,

any suggestion paano gamitin kbreak? nakalimutan ko na kasi 4yrs ko pa last na ginamit yun eh hindi naman nakaindicate sa notes ko, hehehe,

BTW, open loop lang yung SMPS ko,hindi rin kasi ako mahilig magsimulate ng buong circuit,portion by portion ako kung magsimulate, sa actual na yung rest para masaya,  ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: razalas on March 26, 2008, 09:09:05 AM
share ko sa inyo to,

pinakapaborito kong pdf related sa SMPS

http://focus.ti.com/lit/ml/sluw001a/sluw001a.pdf

Thanks for Posting... Ito rin ginagamit kong reference during my Power management test dev days... :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 26, 2008, 09:21:12 AM
yup very useful yan,

pakinote lang po sa iba na yung "Ideal Transfer Function" eh ideal talaga, walang consideration sa diode drops at assumption is continous conduction mode ang inductor current.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on March 26, 2008, 09:40:38 AM
anong simulator?

nakalimutan ko na rin yung KBreak, pero naaalala ko dito pinapasok yung core model...hindi ko pa succesfully nagamit yun kaya mostly ideal mga simulation ko dati...

kung convergence errors, bawasan lang ng konti accuracy ng simulation...

these starting values normally works for me...

RELTOL = 0.005
VNTOL = 100.0u
ABSTOL = 1.0n
STEPGMIN enabled
pwede ring damihan yung iteration limits (pero mabagal na on some computers)

LTSpice (SwitcherCad na ata) is better on this...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 26, 2008, 09:48:40 AM
pspice ng orcad 9 yata yung gamit ko.

thanks for the inputs bosing.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on March 26, 2008, 09:51:54 AM
you're welcome po... ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Siramiko on March 27, 2008, 08:37:57 PM
nakita ko lang site na ito,
http://www.smps.com/
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: fantom_mayonaise on March 28, 2008, 11:12:39 AM
@glutnix

sir nakita itong PDF na ito. Gusto ko sanang itry pero medyo duda ako. TIngin nyo safe sya?

http://www.stonefisk.com/doc-arc/20A_psu.pdf (http://www.stonefisk.com/doc-arc/20A_psu.pdf)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 29, 2008, 02:48:38 PM
We'll mali pagkakaexplain nya bout sa ground thing, hehehe

Usually input lang ang nakaearth ground at floating ang outputs.

On the question kung gagana? Opo gagana xa, pero kung safe that is one thing I cannot guarantee, hehehe, There are possibilities that the current rating ng mga power supplies are not enough for the application, hindi porke nagseries ka ng 3 power supplies ay capable na xa magsupply ng 3x ng current. ;D ;D

I also tried deriving 7V (driving a fan) out of PC power supply using a similar method (Fan + terminal to +12V and fan ground to +5V, Voltage difference 12-5 = 7).

For a conclusion,
Usually we design power supply with safety taken into consideration, kaya hindi ko po masagot tanong nyo if safe kasi merong mga power supply sa market na hindi ikinonsider ang safety,

If it is a power supply na siguradong 5V ang lalabas at siguradong isolated ang primary at secondary at siguradong masashutdown xa if may failure na nangyari, then I would say it is safe to do that trick, ;D ;D ;D, by the way be sure din na hindi masisira CB radio nio if namatay isang supply at 10V ang lumabas sa output(un kasi 2nd pinakapossibile na failure na nakikita ko). I also would like to suggest adding a post regulator and kung kaya ng budget a few output protection.

off topic, maganda nga paglaruan PC power supplies, nakakabili ako dati ng AT PSU na less than 50pesos, hehehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 29, 2008, 02:51:32 PM
nakita ko lang site na ito,
http://www.smps.com/

sir paranz, may mga pspice simulation dun sa link na inisend ni sir techno,sinukuan ko na pspice sa isolated (for now, hehehe), pero ginagawa ko yung simulation sa simetrix, try ko iupload pag natapos ko na lahat.

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on March 30, 2008, 09:32:41 PM
@fantom_mayonaise

check mo kung connected output ground to body ng PSU...maraming PSU na naka-connect ang output ground to metal chassis...kung magkakabit, hindi mo pwede i-join yung chassis nila...ilabas mo lahat ng PSU...

meron ding mga PSU na yung output ground naka-connect sa earth ground terminal ng outlet...check mo rin yun...

this is commonly done in the DIY CNC community, making 24V to 48V rails using series connected supplies...

nagawa ko na 'to making 24V rail...first attempt pumutok yung fuse, dahil connected pala yung mga output ground sa earth terminal...

trace lang kung ano yung mga connection ng ground para maiwasang magshort ang supply...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 01, 2008, 08:00:30 AM
Lesson 7.0    Buck-Boost Converter      20080401

Introduction...

As you may have noticed from the previous lessons we had. Most non-isolated topologies uses only 3 (or four if we are to include the capacitor) components, namely, the transistor, the inductor and the diode. Their location on the circuit defines the type of topology it belongs to.

Same type of components are also used for the Buck-Boost type converter. Buck-Boost, again on its simplest definition is a type of DC-DC Switched-Mode Power Converter that is capable of stepping-up or stepping down input voltages. There are many variation of the Buck-Boost Converter circuit but one should note that the simplest form (meaning- the least number of components used) of this type of converter has an inverted output (negative).

Theory of Operation...

(http://www.fairchildsemi.com/graphics/blockdiagram/buck_boost.gif)

To simplify everything, we won't go over the derivation process because I already showed how to derive it on my previous lessons. But we can analyze the flow of energy when the switch is on and when it is off.

When the transistor is on...

Current will flow from the source through the inductor. At this point of operation the inductor is said to be energizing (storing energy), the diode is reverse biased making the output effectively isolated from the input. The output capacitor is the one supplying the current to the load during this period.

(http://upload.wikimedia.org/wikipedia/commons/thumb/8/82/Buckboost_operating.svg/600px-Buckboost_operating.svg.png)

When the transistor is off...

The inductor, as it always do, will try to maintain the current originally flowing across it. To do this, the inductor will invert its polarity and this time it will release the stored energy to the load. This will forward bias the diode to a direction of current away from the load making the output negative.

The ideal transfer function of the buck-boost converter was derived as...

Vout = - Vin * D / (1 - D)

From the formula we can observe that if our duty is less than 50%, the Buck-Boost Converter produces an output that is less than the input voltage.

Again, using the same formula, if our duty is greater than 50%, our output will be greater than the input voltage.

One must also take note of the negative sign.

Conclusion...

Buck-Boost Converter is very useful on applications requiring adjustable ouput that varies between voltages that is less than or greater than the input voltage. I remember one time we had an application for this when we are required to control the fan speed (12V fan) out of a 12V supply. We did this by varying the voltage supplied to the fan using a Buck Converter but unfortunately, due to voltage drop at the Buck's FET, we can't set the fan to full speed. Using the buck-boost solves the problem. Another useful application of this type of converter is on circuits requiring negative supply such as supply of an amplifier.

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on April 01, 2008, 10:13:31 AM
OT: yung mga 12Vdc brushless fan kayang magwork hanggang 20V...ok as exhaust... ;D

Disclaimer: hindi ko alam ang long term effect sa fan at hindi ko pa na-try sa lahat ng fan...

Buck-Boost are also good for battery applications like cellular phones...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: michael256 on April 03, 2008, 02:02:26 AM
mga pre SMPS tayo ryt..hmmm hirap mag hanap ng parts d2 samin..T_T
san ba maka2bili ng UF,SF na diode pati core hirap hanapin ...

may na assemble na ako pang mobile audio
12V (4-6A) to 36+/-(1.2-3A)
kung gus2nyo makita circuit rep. lng kau d2...
ganda png sounds sa mga motor n wave ^_^
ahh im using tl494cn
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 03, 2008, 08:23:49 AM
may na assemble na ako pang mobile audio
12V (4-6A) to 36+/-(1.2-3A)
kung gus2nyo makita circuit rep. lng kau d2...
ganda png sounds sa mga motor n wave ^_^
ahh im using tl494cn
sige po patingin po kami circuit, ;D

I'll try to provide a design na gagamit ng mga scraps(AT PSU, Cellphone charger, ballast ng flourecent bulb, etc)at pinagiisipan ko pa paano mapapagana ng hindi gagamit ng oscilloscope.

Balak ko magmodify ng cellphone charger pang supply sa projects at saka adjustable na battery operated na power supply(buck-boost), hehehe, post na lang ako nun pag-naumpisahan ko na.

Siguro first step na gagawin ko eh magbuild muna ng LCR meter para malaman inductance ng mga choke, may nakita na ko magandang design sa internet. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on April 03, 2008, 09:02:32 AM
san ba maka2bili ng UF,SF na diode pati core hirap hanapin ...

UF diodes try ph.farnell.com or www.rsphilippines.com

yung cores ang medyo mahirap...meron din sa kanila...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 03, 2008, 09:09:40 AM
meron din yata rs ng mga cores, mejo delikado lang iship yun.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: alyas on April 03, 2008, 09:36:00 AM
sige po patingin po kami circuit, ;D

I'll try to provide a design na gagamit ng mga scraps(AT PSU, Cellphone charger, ballast ng flourecent bulb, etc)at pinagiisipan ko pa paano mapapagana ng hindi gagamit ng oscilloscope.

Balak ko magmodify ng cellphone charger pang supply sa projects at saka adjustable na battery operated na power supply(buck-boost), hehehe, post na lang ako nun pag-naumpisahan ko na.

Siguro first step na gagawin ko eh magbuild muna ng LCR meter para malaman inductance ng mga choke, may nakita na ko magandang design sa internet. ;D
Bro, kung may makita kang source or part number for a high precision (pang calibration) capacitor please paki post mo.  Its the only thing preventing me from building an lc meter.  Wala akong makita or di ko alam kung papaano hanapin.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Born2BeWired on April 03, 2008, 10:16:40 AM
Sir glutnix, can you recommend a quick and effective way to test/determine if the transformer is already driven into saturation by a pwm circuit?

Bro, kung may makita kang source or part number for a high precision (pang calibration) capacitor please paki post mo.  Its the only thing preventing me from building an lc meter.  Wala akong makita or di ko alam kung papaano hanapin.

Bro alyas, if you are living within MM, I can let you use our LCR within our lab so that you can check the accuracy of your homebrew LCR. You can use our HP4275A multifrequency LCR meter (old but reliable) or HIOKI 3522 LCR Meter. PM me if I can be of help. ;)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 03, 2008, 10:39:37 AM
the quickest of course is by using an oscilloscope, if you have a current probe on the inductor you'll notice that inductor current suddenly increases (mejo exponential ang increase instead of ramping line), or using a voltage probe pwede check ang rsense.

without oscilloscope, tenga lang naiisip kong paraan, iba na ang tunog ng nasasaturate na inductor pero mejo mahirap yun kung di tayo sanay,hehehe, isip pa ko ibang paraan. ;D

One way pala eh pagmalimit pumutok FET mo kahit sure ka na tama rating nya, posible na nagsasaturate na choke(or possible din na Vds rating ang naexceed due inductive kick).

.....Ay transformer pala tinatanong, hehehe, same din lang test po.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Born2BeWired on April 03, 2008, 10:44:18 AM
Current probe.. Hmmm. Bakit di ko nga naisip ito!?  Kasalanan ni sir paranz!
Thanks sir glutnix ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: paranz on April 03, 2008, 11:06:05 AM
Current probe.. Hmmm. Bakit di ko nga naisip ito!?  Kasalanan ni sir paranz!
Thanks sir glutnix ;D

bakit naman kasalanan ko ::)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 03, 2008, 12:42:01 PM
regarding dun sa tunog

parang exponential din ung sound in terms of loudness at frequency at pag narinig mo yun may bubulong sa inyo na konsensya na sasabihing...

"baka nagsasaturate na yan. patayin mo na at malapit ng sumabog", hehehehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on April 03, 2008, 01:28:48 PM
"baka nagsasaturate na yan. patayin mo na at malapit ng sumabog", hehehehe

 :o :o :o

 ;D ;D ;D

pag di ka mabilis mag-react, amoy tutong sa paligid pagkatapos...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: michael256 on April 05, 2008, 01:04:37 AM
e2 n diagram q tested na poh e2
 
wag nyo click 2 d pwede copy paste nyo nalang po URL
http://michael256.angelfire.com/111.jpg


ung core lng po mahirap..jn

ung primary q pri.1 12 by(to +12) 12-inch pri.2 in d same direction
di q poh alam ung size e basta ma taba un ung parang alambre ^_^ pareho ung size n ginamit q sa pri.@sec. coil
at sa sec. wind in the opposite direction(4 bttr coupling)
 trial-n-error nyo na lng 
wag nyo munang i connect ung regulator(ung wire n papunta sa sec. coil ung naka connct sa in4148 -malapit sa zener) to simulate the heavy load (to set the MOSFET's in full power)
and measure the output of the sec. with the Ultra Fast diode if u wnt 24V out. at least dapat my 35-50V readings(note:pag mag measure k ng out dapat wala mung capacitor sa output rectifier lng) ka (note: hindi pa naka connct ung reg.)
pag kulng ung n measure mo rewind mo sec. coil. dagdagan mo poh. trial-n-error lng po pag sumobra nmn poh kulangan u lng ^_^ huh O_O nahilona kao nOH...hehe
ex.
na measure mo
V out +-39V
diba 24 ung dapat palabasin
connct nyo n po ung line regulator
ung wire n papunta sa in4184 lapit sa Zener(24v) diode
tapus measure nyo ulit output after conntng the linreg..
..pwede nyo n lagay ung capacitor 4700u 50v
pag tumaas readings mo after pleasing the cap.s at no lead
Normal lng poh..

muntik ko ng makalimutan ung core pala "ferrite" core dapat pwede ung ETD or toroid

di nyo poh nid oscilloscope
i imagine nyo n lng kung ano itsur ng mga waves nya..at frq..

basta kao n bahala sa transformer...hehehe 



good luck poh....




Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: michael256 on April 05, 2008, 01:15:02 AM
para sa mga data sheet
try nyo mga site n to


datasheet4u.com
alldatasheet.com
datasheetcatalog.com
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: michael256 on April 05, 2008, 01:19:01 AM
opps ung 108 ohms/2W na resistor pala
hindi pala 108 yn 180/2w dapat yan...^_^
 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: michael256 on April 05, 2008, 01:28:23 AM
happy n ako s result ng diagram q
marami n akong na assemble na gamit sa diagram n yn...

12V to 220 DC kaya pa ilawin ung energy saver na lamp or ung ordinary n bulb up to 100W na bulb
take note po dc xa hindi AC n 60Hz
kaya d pwede sa mga elec.fan e2 or sa mga linear na power supply

pero pinaka d best ay ung power amplifier 250W2x class D^_^




Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: michael256 on April 05, 2008, 01:39:51 AM
hmm nga pala guys ung diagram n pinakita q regulated xa pero hindi sa pama2gitan ng "duty cycle"
kc ung diagram q ng tl494 fixed out xa 45% ata un or 50% 50by50 ata not sure
sa spikes q renegul8
push-pull operation kc 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: michael256 on April 05, 2008, 01:51:40 AM
I want to reuse the cores found in ATX power supplies. Do you know of their typical specs and how to calculate the number of turns etc?

hmmm 2ngcol sa core n cnasabi mo ung n sa power supply ng PC...
ung ETD n ferrite core mahirap pag hiwalayin ung core n yn na ba2sag kc pag pinokpok hehehe
ung toroid nmn di mo rin maga2mit e2 na pang core sa iba b smps kc kulay yellow ung nsa AT/atx dba...hindi xa ferrite pang filter lng pwde...T_T
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: michael256 on April 05, 2008, 01:59:53 AM
Low V high I
MOSFET option's
NDP7060(60V/75A/0.013 Ohms-RDS(on))
MTP75N06HD(60v/75A 10.0 mOhms(on))
IRF1010EZ(60V/75A/8.5 mOhms-RDS(on))
IRFZ44N(55V/49A/22 mOhms-RDS(on))
IRF540(100V/30A/0.077 Ohms-RDS(on))
IRF3205(55V/110A/8.0 mOhms-RDS(on))
BUZ11(50V/33A/0.04 Ohms-RDS(on))

PWM IC's
SG3525
TL494
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on April 05, 2008, 11:10:05 AM
eto po trick kung gusto niyo paghiwalayin yung core ng PSU...

kuha kayo nga bote ng mayonnaise (or kahit anong bote) na kasya yung transformer...lagay niyo yung transformer at ibabad sa thinner ng matagal na panahon (1 week siguro)...mapapansin niyo kapag unti unti nang natatanggal yung glue...

I did this to rework some transformers...

yung torroids, pang inductors lang siya pwede, or pwede rin sa flyback...distributed gap type kasi yung mga yun...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: michael256 on April 05, 2008, 01:35:45 PM
eto po trick kung gusto niyo paghiwalayin yung core ng PSU...

kuha kayo nga bote ng mayonnaise (or kahit anong bote) na kasya yung transformer...lagay niyo yung transformer at ibabad sa thinner ng matagal na panahon (1 week siguro)...mapapansin niyo kapag unti unti nang natatanggal yung glue...

I did this to rework some transformers...

yung torroids, pang inductors lang siya pwede, or pwede rin sa flyback...distributed gap type kasi yung mga yun...


tnx poh na isip q n rin yn peru dq pa 3nay...^_^
kc tinanong q sa k barkada q n ece.. sabi hindi raw kaya tunawin...
peru ngaUn n sinaB u n itra2y q n poh...^_^
tnx ul8...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on April 05, 2008, 01:37:52 PM
yung ibang transformer lang matagal talagang matunaw...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: michael256 on April 05, 2008, 01:46:05 PM
ah ok...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on April 05, 2008, 01:59:05 PM
yung ibang transformer lang matagal talagang matunaw...
araldite din kaya yung ginamit na pandikit ?  ???
ang baho nun araldite pagsinunog, kahit ng soldering iron ang ginamit na pantunaw..  >:(
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 11, 2008, 05:41:35 PM
nakailang lipat na thread natin, hehehe, pero sa tingin ko eto pinakatamang category nya.

OT: mga bosing, right now I'm working on a "highly confidential"  hobby project, hehehe confidential for now. related sa SMPS and I need a source code for this para makabuo ako ng LC meter.

ganda neto oh, wala nga lang kasamang source code pero pwede rin namang magcode na lang ako pero bakit pa kung meron namang gawa na?anybody po?

http://electronics-diy.com/lc_meter.php
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on April 11, 2008, 10:36:57 PM
ano po yung simplest way to make a DC-AC Zero Volt switching? the circuit will be coming from a High Voltage DC then chopped to a Sinusoidal AC using a Full Bridge..
hindi ko pa na-try 'to..
ang nate-test ko pa lang is yung DC-DC ZVS(zero voltage switching)/ZCS(zero current switching)..
the input is ranging from 300 to 400V, and yung output is 12V (or high as 50V+)..
ang nagiging sinusoidal lang is yung currents sa transformer (kasi resonant converter configuration)..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: beginner wan on April 11, 2008, 10:46:38 PM
galing nung LC meter ah..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on April 11, 2008, 11:12:26 PM
hindi ko pa na-try 'to..
ang nate-test ko pa lang is yung DC-DC ZVS(zero voltage switching)/ZCS(zero current switching)..
the input is ranging from 300 to 400V, and yung output is 12V (or high as 50V+)..
ang nagiging sinusoidal lang is yung currents sa transformer (kasi resonant converter configuration)..

hirap maghanap ng literature tungkol sa improved DC-AC...karamihan nasa IEEExplore tapos mahal yung article...hehehe...

naaalala ko yung president ng Power Electronics Society karamihan ng hobby project DC-AC...pero hindi ko naman makita yung mga full articles niya...hehe...wala na ako sa DC-AC kaya wala na nagpu-push sa akin ng bilhin yung article, nagbabaka sakali na lang na meron akong makitang libre... ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: paranz on April 11, 2008, 11:56:34 PM
@glutnix

thanx for the DIY LC meter link. Gagawa ako nito. i really need this
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: michael256 on April 12, 2008, 12:29:06 AM
gusto ko rin neto..!! ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on April 12, 2008, 06:13:32 AM

Sir Neo, i have made a SMPS 13.8v to + - 48Vdc (3 yrs ago) using SGS3525, ok naman nagoperate at nag regulate kaya lang i inabuso ko yong power capability, approaching 500w nako at biglang KaBoooom!!! ubos ang MOSFETs ko....kaya nag stop ako.

Ngayon ko lang nabasa ang thread na ito at 9 pages na..... hindi alam kung naibigay mo ang formula na gusto ko...

May LCR po ako kaya lang fix po yong Freq. 120hz at 1khz selectable, saka torriod po yong gamit kong ferrite core, ano po ba exact relationship o formula to link the Frequency to Henry to maximize the effeciency nong ferrite transformer, kasi dapat mAmps lang ang drain ng SMPS pag walang load. Gusto ko lang pong malaman kung paano e compute yong frequency na dapat vs. Henry ng transformer at ilang Henry dapat vs. input voltage. ???

Gusto ko kasi gumawa ng step down SMPS (220Vac to 125Vdc) kaya lang i dont like to take chances kasi ang taas na nang primary 300Vdc plus na,...hindi na pwedeng magkamali, Bawal na ang magkamali....he he he he...   :D   thanks in advance.


 

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: michael256 on April 12, 2008, 09:32:48 PM
gagawarin ako ng ganito para sa slim na power amp.. ko dikasi kakasya sa 2'' na hight may na iisip na ako na circuit ng ganito w/tl494  kulang na lang ang mosfet's concern lang ako kung papano sya mag soft start pero gagamit na lang ako ng resistor to start the tl494
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 13, 2008, 03:53:34 PM
hindi ko pa na-try 'to..
ang nate-test ko pa lang is yung DC-DC ZVS(zero voltage switching)/ZCS(zero current switching)..
the input is ranging from 300 to 400V, and yung output is 12V (or high as 50V+)..
ang nagiging sinusoidal lang is yung currents sa transformer (kasi resonant converter configuration)..

same din me, DC-DC lang po ako.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 13, 2008, 04:11:03 PM
ano po ba exact relationship o formula to link the Frequency to Henry to maximize the effeciency nong ferrite transformer, kasi dapat mAmps lang ang drain ng SMPS pag walang load. Gusto ko lang pong malaman kung paano e compute yong frequency na dapat vs. Henry ng transformer at ilang Henry dapat vs. input voltage. ???


well yung efficiency ng core is dependent sa characteristic ng BH curve ng core mo(mas narrow mas maganda, watchout din sa saturation), nasabi lang na may mga frequency na mababa efficiency kasi yung loss is nagmumultiply habang tumataas freq. pero if you're asking for direct relation, marami pong factor ang pwede magcontribute like RMS current(ripple current), etc.

I think sa case nyo po hindi yung core inductor ang problema kundi rating ng mga FETs
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: michael256 on April 13, 2008, 09:39:41 PM
need ko poh ng gumawa ng smps na 220VAC to 36VDC +/-
ano poh bang MOSFET ang pwede kong gamitin ?
yung mga kilala at madaing hanapin poh na pang high Voltage   
N-channel
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on April 13, 2008, 09:46:34 PM
need ko poh ng gumawa ng smps na 220VAC to 36VDC +/-
anong output current/power nito ? ???
sa rated power kasi nagdedepende ang design..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: michael256 on April 13, 2008, 09:48:00 PM
para sa audio amp. 6A siguro ok n
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: uskar on April 23, 2008, 11:01:32 AM
hi sa lahat!
first time ko po gumawa ng smps kaya mejo madami pa ko di magets. pero eto po unang sinubukan ko, ginawa ko ung basic buck ckt using irf510 at sr506 as the switching elements, 555 as the triangle wave generator, lm311 as the comparator, instrumentation amplifier using lm358s para sa error amplifier, ginamit ko pong capacitor ay electrolytic at nagseries ng mga resistor-like na inductors para sa inductor. gumagana po xa pero ang max current lang nya is around 500mA @ 12V output. nasa around 28.~something ung input kasi galing transformer (rated 3A) na nirectify. ganun din po pala ung ginawa ko para sa supply nung mga 555, 311, at 358s. mejo barok, pero hey, its my first time. hehe.
balak ko po sana palitan ng control ic ung mga 555 at 311 meron ako sg3524 at tl494 (nakakainis lang hindi ko masimulate sa multisim kasi walang sg3524 o tl494, sa datasheets lang ako umaasa and so far, ung open loop test ckt pa lang napapagana ko). at ung inductors palitan ng toroid, sadly ung mga galing sa lumang pc atx psu lang ang meron ako.

several questions:
1. alin pa po kelangan kong gawin changes para maitaas ung current? tinry ko sundan ung derivation ng equations ng buck pero hindi ko makita kung san dun papasok ung current ka kayang ibigay ng supply. mapaabot ko lang po ng whole number ung current masaya na ako.
2. tungkol naman po sa cores, may iba pa po bang paraan para makapagwind ng matino? i mean, based dun sa mga nakita kong equations on using ferrite (kung ferrite nga ba talaga ung mga nasa atx) cores eh kasama sa equations ung mga permeability ng material. tama po ba kung magrerely lang ako sa equations na V1/V2=T1/T2 (or baligtad?) if ever na gusto kong gamiting transformer ung mga cores?
3. kaya po ba umabot ng mga 100+ amperes ung basic buck, kahit na may mga components na pasok ung ratings?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 23, 2008, 12:39:10 PM
several questions:
1. alin pa po kelangan kong gawin changes para maitaas ung current? tinry ko sundan ung derivation ng equations ng buck pero hindi ko makita kung san dun papasok ung current ka kayang ibigay ng supply. mapaabot ko lang po ng whole number ung current masaya na ako.
Ang current na kayang ibigay ng buck ay nagdedepende sa rating ng FET at diode. ganun din sa saturation ng inductor, kung di ako ngkakamali may naipost na ko link para sa practical design ng buk sa thread na ito.?

2. tungkol naman po sa cores, may iba pa po bang paraan para makapagwind ng matino? i mean, based dun sa mga nakita kong equations on using ferrite (kung ferrite nga ba talaga ung mga nasa atx) cores eh kasama sa equations ung mga permeability ng material. tama po ba kung magrerely lang ako sa equations na V1/V2=T1/T2 (or baligtad?) if ever na gusto kong gamiting transformer ung mga cores?

When it comes to core, if you're after for inductance kasama talaga sa equation ang permeability ng material. Regarding dun sa equation na V1/V2=T1/T2 , applicable pa rin naman yun when implemented as transformer. Balikan ko kayo regarding transformers, mejo nakalimutan ko na to at may iba akong pinagkakaabalahan ngayon eh,hehehe

3. kaya po ba umabot ng mga 100+ amperes ung basic buck, kahit na may mga components na pasok ung ratings?

kung may makukuha kayong components na papasok sa rating, kayang kaya po.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: uskar on April 23, 2008, 01:01:56 PM
thanks po. ^_^
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on April 23, 2008, 07:43:48 PM
tinry ko sundan ung derivation ng equations ng buck pero hindi ko makita kung san dun papasok ung current ka kayang ibigay ng supply...
kung di ako nagkakamali, ang output current ng buck converter ay equal lang sa average current nung inductor..

Quote

2. tungkol naman po sa cores, may iba pa po bang paraan para makapagwind ng matino? i mean, based dun sa mga nakita kong equations on using ferrite (kung ferrite nga ba talaga ung mga nasa atx) cores eh kasama sa equations ung mga permeability ng material.
pag nagde-design naman ng (ferrite) transformer, ang unang consideration is yung resulting flux density sa core..
iniiwasan sila na mag-saturate (typically, sini-set less than 300millitesla ang peak flux density)..
and sa general equation, pag mas maraming turns ang winding, mas mababa ang flux density..
pero, di ka pwedeng basta-basta na lang magdagdag ng turns, marami pa rin ang dapat na i-consider..

Quote
... kaya po ba umabot ng mga 100+ amperes ung basic buck, kahit na may mga components na pasok ung ratings?
kaya naman ng basic buck ang ganito, pero di na advisable..
pag ganitong kalaking output current, gumagamit na ng synchronous buck.
(pinapalitan yung freewheel diode ng mosfet, and yung mosfet kino-control para mag-act sya as "diode"..
para na syang diode na may sobrang babang forward voltage drop..)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on April 23, 2008, 09:10:38 PM
for 100A multi phase buck na ang kailangan. multiple buck regulators with different phases (turn on allocation).

yung supply ng CPU (VCore) gumagamit ng multi phase buck. typically 4 phase. Pentium 4 can use 100A.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on April 23, 2008, 09:25:56 PM
for 100A multi phase buck na ang kailangan. multiple buck regulators with different phases (turn on allocation).
hanggang two-phase pa lang ang nate-test ko.. pinaka-high current ata na na-test ko is yung 100W na 1.5V..
bale, 180deg out-of-phase yung dalawang naka-interleave na synchronous buck's..
isa pang advantage nito, aside from higher power capability, mas mababa rin ang ripple ng output voltage..
(hindi gaanong "maingay"v ang output)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on April 23, 2008, 09:34:09 PM
100W at 1.5V taas na rin ng current. ;D

isa pang advantage, mas maliliit ang inductors kapag multi phase dahil nga mas mababa ang ripple.

napansin ko sa mga supply ng CPU puro hysteretic converter ang gamit nila. may reason ba yun? ???
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 24, 2008, 08:03:09 AM
sir what do you mean po by hysteretic?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on April 24, 2008, 10:30:42 AM
hindi PWM switching. sample ng ripple then on-off at hysteresis region. walang oscillator, comparator lang with added PD (Proportional Differential) feedback.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 24, 2008, 10:44:16 AM
@rdpzycho

sir are you reffering to self-oscillating flyback(ringing choke)?  ::)or iba, hehehe

hmm  ::) hindi ako aware na ganun ang kalimitang gamit sa PC PSU,

Usual na nakikita ko kasi eh forward at flyback then for the feedback its an error amp with PD. PWM pa rin ang output,

The control is usually current mode (meaning may sample ng output voltage at ripple current). Teka baka un current mode control na nga ang tinutukoy nyo na hysteretic control? ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on April 24, 2008, 11:14:47 AM
sir glutnix_neo, hindi po sa PSU mismo, dun sa VCore supply ng CPU from 12V conversion to < 2V. normally found sa upper leftmost part ng motherboard with 4 inductors and lots of capacitors.

eto po sample IC from TI. medyo luma nga lang ata yan. ;D

http://focus.ti.com/lit/ds/symlink/tps5300.pdf

most abstract din sa IEEEXplore puro hysteretic control ang focus for modern processors. isa lang naaalala kong reason, fast transient response. pero hindi ko in-analyze kung bakit. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 24, 2008, 11:21:19 AM
ah ok, thanks for the info, hindi ko maimagine kanina eh, post regulator na pala tinutukoy nyo, hehehe

check ko to pag may time ako, maganda rin matutunan.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on April 24, 2008, 11:33:50 AM
ngayon ko lang din narinig ang concept ng hysteretic converter..  :D
... isa lang naaalala kong reason, fast transient response. pero hindi ko in-analyze kung bakit. ;D
pabago-bago ba ang load/power consumption ng mga processors ? ???
masyado siguro silang sensitive sa level ng supply, kaya kelangan nya ng very tight line and load regulation..  ::)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on April 24, 2008, 11:41:02 AM
25mV ata ang accepted na ripple. sa naaalala kong figure, nearly flat sa 30A yung consumption then biglang kukuha ng near 100A yung processor. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on April 24, 2008, 11:48:28 AM
eto po sample IC from TI. medyo luma nga lang ata yan. ;D

http://focus.ti.com/lit/ds/symlink/tps5300.pdf
medyo luma na nga.. familiar sakin yung ginamit na oscilloscope.. hehe..

matindi yung testing nila ng transient response (page 18), 30amps per microsecond!  :o
eh yung 1A/us sa ordinary converter, mahirap ng papasahin..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: uskar on April 24, 2008, 03:22:55 PM
mga sirs, i have just learned na 13.8V at 40+ amperes pala dapat final ratings ng smps ko, and off-line pa xa. pede po ba hingi ng advice(s) on how to go through with it? i will definitely try the multiphase buck or maybe i should change to another topology? thanks in advance.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 25, 2008, 07:16:05 AM
master uskar

comment ko lang, for safety reasons mas better to use isolated topology kung offline ang power supply mo( para hindi makuryente paghinawakan ang output terminal, very dangerous!!!!!)

You may use flyback or any variation of forward topology. BTW yung forward eh parang buck din xa na isolated nga lang, pwede ka rin magmultiphase, mejo magastos nga lang.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on April 25, 2008, 10:56:52 AM
@uskar:

medyo mataas na yung power, I'd suggest a half bridge. kasama pa rin siya sa family ng buck-derived converters. simplest ang flyback, or forward, pero sa taas nung power sayang kung hindi optimize yung utilization ng core.

battery charger ba 'to?

a modified PC PSU may do. lapit lang ng 13.8V sa 12V. wala nga lang atang available na may 40A output, pero merong 2 ang 12V output at more than 20A. ;)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: sndchk on April 30, 2008, 09:39:45 AM
hi to all! my first post here after reading through this thread..
medyo malalim talaga yung pinagusapan d2 tungkol sa smps. Sana meron maka2long sa project ko.

I want to make use of my AC-operated home audio electronics (dsp, equalizer, etc.) to be hooked-up in my van's sound system. yes, all will operate in a 12-volt environment.

Since most of these circuits are using +/- 12 to 15 volts split supply (using op amps), i need a dc-dc smps to do this. I already tried using the negative voltage circuitry (don't know what topology) to make a split pwr supply but the audible oscillating frequency discouraged me.

Any ideas you can share with a 12 to 16vdc input and +/- 15vdc output dc-dc smps converter would be appreciated. The only alternative i can think of is salvage a working pwr supply from a bad car amplifier and step it down to +/-15vdc.

thanks!
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on April 30, 2008, 10:47:12 PM
Any ideas you can share with a 12 to 16vdc input and +/- 15vdc output dc-dc smps converter would be appreciated. The only alternative i can think of is salvage a working pwr supply from a bad car amplifier and step it down to +/-15vdc.
mas madali ata kung mas mataas ang input voltage sa 15V..
simple circuit lang sana: buck converter para sa positive 15V, saka buck-boost converter para sa negative 15V..
iisa (tied up) lang ang input nun dalawang converter..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: beginner wan on May 02, 2008, 01:00:57 AM
sir neo baka po pwede makahingi ng tips sa tamang pag kuha ng values (design) ng inductor at capacitor sa mga basic topologies... salamat po. ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: sndchk on May 02, 2008, 10:47:39 AM
mas madali ata kung mas mataas ang input voltage sa 15V..
simple circuit lang sana: buck converter para sa positive 15V, saka buck-boost converter para sa negative 15V..
iisa (tied up) lang ang input nun dalawang converter..

sir julznc,

tama ka medyo madali sana kung yung input voltage is higher than the output. wala akong problema kung gnun. kaya lang car 12volts lang eh!

would you mind sharing a ready-made circuit of a buck/buck-boost converter schematic that has +/-15vdc split output. I cannot guarantee of designing it myself. I'm just an electronic hobbyist and if I can possibly avoid transformers or coils... why not ;D

thanks for the help!
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 02, 2008, 04:19:13 PM
sir neo baka po pwede makahingi ng tips sa tamang pag kuha ng values (design) ng inductor at capacitor sa mga basic topologies... salamat po. ;D ;D ;D

master, nakapagpost na ko ng application note sa pagdesign ng buck converter sa thread na to, check nyo, kasama dun pagcompute ng value, formula lang yun at estimate ng desired ripple (voltage or current)

@ para naman kay master sndchk
since dc-dc kayo at konte lang difference ng input at output, I would agree with julznc kaya na yan ng basic that way maiiwasan mo transformer pero never ang inductor choke,hehehe,

boost sa positive at buck-boost sa negative, for circuit you may want to read yung mga post ko regarding dun sa mga topology na yun and try ko na rin magsearch ng app note sa pagdedesign ng ganun. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on May 02, 2008, 06:12:15 PM
ang isa pang problema, aside sa mga magnetics parts, is yun mismong controller (IC)..
di ko alam kung ano ang mga available local SMPS parts na madaling makuha/mabili locally..
@sndchk, sensya na.. wala akong ready-made (and tested) schematics na kagaya ng kelangan mo..
ang maitutulong lang siguro namin sa'yo (pag may mga pyesa ka na, specially yung controller),
is guidance sa pag-design, particularly ng mga magnetics mo..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: uskar on May 05, 2008, 09:41:43 AM
@glutnix & rdpzycho

thanks po for the advices, i think ill check out flyback first. wish me luck. ^^
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: fantom_mayonaise on May 08, 2008, 10:03:00 AM
Quote
I want to make use of my AC-operated home audio electronics (dsp, equalizer, etc.) to be hooked-up in my van's sound system. yes, all will operate in a 12-volt environment.

Since most of these circuits are using +/- 12 to 15 volts split supply (using op amps), i need a dc-dc smps to do this. I already tried using the negative voltage circuitry (don't know what topology) to make a split pwr supply but the audible oscillating frequency discouraged me.

Any ideas you can share with a 12 to 16vdc input and +/- 15vdc output dc-dc smps converter would be appreciated. The only alternative i can think of is salvage a working pwr supply from a bad car amplifier and step it down to +/-15vdc.



go to www.sound.au.com. That is Rod Elliott's site, meron syang dc-dc na project dun, ang output is 35volts yata. Madami pa syang mga ibang projects dun.

Title: Simple Buck converter design simulation
Post by: beginner wan on May 09, 2008, 12:08:02 AM
mga sir, mawalang galang napo, lalu na sa thread starter na si sir neo.  share ko lang po tong sinubukan kong design ng buck. gamit ko po yung binigay ni sir neo na guide sa tamang pag pili ng mga components. ang requirements po dito sa design na to.

Vin=48v ; Vout=12v ; Iout=3A tapos po yung ibang parameters, sinunod ko nalang yung nasa application note. nga po wala, wala akong nilagay na Esr value sa output cap at wala ding mga parasitic elements na kasama sa simulation. Pinaka-simpleng buck lang po to,pero natuwa ako, gumana at pasok sa required,kahit sa simulation lang. 1st time eh. ;D ;D ;D

(http://img503.imageshack.us/img503/2016/buckvt9.jpg)

ok tong thread na to at malaki na itulong sakin.hehehe..
salamat sa mga tumulong.. patulong uli. ;D iniisip ko lang kasi, kung saan ako magsisimula kung mga complicadong circuits and designs na yung gagawin ko. like yung gagamit napo ako ng mga special PWM na IC.. syempre, pa-unti unti lang yung steps. habang tumatagal, mas humihirap yung designs. kahit simulations muna, makuha ko lang mga tamang techniques sa mga components na gagamitin.

any comments nga po pala sa ginawa ko? may mali po ba? salamat po.. ;D ;D ;D



Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on May 09, 2008, 08:12:49 AM
wan,
ma-post mo rin sana yung mga waveforms, lalo na yung inductor current..
not valid kasi yung pag sinabing tama na yung level ng output voltage, tama na rin yung design..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 09, 2008, 08:28:04 AM
hindi ko makita yung picture pero anyway congrats, ;D

next time try mo sa actual,hehehe, BTW sa simulation mo try mo palitan components ng ideal (let's say yung fet eh switch lang, or yung diode eh gawin mong ideal), you'll notice malaki ang epekto ng parasitics sa actual design mo.

Quote
like yung gagamit napo ako ng mga special PWM na IC..

nung nagaaral pa lang kami eh problema namin saan kami kukuha ng controller kaya pagnagdesign kami eh open loop lang muna using 555 configured as PWM.

my flyback at forward pa nga pala ako lesson dito,hindi ko pa lang nagagawa,busy eh  8 :D, after nun lesson sa controller naman 8) 8)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: beginner wan on May 09, 2008, 08:56:27 AM
wan,
ma-post mo rin sana yung mga waveforms, lalo na yung inductor current..
not valid kasi yung pag sinabing tama na yung level ng output voltage, tama na rin yung design..

ok sir julius. post ko po yung waveform mamaya. sinubukan ko kasi post kagabi,kaso ayaw lumabas yung wave form dito sa pc ko(xp). pero ok naman sa office(ubuntu) yan. hehe..

hindi ko makita yung picture pero anyway congrats, ;D

next time try mo sa actual,hehehe, BTW sa simulation mo try mo palitan components ng ideal (let's say yung fet eh switch lang, or yung diode eh gawin mong ideal), you'll notice malaki ang epekto ng parasitics sa actual design mo.
 
nung nagaaral pa lang kami eh problema namin saan kami kukuha ng controller kaya pagnagdesign kami eh open loop lang muna using 555 configured as PWM.

my flyback at forward pa nga pala ako lesson dito,hindi ko pa lang nagagawa,busy eh  8 :D, after nun lesson sa controller naman 8) 8)

salamat sir. at aabangan ko pa nga post nyo.hehehe... try ko naman yung ibang mga topologies.. basic muna. wala pa talaga ko alam eh. ;D ;D ;D

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: beginner wan on May 09, 2008, 09:26:52 AM
mga sir, eto po mga wave forms. any comments sir? ano po bang dapat kong tanggalin sa waveform? anong kulang? anong sobra? ;D ;D

V and I ng load.

(http://www.4freeimagehost.com/uploads/c3d3701a3c0c.jpg)

current sa inductor and diode.

(http://www.4freeimagehost.com/uploads/de6291088a6e.jpg)

lahat po ng mali, comments at mga suggestions at malugod kong tatanggapin. :) :) :)

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on May 09, 2008, 10:11:39 AM
galing! ayos ah, "malinis" yung mga waveforms.. wala pa siguro yang mga parasitic components..
it's obvious na continuous mode operation yang buck converter mo (hindi nagsi-zero ang current sa inductor)..
pag ganyang continuous and ideal ang mga components, nasusunod yung formulang: Vo=Vin x duty..
kung confident ka na dyan, pwede mo ring i-try mag-closed loop operation..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: beginner wan on May 09, 2008, 05:25:38 PM
yes sir julius, CC mode po sya. base din po kasi sya sa design guides dun sa binigay ni sir neo. at malinis kasi walang parasitic elements. di pa din kasi ko masyadong pamilyar sa mga yun. hehehe.. tanong ko lang sir, may closed loop and open loop.. feedback po yun diba? alam ko yung mga yun sa op-amps.. sa SMPS, pano ko malalaman yung closed-loop? saan ko i-feed yung portion ng output?  ??? ??? ???

base sa nabasa ko kay mr. pressman, pwm yun pupunta. tama ba? sya yung mag-a-adjust ng duty cycle para maregulate or ma-maintain yung output. ano nya po nagagawa yun?  ??? ??? ???
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on May 09, 2008, 05:29:41 PM
negative feedback yun. kapag tumaas ang output Voltage, lumiliit yung feedback voltage, iigsian niya yung PWM by comparing sa Ramp waveform.

automatic na siya. ;D

yang ginawa mo is open-loop. walang feedback na nagsasabi kung ano na ang output voltage.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: beginner wan on May 09, 2008, 05:45:01 PM
ah.. ok.. so kailangan ba ng special IC para dun?  ??? ??? naghahanap ako sa linear tech ng mga IC for Buck,may mga nakita ako, pero diko naman kaya gawan ng design... ??? gusto ko din gawan ng simple, then simulate.. tapos pag gamay na, lipat sa ibang topologies.hehehe... ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on May 09, 2008, 05:48:31 PM
try mo muna TL494, yan kasi pinakamura. 11 pesos ata sa Alexan. ;D

ang mahirap lang naman diyan e yung compensation network. pero since hindi mo pa habol yun, at papaganahin pa lang, ok na muna na hindi masyadong maayos compensation.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: beginner wan on May 09, 2008, 05:57:04 PM
hehehe.. pwede ba sir ma-simulate sa switcherCad yan? kasi wala pa din budget sa pag bili ng components.. isa po akong dukha ngayon.hehehe.. ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on May 09, 2008, 05:58:12 PM
hanap ka na lang ng kahit anong PWM IC sa switcher CAD. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on May 09, 2008, 06:33:13 PM
wan, try mo ang ganitong circuit:
(http://img127.imageshack.us/img127/4239/buckcktfk3.jpg)

ginawa ko sya sa SIMPLIS.. example sya ng isang closed-loop buck converter..
pwede kang mag-simulate kahit wala ka nung mga special PWM ICs..
yung controller circuit sa baba yang ang representation ng isang simple PWM controller..
composed of:
1) Error amplifier and Referrence voltage (Vref)
2) Ramp generator (sawtooth waveform of fixed frequency)
3) PWM comparator
(never mind yung X1, trigger lang sya for simulation purposes)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on May 09, 2008, 06:45:11 PM
yung circuit nga pla sa taas is +12V output din..
check mo yung volatge divider resistors R1 & R2, yung node in between them is almost equal sa Vref (2.5V)..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 12, 2008, 08:33:32 AM
wan, try mo ang ganitong circuit:
(http://img127.imageshack.us/img127/4239/buckcktfk3.jpg)

ginawa ko sya sa SIMPLIS.. example sya ng isang closed-loop buck converter..
pwede kang mag-simulate kahit wala ka nung mga special PWM ICs..
yung controller circuit sa baba yang ang representation ng isang simple PWM controller..


Kung di ako nagkakamali wan meron topic ng ganitong circuit kay pressman or kay mohan
composed of:
1) Error amplifier and Referrence voltage (Vref)
2) Ramp generator (sawtooth waveform of fixed frequency)
3) PWM comparator
(never mind yung X1, trigger lang sya for simulation purposes)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: michael256 on May 12, 2008, 10:27:48 PM
try mo muna TL494, yan kasi pinakamura. 11 pesos ata sa Alexan. ;D

11 ??pesosssss lang yan tl494 wahhh 80 samin huhu....   
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on May 12, 2008, 10:30:04 PM
yan ang naaalala kong price nung nagpapabili ako dati sa procurement namin. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: michael256 on May 12, 2008, 10:35:53 PM
ano po ba yung mga no. ng diode na pang smps  yung mga ultra(super)fast recovery
liban d2??
UF5402
SF33A
BY399

3A lang po mga yan
sino po may alam pa na iba na 3A din or higher ??
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: michael256 on May 13, 2008, 10:37:53 PM
tanong lang po
ano poh ba effect pag yung iron powder core ang gagamintin ko sa smps??
kasi ferrite ginagamit ko di ko pa na so-sobukan yung iron powder ehh
mas madil kasing hanapin yung iron na toriod
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: michael256 on May 13, 2008, 10:43:29 PM
saka pano poh pala ma tatanggal yung noise ng power supply ko
pag nilagay ko yung tone control my na ririnig akong switching noise
36V +/- yung ginawa ko...    ??? ???
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on May 13, 2008, 10:51:04 PM
kapag yung Iron Core, tapos mataas frequency, pwedeng may voltage kang tama, pero pag may load babagsak.

yung noise, try mo kabitan ng common mode choke, madalas common mode noise ang conducted emission. two stages para mas maganda.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 14, 2008, 07:05:10 AM
kung yung noise eh nangagaling sa transformer or mga choke, try mo ilubog sa varnish, this way madadamped yung vibration nia
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: michael256 on May 18, 2008, 01:37:26 PM
ahh ok... thanks poh ok na linagyan ko ng iron powder na ring na may coil yung parang nasa mga power supply ng PC...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: raldski on May 24, 2008, 01:15:26 PM
tanong lang po
ano poh ba effect pag yung iron powder core ang gagamintin ko sa smps??
kasi ferrite ginagamit ko di ko pa na so-sobukan yung iron powder ehh
mas madil kasing hanapin yung iron na toriod


Based from experience in designing transformers and chokes for smps, dipende sa application na gusto mo, kung iron power cores or ferrites. Sa conductivity ng flux, masmganda ang ferrite, so kung gusto mo efficient yung transformer mo lalo na sa high frequency switching, ferrite msmganda. Mas-naccontain nya ang flux sa core. Another is permeability ng ferrite, masmataas kaysa iron powder cores normally, so pwedeng pwede at the same inductance na gusto mo, less number of turns kaysa sa iron power cores. So kung tutuusin, maganda tlga ang ferrite, kya lang.... this is not good for energy storage... di sya pwde sa buck choke, boost choke, unless, my gapping ka na gagawin. Kailangan my iintroduce ka na air gap para dun sa air gap makapgstore ng energy. Iron power cores are good for storing energy kasi inherently, masmalaki yung mga microscopic air gaps nya so no need to add air gap most of the time. So it depends sa application. Ferrites are good for forward topology transformers (ex. Half-bridge, Full-bridge, noise filters, EMI filters.) Can also be used for energy storage application such as flyback transfomers and buck chokes if with gapping). Iron powder cores are good for storing energy, like chokes used in buck, boost converters, etc.

hehe magnetics theory still remains as a black art sa mga electronics engineer. nabasa ko lang to sa isang quotation.  ;)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: raldski on May 24, 2008, 01:25:47 PM
saka pano poh pala ma tatanggal yung noise ng power supply ko
pag nilagay ko yung tone control my na ririnig akong switching noise
36V +/- yung ginawa ko...    ??? ???

Sir michael256, closed-loop na yung power supply mo? Kung audible noise yung naririnig mo, ibig sabihin bka my low frequency oscillation yung output mo. makikita mo lang to kung my oscilloscope ka. kasi kahit na sa volt meter ok yung output, pero sa oscilloscope makikita mo na ngooscillate pla. RMS voltage lng kasi yung nakikita sa volt meter e. Hay... kung meron lang murang oscilloscope na mura, sarap sana gumawa ng smps projects sa bahay. hehe ;D. Kung di kasi optimize yung closed-loop feedback mo, pwede ka makarinig ng audible noise galing sa unstable output.

Tama rin sir glut_nix_neo, bka kailangan lng i-varnish yung transformer.

Sir julznc, Idol kita!!! hehehe. kilala mo ko? ;) ;) magaling tlga yan!!
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 24, 2008, 04:41:20 PM
hehe magnetics theory still remains as a black art sa mga electronics engineer. nabasa ko lang to sa isang quotation.  ;)

naks pahumble pa,hehehe, galing ah. baka kilala din kita,hehehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on May 24, 2008, 08:56:57 PM
sabi ng consultant namin dati sa EMC, (re-worded) "magnetics is not a black art nor a black magic, kailangan mo lang intindihin ang lahat ng computations and theories involved."

IIRC, Clayton R. Paul, Henry Ott, and Mark Montrose also said it in another way. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: raldski on May 24, 2008, 09:15:04 PM
sabi ng consultant namin dati sa EMC, (re-worded) "magnetics is not a black art nor a black magic, kailangan mo lang intindihin ang lahat ng computations and theories involved."

IIRC, Clayton R. Paul, Henry Ott, and Mark Montrose also said it in another way. ;D

Hmmm... I agree. Nung umpisa para syang black art, dahil cguro sa nasanay tau sa ohms law nung college, d msyadong naemphasize ang magnetics theory. pero nung nainvolve na ko sa design ng magnetics, it isn't bad at all pag naintindihan mo na. I only know a few who really  masters the terms and theories in magnetics. Siguro nakakatakot lang sa umpisa yung mga units of measures. medyo kakaiba. mga oerstead and tesla. hehehe.  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on May 24, 2008, 09:29:33 PM
yup. hehehe. tapos puro advance mathematics naman yung complex analysis.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: beginner wan on June 03, 2008, 09:37:00 AM
may tanong lang po ako.. bout sa derivation ng Buck converter... habang pinag-a-aralan ko sya.. may napansin ako. diba ang voltage sa inductor pag ON state ay Vin-Vo.. pero bakit pag OFF state, VL= -Vo?  ??? ??? ??? e di ba po sa analysis ng BUCK, pag off yung switch, nagpapalit ng polarity yung inductor para ma-maintain nya yung current? di po ba dapat VL=Vo sa OFF state kasi nga nag-change na sya ng polarity? ??? ??? ??? please mga sir, enlighten me.. salamat po..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on June 03, 2008, 09:45:04 AM
ang reference ata niyan sa output. so kapag ON, Vl = Vin - Vo. tapos dahil yung reference output pa rin, kapag OFF nasa positive yung reference kaya negative yung voltage.

bali ON , + sa left, - sa right

OFF, - sa left, + sa right.

hindi ba -Vo + 1 diode drop? ???
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: beginner wan on June 03, 2008, 09:48:45 AM
sa wiki ko binasa sir eh.. disregarded yung diode drop..  ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on June 03, 2008, 09:52:45 AM
ah. hehehe. kapag synchronous rectifiers maliit din naman yun. hehe.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on June 03, 2008, 09:59:50 AM
dun talaga sa mga derivation ng basic equations, ideal components ang ginagamit (e.g. ideal diode); saka para mas madali, Continuous Mode (laging may current sa inductor) ang kino-consider na operation.. kung Discontinuous mode na, talagang gagamit ka na ng 'math' sa pag-derive ng equation..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: beginner wan on June 03, 2008, 10:03:23 AM
oo nga sir julznc.. nakita ko sa wiki.. mas magulo yung discontinuous.. mas maraming factors na i-co-consider...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on June 03, 2008, 10:13:27 AM
hehehe. sa Boost at Flyback mas ok naman ang discontinuous. pero meron ding uses ang paggamit ng discontinuous sa buck (high slew rate, yung mga gamit sa PC nasa area ng discontinuous at critical conduction mode), at continuous sa flyback. hindi lang sila common. pero marami ring papers on the net na ginagamit sila. ang problema dun mahirap yung controls. hehehe.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on June 03, 2008, 11:18:20 AM
may tanong lang po ako.. bout sa derivation ng Buck converter... habang pinag-a-aralan ko sya.. may napansin ako. diba ang voltage sa inductor pag ON state ay Vin-Vo.. pero bakit pag OFF state, VL= -Vo?  ??? ??? ??? e di ba po sa analysis ng BUCK, pag off yung switch, nagpapalit ng polarity yung inductor para ma-maintain nya yung current? di po ba dapat VL=Vo sa OFF state kasi nga nag-change na sya ng polarity? ??? ??? ??? please mga sir, enlighten me.. salamat po..

good question, actually nung nagdiscuss ako ng mga lectures ko dito eh inipresent ko xa the way i understand it at di ako maxado nagdepend sa mga books, sa books kasi hindi nya inassume na bumaliktad ang polarity ng inductor due to demagnetizing effect(meaning same direction pa rin as with magnetizing), while sa lectures ko ipinauna ko na na bumabaliktad ang polarity para mas madali maintindihan. Then lagi ko minemention ang "taking the KVL" ;D

Yap mas mahirap magumpisa magaral ng power electronics kung considered agad ang discontinous. Objective ko lang kasi eh magrasp ng beginers yung concept at yung derivation and then sila na bahala magtry ng sarili nilang derivation.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: beginner wan on June 03, 2008, 11:45:37 AM
actually sir neo, yung mga discussions nyo dito yung mga inunang kong basahin.. kaya maraming salamat... mas gusto ko kasi yung simple lang muna then saka ako pupunta sa mas advance...  ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on June 03, 2008, 02:11:08 PM
eto mga master pinakasimpleng explanation para maintindihan ng lahat

sa mga book discussion ng buck ang assumption ng polarity ng inductor eh left side is positive and right is negative at hindi nagbabago either magnetizing or demagnetizing pa.

VL = -Vo @ turn off (demagnetizing)

if you'll check the books VL @ toff is negative

therefore Vo = - (-value of VL)
Vo = value of VL

 :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: fantom_mayonaise on July 21, 2008, 11:12:44 AM
@glutnix : meron na pong ETD core sa e-gizmo. Nakabili na ako ng pamalit dun sa nabali ko hehehe.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 21, 2008, 11:15:43 AM
that's good news. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 21, 2008, 11:18:36 AM
@glutnix : meron na pong ETD core sa e-gizmo. Nakabili na ako ng pamalit dun sa nabali ko hehehe.

ayos!!!. that's very good news, magkakaron na ng mga SMPS hobbyist sa pinas, inductor choke kaya meron sila?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 21, 2008, 11:20:19 AM
BTW I'm working on my flyback lecture, busy pa lang sa thesis ko at contest entry na rin,hehehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 21, 2008, 11:22:53 AM
may contest entry pala si sir glutnix_neo. hehehe.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 21, 2008, 11:27:12 AM
just a remake of my college project with major enhancement, ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 21, 2008, 11:29:37 AM
kung may ETD cores na sila, meron rin kayang Litz Wire? ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: paranz on July 21, 2008, 08:28:06 PM
@glutnix : meron na pong ETD core sa e-gizmo. Nakabili na ako ng pamalit dun sa nabali ko hehehe.

ayan meron na pala sa e-gizmo, time na rin siguro na matuto ng maigi at makagawa na rin ng matinong SMPS.

Puro on-board buck/boost lang nagawa ko dati, using TO-92 transistors and small inductors (resistor-ype). In short, maliit lang na current involve, 5-15 volts din hehehe ;D

Ano po ba solusyon para mawala phobia ko sa kuryente at malalaking voltahe (beyond 20 volts)? ???

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 21, 2008, 08:31:12 PM
exposure sa kuryente. ;D

kung araw araw mo kasi ma-encounter mawawala rin. may narinig ako na meron daw instructor sa Meralco pinapahawak ng flyback yung students niya para mawala takot sa kuryente. ;D pero gagawin lang dapat 'to kung alam na maliit lang ang danger. hindi 'to pwedeng gawin sa mga plants dahil kayang kayang mag-source ng malaking current.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 0b00000111 on July 21, 2008, 08:33:23 PM
Ano po ba solusyon para mawala phobia ko sa kuryente at malalaking voltahe (beyond 20 volts)? ???

i guess normal lang yan na may takot makuryente ... wag ka lang titili sis, baka kung ano ang isipin ng makakarinig sa iyo ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 21, 2008, 08:36:39 PM
hehehehe. naaalala ko yung classmate namin na medyo maliit na ang porsyento ng pagkalalake. nung nakuryente sa EE lab hindi tumili, sumigaw ng sobrang baba. lalaking lalaki. ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: beginner wan on July 21, 2008, 08:40:06 PM
hehehe... naghahanap din ako ng pang-alis n phobia sa kuryente eh..hehehe..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 21, 2008, 08:43:44 PM
try niyo magpaputok ng 12V 40A na fuse. todo ang sparking nito bago pumutok. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: beginner wan on July 21, 2008, 08:46:28 PM
saan makakahanap nun? minsan kasi, naiisip ko, baka masakit tamaan nung spark..hehehe.. pero di ko pa naman nararanasan yun..kasi pag may spark, nabibitawan ko yung hawak ko sa gulat..hehehe... ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: paranz on July 21, 2008, 08:47:59 PM
i guess normal lang yan na may takot makuryente ... wag ka lang titili sis, baka kung ano ang isipin ng makakarinig sa iyo ;D ;D ;D

hahaha sira!  ;D

hehehe... naghahanap din ako ng pang-alis n phobia sa kuryente eh..hehehe..

share mo sa akin kung anung mahanap mo hehe


meron din kasi akong mga ECE na kakilala, based on their experience daw (EE-related kasi work nila) , kung wala lang ground fault interupter, patay na daw sila. Naku grabe naman, kaya nga ako nag ECE para low  current/low voltage lang.

Kahit yung exposed na 220-volt live terminal ng power tranformers, makita ko lang nahihilo na ako ..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 21, 2008, 08:52:58 PM
hehehe. dapat mabilis din ang response time ng katawan mo. ;D

yung sparks kaya hindi ako takot dahil sanay naman ako dati. lagi akong sinasama ng tatay ko sa mga construction site at dinadaan daanan lang yung sa mga galing sa grinder at welding (in reality, mas maraming high velocity particles ang galing sa grinding kaya karaniwang may maliliit na butas ang mga damit ng construction workers). ang masakit lang na spark yung galing sa welding, pumapasok pa sa laman. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: paranz on July 21, 2008, 09:03:19 PM
^ grabe naman yang training mo bro hehe  ;D

yung tito ko na electrician, na-bed-ridden dahil sa na-kuryente sa barko, 220 volts lang yun. In about a year, namatay rin  :(

ahhhh am i just intertaining negative thoughts?  :-[

Kaya siguro hanggan multisim simulation nalang ako basta hi-current SMPS  :(
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 21, 2008, 09:08:06 PM
nakakalungkot naman yun.

malaking current kasi ang kayang i-source ng mains. ilang beses na rin akong nakuryente sa mains pero luckily nakakabitaw ako kaagad.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: beginner wan on July 21, 2008, 09:10:29 PM
makuryente na naman ako.. di ko nga alam na 90Vac pala yung sa phone eh..hehehe.. masaya.. pero nakakagulat.. sa gulat lang ako talaga talo..hehehe.. msasanay din ako...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: paranz on July 21, 2008, 09:14:20 PM
nakakalungkot naman yun.

malaking current kasi ang kayang i-source ng mains. ilang beses na rin akong nakuryente sa mains pero luckily nakakabitaw ako kaagad.

OT:

oo nga malungkot talaga, sabi pa naman ng mga relatives namin  dahil din daw sa bisyo nya sa sigarilyo, pero 41 years old pa naman siya nong time na yun.. No doubt kuryente talaga..

Kaya ayun, kami na nagpapaaral sa nag-iisang anak nya...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 22, 2008, 07:08:45 AM
ayan meron na pala sa e-gizmo, time na rin siguro na matuto ng maigi at makagawa na rin ng matinong SMPS.

Puro on-board buck/boost lang nagawa ko dati, using TO-92 transistors and small inductors (resistor-ype). In short, maliit lang na current involve, 5-15 volts din hehehe ;D

Ano po ba solusyon para mawala phobia ko sa kuryente at malalaking voltahe (beyond 20 volts)? ???



Di ko alam di pa ko nakukuryente dito eh, napaso ng soldering iron marami beses na, minsan sa ilong pa, hehehe, safety first lang siguro lage,
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 22, 2008, 07:14:11 AM
hehehehe. naaalala ko yung classmate namin na medyo maliit na ang porsyento ng pagkalalake. nung nakuryente sa EE lab hindi tumili, sumigaw ng sobrang baba. lalaking lalaki. ;D ;D ;D

meron din ako kilala ganyan sumigaw xa ay!("ti" na note) ay!("ti" ulet) ay!("re") ay!(lower "do" na) ay!("do"), hehehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: paranz on July 22, 2008, 12:23:46 PM
hehe ako rin, during college yearso once lang ako nakuryente ng 220V, since then wala pa.. Am i just too careful? hehe or takot na takot lang talaga..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: fantom_mayonaise on July 23, 2008, 12:46:11 PM
bawasan lang ang pag-inom ng kape. Tapos laging idouble check ang ginagawa para may peace of mind pag high voltage na ang project. Ako lately bumili na ng safety glasses sa Ace hardware.

Nuong college, nasabugan na ako ng LED at capacitor. Meron akong "taning/nunal" sa palad na galing sa sumabog na capacitor. Di na natanggal yung maitim na tuldok maski sungitin ko ng blade at karayom hehehehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 24, 2008, 11:13:42 AM

okay lang kuryente sir "paranz" one hand rule lang ang kailangan saka dapat no touch ang body sa mga ground potentials yong lang....kaya mo up to 250v...

ang kinakatakutan ko ang tilabsik nong pakaging ng component, binutas ba namn yong glass ng window namin tsk tsk tsk don ako nag hands-up....
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on August 15, 2008, 03:17:26 PM
sir im juz starting to design a buck coverter and im experiencing many problems lalo n cguro un titunukoy nyo na high side switching problem...alam ko na my problema kso d ko alam un solution at isa pa im lacking of time pra pag-aralan by myself.


help nmn po....
Experiment 1 Buck Converter(open loop)

Vin = 60 V 25%
Vout = 27 V
Pout = 200 W
F = 50 kHz
∆Vout = 0.5% (ripple)

Dnom = 27/60 = 45%
Dmin = 27/(60*1.25) = 36%
Dmax = 27/(60*0.75) = 60%

Rload = 272 / 200 = 3.645 ohms

Worst case: @ Vin max = 75 V
      
      Lmin = Rload * (1-D) / (2*f)
      
      Lmin = [3.645*(1-0.36)] / (2*50000)
         = 23.328 uH

      Cmin = (1-D) / [8*Lmin*∆Vout*f^2 ]
         = (1-0.36) / [8*32.328uH*0.005*50000^2 ]
         = 274.35uF

      IL max   = ∆IL = [D*(Vout-Vin)] / (L*f)
         = [0.36*(75-27)] / (23.328 uH * 50000)
         = 14.815 A
      
      Iload = 200 W / 27 V
         = 7.407 A
      
      Il peak = Iload + ∆IL/2
         = 7.407 + 14.815/2
         = 14.815  A

      IL rms = √[ Iload^2 + (Il pk /2√3)^2 ]
         = √[7.407^2 + (14.815/2√3)^2 ]
         = 8.55 A(basis on size of wire)

Ton = D * 1/f
      = 0.36/50000
      = 7.2 us

Ripple IL = ∆IL / Iload = 0.4(optimum value)

∆IL = 0.4*Iload
   = 0.4*14.815 A
   = 5.9256 A (optimum)

From
   VL = L di/dt

   During ton
VL = Vin Vout = 48 V
di = ∆IL
dt = ton = 7.2 us

Lopt = (75-27)*7.2us /5.9256
   = 58.32 uH

During off
   toff = 12.8 us
   Vl = Vout = 27 V

VL rms = √{[Vl on^2 *ton + Vl off^2 *toff ]/ T}
      = √{[48^2 * 7.2 + 27^2 * 12.8] / 20}
      = 36 V

Power Core selection: ferrite toroid(available)
   Super mss(sendust) MS106075-2
      Do = 1.06 in
      H = 0.44 in
   Ae = 0.654 cm2
   Le = 6.352 cm
   Al = 94
   ur = 75
   lw = 1.46 in
   Rdc/L = 0.106 Ω/mH

No. of turns = √L(nH)/Al
      = √58320/94
      = 25 turns

No. of turns = √[L(nH)*Le]/[4*pi* ur* Ae]
      = √[58320*6.352]/[ 4*pi*75*0.654]
      = 25 turns

Bmax = [VL rms *108]/[N* Ae*f*√(2*pi)]
   = [36*108]/[25*0.654*50000*√(2*pi)]
   = 1756.81 gauss

∆Bmax = Bmax*∆IL/Isc pk

Isc pk = short-circuit current(based on simulation Il peak) = 57.1 A

∆Bmax = 1756.81 * 5.926/57.1
   = 182.33 Gauss
∆Bmax/2 = 182.33 Ga/2
    = 91.165 Gauss(must be less than 100 at the curve loss at Arnolds magnetics power cores)

Load preset, Rpre:
   Ipre = 0.05* Iload
      = 0.05*7.407 A
      = 370 mA(max)

Minimum Rpre = Vout/Ipre
      = 27 V /370 mA
      = 73 Ω
Wattage = 272/73 Ω
   = 10 W

Snubber design
   RsCs = ton/3
      = 7.2 us/3
      = 2.4 us

Cs > Coss(MOSFET)
   Coss(MOSFET) = 260pF
Let Cs = 1nF, Rs = 2.4kΩ

Wattage Rs = Cs*E^2*f
      =1nF*75^2*50000
      = 281 mW (use .5W)

e2 po un schematic...
http://auecess.org/download/file.php?id=151&mode=view


Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on August 15, 2008, 03:24:44 PM
some uses charge pump for driving high side switch, senxa na cannot reply to you dun sa computations mo, busy mode pa, ;D, try to catch up later. mahalaga lang eh Vgs eh may >5V or more, depende sa FET
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on August 15, 2008, 04:15:21 PM
some uses charge pump for driving high side switch, senxa na cannot reply to you dun sa computations mo, busy mode pa, ;D, try to catch up later. mahalaga lang eh Vgs eh may >5V or more, depende sa FET

slamat po sir neo...pg mron n po kyo time pacheck n rin po ng schematic...ano po un charge pump at pno implement???binabrowse ko po previous discussion nyo at un po nandun un problem n pg nka-on Vgs=Vs..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on August 15, 2008, 04:33:16 PM
e2 po un schematic...
http://auecess.org/download/file.php?id=151&mode=view

Quote
Information

You are not authorised to download this attachment.
???
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on August 15, 2008, 04:44:37 PM
nakailang lipat na thread natin, hehehe, pero sa tingin ko eto pinakatamang category nya.

OT: mga bosing, right now I'm working on a "highly confidential"  hobby project, hehehe confidential for now. related sa SMPS and I need a source code for this para makabuo ako ng LC meter.

ganda neto oh, wala nga lang kasamang source code pero pwede rin namang magcode na lang ako pero bakit pa kung meron namang gawa na?anybody po?

http://electronics-diy.com/lc_meter.php


sir astig un LC meter...mejo late n nga lng ako sa thread n 2...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 1110000 on August 15, 2008, 04:49:00 PM
hahaha sira!  ;D

share mo sa akin kung anung mahanap mo hehe


meron din kasi akong mga ECE na kakilala, based on their experience daw (EE-related kasi work nila) , kung wala lang ground fault interupter, patay na daw sila. Naku grabe naman, kaya nga ako nag ECE para low  current/low voltage lang.

Kahit yung exposed na 220-volt live terminal ng power tranformers, makita ko lang nahihilo na ako ..

hehehe ako nasanay ako nung 6 y/y palang ako lagi napuputok ang fuse ng bahay at bumababa ang circuit breaker ;D  hehehehehe tapos lagi ako nangingisay :o hehehehehehe nasanay na rin hehehehehehe
bilib nga yung kapit bahay namin eh kapag hinahawakan ko yung live na wire sa socket nila hehehehehehe pag nag kakabit kasi ako ng bukilya ng ilaw di ko na pinapapatay yung mains :o ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on August 15, 2008, 05:01:29 PM
???

gnon po b..sori po..pno po b mag-attach ng pix d2
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on August 15, 2008, 05:03:33 PM

ok naman computation mo. hindi ko nga lang makita circuit mo. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rowan on August 15, 2008, 05:07:25 PM
Sir glutnix, ask ko po kung paano itest ang KA1M0880 (Semicondutor Power Switch) kung ok pa using a tester..tnx
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on August 15, 2008, 05:09:44 PM
ok naman computation mo. hindi ko nga lang makita circuit mo. ;D


pno po b mag-attach ng pix d2???
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 1110000 on August 15, 2008, 05:12:26 PM
sir astig un LC meter...mejo late n nga lng ako sa thread n 2...

may mas astig dyan :) mas konti ang piyesa :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 1110000 on August 15, 2008, 05:16:43 PM
http://ironbark.bendigo.latrobe.edu.au/~rice/lc/index2.html
iyan :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on August 15, 2008, 05:21:54 PM
mga sirs e2 n po un schematic..

http://i309.photobucket.com/albums/kk387/ericsondimaunahan/schematic.jpg
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on August 15, 2008, 05:28:10 PM
mga sirs e2 n po un schematic..

http://i309.photobucket.com/albums/kk387/ericsondimaunahan/schematic.jpg
mosfet driver nga ang problema.. di pwede yung simple totem pole circuit..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 1110000 on August 15, 2008, 05:28:49 PM
"(http://lagyan nyo po ng ganito)"
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on August 15, 2008, 05:32:50 PM
mosfet driver nga ang problema.. di pwede yung simple totem pole circuit..

Di rin pwede kasi pag nagequal na potential ng source at gate wrt ground wla na current na dadaloy.

search nyo topic about bootstrap gate drive for high side switching or simply FET high side switching.

Gamit na lang kayo P-channel.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on August 15, 2008, 05:57:16 PM
mosfet driver nga ang problema.. di pwede yung simple totem pole circuit..

wat can i do???

pde b driver IC??mron b availble???
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on August 15, 2008, 06:08:10 PM
Di rin pwede kasi pag nagequal na potential ng source at gate wrt ground wla na current na dadaloy.

search nyo topic about bootstrap gate drive for high side switching or simply FET high side switching.

Gamit na lang kayo P-channel.

sir n-channel pinapagamit smin...mron po b kyo sample schematic ng bootstrap??Cnubukan po nmin un gling sa net kso di tumataas un voltage sa bootstrap capacitor
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on August 15, 2008, 06:19:36 PM
Di rin pwede kasi pag nagequal na potential ng source at gate wrt ground wla na current na dadaloy.

search nyo topic about bootstrap gate drive for high side switching or simply FET high side switching.

Gamit na lang kayo P-channel.

sir e2 un trial nmin with bootstrap...
hindi xa nagwowork in actual pro ok nmn sa simetrix..

http://i508.photobucket.com/albums/s329/nice_start/boots.jpg
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on August 15, 2008, 06:26:08 PM
e2 p po un isa circuit n sinubukan nmin..
di rin ngwork in actual...di tumataas un voltage

http://i508.photobucket.com/albums/s329/nice_start/bootstrap.jpg
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on August 15, 2008, 06:26:51 PM
ito pa ang example ng naka-bootsrap na buck mosfet driver:
(http://i38.tinypic.com/10zbv5e.jpg)

tried and tested na, pero sa low voltage buck pa lang..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on August 15, 2008, 06:33:39 PM
ito pa ang example ng naka-bootsrap na buck mosfet driver:
(http://i38.tinypic.com/10zbv5e.jpg)

tried and tested na, pero sa low voltage buck pa lang..

pde po ba un Vin ay the same sa supply ng driver???
ska sir ang design po nmin ay Vin=60V, Vout=27V, Pout=200W...un po requirement smin kya mejo mhirap knowing that this is our first time to design..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on August 15, 2008, 06:36:45 PM
ito naman, kung ayaw mong gumamit ng bootstrap:
(another configuration ng buck, iba nga lang yung negative side ng output)
(http://i36.tinypic.com/vzd0tf.jpg)

hehe :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on August 15, 2008, 06:41:12 PM
ito naman, kung ayaw mong gumamit ng bootstrap:
(another configuration ng buck, iba nga lang yung negative side ng output)
(http://i36.tinypic.com/vzd0tf.jpg)

hehe :D

ano po ibig nyo sbihin na iba ang negative side ng output???
ska bkit po hindi ito un kdalasan na ginagawang configuration?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on August 15, 2008, 06:44:38 PM
pde po ba un Vin ay the same sa supply ng driver???
hindi ata pwede sir,
kasi dapat yung supply ng bootstrap circuit ay dapat yung kaya lang ng Vgs ng mosfet..
typical maximum na yung 20V na Vgs. more than this, masisira na ang fet..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on August 15, 2008, 06:47:02 PM
ano po ibig nyo sbihin na iba ang negative side ng output???
di na common yung "ground" ng Vin saka Vout..

Quote
ska bkit po hindi ito un kdalasan na ginagawang configuration?
yan ang usually na ginagamit na configuration ng buck pag high voltage operation..

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on August 15, 2008, 06:50:35 PM
di na common yung "ground" ng Vin saka Vout..
yan ang usually na ginagamit na configuration ng buck pag high voltage operation..



sir slamat....dmi ko ntutunan..ok lng nmn po cguro i-apply un mga components na design para dun sa other config. n floating un switch??
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on August 15, 2008, 06:54:28 PM
....ok lng nmn po cguro i-apply un mga components na design para dun sa other config. n floating un switch??
just make sure na lang siguro na tama yung mga voltage ratings ng mga gagamitin mong components..

other options:
(1) pwede rin gumamit ng driver transformer
(2) or gumamit mismo nung mga high-side mosfet driver IC, para di na mahirapan mag-compute ng mga values..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on August 15, 2008, 07:10:16 PM
sir pno ba maayos un error sa simetrix na no convergence in transient analysis???
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on August 15, 2008, 07:14:49 PM
sir pno ba maayos un error sa simetrix na no convergence in transient analysis???
ang usual na ginagawa ko ay ina-adjust ko yung time step ng simulation..
di ko sure kung ito ay tamang way para dyan, pero minsan gumagana naman.. hehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on August 15, 2008, 07:19:29 PM
ang usual na ginagawa ko ay ina-adjust ko yung time step ng simulation..
di ko sure kung ito ay tamang way para dyan, pero minsan gumagana naman.. hehe

ano po ba kadalasan settings nun sir?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on August 15, 2008, 07:23:32 PM
ano po ba kadalasan settings nun sir?
wala din akong idea nung optimum settings..
ang kadalasang ginagawa ko, ina-uncheck ko yung default,
and then iniiklian ko yung time steps..
wag lang masyadong maikli, kasi siguradong tatagal ang simulation nyan..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on August 15, 2008, 07:28:58 PM
sir pno ba maayos un error sa simetrix na no convergence in transient analysis???
minsan gumagana din yung maglalagay ka ng mga initial values..
initial values like capacitor initial voltage ang inductor initial current..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on August 15, 2008, 07:29:39 PM
wala din akong idea nung optimum settings..
ang kadalasang ginagawa ko, ina-uncheck ko yung default,
and then iniiklian ko yung time steps..
wag lang masyadong maikli, kasi siguradong tatagal ang simulation nyan..

ok sir..salamt ng mrami..idol kyo!!!
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 1110000 on August 15, 2008, 09:59:39 PM
ito question ko:

ilang watts ang kaya ng isang E core pair na ganito ang size

2.5 inches ang lapad 1.35 inches ang tangkad 2.150 inches ang kapal

may nabiling limang pirasong ganyan ang tatay ko ;;) may coil pa
matataba yung isang winding tapos yung isa payat high voltage ata ::)

parang ignition coil ang pagkakaconnect ng windings bale talo na lang ang lumabas na wire ???
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on August 16, 2008, 12:34:31 AM
ito question ko:

ilang watts ang kaya ng isang E core pair na ganito ang size

2.5 inches ang lapad 1.35 inches ang tangkad 2.150 inches ang kapal

may nabiling limang pirasong ganyan ang tatay ko ;;) may coil pa
matataba yung isang winding tapos yung isa payat high voltage ata ::)

parang ignition coil ang pagkakaconnect ng windings bale talo na lang ang lumabas na wire ???

depende kasi sa frequency 'yan. pero depende naman ang losses (efficiency) sa taas ng frequency. pansinin mo 'yung mga core sa motherboard maliliit lang pero nasa 100W pataas ang rating ng supply. 'yung iba kasi dito Megahertz switchers (or nasa 500kHz) na kaya maliliit.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 1110000 on August 16, 2008, 01:19:01 PM
depende kasi sa frequency 'yan. pero depende naman ang losses (efficiency) sa taas ng frequency. pansinin mo 'yung mga core sa motherboard maliliit lang pero nasa 100W pataas ang rating ng supply. 'yung iba kasi dito Megahertz switchers (or nasa 500kHz) na kaya maliliit.
ano kaya magandang application dito ??? ::) ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on August 19, 2008, 08:50:00 PM
just make sure na lang siguro na tama yung mga voltage ratings ng mga gagamitin mong components..

other options:
(1) pwede rin gumamit ng driver transformer
(2) or gumamit mismo nung mga high-side mosfet driver IC, para di na mahirapan mag-compute ng mga values..

sir mron po b high side mosfet driver IC n kya ang 60 V input, 27 V, 200 W output?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on August 19, 2008, 08:57:16 PM
sir mron po b high side mosfet driver IC n kya ang 60 V input, 27 V, 200 W output?
marami ng mga high side mosfet driver ICs (600Vdc so far ang nakita ko sa actual)..
ewan ko lang kung available locally dito sa Pinas..
check mo 'to: IR2110 san maka order sa pinas? (http://www.electronicslab.ph/forum/index.php?topic=2192.msg32941;topicseen#msg32941)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on August 19, 2008, 08:58:40 PM
yung mga driver ng H-Bridge sa stepper pwede ba yun? diba nakakadrive yun ng high side na transistor?  ???
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on August 19, 2008, 09:01:08 PM
I'm back!!!! after a long weekend, dami ko namiss dito, hehehehe,

Ganda sa tagaytay lalo na sa peoples park, para akong nagtour sa spanish era.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on August 19, 2008, 09:10:56 PM
yung mga driver ng H-Bridge sa stepper pwede ba yun? diba nakakadrive yun ng high side na transistor?  ???

'yung gamit ko dati hanggang 48V lang. from Intersil HIP4080 and HIP4081.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on August 26, 2008, 02:47:56 PM
gud day sirs!!!!!pno po ba mlalaman un value ng Cbst para sa hi-side driver na 5181?
(http://s508.photobucket.com/albums/s329/nice_start/?action-view&current=hidrive.jpg)

http://s508.photobucket.com/albums/s329/nice_start/?action=view&current=hidrive.jpg
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on August 26, 2008, 03:22:24 PM
^ typical values nyan ata ay around 100nF..
check this articles:
Bootstrap Component Selection For Control ICs (http://www.irf.com/technical-info/designtp/dt98-2.pdf)
Using monolithic high voltage gate drivers (http://www.irf.com/technical-info/designtp/dt04-4.pdf)

mukhang nakahingi kayo ng samples sa batch 12 ::)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on August 26, 2008, 06:04:50 PM
^ typical values nyan ata ay around 100nF..
check this articles:
Bootstrap Component Selection For Control ICs (http://www.irf.com/technical-info/designtp/dt98-2.pdf)
Using monolithic high voltage gate drivers (http://www.irf.com/technical-info/designtp/dt04-4.pdf)

mukhang nakahingi kayo ng samples sa batch 12 ::)

bkit po kya naaapektuhan un pwm output pag tinataasan nmin ang input voltage Vs?kpag 2V above po un Vs compared sa supply voltage Vcc ng driver IC lumiliit un pulse width.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on August 26, 2008, 06:44:06 PM
^ di ba separate IC naman yang PWM source nyo? ??? dapat di sya apektado ???
tama ba yung nailagay nyong bootstrap diode? (o meron ng internal diode yung driver IC ?)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: beginner wan on August 26, 2008, 09:30:36 PM
bro nice_apprentice.. hehehe.. para di ka na mahirapan.. ganito gawin mo pag magpo-post ka ng picture sa forum..

(http://img33.picoodle.com/data/img33/3/8/26/f_untitledm_acb58c3.jpg)

click mo yung insert image icon pag magpo-post ka ng reply... may lalabas na  "[img ]http://[ /img]"

then, sa gitna, dun mo ilalagay yung link ng picture(image location) mo na naka-upload sa host..

"[img ]<post your image location here>[ /img]"

hehehe.. sana makatulong..  ;D ;D ;D

eto na yung pinost mong pic..:D

(http://i508.photobucket.com/albums/s329/nice_start/hidrive.jpg?t=1219756806)

eto yung code

 "[img ] http://i508.photobucket.com/albums/s329/nice_start/hidrive.jpg?t=1219756806[ /img]"

Note:
wala talagang space yung mga [img], nilagyan ko lang para lumabas.. di kasi makita  pag walang space eh..hehehe.. :D

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on August 27, 2008, 07:33:43 AM
bkit po kya naaapektuhan un pwm output pag tinataasan nmin ang input voltage Vs?kpag 2V above po un Vs compared sa supply voltage Vcc ng driver IC lumiliit un pulse width.

diba output ang Vs nyo?
based sa diagram na inipost ni master wan eh output xa na papunta sa inductor.

So kung nagpasok ka ng voltage dun makikita rin increase ng voltage sa output ng buck and in effect madedetect ng pwm yun. At since nakita nya na mas mataas output voltage kaysa sa required bababawa nya duty cycle hoping na mapapababa nya output voltage.

ang input po dun eh yung drain ng FET na may label na "up to 600V"
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: fantom_mayonaise on September 03, 2008, 11:32:15 AM
@glutnix

sir, pwede magpatulong iconvert yung 5v output ng PC PSU to 7.2volts? mahirap bang gawin yun? Okay sana kasi yung mga PSU ngayon kasi antataas ng amperage. Kailangan ko sa ng at least 40amps capacity @ 7.2volts. Maski magparallel ako ng 2 psu since mura naman sila. Yung pag-modify lang ang di ko sure kung paano

Thanks.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on September 03, 2008, 11:37:39 AM
OK, let's start

ano power supply yang icoconvert nyo?(I mean saan galing, PC PSU ba yan or anything?)

basically ano specs nung power supply na icoconvert mo?(original specs)

mahirap bang gawin yun?

madali lang po specially kung same power output lang, it's a matter of changing transformer's turns ratio and feedback resistors and mga output caps na rin.

post ka na rin ng pic para mas enjoy. ;)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: fantom_mayonaise on September 03, 2008, 12:20:52 PM
Ay sige... bili muna ako ng 3 identical PSU sa TPC hehehe. (few people realize na virtual gold mine yung mga junk nila for us, solderheads)

I left my laptop at home. dami ko sana pic ng existing PSU ko dun. Bukas sir post ako sa new thread.

Thanks ulit
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on September 03, 2008, 10:45:03 PM
7 volts - pwede mo i-tap between 12V and 5V. masusunod ang max Ampere rating na lowest among the two.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on September 04, 2008, 07:47:44 AM
7 volts - pwede mo i-tap between 12V and 5V. masusunod ang max Ampere rating na lowest among the two.

yun eh kung pc power supply gamit nya, hehe duda ko adaptor eh,
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: fantom_mayonaise on September 04, 2008, 12:31:26 PM

PC power supply nga po sir Glutnix. I'm wondering how to chop off the other windings and rewire the 5volt output to maximize the available power. Yung binuksan kong PSU walang trimmer to adjust voltage levels.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on September 04, 2008, 01:22:25 PM
PC power supply nga po sir Glutnix. I'm wondering how to chop off the other windings and rewire the 5volt output to maximize the available power. Yung binuksan kong PSU walang trimmer to adjust voltage levels.

usually ang feedback ng mga pc power supply na maraming output eh nangagaling sa output na may pinakamataas output voltage, hanapin mo yung output na may nakakabit sa output na divider resistor, pwede ka rin magtrace simula sa input ng optocoupler.

pero kung 7V nga kailangan mo pwede mo gawin suggestion ng sir RD.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on September 14, 2008, 11:39:24 PM
any1 please help.

we are currently doing a forward converter using reset winding.
24 v input and 6 v output, 50 w.

im currently having a problem sa mosfet kasi umiinit sya ng mabilis. may snubbers naman ako.
wat can i do to at least maiwasan ko ang pgkasira at pginit ng mosfet ko.

and any ideas na mas makakapagpababa ng spikes due to transformer leakages.

please help.

tnx
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on September 15, 2008, 12:02:13 AM
try niyo ayusin 'yung transformer baka pwede pa pababain ang leakage. kung wala talaga, baka hindi pa fully optimized 'yung snubber. trial and error na lang. meron kasing parasitics na mahirap i-include sa computations.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on September 15, 2008, 08:06:33 AM
sa power supply lang ako natutong magtrial ang error, hate na hate ko yang technique na yan dati, hehehehe

tama suggestion ni rdpzycho,

mas maganda kung makakapagpost ka ng waveform ng current and voltage ng D-S ng FET mo. Or at least voltage lang.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on September 15, 2008, 11:28:23 AM
ayaw ko rin dati ang trial and error. kapag pinapagamit kami dati ng trial and error sa thermodynamics mas gusto ko yung method of approximation ni newton kaysa isa isa ite-test. hehe.

pero meron talagang kahit tama computation mo paikutin mo pa lahat ng variables, mali pa rin sa actual. hehehe.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on September 16, 2008, 02:39:34 PM
hello.
question po ulit.
forward converter
Vin=18 to 24 V.
Vout= 6 V
Pout= 50 W.


natry na po namin itest til 4 A load.
pero exceeding 4 A, di na namin maabot yung desired output of 6 V.
kung iaadjust ko nmn po yung duty cycle ng pwm ko, nageexceed na sya ng 0.4.
naabot nya yung voltgae for a while tapos unti unting mgddrop ang vout ko, or worse ngshoshort na yung supply ko.
may nagsabi po na baka di kaya ng transformer ko na issuply yung current na kelangn ko sa load.'

tnx. need clarifications bout this. tnx again.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on September 16, 2008, 02:51:14 PM
may computations ba kayo sa transformer windings?

wala ka pa bang feedback? naa-adjust kasi 'yung duty cycle.

gaano kataas sa 0.4? guideline lang naman 'yung 0.4, may mga novel designs na kayang mag-operate at 0.8 duty cycle pero advance na ang circuit nito.

kung umaangat na sa 0.4 ibig sabihin, kulang windings niyo. dapat kasi sa 0.4, sa maximum voltage at current, tama ang output voltage.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on September 16, 2008, 02:53:06 PM
hello.
question po ulit.
forward converter
Vin=18 to 24 V.
Vout= 6 V
Pout= 50 W.


natry na po namin itest til 4 A load.
pero exceeding 4 A, di na namin maabot yung desired output of 6 V.
kung iaadjust ko nmn po yung duty cycle ng pwm ko, nageexceed na sya ng 0.4.
naabot nya yung voltgae for a while tapos unti unting mgddrop ang vout ko, or worse ngshoshort na yung supply ko.
may nagsabi po na baka di kaya ng transformer ko na issuply yung current na kelangn ko sa load.'

tnx. need clarifications bout this. tnx again.

try nu kaya dagdagan output number of turns.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on September 16, 2008, 03:51:07 PM
yap wala pa po akong feed back. open loop.

kaso di na kaya ng converter ko ang load greater than 4 A when it was supposed to output a maximum of 8.333 A.
around 1 V n lng output ko pg gnun ang load current.

transformer calculations po?
1 is to 1 is to 1 ang primary secondary at reset.

tnx.
 6turns lahat.

tnx
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on September 16, 2008, 04:01:18 PM
0.4 * 18, dapat nasa 7.2V pa 'yun.

6 turns per winding?

hindi ko na maalala computations ng transformer pero related ang voltage, frequency, core properties (maximum flux density at area), at number of turns. kung ano man ang lalabas diyan, lalagyan pa ng allowance dahil merong unforeseen miscalculations o outside event (kapag na-short bigla 'yung output at sagad sa limits ang computation madalas hindi na makaka-recover ang transformer, may oscillations na). kapag sumobra 'yung flux density, effectively air core 'yung transformer at maliit lang ang kayang i-transfer na energy from primary to secondary.

madalas ako dati pag nag-compute, plus 2 turns pa kung kakayanin naman nung window.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on September 20, 2008, 08:08:06 AM
follow up po sa one switch forward namin.
i think hindi transformer yung may prob sa min. mosfet po siguro kasi umiinit.

anyways. nakaconnect yung pwm namin in series with 33 ohm resistor sa gate ng mosfet.
kaso as we increase the load current.
may lumalabas ng negative spike sa Vgs graph.
na lumalampas pa minsan or too close sa vgs max ng mosfet namin which is + -30 v.
any1 who knows to eliminate this spike.

same thing, as we increase our load current to 4A (half load) ngshoshort na yung buong setup namin tnx.

(http://i309.photobucket.com/albums/kk387/ericsondimaunahan/09192008248.jpg)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on September 21, 2008, 10:15:07 AM

anyways. nakaconnect yung pwm namin in series with 33 ohm resistor sa gate ng mosfet.
kaso as we increase the load current.
may lumalabas ng negative spike sa Vgs graph.
na lumalampas pa minsan or too close sa vgs max ng mosfet namin which is + -30 v.
any1 who knows to eliminate this spike.
negative spike? baka yung probing nyo lang ang may problema..
try nyo naka-shortest path yung pagkakalagay ng voltage probe (nakatutok mismo dun sa gate-source pins ng FET)

Quote
same thing, as we increase our load current to 4A (half load) ngshoshort na yung buong setup namin tnx.
natsi-check nyo ba yung currents sa transformer (e.g primary winding)?
di naman ba nagsa-saturate?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on September 21, 2008, 02:23:16 PM
yap natry namin ng nakashortest distance. pero sa breadboard palang po yung setup.
di pa namin nalalagay sa pcb kasi may gnito ngang problema.

papano ko pa machecheck yung kung ngsasaturate yung transformer?
tnx
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on September 22, 2008, 10:25:14 PM
'yung pababa malamang bounce lang siya. ang best way sa pag-probe, ipupulupot 'yung grounding clip sa body para walang loop. pwede ring gumawa ng pang-ground na solid wire.

kahit may spikes siya basta tama duty cycle, dapat matra-translate pa rin siya as output sa load. kung tama duty cycle sa drain, tapos iba na sa secondary, hindi 'yung MOSFET ang may kasalanan. kung malaki difference ng itsura ng primary waveform sa secondary waveform, may problem sa transformer.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on September 23, 2008, 10:57:36 AM
yung spike po ay lumalaki as the load current increases? probing lang po ba ang problema pag ganun?

ok. ill check the duty cycle for primary and secondary.

pero mga sir,
question po.
what's the best way to know that the transformer saturates.

at kung anu yung indication na nagsasaturate na sya.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on September 23, 2008, 11:36:30 AM
the best way is to check mismo yung current sa primary winding..
(low voltage lang nga pala kayo, kunti lang yung chance na magsa-saturate yung transformer)
kung wala kayong current probe, pwedeng maglagay na lang ng current sense resistor in series sa primary FET..

another suggestion:
wag kayong gagamit ng breadboard (lalo na sa power section)
kasi maraming mai-introduce na parasitics yang ganyang setup..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on September 23, 2008, 01:33:34 PM
yung secondary current po, kaya po ba naming icheck yun kung ngsasaturate? ano po indication n ngsasaturate, i'm browsing papers bout transformers pero walang sinabing way to check kung saturated na yung transformer. tnx
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on September 23, 2008, 02:27:52 PM
i think, hindi sya halata sa secondary..
(saturate, parang sa BJT, pag sinabing saturate eh para syang "shorted")
ang indication sa waveform na nagsa-saturate ang inductor/transformer
ay kung di na nasusunod yung equation na VL=L(di/dt)..
mush better ata kung ipo-post mo rin dito yung transformer design nyo..

regarding sa FET, na-compute nyo na ba yung loss nya (power dissipation)?
baka mataas talaga ng loss.. anong gamit nyong fet?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on September 23, 2008, 09:46:23 PM
yung spike po ay lumalaki as the load current increases? probing lang po ba ang problema pag ganun?

ok. ill check the duty cycle for primary and secondary.

pero mga sir,
question po.
what's the best way to know that the transformer saturates.

at kung anu yung indication na nagsasaturate na sya.

current to the ground also increases kaya tataas din 'yung spikes.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on September 23, 2008, 09:56:18 PM
yung secondary current po, kaya po ba naming icheck yun kung ngsasaturate? ano po indication n ngsasaturate, i'm browsing papers bout transformers pero walang sinabing way to check kung saturated na yung transformer. tnx

Hind lang ako sigurado, pero yong BH curve ng core ata ang basihan kung saan dapat maglalaro ang freq at capacity ng transformer core...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on September 23, 2008, 10:02:08 PM
tama po sir shrekk. merong schematic na binigay sa akin dati 'yung consultant namin para makita sa X-Y ng oscilloscope ang BH curve ng transformer. nagbabago din kasi depende sa gapping.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on September 23, 2008, 10:05:01 PM
'pag ferite core (e.g. 3C96 material) usually nasa 390 miliTesla ang limit ng flux density..

kung ko-computin ang flux density, ang madalas na gamitin na equation ay:
B= (Von x Ton) / (Np x Ae)

where : B = flux density (Tesla)
           Von = voltage across sa winding (volt)
           Ton = duration nung inaply na voltage (seconds)
           Np = number of wndg turns
           Ae = cross-sectional area ng core (m2)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on September 23, 2008, 10:18:27 PM
@rdpzycho and yus

I have this torroid ferrite core, and i have the BH curve of the core (na dowload ko sa net) can you guide me how to compute the desired freq at pulse width ?

Ito sana gusto kung gagawin na SMPS:

Input = 220Vac
Output = +/- 20Vdc @ 8 Amps

using the totem pole IC SG3425 ba yon?

i have the design how to do it, ang problema ko ay yong tamang freq para sa core ko hindi kasi ako sigurado....
 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on September 23, 2008, 10:24:13 PM
'pag ferite core (e.g. 3C96 material) usually nasa 390 miliTesla ang limit ng flux density..

kung ko-computin ang flux density, ang madalas na gamitin na equation ay:
B= (Von x Ton) / (Np x Ae)

where : B = flux density (Tesla)
           Von = voltage across sa winding (volt)
           Ton = duration nung inaply na voltage (seconds)
           Np = number of wndg turns
           Ae = cross-sectional area ng core (m2)


Yus, saan banda ng BH curve ako babasi para sa flux density (B) ko para malinis ang transition ng pulse ko?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on September 23, 2008, 10:27:20 PM
^ pag typical Ferrite core ang ginagawang margin ay less than 300mT lang
(for tolerance/derating and safety)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on September 23, 2008, 10:31:26 PM
^ pag typical Ferrite core ang ginagawang margin ay less than 300mT lang
(for tolerance/derating and safety)

Applicable ba ito Yus, kahit torroid o EI ferrite core ang gagamitin?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on September 23, 2008, 10:35:56 PM
Applicable ba ito Yus, kahit torroid o EI ferrite core ang gagamitin?
'pag toroid naman (na hindi ferrite), like MPP, High Flux, Sendust, etc.,
kino-consider pa yung permeability drop
(nagbabago ang permeability depende sa load, kaya medyo mahirap mag-compute ng flux density nito)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on September 23, 2008, 10:46:47 PM
^ So applicable ito Yus, kasi ferrite yong torroid core ko.


Sa formula mong B=(Von x Ton) / (Np x Ac)

Yong Ton Yus ay 1/2 of pulse period ba yon o yon na ang pulse width ko at full load?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on September 23, 2008, 10:52:28 PM
^ not always 1/2
Ton = (pulse duty) / ( pulse frequncy), or duty x period, or pulse width
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on September 23, 2008, 11:02:32 PM
Ahh okay, so from flux density (B) basing on BH curve ng core, don ko malalaman ang capability ng core, tapos yong freq basing on max. pulse width base sa formula ng Ton don ko ma estimate ang kaya ng regulation ng SMPS, tama ba Yus?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on September 23, 2008, 11:11:19 PM
^ yup, ganyan nga usually..

another equation ng pag-compute ng flux density ay:
B = (L x IL) / (Np x Ae)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on September 23, 2008, 11:16:27 PM

Ahh okay Yus thanks at pinalabas mo yong IL wwwhhhhewww....i think its my missing link.. hehehehhehe  :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on September 23, 2008, 11:19:23 PM
mas appropriate ata yung equation using IL, lalo na sa mga inductors..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on September 23, 2008, 11:28:27 PM

another equation ng pag-compute ng flux density ay:
B = (L x IL) / (Np x Ae)

Paki detalye nga Yus ano talaga yong L at IL sa formula...primary inductance at primary current ba ito ng transformer?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on September 24, 2008, 07:53:46 AM
^ L = inductance (Henry)
   IL = inductor/transformer current (Amps)

galing lang yan dun sa definition ng VL=L*(di/dt), or VL*dt = L*di
(related lang dun sa previous equation)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on September 24, 2008, 04:16:05 PM
st w20nk50z po yung mosfet.

transformer design namin:
6 turns lahat yung primary at secondary at reset.
pero in actual tinaasan ko na ng 8 turns yung secondary para mas mataas yung voltage output.

10 strands ng awg 23 yung gnamit namin.

thank you po. need help on this project mejo kakaiba kasi yung mga lumalabas na output from what is expected.
test ko na lng yung transformer after matapos yung pcb namin
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on September 24, 2008, 04:29:06 PM
1:1 yung transformer ratio? ???

hindi ata appropriate yung napili nyong mosfet..
mataas yung Rdson nyan (kasi mataas na rin yung Vds rating)
baka yan ang main reason kung bakit sobrang init ng FET, mataas ang conduction loss!
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on September 24, 2008, 04:36:22 PM
ah ganun po ba?
meaning mas ok kung mas mababang rating ng mosfet?
yun po bang conduction loss na yun can short a mosfet?
tnx
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on September 24, 2008, 04:49:52 PM
^ not necessarily na pag mas mababa yung ratin eh maganda na..
sa case nyo mas maganda kung mababa lang yung Rdson ng mosfet..
(pero generally, pag mas mababa yung Vds rating, mababa rin ang Rdson)..

yung conduction loss included sya sa power dissipation ng fet
(conduction loss = Idrms x Rdson )
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on September 24, 2008, 05:37:44 PM
^ L = inductance (Henry)
   IL = inductor/transformer current (Amps)

galing lang yan dun sa definition ng VL=L*(di/dt), or VL*dt = L*di
(related lang dun sa previous equation)


ahh okay Yus thanks uli... :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: imorph on October 08, 2008, 03:58:43 PM
 :-[isa po kaming hamak na tiga-kumpuni ng mga industrial SMPS (ie. Astec MVP series  (http://www.farnell.com/datasheets/74854.pdf), Vicor etc..)

ang gusto ko po tanungin ay kung saan ako makakabili ng thermistor na eto:

part number                                        :   SCK206
description                                          :     NTC Power Thermistor
Zero Power Resistance @ 25C      :   20Ω
Max. Steady State Current @ 25C    :   6A
Approx. Resistance @Max. Current   :   190m Ω
Thermal Dissipation Constant      :   28mW/C
Thermal Time Constant      :   107 sec
Operating Temperature      :   -40~+200C

 :-[
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on October 08, 2008, 06:36:14 PM
part number                                        :   SCK206
description                                          :     NTC Power Thermistor
mukhang pang-inrush current protection ito ah..
ito yung kulay green na disc type thermistor..  ::)

...
(conduction loss = Idrms x Rdson )
mali pala ito, ngayon ko lang napansin.  :D
dapat ay: conduction loss = Idrms2 x Rdson
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: MR. JUAN on October 08, 2008, 06:54:33 PM
Tanong lng po ng bata.. hehehe ;D

Sino po ba nakagawa na s inyo ng Switched-mode Sine wave Inverter ?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on October 09, 2008, 09:36:48 PM
present. ;D pero may confidentiality agreement pa ako sa pinanggalingan kong company kaya hindi ko ma-share masyado. hehehe.

maraming papers nito sa IEEE. konti rin ang players dito. mas marami ang nasa DC-DC. ;D 'yung pinaka-mababa ang Harmonic content na nakita ko (using standard PWM techniques) 3-level ang gamit sa output. +, GND, -.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: beginner wan on October 09, 2008, 09:48:58 PM
@ TOPIC:

Possible ba na gumawa ng SMPS na solar powered? multiple outs? 48v, 30, 15, 12, 9, 5, 3v? tapos sa mga nabanggit na outs ay may tig-tatlong output? meaning 3x 48, 3x 30..etc..? tapos upto 2A ang kanyang i-source?

meron kasi sa skul namin, yun yung pinapagawa sa kanilang project study.. sa march ang pasahan.. nagpapatulong sakin.. kung pwede daw ba yun?  ???
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on October 10, 2008, 07:30:54 AM
@ TOPIC:

Possible ba na gumawa ng SMPS na solar powered? multiple outs? 48v, 30, 15, 12, 9, 5, 3v? tapos sa mga nabanggit na outs ay may tig-tatlong output? meaning 3x 48, 3x 30..etc..? tapos upto 2A ang kanyang i-source?

meron kasi sa skul namin, yun yung pinapagawa sa kanilang project study.. sa march ang pasahan.. nagpapatulong sakin.. kung pwede daw ba yun?  ???

possible depende sa capacity ng solar panel na gagamitin,mukhang malaki ang output power requirement eh, pero ciempre you cant have over 100%
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: RaffT on October 10, 2008, 07:34:39 AM
^^ ok lang cguro kun STEP-DOWN gagawin , ok pa ang effeciency... .pero ibang usapan na kung STEP-UP..medyo malaki ang losses nun in relation to its input.. isang halimbawa, 1A 5V input mo tapos output is 12V pero mga 300mA nalang ang output current capacity nya...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: MR. JUAN on October 13, 2008, 11:30:54 AM
present. ;D pero may confidentiality agreement pa ako sa pinanggalingan kong company kaya hindi ko ma-share masyado. hehehe.

maraming papers nito sa IEEE. konti rin ang players dito. mas marami ang nasa DC-DC. ;D 'yung pinaka-mababa ang Harmonic content na nakita ko (using standard PWM techniques) 3-level ang gamit sa output. +, GND, -.

Sir, bka pwede secret lng natin dalawa... hehehehehe ;D

...anu po ba ang mas-economical to use as the boost stage ?   ..yung boost converter with inductor ..o yung with xformer 
 ..tnong lng po ulit ng makulit na bata ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on October 13, 2008, 11:34:54 AM
mukhang malaking solar panel 'yun ah kung 2A kahat. 48V x 2A x 3 output ports = 96W x 3 = 286W. malamang nasa 200,000 ++ ang presyo ng ganyang panel. ;D

kung 'yung prof ang gagastos ng panel ok lang 'yan. hehehe. doable naman 'to pero output power siguro dapat ang given at kung ano lang 'yung kayang mag-source ng 2A or higher. pwede rin ang multiple output transformer tulad ng gamit sa mga PSU ng PC.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on October 13, 2008, 11:37:09 AM
Sir, bka pwede secret lng natin dalawa... hehehehehe ;D

...anu po ba ang mas-economical to use as the boost stage ?   ..yung boost converter with inductor ..o yung with xformer 
 ..tnong lng po ulit ng makulit na bata ;D

mas maganda 'yung transformer. medyo mahirap i-control 'yung boost kapag nasasagad na 'yung power. wala na sa bookmark ko 'yung mga link dati pero maraming design na single stage na lang ang conversion pero bidirectional 'yung switch dapat (sabi sa akin ng boss ko dati hindi daw pwede 'yun pero maraming patents at ibang gumagawa. hehehe).
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: MR. JUAN on October 13, 2008, 11:44:56 AM
mas maganda 'yung transformer. medyo mahirap i-control 'yung boost kapag nasasagad na 'yung power. wala na sa bookmark ko 'yung mga link dati pero maraming design na single stage na lang ang conversion pero bidirectional 'yung switch dapat (sabi sa akin ng boss ko dati hindi daw pwede 'yun pero maraming patents at ibang gumagawa. hehehe).

Ahm... sir, pede po ba explain nyo po ulit yun pra sa isang undergrad.. hehe  ;D   ..eh d ko po masyado ma-gets yung "single stage na lang ang conversion pero bidirectional 'yung switch dapat " ..hehehe ;D

Ty
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on October 13, 2008, 11:52:44 AM
ah. hehe. typical kasi sa Sine Wave Inverter merong DC Link. kung from 12V (or any lower voltage) to 220Vac for example, merong stage na 12Vdc to 330Vdc or sa case ng AC to AC inverter merong AC rectification to DC. after nung Higher Voltage DC Link merong chopper to create the sinusoidal output. sa 12V battery case, 2 stages siya lumalabas.

merong designs na instead of 2 stages from 12V, gagawing 1 stage na lang. 'yung technique, hindi diode ang gagamitin as output rectifier after ng transformer. back to back MOSFET ang gamit (as active rectifier) that can serve as bidirectional switch ('yung configuration dapat blocked 'yung body diode ng MOSFET). sa positive half-cycle ng output Sine, sa isang direction pinadadaan 'yung half-wave sine tapos sa negative half-cycle sa kabila naman.

'yung isa namang method, ang output ng transformer at ng rectifier niya ay puro positive half-cycles pero after nung half cycle merong output H-Bridge na pwedeng i-invert 'yung direction.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on October 13, 2008, 12:44:17 PM
totoo ba yung sabi nila na bibihira pa lang yung mga inverter na operated sa >100kHz SMPS ? ???
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on October 13, 2008, 01:49:52 PM
wala pa akong nakikitang inverter na resonant topology ang gamit. isa siguro sa reason para mababa na lang ang switching losses. typical na nakikita ko 50kHz to 100kHz ang operating frequency.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: MR. JUAN on October 13, 2008, 02:07:32 PM
ah. hehe. typical kasi sa Sine Wave Inverter merong DC Link. kung from 12V (or any lower voltage) to 220Vac for example, merong stage na 12Vdc to 330Vdc or sa case ng AC to AC inverter merong AC rectification to DC. after nung Higher Voltage DC Link merong chopper to create the sinusoidal output. sa 12V battery case, 2 stages siya lumalabas.

merong designs na instead of 2 stages from 12V, gagawing 1 stage na lang. 'yung technique, hindi diode ang gagamitin as output rectifier after ng transformer. back to back MOSFET ang gamit (as active rectifier) that can serve as bidirectional switch ('yung configuration dapat blocked 'yung body diode ng MOSFET). sa positive half-cycle ng output Sine, sa isang direction pinadadaan 'yung half-wave sine tapos sa negative half-cycle sa kabila naman.

'yung isa namang method, ang output ng transformer at ng rectifier niya ay puro positive half-cycles pero after nung half cycle merong output H-Bridge na pwedeng i-invert 'yung direction.

GUD PM..

Salamat po Sir sa explaination... ayan medyo gets ko na  ;D

Sir, dun po sa mga technique na nabanggit nyo.. alin po dun yung mas efficient at hindi masyado complicated .. I mean yung mga parts eh madaling mahanap d2 sa pinas (esp. yung high f  Xformer).

..at Sir can you provide some link or sample diagram para po mas maunawaan ko.. iba po kc pag my diagram.. hehehehe  ;D


Ty

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on October 13, 2008, 02:23:23 PM
hindi ko mahanap 'yung mga links. mas efficient 'yung pangalawa dahil 60Hz lang switching nung output na bridge.

meron pang isang method using buck-boost topology pero hindi ko na maalala kung paano iniimplement 'yun. basta ang naaalala ko bridge din 'yung output tapos may inductor at diode na nakainsert sa ibang leg. pwede 'yun ng wala ng transformer, inductor na lang. though malaki naman ang losses doon sa diode na pang-block.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on October 13, 2008, 02:29:00 PM
eto pala. US Patenet 7333349. may drawing din siya ng Prior Art circuits na ginagamit sa sine wave inverter.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: MR. JUAN on October 13, 2008, 02:57:12 PM
^ Sir meron po bang mas efficient d2  >>> http://www.patentgenius.com/image/7333349-3.html
..dalawang stage din po yan dba?  ..bale dalawang stage ng h-bridge. Meron po ako nakita sa net.. push-pull lng ang gamit sa low side MOSFET.. pede po ba yun? ..para mas konti yung components.. hehehe

My alm po b kaung basic tutorial para maiintindihan ko 2 hanggang a kaloob-looban...hehe
;D ;D ;D


Ty








Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on October 13, 2008, 03:15:51 PM
nakit mo ba 'yung ibang pic? actually 'yung iba 2 stage talaga na pinagsama sa isang circuit. lumalabas din na isang PWM control na lang.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: trilobugz on October 18, 2008, 02:09:24 PM
pwede po kayang i-pwm ung 12volts na source tapos lagyan ng  filter para makaproduce ng half cycle a sinewave? tapos eh i-feed xa sa isang push pull transformer para mastepup to 220v.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on October 22, 2008, 02:16:33 PM
Medyo nalulungkot na mga tao dito ah, :)

I'll give you something na magpapasaya ng buhay nyo, ;D ;D ;D

Source (Index of Topics)                           - http://www.venable.biz/tr-papers2.php#3

Testing Power Sources for Stability             - http://www.venable.biz/tp-01.pdf   
Specify Gain and Phase Margin                   - http://www.venable.biz/tp-02.pdf
Current Mode Control                                - http://www.venable.biz/tp-05.pdf
Testing and Stabilizing Feedback Loops        - http://www.venable.biz/tp-17.pdf
Optimum Feedback Amplifier Design              - http://www.venable.biz/tp-03.pdf (Highly Recommended)

pinachallenging na part siguro sa design ng power supply
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on October 28, 2008, 11:24:32 AM
mga sirs,,, bka po mron kyong lectures or papers about sa basics ng Zero-vlotage switching half-bridge converter...un po snang mejo simple at mbilis maunawaan ung approach lalo na 4 beginners..mejo mhirap po kc maintindihan agad un mga nddownload sa net...tnx
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: maldihtah13 on October 28, 2008, 11:38:53 AM
mga sirs,,, bka po mron kyong lectures or papers about sa basics ng Zero-vlotage switching half-bridge converter...un po snang mejo simple at mbilis maunawaan ung approach lalo na 4 beginners..mejo mhirap po kc maintindihan agad un mga nddownload sa net...tnx

ito ba yung may zero crossing detector tapos yung conduction angle ang kinocontrol?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on October 28, 2008, 11:57:09 AM
ito ba yung may zero crossing detector tapos yung conduction angle ang kinocontrol?

ang alam ko plang po about zero-voltage switching ay inimprove nya un efficiency at nirereduce un stresses through resonant circuits...prang wla p ako nbasa na mron zero crossing detector..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on October 28, 2008, 12:23:29 PM
yup zero voltage switching.

Ideally kung operated ang transistor as a switch kung high ang current dapat zero ang voltage(saturation), kung high ang voltage dapat zero ang current(cutoff).Pero in real life nagkakaron ng time na habang pababa current Id eh pataas naman yung Vds nya. One cause is the miller capacitance sa mga mosfets.

-------\     /--------Vgs
           \   /
             X
           /   \
-------/      \-------Id

             ^
             ^
             |
          Losses

Yung overlap ng Id at Vgs(area below Id at VGS overlapping) ay ang tinatawag na switching loss na bumabawas sa efficiency ng SMPS.

Nasosolve ganito problem by ensuring na kung papataas na ang voltage eh dapat nauna nang nagzero ang current. Maraming paraan para gawin yun, in many cases may nakikita akong ginawang sinusoidal ang current(see resonant converters)

Eto po magandang link...
http://www.powerdesigners.com/InfoWeb/design_center/articles/ZVS%20Converters/zero_vol.shtm
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on October 29, 2008, 12:21:52 PM
thank you very much sir neo
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: tony v. on October 31, 2008, 11:36:41 AM
Sir may sample diagram ba kayo ng zero crossing detector para mapag aralan ko circuit ... thanks  :D :D :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on October 31, 2008, 11:42:11 AM
Sir may sample diagram ba kayo ng zero crossing detector para mapag aralan ko circuit ... thanks  :D :D :D

ano ibig sabihin nyo po sir? medyo hindi na po ata related yan sa smps, but may thread po dito na dinidiscuss un
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: highvolt on November 09, 2008, 08:01:29 AM
Bro salamat s thread m mrami aq n222nan, pahingi nman po circuit ng voltage regulator para maibaba q sa 5v 500mA ung 12v motolite motorcycle baterry para magamit panchrge ng celphone battery ska circuit ng overcharge controller rn po n my indicator para malaman qng fullcharge n ung cp battery..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: lrs_05 on November 21, 2008, 02:22:39 AM
@sshrekk

Input = 220Vac
Output = +/- 20Vdc @ 8 Amps

using the totem pole IC SG3425 ba yon?

sir baka pwede pa share naman nung schematic mo for this circuit... gusto ko din sana gumawa nito for my amplifier!! thanks!!
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on February 14, 2009, 10:21:21 PM
mga sir pwedeng humingi ng tulong?
baka may maisusuggest kayong controller para sa ganitong project
200kHz interleaved ZVS synchronous tapped inductor buck converter
vin= 24 V
vout = 1.5V
Power=100W
efficiency is greater than 83%


thank you.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on February 15, 2009, 08:10:06 AM
^ baka meron nyan sa Intersil: http://www.intersil.com/power/
 o kaya sa ONSemi.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 16, 2009, 08:06:21 PM
speaking of on semi, umorder ako ng free sample sa kanila, ang mahal ng binayaran ko sa shipping almost 1K, balak ko buohin yung open design nila nag ATX PSU, as a reference PSU for my thesis,
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on February 18, 2009, 09:53:56 AM
e sa intersil kaya mga sir, may bayad ang free sample???
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on February 18, 2009, 12:05:51 PM
hindi ko alam kung nagpapadala pa sila dito.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on February 18, 2009, 02:10:58 PM
sir natry nyo ng gumawa nung sinabi kong project? anu dapat iconsider kung ilang interlap ang gagawin
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on February 18, 2009, 07:47:45 PM
hindi ako familiar sa tapped-inductor buck ???
yung nakita kong interleaved synchronous buck, 2-phase ang ginamit..
1.5V din yun and 100W pero 12V nominal input..

naka-pag-test na rin ako ng interleaved ZVS buck pero hindi sychronous kasi high-voltage output yun.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: HexFET on February 28, 2009, 04:20:53 AM
I'm very proud a lot people are working on SMPS, keep it up... any question on this just pm me. Cheers!
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: imorph on March 02, 2009, 11:25:55 AM
Friends,

Try this UC2825 PWM Controller and UC2902 Load Share Controller. very good ICs to use in SMPS
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on March 25, 2009, 09:09:39 AM
sir any1 tried to make a zvs multiphase buck? can any1 suggest an ic to use. tnx
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on April 12, 2009, 09:31:15 PM
I started understanding switching mode power supply sa "DC-DC converter" thread. Somehow sis Rafft (thanks to you) have made it clear to me. (pero di pa ako nakakagawa)

Now, i want to try from ac to dc SMPS. say 220 input 5V output with at least 2A (3A). ano ba yung very common design to do this? Also, if someone can make me understand at least the very basics.

True, that i can simply hack a mobile phone charger as power supply, pero di ko naman naiintindihan ang operation.

Thanks. :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hunter. on April 13, 2009, 01:10:22 AM
(http://img228.imageshack.us/img228/2945/smps2.jpg)

(http://img228.imageshack.us/img228/1225/smps1b.jpg)

sis marci yan ang gamit namin sa temperature controller namin... made to order ang transformer.. medyo may kahirapan ang design ng transformer. neway makakakuha ka ng idea kung pano gumagana ang smps.

yong r2 ang nag-tritriger during cold start.... tapos ida-drive nong v2 ang xformer... tapos magkakameron ng output sa pin 3 & 5 ng xformer... ayon cycle na ang operation. the voltage is control by z1 and associated circuit.  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: maldihtah13 on April 13, 2009, 09:04:32 AM
San pwede magpagawa ng transformer?

May seminar nga pala sa UP NEC about Power Electronics SMPS Principle and Applications. May 13-15
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on April 13, 2009, 11:10:16 AM
hmmm.... curious...

mahirap nga maghanap ng transformers. what about i utilize the transformers that i could hack from old AT- PS? di ba may dalawang transformers?

naisip ko kasi lagi kong ginagamit ang 12V at 5V sa mga apps ko... so magiging tamang tama to.  nakikita ko din sa circuit mo ate engot na pwede kong ihiwalay ang ground ng bawat output voltage.

On the other hand, maari ko din naman gamitin nalang ang at-ps na working pa... heheheh ;D ;D ;D

pero di ako matututo!!! :)

ate engot, saan nakakabot yung 290-300V?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hunter. on April 13, 2009, 11:34:52 AM
hmmm.... curious...

mahirap nga maghanap ng transformers. what about i utilize the transformers that i could hack from old AT- PS? di ba may dalawang transformers?

naisip ko kasi lagi kong ginagamit ang 12V at 5V sa mga apps ko... so magiging tamang tama to.  nakikita ko din sa circuit mo ate engot na pwede kong ihiwalay ang ground ng bawat output voltage.

On the other hand, maari ko din naman gamitin nalang ang at-ps na working pa... heheheh ;D ;D ;D

pero di ako matututo!!! :)

ate engot, saan nakakabot yung 290-300V?
nakakabit ba?  ;D ;D ;D sa V+ . pag me extra ako send kita ng transformer ng mapag-aralan nyo. maliit lang sya pero and load nya ay 3 24v relays... 2x5 seven segmet led... mcu ... analog ic.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on April 13, 2009, 11:39:14 AM
nakakabit ba?  ;D ;D ;D sa V+ . pag me extra ako send kita ng transformer ng mapag-aralan nyo. maliit lang sya pero and load nya ay 3 24v relays... 2x5 seven segmet led... mcu ... analog ic.

hehehe... NAKAKABIT! magkatabi kasi sa keyboard ang 'o' at 'i'. hehehe...

wow!!! sige nga... sana may extra pa nga! hehhee ;D

mwah! :-*
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 14, 2009, 07:14:35 AM
I started understanding switching mode power supply sa "DC-DC converter" thread. Somehow sis Rafft (thanks to you) have made it clear to me. (pero di pa ako nakakagawa)

Now, i want to try from ac to dc SMPS. say 220 input 5V output with at least 2A (3A). ano ba yung very common design to do this? Also, if someone can make me understand at least the very basics.

True, that i can simply hack a mobile phone charger as power supply, pero di ko naman naiintindihan ang operation.

Thanks. :)

Design a flyback converter using mobile phone charger's transformer and UC3842 IC na available sa alexan, ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on April 14, 2009, 09:55:14 AM
Design a flyback converter using mobile phone charger's transformer and UC3842 IC na available sa alexan, ;D
is UC3842 and U3842 the same? nagkamali kasi ako maggoogle... ngayon yung U3842 sakto ang application circuit na binigay... heheh ;D

(http://i179.photobucket.com/albums/w313/kiashee/4-14-20099-48-09AM.png)

but then again, transformer will be an issue.

thanks sis glutnix
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on April 14, 2009, 10:10:44 AM
regarding flyback, maari palang gamitin as PWM ang 555 timer... just thinking aloud.
(http://www.dos4ever.com/flyback/flyback7.gif)





I guess this is the basic thing i want to know. a PWM that basically generate the pulses for switching a switch (in this case a mosfet). a feedback (di lang isolated dito).

Sa pagkakaintindi ko sa simple design above, dahil sa ratio ng xformer, na increase the voltage output... tama ba? but since 1:10 lang ang ratio, it should have been 120V... i guess this is affected by the switching speed of the PWM (555 timer), tama ba?


schematic source: http://www.dos4ever.com/flyback/flyback.html
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hunter. on April 14, 2009, 11:44:07 AM
http://www.instructables.com/id/EOQJZUJ76ZEP2870CF/  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 14, 2009, 04:38:44 PM
regarding flyback, maari palang gamitin as PWM ang 555 timer... just thinking aloud.
(http://www.dos4ever.com/flyback/flyback7.gif)





I guess this is the basic thing i want to know. a PWM that basically generate the pulses for switching a switch (in this case a mosfet). a feedback (di lang isolated dito).

Sa pagkakaintindi ko sa simple design above, dahil sa ratio ng xformer, na increase the voltage output... tama ba? but since 1:10 lang ang ratio, it should have been 120V... i guess this is affected by the switching speed of the PWM (555 timer), tama ba?


schematic source: http://www.dos4ever.com/flyback/flyback.html


kung open loop tama po kayo, pag nagincrease secondary turns increase din output, but since closed lood kayo magrereact lang sa feedback voltage ang PWM nyo at makikita nyo na same output pa rin kahit taasan secondary turns.

Analysis would show that having same circuit with different # of turns on the secondary eh mas maliit ang duty na required to produce same voltage sa mas maraming turns na transformer. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 14, 2009, 04:43:50 PM
regarding sa schematic, parang may mali, astable ang configuration ng 555 at may voltage na ipinapasok sa pin5. ang effect ng voltage na yun eh baguhin ang output frequency at hindi ang duty?  ??? ??? ???
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: RaffT on April 14, 2009, 04:59:57 PM
^yep.. the higher the freq, the LOWER will be the voltage output from flyback.. may circuit din akong HV(flyback) related, pag MAS mataas ang freq, bababa ang output voltage...

 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 14, 2009, 05:07:35 PM
kailangan ko yata magsimulate, hehehe, theoretically hindi dapat magbago ang output kung magbago ang frequency kasi ang formula ng flyback eh


Vout = Vin (D/ (1-D)) * Ns/Np

pero maaring nagbabago din ang duty ng 555 habang nagaadjust ang frequency sa ganung configuration kaya nagbabago output, kailangan talga natin simulations para mas maintindihan,hehehe.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: the_next_big_name on April 27, 2009, 12:37:59 PM
kung open loop tama po kayo, pag nagincrease secondary turns increase din output, but since closed lood kayo magrereact lang sa feedback voltage ang PWM nyo at makikita nyo na same output pa rin kahit taasan secondary turns.

Analysis would show that having same circuit with different # of turns on the secondary eh mas maliit ang duty na required to produce same voltage sa mas maraming turns na transformer. ;D
papano yan gagamitin sa mcu controlled light dimmer?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 27, 2009, 12:53:31 PM
kung ako ang gagawa ng lamp dimmer gagamit ako ng thyristor (triac or SCR) na triggered by microcontroller ang turn-on, bale yung microcontroller eh may zero crossing detector at bumibilang lang ang MCU ng delay from zero crossing bago nya iturn-on ang lamp.

hindi na ako mangangailangan ng complex circuitry sa ganung paraan, same efficiency(although hindi sya masasabing switched-mode power supply  ??? ??? ??? ;D). 8)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on April 27, 2009, 01:30:39 PM
ate glut, anong tawag dun sa power supplies na may optocoupler pa...?

yung katulad nito... i got this from an broken printer... may 35V then pumasok sa mc34063 for the 5V.

(http://i179.photobucket.com/albums/w313/kiashee/IMG_3863.jpg)

ano ba ang work ng optocoupler dyan? dyan an ba pumapasok ang feed back?
also after nung transformer, may diode lang (natatakpan sa picture) then 35-36V na... I traced it, yun na din pala ang output na 35V. may paraan ba para ma tweak ko ang katulad nito para mailower ko sa 12V (or 24)? may paraan din na para malaman ang current rating?

katulad din ba ito nung self oscilating na ipinot ni engot? nagbased lang ang out nung sa transformer ratio. ganun din ba kaya ito?

pala: nakuryente ako ng malaking caps... may stored power pala yan kahit nakatangal na sa supply! i measured it, nearly 300Vdc. bwahahaha...  ayos!
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 27, 2009, 02:17:51 PM
ate glut, anong tawag dun sa power supplies na may optocoupler pa...?

yung katulad nito... i got this from an broken printer... may 35V then pumasok sa mc34063 for the 5V.

(http://i179.photobucket.com/albums/w313/kiashee/IMG_3863.jpg)

ano ba ang work ng optocoupler dyan? dyan an ba pumapasok ang feed back?
also after nung transformer, may diode lang (natatakpan sa picture) then 35-36V na... I traced it, yun na din pala ang output na 35V. may paraan ba para ma tweak ko ang katulad nito para mailower ko sa 12V (or 24)? may paraan din na para malaman ang current rating?

katulad din ba ito nung self oscilating na ipinot ni engot? nagbased lang ang out nung sa transformer ratio. ganun din ba kaya ito?

pala: nakuryente ako ng malaking caps... may stored power pala yan kahit nakatangal na sa supply! i measured it, nearly 300Vdc. bwahahaha...  ayos!

too bad di ko makita picture,hehehe,(pwede nyo try sa XS.to, no need for an account there)

kung sya lang opto coupler na nakikita nyo jan, malamang feedback xa ng isolated type SMPS, for isolation lang talaga purpose ng opto jan na kung saan ang output information na nasa secondary at dinadala sa primary kung saan andun yung switching element at ang PWM.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: the_next_big_name on April 27, 2009, 02:18:49 PM
kung ako ang gagawa ng lamp dimmer gagamit ako ng thyristor (triac or SCR) na triggered by microcontroller ang turn-on, bale yung microcontroller eh may zero crossing detector at bumibilang lang ang MCU ng delay from zero crossing bago nya iturn-on ang lamp.

hindi na ako mangangailangan ng complex circuitry sa ganung paraan, same efficiency(although hindi sya masasabing switched-mode power supply  ??? ??? ??? ;D). 8)
i-post mo nga yung ckt mo?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 27, 2009, 02:29:23 PM
ate marce

nakita ko na picture,malamang flyback sya dahil sabi nyo isang diode lang sa secondary from the transformer, malamang self-oscillating kasi walang PWM sa primary (not unless integrated sa switching element yung PWM, 3 terminal device na malapit sa primary side ng transformer, maari ding FET lang ito).

Yung opto nyo dalawa, isa dun ay voltage feedback, yung isa maaring curret ??? ??? ???, maari ding PS_ON/OFF signal.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on April 27, 2009, 03:17:36 PM
ate marce

nakita ko na picture,malamang flyback sya dahil sabi nyo isang diode lang sa secondary from the transformer, malamang self-oscillating kasi walang PWM sa primary (not unless integrated sa switching element yung PWM, 3 terminal device na malapit sa primary side ng transformer, maari ding FET lang ito).

Yung opto nyo dalawa, isa dun ay voltage feedback, yung isa maaring curret ??? ??? ???, maari ding PS_ON/OFF signal.

yes, fet nga yan... its 2SK2718, FET n-channel MOS type.

So yung 2 opto, magkabilaan ang directions.

eto yung other view ng PS.
(http://i179.photobucket.com/albums/w313/kiashee/IMG_3865.jpg)
makikita mo na dyan yung diode...

eto naman yung PCB side...
(http://i179.photobucket.com/albums/w313/kiashee/IMG_3866-1.jpg)

so, wala tong paraan para mabago ko ang voltage output di na?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 27, 2009, 03:37:22 PM
yes, fet nga yan... its 2SK2718, FET n-channel MOS type.

So yung 2 opto, magkabilaan ang directions.

eto yung other view ng PS.
(http://i179.photobucket.com/albums/w313/kiashee/IMG_3865.jpg)
makikita mo na dyan yung diode...

eto naman yung PCB side...
(http://i179.photobucket.com/albums/w313/kiashee/IMG_3866-1.jpg)

so, wala tong paraan para mabago ko ang voltage output di na?

kabilaan? hmmm, interesting, ano kaya un?

kaya pa baguhin output nyan ciempre,hanapin nyo lang yung divider resistors(eto yung nagscale ng feedback voltage) between output and ground, laruin nyo yun at makikita nyo magiiba output ;)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 27, 2009, 03:45:42 PM
i-post mo nga yung ckt mo?

master, wala akong circuit eh, nasa isip ko lang concept,

Una ko siguro gagawin eh power supply ng MCU, gagamitin ko yung transformerless power supply ng micrchip(check nyo website nila for application notes)

Alamin nyo kung paano iturn on at iturn off ang triac, gagamitin ko siguro yung ttl compatible na triac kung merong enough para sa lamp ko.

Then meron din sa website ng microchip kung paano iiimplement ang zero crossing detection using PIC micro.

lastly design ng pang trim ng dim, gagamitin ko remote ng tv instead na maglagay ako ng potentiometer sa power supply na walang isolation(actually nakuryente na ko nung huling sinubukan ko yun sa X-10 project ko eh, aw!!!, hehehe). then lalagyan ko ng IR reciever ang MCU ;D

gagamitin ko siguro PIC eh 16F84A or any 8pin MCU.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on April 27, 2009, 03:51:01 PM
kabilaan? hmmm, interesting, ano kaya un?

kaya pa baguhin output nyan ciempre,hanapin nyo lang yung divider resistors(eto yung nagscale ng feedback voltage) between output and ground, laruin nyo yun at makikita nyo magiiba output ;)

sorry i was actually asking kung magkabilaan...  hehehe ;D
di ko kasi maintidihan yung marking sa optocoupler but it is from toshiba...

ano ang palatandaan na yun na ngang resistors na yun ang tinitignan ko?
yung sa mc34063, nakuha ko na yung resistors kasi kabisado ko yun.... pero yung sa 35V, gusto ko sanang babaan to 24 or 12V.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 27, 2009, 03:57:21 PM
^
sa opto, usually(correct me if I'm wrong ;D) yung may tapias or yung may dot eh andun yung pin1, yung pin1 eh usually anode ng diode ng opto.


ang clue.... ordinary resistor xa,hehehehe,

dalawang resistor na nakaseries at nakaconnect sa output at ground, dun sa dugtungan nila eh yun yung feedback voltage. I suggest galawin nyo eh yung resistor na malapit sa ground (taasan nyo ang value at bababa ang output and vice versa).
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on April 27, 2009, 04:05:26 PM
^
sa opto, usually(correct me if I'm wrong ;D) yung may tapias or yung may dot eh andun yung pin1, yung pin1 eh usually anode ng diode ng opto.


ang clue.... ordinary resistor xa,hehehehe,

dalawang resistor na nakaseries at nakaconnect sa output at ground, dun sa dugtungan nila eh yun yung feedback voltage. I suggest galawin nyo eh yung resistor na malapit sa ground (taasan nyo ang value at bababa ang output and vice versa).


ok... hehehe ;D
resistor na nakseries at yung isa nakaconnect sa ground. of course yung middle ng dalawa ay ang feed back...
teka, saan part sa high-voltage or sa low-voltage part?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 27, 2009, 04:11:08 PM
not sure kung gaano karami output flyback nyo pero usually kinukuha ang feedback sa main output or yung output na may pinakamataas na output power. Secondary lahat un.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 27, 2009, 04:13:04 PM
papano yan gagamitin sa mcu controlled light dimmer?

master kung flourecent light nga pala tinutukoy mo iDIM eh ibang usapan na yun, ang binabanggit ko eh para sa mga incandecent bulb
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on April 27, 2009, 04:25:54 PM
not sure kung gaano karami output flyback nyo pero usually kinukuha ang feedback sa main output or yung output na may pinakamataas na output power. Secondary lahat un.

bwahahahaha!!! nakuha ko kaagad...! :D

may naka series na 41.2k at 10k, with 10k ang nakaground. 41.2k is connected to 35V. i replaced the 41.2k with 9.1k... presto! 12.9V ang out! hehehe ;D
i was inspired by the DC-DC converter L4978, may table na kasi dun. resistor near the ground i never changed. yung other resistor lang!!!

yeah!.  thanks to you...
pogi mo (at ako!) hehehe

nga pala, what is the best way so that the big capacitor will be discharge when disconnected to AC supply?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 27, 2009, 04:33:23 PM
we use bleeder resistors for that, remember the RC time constant back in college? that's what we use to compute the value of resistor if we want to discharge it after some time, ;D

nakaparallel yun sa cap, watchout sa power rating na rin
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on April 27, 2009, 05:10:54 PM
we use bleeder resistors for that, remember the RC time constant back in college? that's what we use to compute the value of resistor if we want to discharge it after some time, ;D

nakaparallel yun sa cap, watchout sa power rating na rin

wow! refreshing!!! hehehe

yaos, mnakuha ko na yung 24V... 24.3V,ok na din yan... hehehe :D anyway, di naman accurate ang multimeter ko! hehehe

next question, how would i determine the power rating of the power supply? ilang current ba ang maibibigay ng orignally 35V (24.3 na ngayon)? sa ngayon, yung 5V could have 1.5A (current rating ng MC34063). Ano or anu-ano ang palatandaan kung papano ko medetermine and current rating? pwede kay ayun?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on April 27, 2009, 05:14:20 PM
parang alam ko na din naman ang sagot? pakicorrect nalang ako kung mali...

since gumamit ng 2sk2718 which has a maximum rating of 2.5A for drain current (for DC to, 7.5A for pulse), perhaps, yan na ang maximum current na maidedeliver...
tama ba yun ate glut?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: motion55 on April 27, 2009, 05:54:31 PM
The resistor will continue to discharge current even when the power is turned ON. Make sure the resistor will not overheat during this time. That is what glut means by keep an eye on the power rating.

Power = V^2/R where V is the voltage across the capacitor (and the resistor).


Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on April 27, 2009, 06:08:58 PM
...
since gumamit ng 2sk2718 which has a maximum rating of 2.5A for drain current (for DC to, 7.5A for pulse), perhaps, yan na ang maximum current na maidedeliver...
...
'di ba yang 2sk2718 ay ang mosfet sa primary side? ???
so, iba naman yung sa current secondary side (output)..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on April 27, 2009, 06:45:25 PM
The resistor will continue to discharge current even when the power is turned ON. Make sure the resistor will not overheat during this time. That is what glut means by keep an eye on the power rating.

Power = V^2/R where V is the voltage across the capacitor (and the resistor).


yes sir... noted.

nagtataka lang ako bakit walang bleed resistor to... i tried put a very light load. LED on the 5V (under mc34063). pero di pala na didischarge yung nasa primary na capacitor hehehe ;D. it makes naman... kasi wala nang oscillation kapag wala nang power sa main.


'di ba yang 2sk2718 ay ang mosfet sa primary side? ???
so, iba naman yung sa current secondary side (output)..

oo nga pala no... magkaiba ang primary sa secondary...  so any suggestion of how to obtain it (the current)?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hunter. on April 27, 2009, 06:57:37 PM

nagtataka lang ako bakit walang bleed resistor to... i tried put a very light load. LED on the 5V (under mc34063). pero di pala na didischarge yung nasa primary na capacitor hehehe ;D. it makes naman... kasi wala nang oscillation kapag wala nang power sa main.


usually ang smps ay nagdi-discharge sa load kaya walang bleeding resistor. Cguro nag-test ka ng walang load kaya nakiliti ka sis  :D :D :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on April 27, 2009, 07:08:34 PM
usually ang smps ay nagdi-discharge sa load kaya walang bleeding resistor. Cguro nag-test ka ng walang load kaya nakiliti ka sis  :D :D :D

hehehehe... ganun ba yun.
i measured it 265Vdc. solve! ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on April 27, 2009, 07:13:55 PM
Meron naba nakagawa ng SMPS gamit ang IGBTs?

TIA of any How To tips hehehehe.....

Hanga kasi ako sa mga motor controllers na ang gamit ay IGBTs, in terms of kilowatts ang driver!  :o
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on April 27, 2009, 07:35:33 PM
Meron naba nakagawa ng SMPS gamit ang IGBTs?
ang isang advantage ng IGBT over sa Mosfet ay ang lower power disipation pagdating sa high voltage-high current application.
for example, magko-compare tayo ng isang Mosfet na may 0.1 ohm Rdson saka IGBT na may 1V Vcesat
kung magpa-pulse tayo ng 20A, sa mosfet: (20A)2*(0.1ohm) = 40W instantaneous power;
while sa IGBT: (20A)*(1V) = 20W instantaneous power (mas mababa)

Quote
TIA of any How To tips hehehehe.....
ang main disadvantage naman eh sobrang bagal ng IGBT..
kaya kung ida-drive sya, usually less than 20kHz ang operating frequency nya.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on April 27, 2009, 08:06:36 PM
ang isang advantage ng IGBT over sa Mosfet ay ang lower power disipation pagdating sa high voltage-high current application.
for example, magko-compare tayo ng isang Mosfet na may 0.1 ohm Rdson saka IGBT na may 1V Vcesat
kung magpa-pulse tayo ng 20A, sa mosfet: (20A)2*(0.1ohm) = 40W instantaneous power;
while sa IGBT: (20A)*(1V) = 20W instantaneous power (mas mababa)
ang main disadvantage naman eh sobrang bagal ng IGBT..
kaya kung ida-drive sya, usually less than 20kHz ang operating frequency nya.

Thanks Yus, mababa pa pala switching capability ng mga IGBTs sa ngayon, kaya pala hindi ito clik sa mga SMPS.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on April 27, 2009, 09:07:16 PM
madalas siyang gamit sa High Voltage High Power Industrial applications tulad ng malalaking inverter at active rectifiers. ang forte nila 400V and up.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on April 28, 2009, 01:39:36 PM
wala ba talgang paraan kung papano malaman ang max current rating ng PS?

next question:
with the one i posted, kung saan binago lang natin yung resistor ratio, nagbago na yung voltage output.
ganun din ba ang AT/X-PS? may babaguhin lang ang resistor then yung output voltage may vary with it?

For example yung +12 rail, for example 10A yung maximum current, if I adjust this to 24V, it could reach 5A syempre...  does SMPS, follows this linearity of relationships?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 28, 2009, 04:47:20 PM
wala ba talgang paraan kung papano malaman ang max current rating ng PS?

next question:
with the one i posted, kung saan binago lang natin yung resistor ratio, nagbago na yung voltage output.
ganun din ba ang AT/X-PS? may babaguhin lang ang resistor then yung output voltage may vary with it?

For example yung +12 rail, for example 10A yung maximum current, if I adjust this to 24V, it could reach 5A syempre...  does SMPS, follows this linearity of relationships?

for ATX at sa mga multiple outputs na flyback, baguhin mo yang resistor ratio na yan at magbabago lahat ng output ;D, Iisa lang kasi yang resistor na yan para sa lahat, usually nagreregulate lang xa sa output na may pinakamataas na output power.

Ang solution eh baguhin resistor ratio (if and only if yung main output ang gusto nating baguhin), then adjust # of turns ng ibang outputs.

Kung hindi naman main output ang gusto nating baguhin eh # of turns lang ang gagalawin natin.

sa case nung question 1 mo, may post regulator yung isang output kaya ok lang tumaas yung voltage sa windings nya, konteng bawas lang sa efficiency ang price nun.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 28, 2009, 04:51:34 PM
Ang max current rating eh nakasalalay sa rating ng output diode, 50%-80% ng diode rating yung possible na max rating ::)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: the_next_big_name on April 28, 2009, 04:53:22 PM
pwede magdesign ng switch mode power supply na variable from 3v to 28v 10amps max at ang over all dimension eh 1"x1"?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 28, 2009, 04:58:01 PM
Ang max current rating eh nakasalalay sa rating ng output diode, 50%-80% ng diode rating yung possible na max rating ::)

ooops, yan eh max current nung di pa namomodify,

kung tinaasan mo output voltage, ang maglilimit ng current mo ngayon eh ang mosfet ng primary(tumaas kasi output power mo if you will try to draw same max current from it, in effect tataas din primary current)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 28, 2009, 05:02:57 PM
pwede magdesign ng switch mode power supply na variable from 3v to 28v 10amps max at ang over all dimension eh 1"x1"?

wow bigatin power supply mo master, problema jan saan ka kukuha pyesa? ???
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: the_next_big_name on April 28, 2009, 05:19:09 PM
kaya? papanu? paturo naman lolo
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on April 28, 2009, 05:33:30 PM
kung napagkasya 'yan sa 1" by 1", ang taas ng power density nito. ;D ;D ;D kailangan dito MHz switching tulad nung onboard converter sa motherboard.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: maldihtah13 on April 28, 2009, 05:36:38 PM
oo nga anliit nman nun.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: the_next_big_name on April 28, 2009, 05:39:28 PM
kakaiba nga requirement, ggamitin ko kase para dun sa relay, mas rating na kaya nya kase i-drive eh 28vdc 10amps, and enclosure eh 3"x4" or a little bit smaller. additional question, and transformer ko kase eh 9v,10milliamps(ipinagawa ko sa quiapo yung rewinding at yung original ay yung mga signal transformers sa alexan na mas maliit pa sa 1 peso coin), may current amplifier ckt ba kayo na kaya nya iboost yung current up to 500mAmps?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on April 28, 2009, 05:49:30 PM
para ma-boost ang current mo kailangan mo rin ng source na panggagalingan nung current, remember energy can neither be created nor destroyed.

ano requirement nung relay?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: the_next_big_name on April 28, 2009, 05:58:31 PM
kahit 50mAmps lang, kaso may mga non-volatile memory, rf tranceiver, gsm modem at max232 pa
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hunter. on April 28, 2009, 06:16:27 PM
parang malabo ang question  ??? meron kang 10mA na transformer tapos gusto mo pataasin sa 50mA... malabo atang mangyari yun sister  :D :D :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on April 28, 2009, 06:18:58 PM
9v 10mA pwede lang maging 1.8V 50mA.  constant power lang ang conversion with losses. para magkaroon ng boost kailangan ng external supply like amplifiers. maliit lang naman 9V 100mA na transformer, madaling makakita nito sa mga generic PC speaker.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: the_next_big_name on April 28, 2009, 06:25:13 PM
yun nga i-amplify na lang yung current from 10mA to 500mA....may nakita ako sa sparkfun na kasing liit din lang ng 1 peso coin...kaya lang...gusto ako na lang magdesign
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: the_next_big_name on April 28, 2009, 06:27:19 PM
going back to the old topic...di kaya ng 1"x1", ok lang kahit 2"x2"? kaya kaya? ang height pala ng enclosure eh 24mm
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on April 28, 2009, 06:30:46 PM
kung tataasan mo nga 'yung current, either bababa ang voltage or kailangan na mas malaking supply or external supply. power out = power in + losses, no way na maging 9V 500mA 'yung 9V 10mA, saan niya kukunin 'yung 9V 450mA, though pwede siyang maging 0.18V 500mA.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hunter. on April 28, 2009, 06:31:40 PM
yun nga i-amplify na lang yung current from 10mA to 500mA....may nakita ako sa sparkfun na kasing liit din lang ng 1 peso coin...kaya lang...gusto ako na lang magdesign
ok yun ah? meron ka ba link ng sparkfun?  :D :D :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on April 28, 2009, 07:08:07 PM
pwede magdesign ng switch mode power supply na variable from 3v to 28v 10amps max at ang over all dimension eh 1"x1"?
may nakita na akong halos 1 cu. in lang na SMPS, kaso 5W lang (5V 1A) .. :D

baka si Bulma (ng dragon ballz) alam kung pa'no gumawa nyan.. hehe ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on April 28, 2009, 07:32:25 PM
db un mga transformer ng charger smaller than 1 peso coin un kso low voltage at low current lng un...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on April 28, 2009, 07:35:29 PM
high frequency na kasi 'yun kaya mas maliit. ;)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: the_next_big_name on April 28, 2009, 09:10:06 PM
ahhh...alam ko na...may backup battery pala ako na 6.6v, 400mA, di ko na kaillangan ng ampli
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 29, 2009, 07:11:14 AM
^Master, I doubt na kakailanganin mo ng 10A ??? ??? ???, ano ba klaseng relay yang idadrive mo?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hunter. on April 29, 2009, 07:28:54 AM
baka car ignition  :D :D :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on April 29, 2009, 07:37:02 AM
Tingin ko kasi namisinterpret lang rating ng relay, baka yung 10A is rating ng contact at hindi ng coil. ::)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: the_next_big_name on April 29, 2009, 11:15:10 AM
yung power supply ng load...kase dapat built-in na yun sa device.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on April 29, 2009, 11:33:07 AM
Tingin ko kasi namisinterpret lang rating ng relay, baka yung 10A is rating ng contact at hindi ng coil. ::)

ganun din ang hinala ko...

di ba for a 6V relay, yung coil could be driven by 4.5 to 7V, pero low current lang yung. usually being driven with a help of a typical to-92 transistor. I typically make use of 2n3904 (for low side switching), 200mA ang maximum IC nyan. Ib, current to switch it ON, pwede na ang 5mA. However yung contact side could reach as high as 30A for 220V (example: http://www.sparkfun.com/commerce/product_info.php?products_id=101). Typical that could be bought on local electronic stores is 7A at 220Vac, 10A at 110Vac or 10A at 24Vdc.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hunter. on April 29, 2009, 11:39:22 AM
^ agree... pag madaming relay naman ang gamit ko ULN2003  ;)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on April 29, 2009, 11:51:33 AM
^ agree... pag madaming relay naman ang gamit ko ULN2003  ;)
\
thanks for reminding me... meron din ako nyan... heheh
may pinapagawa kasi yung friend ko.

similar dito:http://www.olimex.com/dev/pdf/PIC/PIC-IO.pdf
sakto ang uln2003. heheh ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ajak on May 02, 2009, 04:21:43 PM
SMPS Design Toolkit.. from fairchild semi

baka makatulong.

1D96b^S8*@.*<8&8.](56^+/558TZa\V`eYWZ^wrx#hyYe$/7C9'5<R8*B
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: MonDU1FV on May 03, 2009, 03:08:04 AM
hello! May i ask what is the easiest way to test the health of a old switch mode transformer? Kung may shorted turn, etc? also. what is the most common mode of failure mode of these transformers? Is there a place where we could have them tested?
thanks!
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: the_next_big_name on May 03, 2009, 01:35:17 PM
SMPS Design Toolkit.. from fairchild semi

baka makatulong.

1D96b^S8*@.*<8&8.](56^+/558TZa\V`eYWZ^wrx#hyYe$/7C9'5<R8*B
papano ko ito makikita?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ajak on May 03, 2009, 01:48:36 PM
http://www.electronicslab.ph/forum/index.php?topic=3406.msg53630#msg53630
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on May 03, 2009, 01:49:10 PM
http://www.seabreezecomputers.com/encrypter/

default key: elab ;)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on May 03, 2009, 01:52:55 PM
ay may tanong nanaman ako...

ano ba yung hissing sound sa mga smps? parang galing sa transformer... nabagsak ko kasi, tapos alog na yung core(ferrite)... paghinahawakan ko, medyo tumitigil ang hissing sound. papano ko ba yun aalisin (tunog)? anong adhessive yung ginagamit sa transformers?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on May 03, 2009, 01:55:31 PM
mighty bond lang gamit ko dati. ;D pwede ring nagkabasag sa pagitan. kay may hissing sound dahil sa cycle, nag-attract talaga 'yung core. pwede mag-experiment nito. hehehe. kapag masyadong mataas Gauss, bigla magdidikit 'yung core. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on May 03, 2009, 01:57:03 PM
... anong adhessive yung ginagamit sa transformers?
Araldite ang gamit namin, except dun sa mga high power (mataas na temp.)
(http://img7.imageshack.us/img7/2688/photo002g.th.gif) (http://img7.imageshack.us/my.php?image=photo002g.gif)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 04, 2009, 07:24:47 AM
hello! May i ask what is the easiest way to test the health of a old switch mode transformer? Kung may shorted turn, etc? also. what is the most common mode of failure mode of these transformers? Is there a place where we could have them tested?
thanks!

The easiest of course is by using an instrument. Hindi ko maalala ginagamit nung iba na intrument para dito pero yun yung nakikita nila yung BH curve ng transformer (maari ding curve tracer lang yun with some signal na iniinject)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on May 04, 2009, 09:07:25 AM
merong method sa oscilloscope. nakalimutan ko na 'yung link sa circuit, nadaanan namin dati ng consultant namin.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on May 04, 2009, 12:44:43 PM
ito yung ginawa ko last time (actual circuit):
Quote
(http://info.ee.surrey.ac.uk/Workshop/advice/coils/BHCkt/BH_circuit.png)
Plotting Magnetization Curves (http://info.ee.surrey.ac.uk/Workshop/advice/coils/BHCkt/index.html)

pero hindi successful .. :D
hindi napalabas ang gaya nitong plot: :-\
(http://www.cliftonlaboratories.com/userimages/type_410.jpg)
http://www.cliftonlaboratories.com/type_43_ferrite_b-h_curve.htm
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: MonDU1FV on May 05, 2009, 02:38:49 AM
re: tester
thanks for your replies.
all i really need is a go - no go tester.
 i did some mind experiments. and thought i'd try this soon:
well the transformer is like a gong (or bell). if you hit the bell with a hard object it is going to make a sound, a damped oscillation, if it is "healthy".  if i momentarily connect a dc voltage across a pair of terminals (making "kiskis") on a multi winding transformer (pulsing it), i should see a "ring" on another set of windings.  windings. i have a digital storage oscilloscope handy and i will see what happens. i suppose even a analog scope might work.
i have seen the diagraqm of the lopt tester on the net. but before i build that. let me try this.
thanks all!
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 05, 2009, 07:25:20 AM
ok yan ah,mukhang feasible (pwedeng panthesis,hehehe) pero I don't think magiging madali madetect kung may crack ang transformer, iba ang reponse ng transformer sa low freq(maaring cause by pagpalo dito) at sa high freq. Maaring kailanganin mo processing similar sa voice recognition. ;D

Anyway goodluck... ;)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on May 06, 2009, 11:12:22 PM
mga sir,

may alam ba kayong circuit na pangphase shift 180 degrees. for interleave SMPS sana.
di kasi pwedeng IC na may nakaphase shift na 180 na kaya we need a circuit to phase shift the PWM output.

thanks.

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on May 06, 2009, 11:16:09 PM
^ pwedeng gumamit ng flip-flop, like D-type, then kunin yung output sa "Q" and "Q#"..
kaso laging 50% yung duty nung output ang magiging kalahati pa ang freq..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on May 06, 2009, 11:19:45 PM
pwede naba sa yo itong controller na to for interleaved?

http://focus.ti.com/lit/ds/symlink/ucc28220-q1.pdf
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on May 07, 2009, 12:00:03 AM
sir variable frequency operation yung kailangan namin, na pag nagbago yung duty cycle nung pwm sasabay dapat yung outphase na signal sa pagbabago ng duty cycle..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on May 08, 2009, 05:19:56 AM
mga sir question ulit,
papano idedelay ang pwm signal pero dapat mapreserve yung duty cycle..??

thanks. :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 08, 2009, 07:13:31 AM
mga sir question ulit,
papano idedelay ang pwm signal pero dapat mapreserve yung duty cycle..??

thanks. :)

May question din ako sino nag-gegenerate ng PWM duty? And ano topology?

Ang nagawa ko kasi dati eh may pwm talga na pang interleaved, sa case mo tingin ko gamit ka dalawang PWM, controlling mo yung voltage sa capacitor ng oscillator in such a way na alternately nago-on yung dalawang pwm.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on May 08, 2009, 02:35:12 PM
sir variable frequency operation yung kailangan namin, na pag nagbago yung duty cycle nung pwm sasabay dapat yung outphase na signal sa pagbabago ng duty cycle..

yong logic inverter di ba 180 out of phase yon (inverted pulse)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 08, 2009, 05:00:53 PM
yong logic inverter di ba 180 out of phase yon (inverted pulse)


inverted pero di out of phase, ang duty mo magiging 1-Orig_Duty

correction nga pala dun sa pagcontrol sa charge ng cap, usually pag pull down ang cap eh ang output is high. mas mainam na sa ibang pin mo ihack ang PWM.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on May 08, 2009, 05:07:02 PM
medyo madugo yang magkahiwalay ng PWM IC.
(although possible, may na design na ang isang tech core samin. at napagana namin yun.. :) )
mas ok yung single IC na lang, dedicated sa interleaving..
ang TI, Fairchild, Intersil, etc. meron na silang ganyang IC sa market..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on May 08, 2009, 05:34:06 PM
inverted pero di out of phase, ang duty mo magiging 1-Orig_Duty


ahh okay.....interleave PWM, ito ba yong tinatawag noon na totem-pole na PMW, like SG3524 or SG3525A na IC?

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on May 09, 2009, 09:35:17 PM
merong multiple interleave, n phases.

'yung totem pole design nung gate drive circuit na output nung PWM IC, 'yung ibang unang PWM kasi uncommitted transistors 'yung output, madalas sa isang side lang siya mabilis mag-switch.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on May 09, 2009, 10:00:41 PM

ah okay thanks Rd...

merong multiple interleave, n phases.

'yung totem pole design nung gate drive circuit na output nung PWM IC, 'yung ibang unang PWM kasi uncommitted transistors 'yung output, madalas sa isang side lang siya mabilis mag-switch.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on May 09, 2009, 10:05:41 PM
mga sir question ulit,
papano idedelay ang pwm signal pero dapat mapreserve yung duty cycle..??

thanks. :)
gets ko na gusto mo,interleaved na ZVS operation(variable frequency) pero nakainterleave,medyo madugo talaga yan,dapat meron ka talaga sync circuit pero dapat variable frequency yung controller.eto yung ZVS controller na gusto nya siguro implement.

http://focus.ti.com/lit/ds/symlink/uc3865.pdf

baka yung parallel operation ginagamit nya kaya gusto nya idelay,sana kung may sync pin itong controller na ito solve na.sa akin better to stick with my previous suggested controller(interleaved) then paganahin sya as ZVS operation.medyo may idadagdag kapa talaga na circuit para maging variable frequency.


Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on May 09, 2009, 10:49:01 PM
mga sir,

may alam ba kayong circuit na pangphase shift 180 degrees. for interleave SMPS sana.
di kasi pwedeng IC na may nakaphase shift na 180 na kaya we need a circuit to phase shift the PWM output.

thanks.


si Dember ng sinundan nyong batch, PE,
 may ini-evaluate na controllers form Fairchild saka TI.
 ZVS interleave yun, designed for PFC,
 pero pwede atang i-modify para sa Buck converter

::) :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on May 09, 2009, 10:49:02 PM
mga sir. we used uc3864, may two outputs sya. kaso parallel output yung pwm. balak sana namin idelay yung output b para sa interleave implementation.

kasi di pwede yung variable frequency sa 3863 na may alternating output ng pwm.

kaya we need a delay circuit para sa output b.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on May 09, 2009, 11:04:33 PM
mga sir nakapagsimula na kami sa uc3864. and defense na sa first week ng june kaya mejo mahirap ng magpalit ng controller.
kaya parang stick muna kami sa controller na yun. kailangan lang namin ng delay circuit para sa output b. 180 deg na delay sa output b.

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on May 09, 2009, 11:12:07 PM
si Dember ng sinundan nyong batch, PE,
 may ini-evaluate na controllers form Fairchild saka TI.
 ZVS interleave yun, designed for PFC,
 pero pwede atang i-modify para sa Buck converter

::) :D

ayus,pwede na pala sa yo to noscire8,topology lang pala pagkakaiba hehehe  ;D ;D ;D

Quote
mga sir nakapagsimula na kami sa uc3864. and defense na sa first week ng june kaya mejo mahirap ng magpalit ng controller.
kaya parang stick muna kami sa controller na yun. kailangan lang namin ng delay circuit para sa output b. 180 deg na delay sa out

hingi ka nalang kay sir yus ng controller at schematic baka pwede itong second options  ::)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on May 10, 2009, 01:32:04 AM
saang team ko makikita si sir yus? hehe sige mga sir salamat sa 2nd option.
sana may marefer kayong delay circuit.

3 weeks na lang kasi at defense na. kaya mejo critical bawat oras
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 10, 2009, 06:17:00 PM
^taga emerson din?  ??? ;D

medyo madugo yang magkahiwalay ng PWM IC.
(although possible, may na design na ang isang tech core samin. at napagana namin yun.. :) )
mas ok yung single IC na lang, dedicated sa interleaving..
ang TI, Fairchild, Intersil, etc. meron na silang ganyang IC sa market..

wala na ko balita sa HW ngayon pero I think hackable naman ang PWM for this application, hindi nga lang guaranteed sa commercial applications, at depende sa PWM na gagamitin, the best pa rin idea ni yus, gamit na lang ng PWM designed for your applications
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: the_next_big_name on May 10, 2009, 06:31:38 PM
hi, papano imodify ang ckt na ito para maging 10a?
(http://www.danielbauen.com/robotics/RC-Dimmer-Schematic-crop.jpg)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 10, 2009, 06:40:59 PM
^ Master para madevelop ng maayos project mo I suggest gawa ka thread asking help sa design mo.

Additional comment, yung cap mas magandang after ng rectifier ilagay. at saka based sa circuit mo hindi mo kakailanganin ng 10A for Microcontroller, yung load mo ang maaring mangailangan pero walang kinalaman dun yung 5V regulator mo kasi PIC lang ang sinusupplyan nun,
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: the_next_big_name on May 10, 2009, 06:44:13 PM
di ba this can satify my requirement kanina?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 10, 2009, 06:47:15 PM
 :-X
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 10, 2009, 06:48:58 PM
OK ganito na lang, para maging 10A yan, hanap ka ng n-Channel na MOSFET na >10A ang rating, ayos ba? ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: the_next_big_name on May 10, 2009, 06:50:55 PM
ganun lang?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: the_next_big_name on May 10, 2009, 06:52:35 PM
geezzz...papano kaya iprogram yang pic na yan?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 11, 2009, 07:04:49 AM
geezzz...papano kaya iprogram yang pic na yan?

sabi ko naman sayo master gawa ka sarili mo thread for your project,

I'm sure hindi lang power supply ang magiging issue mo, at least marami pwede sayo mag-guide


ganun lang?

simplicity is beauty master,

now I assume na from AC line ka kukuha ng power mo at hindi sa gaya ng nakasulat sa schematic DC na agad ang input, pwede ka maglagay ng transformer, rectifier, at malaking filter cap to produce that 30V DC, hindi mo kakailanganin ng SMPS, or linear or any regulated power supplies jan kasi hindi naman demanding load mo.


pakitanggal din yan 270Ohms na resistor pakilipat ng 100uF na capacitor after the diode.Ilagay nyo between cathode and ground(Hindi ko alam kung ano pinaggagagawa sa buhay ng author nyang circuit na yan,hehehe), Dapat ang supply ng sa MCU eh 9V lang kung manggaling sa AC ang voltage
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on May 11, 2009, 10:37:33 AM
^taga emerson din?  ??? ;D

wala na ko balita sa HW ngayon pero I think hackable naman ang PWM for this application, hindi nga lang guaranteed sa commercial applications, at depende sa PWM na gagamitin, the best pa rin idea ni yus, gamit na lang ng PWM designed for your applications

sila ata yung pinakabago na PE ngayon(nasa batch 14) sir glutnix_neo medyo sa controller lang sila nagkakaproblema,kaya lang sana pwede yung PFC na controller sa buck kasi may modulation na yung PFC controller(para maging in phase yung voltage to current)di ko pa kasi nakikita yung controller,tanong nalang sila kay sir yus sa suggestions.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 11, 2009, 10:48:48 AM
sila ata yung pinakabago na PE ngayon(nasa batch 14) sir glutnix_neo medyo sa controller lang sila nagkakaproblema,kaya lang sana pwede yung PFC na controller sa buck kasi may modulation na yung PFC controller(para maging in phase yung voltage to current)di ko pa kasi nakikita yung controller,tanong nalang sila kay sir yus sa suggestions.

May ginamit kaming controller sa DC-DC project(bawal sabihin name,hehehe) same for boost and buck, interleaved na, yun yung project ko before ako umalis sa EW1, pwede kayo ask kay jeremy or emer baka pwede yun, ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: maldihtah13 on May 12, 2009, 11:34:57 AM
Wla kayang aattend dito ng seminar sa UPNEC bukas EB tayo. Seminar will be about power electronics (SMPS).
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on May 12, 2009, 04:10:42 PM
May ginamit kaming controller sa DC-DC project(bawal sabihin name,hehehe) same for boost and buck, interleaved na, yun yung project ko before ako umalis sa EW1, pwede kayo ask kay jeremy or emer baka pwede yun, ;D ;D

yun ba yung HIGAD project master glutnix? ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 12, 2009, 04:24:38 PM
yun ba yung HIGAD project master glutnix? ;D ;D

Ay hindi yun, first project ko pa yun sa EW1, nakadalawang projects pa ko after nun, ang tinutukoy ko eh yung Osbourne project ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on May 12, 2009, 05:38:37 PM
Ay hindi yun, first project ko pa yun sa EW1, nakadalawang projects pa ko after nun, ang tinutukoy ko eh yung Osbourne project ;D

OT:

interleaved pala ginamit dun  ;D ;D ;D saka iba na master yung tag na nakalagay sa baba mo,galing ata sa kabilang forum yan(ai sauce  ;D)  :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 13, 2009, 08:23:58 AM
Ang problema sa mga interleaved na high current(or even low current) eh sharing lalo na pag pinapasok ng noise ang feedback.

ai sauce!!! hehehehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: drin20 on May 20, 2009, 10:57:19 PM
mga bossing... pedi ba gawing battery charger na Lead Acid Battery ang SMPS PSU ng Computer?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on May 21, 2009, 12:01:50 AM
mga bossing... pedi ba gawing battery charger na Lead Acid Battery ang SMPS PSU ng Computer?

kung pwede itaas ng kunti ang voltahe sa 14V para makapagFullCharge ng 12V LeadAcid na battery...pero kailangan parin ng current limiter e...para maiwasan ang sonugan ....

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: drin20 on May 21, 2009, 12:06:39 AM
dapat 3 amp lang mag feed sa SLA battery po ba??? diba merong +12 volts and -12 volts ang atx power supply? hindi po ba pwedi gawin yun?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on May 21, 2009, 12:10:47 AM
'yung current limit dapat mas mababa pa doon sa current limit nung PSU talaga. tapos papalitan 'yung resistor values nung nagse-set ng voltage para maging hanggang 14.4V (kung standby charge).

hindi ko sigurado kung gaano na kaganda 'yung current limit ng mga bagong generic PSU ngayon kasi sa mga lumang PSU mamatay kaagad kapag sinaksak mo 'yung battery (lalo na kung fully drained) dahil mag-register 'to as short circuit (actually kahit malaking capacitor lang mamamatay na 'yung PSU, nasa ATX specifications kung gaanong kalaking capacitor lang kaya).

dapat 3 amp lang mag feed sa SLA battery po ba??? diba merong +12 volts and -12 volts ang atx power supply? hindi po ba pwedi gawin yun?


mababa 'yung current na kayang i-supply nung mga negative voltages. nagagmit ko 'yan sa mga fan para kumuha ng 17V to 24V.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: JOrax on May 22, 2009, 08:47:13 PM
bro nice_apprentice.. hehehe.. para di ka na mahirapan.. ganito gawin mo pag magpo-post ka ng picture sa forum..

(http://img33.picoodle.com/data/img33/3/8/26/f_untitledm_acb58c3.jpg)

click mo yung insert image icon pag magpo-post ka ng reply... may lalabas na  "[img ]http://[ /img]"

then, sa gitna, dun mo ilalagay yung link ng picture(image location) mo na naka-upload sa host..

"[img ]<post your image location here>[ /img]"

hehehe.. sana makatulong..  ;D ;D ;D

eto na yung pinost mong pic..:D

(http://i508.photobucket.com/albums/s329/nice_start/hidrive.jpg?t=1219756806)

eto yung code

 "[img ] http://i508.photobucket.com/albums/s329/nice_start/hidrive.jpg?t=1219756806[ /img]"

Note:
wala talagang space yung mga [img], nilagyan ko lang para lumabas.. di kasi makita  pag walang space eh..hehehe.. :D



Kaya pala hindi ako makapag-post ng picture by pasting it..Kailan ba talaga na i-upload muna sa host ang picture para makapagpost dito?..Wla naba iba paraan sir?..Salamat..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on May 22, 2009, 11:50:05 PM
mga sir question.
pag buck converter ba at nakagate drive transformer ako
kailangan kong iisolate din ang feed back?
thanks
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on May 23, 2009, 12:08:57 AM
di dapat naka isolate,non isolated kasi yung buck dapat kung ano ground ng input ganun din output,output feedback ground must be the same as input ground.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on May 23, 2009, 01:32:43 AM
purpose nung gate drive, para ma-break 'yung ground reference i.e. magiging reference nung Gate Drive voltage 'yung Source ng MOSFET. 'yung output voltage mo hindi naman na-shift 'yung reference kaya ground referenced pa rin. ;)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Supermendur on May 23, 2009, 12:57:00 PM
Ask ko lang sir...

In terms of EMI po..ano mas less emission/noise...DCM (high peak current ) or CCM ( w/ peak current due to switching transition )
considering na walang snubber and assuming power switch ratings can handle all the currents..

Isa pa po..

I am wondering why most Buck/Forward and Full/Half bridge topologies requires a secondary stage output rectifier while a
a typical Boost and Flyback Systems wala naman po..

mas mataas po ba ripple current ng mga ito..kasi weird dahil flyback are usually operated in DCM (large ripple current) pero sila yung walang secondary filters usually..or dahil cost additive lang yung filters kasi pag flyback implementation more likely cost effective..

thanks
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on May 23, 2009, 02:05:11 PM
....
In terms of EMI po..ano mas less emission/noise...DCM (high peak current ) or CCM ( w/ peak current due to switching transition )
considering na walang snubber and assuming power switch ratings can handle all the currents..
...
sa PFC (boost) na fornt-end,
between DCM (discontinuous conduction mode) and CCM (contiuous C M),
mas mahirap i-solve ang EMI ng DCM,
kasi yun nga mas mataas ang peak-to-peak nung mga switcing current for the same power/volatge
madalas, kelangan pa ng additional differential mode (DM) choke sa DCM-PFC.


Quote
...
I am wondering why most Buck/Forward and Full/Half bridge topologies requires a secondary stage output rectifier while a
a typical Boost and Flyback Systems wala naman po..

mas mataas po ba ripple current ng mga ito..kasi weird dahil flyback are usually operated in DCM (large ripple current) pero sila yung walang secondary filters usually..or dahil cost additive lang yung filters kasi pag flyback implementation more likely cost effective..
...
mahirap i-compare ang boost (e.g. PFC) saka Full/Half bridge..
ang PFC kasi eh pang primary side lang usually, kaya ok lang kahit mataas ang ripple.
yung mga bridge topologies naman, usually pang secondary (output stage) kaya dapat mababa na ang ripple. (kaya may additional filter pa)..

sa flyback naman, cost talaga ang main concern.. less parts count, mas ok..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on May 23, 2009, 09:11:14 PM
Ask ko lang sir...

In terms of EMI po..ano mas less emission/noise...DCM (high peak current ) or CCM ( w/ peak current due to switching transition )
considering na walang snubber and assuming power switch ratings can handle all the currents..

Isa pa po..

I am wondering why most Buck/Forward and Full/Half bridge topologies requires a secondary stage output rectifier while a
a typical Boost and Flyback Systems wala naman po..

mas mataas po ba ripple current ng mga ito..kasi weird dahil flyback are usually operated in DCM (large ripple current) pero sila yung walang secondary filters usually..or dahil cost additive lang yung filters kasi pag flyback implementation more likely cost effective..

thanks


'yung 2nd order filter ba 'yun? sa Boost/Flyback kasi, 'yung main magnetics na ang energy storage, sa Buck-derived family, walang stored energy sa transformer (ideally, totally wala) kaya kailangan ng inductor.

kapag nagde-design ako dati ng flyback linalagyan ko rin ng maliit na inductor para lumiit 'yung output spike, typically, C - LC. nasa uH range lang ginagamit ko.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: noscire8 on May 25, 2009, 12:31:29 AM
ahhh okay mga sir . meaning kahit d n kami gumamit ng optoisolator kahit naggate drive transformer kami?

tnx tnx
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on May 25, 2009, 07:28:19 AM
kung Buck 'yung topology ok lang dahil hindi naman talaga siya isolated. ;)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 25, 2009, 07:39:51 AM
Ask ko lang sir...

In terms of EMI po..ano mas less emission/noise...DCM (high peak current ) or CCM ( w/ peak current due to switching transition )
considering na walang snubber and assuming power switch ratings can handle all the currents..

Isa pa po..

I am wondering why most Buck/Forward and Full/Half bridge topologies requires a secondary stage output rectifier while a
a typical Boost and Flyback Systems wala naman po..

mas mataas po ba ripple current ng mga ito..kasi weird dahil flyback are usually operated in DCM (large ripple current) pero sila yung walang secondary filters usually..or dahil cost additive lang yung filters kasi pag flyback implementation more likely cost effective..

thanks


slope at magnitude ng current ang nagdidikta sa EMI emission mo master, so kahit mataas ang current mo at gentle naman ang slope eh ok lang, worst eh yung step function ng very high current ;)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on May 25, 2009, 07:45:05 AM
^ 'yung impulses malakas ang EMI, like digital circuits at 'yung current sa gate drive, low current (though sa gate kung mabilis ang turn on malaki rin ang current) pero kung mali ang design hindi papasa sa EMC standards. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 25, 2009, 07:52:42 AM
^ 'yung impulses malakas ang EMI, like digital circuits at 'yung current sa gate drive, low current (though sa gate kung mabilis ang turn on malaki rin ang current) pero kung mali ang design hindi papasa sa EMC standards. ;D

yun isa pa nga pala yun at mas matindi ang mga impulses.

bottom line is hindi naman talaga sa mode ng current ang problema kundi nagkataon lang na mas mataas emi sa discontinuous against sa continuous kasi mas steeper ang slope sa discontinuous para marating yung peak na nagkataong mas mataas din against sa continuous to produce the same average current  ??? ??? ???
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on May 25, 2009, 07:58:49 AM
kaya marami ring attempts to use CCM sa Flyback and Boost pero hindi pa rin mawawala 'yung case ng RHP Zero, pwede lang maging mabilis response nung Control design pero mag-persist pa rin siya for few cycles, worst 'di na talaga babalik. ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on June 04, 2009, 01:55:07 PM
mga master, may nakagawa na ba dito ng flyback na dine-detect 'yung kickback ng storage transformer para mag-ON 'yung main FET? napansin ko kasi ganun 'yung mga circuit ng flash capacitor charger, exactly kapag naubos 'yung stored energy, mag-switch 'yung FET.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on June 04, 2009, 04:33:28 PM
hindi ko pa po natry, pero pano yun, diba magstart na yun makick pagkakaturnoff pa lang nya?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on June 04, 2009, 04:50:39 PM
ang hinihintay niya bali sir glutnix, 'yung reverse recovery nung diode sa secondary, kapag naubos kasi 'yung energy, partially 'yung capacitor magkakaroon ng reverse current papunta sa transformer, tapos dadaan sa body diode nung FET sa primary magkakaroon ng maliit na negative voltage, tapos sa drain merong comparator. 'yung comparator bali na 'yun ang main job niya i-sense kung nag-reverse recovery na 'yung rectifier diode.

depende rin siguro sa design ng transformer at nung mga nakapaligid na snubber, minsan kasi maliit lang 'yung makikita na negative voltage.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on June 05, 2009, 07:06:10 AM
ang hinihintay niya bali sir glutnix, 'yung reverse recovery nung diode sa secondary, kapag naubos kasi 'yung energy, partially 'yung capacitor magkakaroon ng reverse current papunta sa transformer, tapos dadaan sa body diode nung FET sa primary magkakaroon ng maliit na negative voltage, tapos sa drain merong comparator. 'yung comparator bali na 'yun ang main job niya i-sense kung nag-reverse recovery na 'yung rectifier diode.

depende rin siguro sa design ng transformer at nung mga nakapaligid na snubber, minsan kasi maliit lang 'yung makikita na negative voltage.

Oh I see, interesting po.(maisimulate nga,hehehe)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Born2BeWired on June 17, 2009, 10:17:03 AM
The legendary analog guru, Jim Williams, has a new video which might be of interest to you, SMPS savants.

Measuring Switching Regulator Noise

http://www.linear.com/designtools/video/ltchannel_switchregnoise.jsp

Medyo sluggish lang ang connection, perhaps due to high traffic. But it will worth the wait. Enjoy ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: erick_214 on September 30, 2009, 11:37:08 PM
tol...tanong ko lang baka masolve mo itong problem ko...
nagsesearch kasi ako ng regulated power supply para ilagay ko sa motor ko para lumakas ng konti yung charging nya dahil nagdagdag ako ng ilang accessories na malakas kumunsumo ng battery...actually may ginawa na yung technician sa motor ko which is nadisconnect na nya yung yellow wire from the alternator going to the rectifier-regulator...Medyo lumakas na yung pagchacharge pero kulang pa rin...

ngayon tinester ko yung yellow wire na galing sa alternator at yung reading nya ay 8Vac(at idling) to 100Vac(at full rev)...so may mairerecommend ka ba na circuit para magkaron ng output voltage na 12.5Vdc(idle) 14Vdc(max)..? sana yung gumagamit lang ng diode, zener at transistor...posible ba ito..?

Maraming thanks in advance...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on October 01, 2009, 07:57:46 AM
Sorry to disappoint you master but I think you're asking for a miracle (Universal Law of Conservation of Energy). Isang accessory pa at masusunog na alternator ng motor mo. ;D

Your problem maybe not the voltage but the power your alternator is providing.

Hindi ko masyado maintindihan kung ano ginawa ng technician pero base sa kwento nyo, malamang nagbypass sya ng voltage regulator para lang mapataas output which is very dangerous sa mga electronics mo kasi hindi na sya protected sa high voltage spikes.

There's hope na maari ding power supply ang naglilimit ng power at kailangan mo lang palitan ito ng mas mataas na rating pero ang intuition ko eh alternator na ang alanganin
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: alyas on October 01, 2009, 08:57:30 AM
Alternator problem nga ang problema diyan.  Yung mga car audio enthusiast, when they install those high audio power amps, usually pinapalitan nila yung alternator ng car nila ng mas mataas ang power output.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on December 14, 2009, 07:53:35 PM
i want to do this:

(http://i179.photobucket.com/albums/w313/kiashee/q.png)


what could possibly go wrong kapag mali ang value ng inductor ko?

kasi gumawa lang ako ng sarili kong inductor (with a ferromagnetic material that i don't know. basta galing sa monitor.)... gamit yung DIY LC meter.

sa kadahilanang imposible naman na magawang sakto yung value, anong pipiliiin ko? higher or lower?
kasi sa 12 turns, 138uH na. kapag 11 turns naman 118uH na...

Higher or lower? ;D ;D ;D


Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on December 14, 2009, 08:03:03 PM
pwedeng ibalik sa computation sis kung ano ang magiging limits nung current na CCM (Continuous Conduction Mode) pa rin. ;D pero kung ako, sa higher. ;D

check mo lang sis kung mag-saturate 'yung inductor, mukhang mataas ang permeability ng core mo sis (malaki ba 'yan) kaya 12 turns lang mataas na ang inductance. kung transformer type core 'yan sis, pwedeng lagyan ng gap (kikil lang). tapos kung toroid naman, kuha na lang sa ginamit na inductor talaga. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on December 14, 2009, 08:23:19 PM
ang totoo nyan, eto ang gusto kong gawin.

(http://i179.photobucket.com/albums/w313/kiashee/f0713.gif)
gagawin kong parang transformer.

eto yung coil:
(http://i179.photobucket.com/albums/w313/kiashee/IMG_5033.jpg)

di nga ako sure sa core material. parang di naman pang transformer. dapat siguro yung kulay yellow.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: zer0w1ng on December 15, 2009, 07:20:40 AM
Sir, it's look like the core is from an EMI filter. Ito yung naka-series sa mains voltage.
If I am correct, this is not good for switching PS use. (I am not an expert on this, sir glutnix can confirm this)

I usually use the transformers of the PC power supply as cores.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: RaffT on December 15, 2009, 07:33:08 AM
sis marce,

 kung madami ka TYPE of cores, maybe you could wind 10 turns per CORE and measure inductance... yung may pinakamataas na inductance reading, yun ang gamitin mo.. with 10T (kung high permeability yan) could read 300uH and above... depende na rin yun sa laki ng core...

teka upload ako ng pic.. be back in a few minutes
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: RaffT on December 15, 2009, 07:43:31 AM
nakup double post.. paki delete nalang.. heheh
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: RaffT on December 15, 2009, 07:44:05 AM
ok et na..

(http://i46.tinypic.com/2w1wp4x.jpg)

 LEFT  smaller torroid is #27 12T measures 558uH.. on the right corner (bigger torriod) has about 12T also using #25 but measures only 115uH... so this means yung mas maliit ay mataas ang AL(permeability) nya...  ;)

sana nakatulong sis  :-*
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on December 15, 2009, 08:39:12 AM
Sir, it's look like the core is from an EMI filter. Ito yung naka-series sa mains voltage.
If I am correct, this is not good for switching PS use. (I am not an expert on this, sir glutnix can confirm this)

I usually use the transformers of the PC power supply as cores.

sir, apparently, it worked! heheh ;D and yes, yung core nga na nakalagay sa  EMI filter to... i see at least two of these inside the monitor.
i was so curious last night that i was not able to wait for your answer! ;D ;D ;D

i tried to use that yellow one from ATX power supply, pero sobrang baba ng inductance. naamazed nga ako actually nitong 

Anong mangyayari if i continually use this one?

@rafft, parang galing din yan sa emi filter cores mo di ba?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on December 15, 2009, 10:03:20 AM
the simplest SMPS ICs i've seen TNY254, TNY264 etc..try nyo lang google mga datasheets ng TNY ICs

(http://img696.imageshack.us/img696/1767/tny254n.jpg)

kaya ng IC ang voltage swing natin  ;)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on December 15, 2009, 10:59:50 AM
sir, apparently, it worked! heheh ;D and yes, yung core nga na nakalagay sa  EMI filter to... i see at least two of these inside the monitor.
i was so curious last night that i was not able to wait for your answer! ;D ;D ;D

i tried to use that yellow one from ATX power supply, pero sobrang baba ng inductance. naamazed nga ako actually nitong 

Anong mangyayari if i continually use this one?

@rafft, parang galing din yan sa emi filter cores mo di ba?

tama si sir zerowing sis, 'di ideal gamitin ang high permeability sa inductor unless filter lang siya at 'di gagamitin sa energy storage.

ang problema sa high permeability sis 'yung saturation. kaya madalas 'yung distributed gap ang gamit sa inductor (sa gaps kasi nag-store ng energy ang inductor). aandar siya, pero malaki ang possibility na madalas mukhang wala na 'yung inductor at first order filter na lang 'yung output. mache-check mo 'yan sis sa scope, mag-series ka ng maliit na resistor para makita 'yung current sa inductor.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on December 15, 2009, 11:23:04 AM
tama si sir zerowing sis, 'di ideal gamitin ang high permeability sa inductor unless filter lang siya at 'di gagamitin sa energy storage.

ang problema sa high permeability sis 'yung saturation. kaya madalas 'yung distributed gap ang gamit sa inductor (sa gaps kasi nag-store ng energy ang inductor). aandar siya, pero malaki ang possibility na madalas mukhang wala na 'yung inductor at first order filter na lang 'yung output. mache-check mo 'yan sis sa scope, mag-series ka ng maliit na resistor para makita 'yung current sa inductor.

anong expected currents ko sis?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on December 15, 2009, 11:40:51 AM
makikita mo na tumataas bigla yung current(kung expected mo eh saw tooth, may makikita ka spike sa ibabaw ng saw tooth, tingin ko hindi lang basta spike yun)

normal

(http://www.elecfans.com/article/UploadPic/2008-10/2008101081719753.gif)

saturated

(http://www.elecfans.com/article/UploadPic/2008-10/2008101081718127.gif)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on December 15, 2009, 11:59:55 AM
'yan may scoped current na si sis glutnix. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: RaffT on December 15, 2009, 12:22:39 PM
@sis glutnix,

 pwede kaya YANG TEST with 1KHz(or below) square wave? balak ko din sana kasi i-test kung nag sasaturate yung core ko.. gamit ko kasi yun sa tesla ko.. driver ng mosfet h-bridge

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on December 15, 2009, 12:50:11 PM
@sis glutnix, salamat.

ganyan pala yan. lookup ko yan mamaya.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on December 15, 2009, 12:52:46 PM
@sis glutnix,

 pwede kaya YANG TEST with 1KHz(or below) square wave? balak ko din sana kasi i-test kung nag sasaturate yung core ko.. gamit ko kasi yun sa tesla ko.. driver ng mosfet h-bridge



mas kita yan sa lower frequency,

minsan parang square wave na lang nakikita mo kasi most of the time eh saturated na sya.

parang capacitor lang yan na nafullcharged na, pag full na, hindi na pwede tumaas pa voltage
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: RaffT on December 15, 2009, 02:13:52 PM
^ganun ba? cge buohin ko ulit ung lcd scope ko.. PM kta pag nagawa ko na..paturo ako paano connection setup... :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: torps04 on January 03, 2010, 07:17:12 PM
meron po b kayo circuit ng 15volts power supply? hehe
pasenxa po baguhan lng sa ganitong industry :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: maldihtah13 on January 03, 2010, 07:54:31 PM
Pwede ba tayo gumawa ng adjustable na power supply na SMPS? 0-30V sana.

Baka may link kayo?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcialnasi on January 14, 2010, 01:42:38 PM
question: saan or paano ako makakapagdesign ng ac to ac converter 220vac to 12vac 60 amp maximum pro medyo compact cya dahil sa chandelier cya ginagamit.nawala na kc ung orig na power supply.baka meron kang design patulong naman.switch mode type din po cya kc me apat na epitaxial transistor na ginamit.ty
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on January 14, 2010, 04:35:22 PM
question: saan or paano ako makakapagdesign ng ac to ac converter 220vac to 12vac 60 amp maximum pro medyo compact cya dahil sa chandelier cya ginagamit.nawala na kc ung orig na power supply.baka meron kang design patulong naman.switch mode type din po cya kc me apat na epitaxial transistor na ginamit.ty

aw, mahirap ata yan, hanap ka muna ng available controller para dyan, yung datasheet nun may sample circuit
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: updated on January 14, 2010, 04:38:48 PM
Pwede ba tayo gumawa ng adjustable na power supply na SMPS? 0-30V sana.

Baka may link kayo?


may nakuha ka na bang smps?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on January 14, 2010, 04:40:33 PM
Pwede ba tayo gumawa ng adjustable na power supply na SMPS? 0-30V sana.

Baka may link kayo?

Try ko maghanap ng sample designs
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on January 14, 2010, 04:48:08 PM
Eto adjustable pero hindi regulated, pwede namang imodify para maging regulated,

Di ko pa maxado naaral circuit pero baka pwede gamitin UC3842 na locally available...
http://www.zen22142.zen.co.uk/Circuits/Power/oafc.htm (http://www.zen22142.zen.co.uk/Circuits/Power/oafc.htm)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: updated on January 14, 2010, 05:04:15 PM
mukang pwede nga sir. naka kuha din ako ng max5020 dito. try ko gamitin yun. tnx
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Vhelt on January 27, 2010, 10:15:08 PM
Mga Sir bago lang ako dito pero talagang ganda ng topics dito regarding smps. My tanong lang ako sir Glutnix anong section ba ng smps ung responsible sa stability ng output voltage nya. 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on January 27, 2010, 10:21:48 PM
^ 'yung control part sa feedback loop. few components lang pero makes or breaks a design. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Vhelt on January 27, 2010, 10:31:50 PM
Sir Glutnix bago lang ako dito pero talagang ganda ng forum na ito informative. May tanong lang po ako regarding smps anong section po ba responsible sa stability ng output voltage. TIA.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on January 28, 2010, 08:01:47 AM
Tama sabi ni boss RD, yung feedback control loop

main part dun eh yung error amp. Then may voltage divider na nagtetake ng sample ng output at ipinapasok sa error amp. at may mga compensation components na nakakabit sa error amp.

mawala isa dun, hindi magaguarantee na stable output.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Vhelt on January 31, 2010, 07:10:19 PM
Another question sir Glutnix tungkol sa dc varistor dun sa my overvoltage protection ng mga branded na ATX psu saan po ba nakakabili nun wala kasi akong mabili nun dito sa lugar namin. minsan tinatangal ko nalang kapag wala akong makahoy na varistor.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 01, 2010, 12:14:40 PM
hindi ko pa rin natry bumili nun locally.

it should work naman kung wala nun, wala nga lang protection.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: pete on February 01, 2010, 12:53:21 PM
glutnix_neo ok to ah.. pogi points +1 mona sir...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Vhelt on February 01, 2010, 09:16:25 PM
Mga sir my forum po ba dito regarding sa power amplifier tia....
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Vhelt on February 07, 2010, 03:35:42 PM
Sir Glutnix anong klaseng design ng smps ung karaniwang ginagamit sa mga atx power supply ng computer. at anong purpose ng mga torodial coil sa secondary side. pasenya na maraming tanong medyo magulo pa kasi sa akin operation ng atx psu...tia
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 08, 2010, 08:51:27 AM
Yung mga mumurahin at kalimitang nakikitang may switch for 110 and 220 eh mostly forward converter ang topology. Older low power PSUs eh gumagamit din ng Flyback Converter.

yung mga medyo mahal at mataas ang efficiency eh mga bridge type na SMPS. AFAIK they are moving towards bridge and resonant converters para mameet yung 80plus (http://www.80plus.org/) na standard ngayon.

regarding sa choke, nagstore sya ng energy para malower yung ripple current sa output. Mostly for filtering purposes. You can find more info about it sa simula nung thread na ito, yung discussions about buck converter.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Vhelt on February 08, 2010, 09:33:46 AM
Sir thanks sa paliwanag mo atleast ngayon alam ko na ung design, topology na ginamit magresearch nalang ako about this.One thing na di ko maintindihan minsan kahit na good ung primary side may standby power 5v sa secondary eh ayaw gumana na try ko na din ishort ung green wire to black wire wala namang sirang diode sa 2ndary posible din ba masira ung power management ic? mostly na encounter ko ito sa barnded atx psu.Tia.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 08, 2010, 10:45:01 AM
madaming possibleng dahilan, pero kung lahat ng output (except sa standby) ang walang output voltage, maaring yung FET sa primary ang sira or yung PWM(IC) na nga.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: namzer0 on March 06, 2010, 01:02:55 PM
mga sers, tingin ko po, may kadalian po gumawa ng switching converters pag battery. na try ko na po gumawa ng replica ng camera circuit(switching trans4mer type)...
panu po kung galing sa AC line? voltage divider lang po ba? para pababain ung V & I?
marami po akong mga sirang CP chargers... wish ko po imodify para sa higher V&I output.

ganda po talaga pag SMPS kesa sa Xformer type, very light, smaller and mura(ewan ko po sa IC kung mura, transistorized SMPS kasi).
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on March 06, 2010, 10:43:52 PM
direct sa transformer 'yung rectified AC, tapos turns ratio na nung transformer ang basis nung secondary voltage. then sa range ng possible secondary voltages, doon 'yung regulation.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: namzer0 on March 08, 2010, 01:56:40 PM
direct sa transformer 'yung rectified AC, tapos turns ratio na nung transformer ang basis nung secondary voltage. then sa range ng possible secondary voltages, doon 'yung regulation.

di kaya po sumabog yung ferrite xformer pag direkta?
Pero nakita ko po, manipis yung magnet wire sa mga CP Chargers, tapos malaki-laki na sa secondary(3.7-4.2V)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on March 08, 2010, 01:59:09 PM
nope, basta tama 'yung design. ;) ganyan din 'yung PSU ng mga PC.

'yung sa ibang murang cellphone charger merong capacitive divider sa input. ang gamit kasi nilang transistor e 'yung medium voltage lang, then naka self-oscillating ang configuration.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: genocide139 on March 15, 2010, 10:10:19 PM
mga sir, bago lang po ako sa field ng smps at meron akong project na magconstruct ng isang smps. meron po akong nakita sa isang site, isang design na low cost daw, at ipinakita ko po ito sa aking instructor. sabi nya po ay hindi daw ito smps. kung pwede po, pa-explain naman po sa akin ung reason kung bakit hindi ito smps (kahit sabi na sa site ay smps ito)

http://www.romanblack.com/smps/a02.htm (http://www.romanblack.com/smps/a02.htm)

sana po ay may makatulong.. thanks in advance
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 15, 2010, 10:23:04 PM
simple lang sagot dyan master, di maintindihan ng instructor mo yung drawing,hehehe


It's a self oscillating buck converter po. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: genocide139 on March 15, 2010, 10:39:30 PM
galing nyo naman po, sana kaw nalang instructor ko. haha.

hmm, so meaning, ito po ay isang smps na hindi na kelangan ng pwm? tama po ba? alin naman po dito ung component na nagbibigay ng pulse para mag on and off ung transistor? sensya na po, daming tanong.

salamat po sa mabilis na reply sir.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on March 16, 2010, 07:28:37 AM
sa totoo lang hirapan din ako ianalyze circuit, puro linya lang kasi nakikita ko dun, hehehe


Q1, L1, C at D1 are parts of the buck converter, the rest are parts of the PWM circuit. Zener ang nagdidictate ng output voltage (Zener V - diode drop sa transistor Q2). Kaya siguro naisip ng instructor nyo na hindi sya SMPS eh same circuit lang kasi sa linear regulator yung zener at Q2 configurations.

Parang ganito(Linear Regulator to)...

(http://www.satcure-focus.com/tutor/images/regulat.gif)


Kung makikita mo yung graph below dun sa site yung frequency eh dependent sa output current nya.

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: genocide139 on March 16, 2010, 07:33:59 PM
ahh ganun pala un. salamat po ulit sa tulong nyo sir. meron po kaming bagong idea ng classmates ko, ang plan po namin ay magkakabit nalang po kami ng isang pwm sa base ng isang mosfet para maging smps na. meron po ba kayong maisusuggest na mosfet? un pong low cost sana.  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Vhelt on June 14, 2010, 09:18:32 PM
Sir glutnix magtatanong lang po ako regarding sa power supply ng monitor may ginagawa kasi ako working ung monitor pero may hissing sound sigurado na ako na sa power supply galing kasi hang ko na ung b+ line papunta flyback nung una kala ko high v. leak pero di pala... Patulong naman sir kung paano ko matatangal un at kung anong part ng circuit responsible dun Tia......
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on June 14, 2010, 10:05:36 PM
Pasubscribe... back read lang uli ako. Para masundan. Puro kasi SMPS na gamit ngayon.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on June 14, 2010, 10:31:44 PM
Sir glutnix magtatanong lang po ako regarding sa power supply ng monitor may ginagawa kasi ako working ung monitor pero may hissing sound sigurado na ako na sa power supply galing kasi hang ko na ung b+ line papunta flyback nung una kala ko high v. leak pero di pala... Patulong naman sir kung paano ko matatangal un at kung anong part ng circuit responsible dun Tia......

mahirap masabi not unless makita ko yung transformer current. kung may oscilloscope ka pwede mo tingnan yung resistor na nakaseries sa MOSFET.

Marami reason ng hissing eh, ilan dito ang instability sa control loop, pwede rin saturation ng transformer core pwedeng dahil may crack yung transformer, or pwede rin maluwag lang yung transformer na usually nasosolve sa paglubog ng transformer sa varnish.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: chadex on June 15, 2010, 03:54:05 AM
Sir meron ako powered sub na gumamit ng smps. Ang problem is walang output voltage (+)13.5, (-)13.5vdc .. Nacheck ko na yung mosfet (irf740) good naman sya. Nacheck ko na rin yun ibang passive parts like diodes and resistors, ok naman din. May nasukat ako 328vdc after ng bridge diode. Posible kaya na yun pwm controller (uc3842) ang sira? May nasukat nga pala ako na 12vdc sa pin7 at pin5. Pwede ko po ba i-post dito yung diagram? pano po? TIA
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: pEN DoTA on June 15, 2010, 06:10:26 AM
Brief Explaination lang ng problem sa high side switching, common to hindi lang sa power electronics kundi sa mga VLSI na rin.

 High-side switching means the MOSFET is operated on a high side or there's a high impedance between the source and the ground(opposite: low side, source is connected to ground)

Usually the problem appears when the gate drive voltage is equal to the drain voltage with respect to ground (or (Vg - Vd)  < Vth).
Remember that there's a requied Vgs voltage(Vth) to fully turn on the MOSFET.

Let's have an example, ang gate drive voltage is 12V, supply ng buck is 12V, Vth required is 5V,
Before mag-turn on ang FET sa buck usually ang diode ay nakaforward bias, so may drop yun na -0.7 wrt ground.
Magsusupply ng 12V ang gate drive and syempre magtuturn-on ang FET because Vgs = 12-0.7 > Vth (5V),

but what happens if nagturn-on na ang FET? Drain would be shorted to Source and Vd would be equal to Vs wrt Ground.
At this point hindi na nasatisfy yung condition para magturn-on ang FET kasi Vgs would be equal to 0 that is < Vth.

Sa high side switching hindi marereach ang turn-on condition dahil magstop na magincrease bias the moment na Vgs becomes < Vth.

May mga technique para makapagswitch sa high side, (search nyo sa net ibat-ibang ways para dito)



nice bro!. point 4 u. thnks 4 starting this thread. ;) ;) ;)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on June 15, 2010, 07:29:44 AM
Sir meron ako powered sub na gumamit ng smps. Ang problem is walang output voltage (+)13.5, (-)13.5vdc .. Nacheck ko na yung mosfet (irf740) good naman sya. Nacheck ko na rin yun ibang passive parts like diodes and resistors, ok naman din. May nasukat ako 328vdc after ng bridge diode. Posible kaya na yun pwm controller (uc3842) ang sira? May nasukat nga pala ako na 12vdc sa pin7 at pin5. Pwede ko po ba i-post dito yung diagram? pano po? TIA

sige pakipost ng diagram
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Vhelt on June 15, 2010, 08:16:05 AM
Ah salamat sir Glunix kahit paano may idea na ko sa trouble n un...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on June 15, 2010, 08:23:18 AM
Ah salamat sir Glunix kahit paano may idea na ko sa trouble n un...

isang cause din ng saturation eh over current. hindi mo napupuna may sira palang pyesa na sinusuplyan ang power supply na maaring nagdodraw ng mas mataas na current kaysa sa rating nito.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on June 15, 2010, 09:19:50 AM
Sir meron ako powered sub na gumamit ng smps. Ang problem is walang output voltage (+)13.5, (-)13.5vdc .. Nacheck ko na yung mosfet (irf740) good naman sya. Nacheck ko na rin yun ibang passive parts like diodes and resistors, ok naman din. May nasukat ako 328vdc after ng bridge diode. Posible kaya na yun pwm controller (uc3842) ang sira? May nasukat nga pala ako na 12vdc sa pin7 at pin5. Pwede ko po ba i-post dito yung diagram? pano po? TIA

Baka sir glutnix bumigay lang startup resistor po nito. Range neto karaniwan 56kohms on 110VAC and 110kohms for 220VAC supply.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on June 15, 2010, 09:51:18 AM
Sir meron ako powered sub na gumamit ng smps. Ang problem is walang output voltage (+)13.5, (-)13.5vdc .. Nacheck ko na yung mosfet (irf740) good naman sya. Nacheck ko na rin yun ibang passive parts like diodes and resistors, ok naman din. May nasukat ako 328vdc after ng bridge diode. Posible kaya na yun pwm controller (uc3842) ang sira? May nasukat nga pala ako na 12vdc sa pin7 at pin5. Pwede ko po ba i-post dito yung diagram? pano po? TIA

wow 3842 pala gamit mo, kahit nakapikit ako kabisado ko circuit nyan,si icefire at yus kabisado rin siguro, hehehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: chadex on June 15, 2010, 10:06:05 AM
sir eto yung diagram. Pahelp sa problem ah ???


(http://i997.photobucket.com/albums/af95/caro81/SMPS%20DIAGRAM/LINEFILTERBOARD.jpg)


(http://i997.photobucket.com/albums/af95/caro81/SMPS%20DIAGRAM/POWERSUPPLY1of2.jpg)


(http://i997.photobucket.com/albums/af95/caro81/SMPS%20DIAGRAM/POWERSUPPLY2of2.jpg)

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: chadex on June 15, 2010, 10:14:18 AM
nahihilo na ko sa pag troubleshoot.. :( Kelangan na tulong ng mga Masters
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on June 15, 2010, 11:14:22 AM
sir eto yung diagram. Pahelp sa problem ah ???


(http://i997.photobucket.com/albums/af95/caro81/SMPS%20DIAGRAM/LINEFILTERBOARD.jpg)


(http://i997.photobucket.com/albums/af95/caro81/SMPS%20DIAGRAM/POWERSUPPLY1of2.jpg)


(http://i997.photobucket.com/albums/af95/caro81/SMPS%20DIAGRAM/POWERSUPPLY2of2.jpg)



wala ako makita, nakablock kasi dito sa office, hehehe

try nyo master dito upload...
http://www.mypixelspace.net/ (http://www.mypixelspace.net/)

pwede nyo matest ang UC3842 kung ok by doing a back driving, supplyan nyo lang ang IC from an external DC source(around 15V).

Then ishort nyo Isense(pin3) at Vfb(Pin2) to ground. Sa output pin(pin10), May masusukat kayo voltage na slightly lower sa supply voltage nyo.

Kung may frequency counter kayo ang masusukat na freq ay 1.8/(Rt*Ct), check nyo datasheet.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on June 15, 2010, 01:17:45 PM
di ko rin makita sir yung pic,di ko parin alam kung flyback topology ang SMPS ni sir chadex,kalimitan pag flyback nasusunog yung Rsense resistor pag may nangyayaring trouble,isa pa baka sira din yung 3842 na IC kasi pag di na nya kaya yung stress.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Vhelt on June 15, 2010, 10:40:51 PM
Ok na ung monitor sir Glunix nakita ko na ung sira sa secondary along 80volts line to crt driver may shorted na 2 zener diode pagtangal ko nagtaka ako my hissing sound pa rin tapos walang dc voltage parang ac ung nareading sa tester un pla my leak ung ceramic cap na naka parallel sa diode ng ng 80volts pag tangal ko ok na nag karoon na ng dc 80volts pinalitan ko na ung zener ok na tahimik na ....Salamat sa tips sir God Bless......
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on June 15, 2010, 10:46:14 PM
Ok na ung monitor sir Glunix nakita ko na ung sira sa secondary along 80volts line to crt driver may shorted na 2 zener diode pagtangal ko nagtaka ako my hissing sound pa rin tapos walang dc voltage parang ac ung nareading sa tester un pla my leak ung ceramic cap na naka parallel sa diode ng ng 80volts pag tangal ko ok na nag karoon na ng dc 80volts pinalitan ko na ung zener ok na tahimik na ....Salamat sa tips sir God Bless......

ayun so over current ang dahilan ng hissing.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: chadex on June 15, 2010, 11:12:41 PM
sir glutnix at subzero bakit po kaya hindi nyo makita image? Mali po kaya pag upload ko ng images? sir glutnix na-upload ko na po sa mypixelspace

Try ko rin po gawin yun advice nyo sir. Update ko kung ano status hehe
Salamat mga master!
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on June 16, 2010, 07:07:49 AM
sir glutnix at subzero bakit po kaya hindi nyo makita image? Mali po kaya pag upload ko ng images? sir glutnix na-upload ko na po sa mypixelspace

Try ko rin po gawin yun advice nyo sir. Update ko kung ano status hehe
Salamat mga master!

tama pagupload mo, nakikita ko sa bahay eh, sa office lang hindi kasi maraming website dito ang nakablock including yung pinapostan mo na site. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Vhelt on June 16, 2010, 11:49:02 AM
sir Glutnix bumalik monitor ko bigla nalang daw nawala power pag check ko short uli ung 2 z diode sa 80v out at ung her rectifier ng matangal ko ung short na parts pag test ko bumalik uli hissing sound wala na po akong makitang problem sa secondary lahat ng rail may dc output. patulong uli sir aling part kaya ng circuit sa primary responsible d2 this design using 3824a ic but without optocoupler wala akong oscilloscope d2.....Tia..... 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on June 16, 2010, 12:46:05 PM
sir Glutnix bumalik monitor ko bigla nalang daw nawala power pag check ko short uli ung 2 z diode sa 80v out at ung her rectifier ng matangal ko ung short na parts pag test ko bumalik uli hissing sound wala na po akong makitang problem sa secondary lahat ng rail may dc output. patulong uli sir aling part kaya ng circuit sa primary responsible d2 this design using 3824a ic but without optocoupler wala akong oscilloscope d2.....Tia..... 

now that's interesting. Reason kaya ganun eh posibleng secondary failures lang ang sira na nakita mo, may ibang dahilan bakit nasisira yun na kailangan mo malaman.

may schematic ka or kahit picture nung ibabaw at ilalim ng board? Medyo nalito ako eh, hindi ko napuna dalawa pala kayo nagtatanong, hehehe.

dito mo na lang upload para nakikita ko.
http://www.mypixelspace.net/ (http://www.mypixelspace.net/)

yung sayo 3842 din ang pwm?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: / on June 16, 2010, 03:00:01 PM
subscribing....

basa mode..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: backspace on June 16, 2010, 04:58:49 PM
Alternator problem nga ang problema diyan.  Yung mga car audio enthusiast, when they install those high audio power amps, usually pinapalitan nila yung alternator ng car nila ng mas mataas ang power output.

one option is to install large capacitor ranging 1-2 Farad.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Vhelt on June 17, 2010, 07:06:17 PM
Sir Glutnix senxa na newbie lang hindi ko ma up load ni resize ko na jpeg naman file extention paano kya un.....
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Vhelt on June 19, 2010, 05:51:05 PM
Sir Glunix dahil sa di ko ma upload ung pixs nag troubleshoot nalang ako sa primary side parang ok naman my output ung pwm controller ic Ka3842 i measure it using my analog multimeter 10vac pumipitik ung meter pointer up to 3.7 vac  kya lang di ko alam kung mataas ung oscillation nun kaya naninira ng secondary diodes. Isa pa gusto ko po sana malaman anong function ng trimmer resistor dun kung anong inaadjust nun pa tulong naman sir...Tia....
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on June 19, 2010, 10:44:50 PM
Sir Glunix dahil sa di ko ma upload ung pixs nag troubleshoot nalang ako sa primary side parang ok naman my output ung pwm controller ic Ka3842 i measure it using my analog multimeter 10vac pumipitik ung meter pointer up to 3.7 vac  kya lang di ko alam kung mataas ung oscillation nun kaya naninira ng secondary diodes. Isa pa gusto ko po sana malaman anong function ng trimmer resistor dun kung anong inaadjust nun pa tulong naman sir...Tia....

upload mo lang dito http://www.mypixelspace.net/, (http://www.mypixelspace.net/,) then copy mo yung link na ibibigay sayo after maupload at paste mo sa post mo dito. piliin mo yung BB Code.

Dapat DC ginamit mo panukat dun sa output ng 3842. yung trimmer naman kung nasa secondary sya eh I would assume pangfine tune sya ng output voltage mo. Can't confirm lang hanggat di ko pa nakikita circuit.

Ang secondary ba eh multple output o single lang?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Vhelt on June 21, 2010, 03:47:31 PM
Try ko pumasok dun sa site na binigay mo sir kya lang 404 Not Found yan ung lumabas. regarding sa ginagawa ko ung trimmer nakalagay sa primary side then ung secondary out nya multiple 15.2v,7.2,13,50, at 80v output nya secondary..... Tia.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Vhelt on June 21, 2010, 03:53:00 PM
Try ko pumasok dun sa site na binigay mo sir kya lang 404 Not Found yan ung lumabas. regarding sa ginagawa ko ung trimmer nakalagay sa primary side then ung secondary out nya multiple 15.2v,7.2,13,50, at 80v output nya secondary..... Tia.
Ok na sir nakapasok na ko sa site na binigay mo enedit ko my comma lang pla sa dulo ..
sa imageshack ko na upload sir eto. (http://img535.imageshack.us/img535/2945/smps2.jpg)(http://img267.imageshack.us/img267/2382/smps1.jpg)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on June 21, 2010, 04:01:12 PM
Try ko pumasok dun sa site na binigay mo sir kya lang 404 Not Found yan ung lumabas. regarding sa ginagawa ko ung trimmer nakalagay sa primary side then ung secondary out nya multiple 15.2v,7.2,13,50, at 80v output nya secondary..... Tia.

ok abangan ko, pero baka bukas ko na mareview yan,babyahe pa ko pabalik manila ngayon eh.hehehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Vhelt on June 21, 2010, 04:24:35 PM
 
Ok na sir nakapasok na ko sa site na binigay mo enedit ko my comma lang pla sa dulo ..
sa imageshack ko na upload sir eto.  (http://img267.imageshack.us/img267/2382/smps1.jpg)
 (http://img36.imageshack.us/img36/1963/sdc10365u.jpg)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Vhelt on June 23, 2010, 01:03:39 PM
Sir Glutnix pasensya na po malabo ung picture at di ko xa na upload sa ibinigay mo na site. Sana kahit paano kapag my time ka ma review mo. Hirap na ko jan na check ko na halat ng resistor diode, ceramic,mylar at electrolytic caps nyan ok naman pinalitan ko nga ng same value voltage ung iba na meron ako. may hissing sound pa rin. sana matulungan mo ko sir Tia......
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on June 24, 2010, 09:27:18 PM
ang hirap naman makita pic

pano kaya kita matutulungan?hmmmm. ??? ??? ???

Kaya mo idraw schematic?

nagtataka ako sa zener sa 80V output. Ano zener ang ipinalit mo? at sa kung nasa output sya nakalagay less likely na short ang failure mode nya.

Disconnect mo yung power supply sa monitor. try mo tanggaling yung zener sa 80V output then measure mo voltage, try mo dahandahan iadjust yung trimmer then check mo kung nagbabago output.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 05, 2010, 02:07:25 PM
sir, itatanung ko lang po sana kiung saan pwede magstart mag troubleshoot ng PWMPS. May feedback po kasi ung PWM sa isang controller tapos d na d na natritrigger ung PWM dahil walang feedback mula dun sa controller niya. Bali ang looping niya eh, ac input ---> controller----> PWM---->coil ----> MOSFET ----> primary ng transformer -----> secondary ng transformer----> tapos ung high voltage out put na. May standby voltage nga pla ung PWM na 300V. tnx
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: kaizer on July 05, 2010, 02:33:18 PM
NOW SUBSCRIBING/...

mabasa nga ito sa vacant time=)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 05, 2010, 04:43:19 PM
Problem: PWMPS no output voltage. Hindi nakakapag trigger/ no output ung PWM.

Process: Input ACV ---> choke coil ---> filter coil ---> controller ---> PWM w/ standby voltage of 300V  (UC3825DW) ---> coil ---> MOSFET (W15NA50) ---> primary coil of the transformer ---> secondary coil of the transformer ---> MOSFET's --->  Output voltage.

Note: bali ung controller eh ung feedback ng PWM.

tnx.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 05, 2010, 04:52:59 PM
Master medyo nalito ako sa system mo kaya inaantay ko na lang ibang masters ang magreply, hehehe,

may tanong ako, may standby output ka? pero wala ka output? tama ba?

o yung tinutukoy nyo standby eh supply ng PWM IC? kasi kung 300V ang supply ng IC, naku tustado malamang yun.

Eto may sample circuit. Check nyo PDF page 8...
http://www.chipsinfo.com/TI/UC3825DW.htm (http://www.chipsinfo.com/TI/UC3825DW.htm)

Dun sa circuit, hindi lalampas ng 15V dapat ang supply ng IC.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on July 05, 2010, 05:27:57 PM
Patanong sir icarus08, meron ba itong diode(bridge) rectifier? Dito ba galing yung nasusukat mong 300V? Check mo kaya sir yung resistor sa supply nung IC uc3825 baka open or change value na.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 06, 2010, 08:02:25 AM
Sir glutnix, ung 300V po eh standby output po sir. bali iddrive po ng PWM ung 300V na un papunta sa coil ---> MOSFET's (2) ---> primary coil nung transformer. Eh ang nangyayari po eh hndi na naddrive ng PWM ung 300V para tumuloy sa coil papuntang MOSFET's to primary coil ng transformer. Kailangan kasi ng feedback mula dun a controller/motherboard nung PS.

tnx.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 06, 2010, 08:15:08 AM
sir jassharing, capacitor po ung nakkabit doon sa supply ng PWM.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 06, 2010, 08:15:38 AM
Actually ang PWM po dun eh yung IC lang so I think hindi sya tatanggap ng supply ng 300 kasi nga masisira sya, baka yung 300V eh supply ng DCDC converter.

try mo sukatan voltage sa supply pin mismo ng IC. Then sukatan mo na rin voltage sa output pin ng IC, yun yung papunta sa MOSFET.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 06, 2010, 08:17:06 AM
Tama boss, palagay ko natatawag nyo na PWM yung DCDC converter kaya tayo nagkakalituhan.

Ang PWM dun sa circuit eh yung IC lang.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 06, 2010, 08:35:33 AM
aw sorry po kung nalito kayo sir. yap ung PWM ung IC. huh huh huh ok sir kung ganun po ung nagyayari eh bakit po walang output voltage?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 06, 2010, 08:38:50 AM
Huh Huh Huh
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 06, 2010, 09:02:19 AM
so yun nga, dapat ang supply ng IC eh malapit lang sa 15V(absolute max is 30V), kung 300V yun  :o that explains why wala kang output ;D

I suggest mismong sa supply pin ka magmeasure ng voltage (pin15) then sukatan mo rin yung output kung ano voltage nila (Pin 11 and Pin 14)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 06, 2010, 11:07:13 AM
Sir, meronng Voltage supply ung PWM IC, kaso wala pong Voltage output ung PIN 11 at Pin 14. ano pong possible problem?

 tnx
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 06, 2010, 02:12:54 PM
OK that's good...

Ituturo ko ngayon sayo ang super secret art of "Back Driving". ;D ;D ;D

Setup...
1. ishort mo yung COMP at FB pin to ground. Gamit ka ng wires.
2. Try to desolder first the MOSFET
3. using a DC source, I set mo ang current limit to around 500mA and 15V
4. supplyan mo ngayon yung PWM IC, (wag mo isasaksak yung power source, DC source lang ang gagamitin at sa Vcc and Ground ng IC ka lang magsusuply.

Stage 1
1. kung nakikita mo na naglilimit yung current taasan mo ng bahagya at dahandahan ang current limit
2. kung may makita ka usok, nasira na ang IC mo,
3. pwede mo rin kapain ang IC para malaman kung nagiinit, kung mainit malamang eh nasira na ang IC mo
4. kung wala ka nakitang problema goto stage 2

Stage 2
1. Sukatan ng voltage yung mga output pins na tinutukoy ko, mas maganda kung may oscilloscope para makita kung may pulses at malaman anong frequency.
2. kung may voltage na malapit at mababa ng konte sa Vcc (15V), ibig sabihin good ang PWM at maaring nasa iba ang sira
3. kung walang output sira na ang IC.


Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 06, 2010, 03:02:47 PM
ok sir nagawa na namin.  hindi naman po uminit ung IC, hindi din naman po umusok hehe! tapos wala pa din pong sukat sa output pins ng PWM. Pinalitan na po namin ung PWM IC kaso ganun pa din po ung problem,

san pa po kaya ung possible cause ng problem kung bakit hindi gumagana ung PWM? Kung tama po ang aking naiisip eh, naghihintay po ng signal ung PWM para gumana.

tnx po ng madame. :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 06, 2010, 03:18:33 PM
yup, hinihintay nya yung voltage mula sa output papunta sa FB input ng IC.

kung mababa voltage lalake dapat duty cycle, kung mataas voltage liliit naman duty, ganung paraan nya nareregulate ang output voltage.

kaya ko ipinashort FB at COMP to ground eh para masimulate yung condition na masyadong mababa output voltage. so expect natin na tataas ng todo ang duty cycle hanggang maabot yung maximum.

BTW, DC voltage nga pala dapat ang susukatin nyo at di yung RMS

tinanggal nyo na yung FET sa circuit bako kayo magtest?ang inaalala ko kasi eh baka damaged din yung FET kaya wala kayo masukat sa output ng PWM.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 06, 2010, 03:53:36 PM
Aun sir hindi po namin natangal ung 2 MOSFET (sorry po). In circuit po ung ginawa naming testing kanina o kailangan off circuit po ung gagawin namin?

 Ano po pala ung COMP?. Ung feedback po ba ung from pin1 to pin7? ung error amp, oscillators at ung Ramp?

Ang connection po kasi ng PWM sa circuit eh pin6 and pin7 ay shorted connected to ground, pin5 connected to 13.3k resistor and connected to ground, pin 1 shorted to ground, pin2 ay connected sa coil, ung isang side ng coil eh connected na po sa MOSFET.

Kung tama po ung iniisip ko eh ung PWM input eh nagbabase siya sa out na ibibigay pagkatapos ng Soft Start? so kung hndi po mattrigger ng Soft Start ung mga input at wala pong lumabas na output eh continuous lang ung PWM na mag Soft Start so hindi gagana ung PWM.

sobrang tnx sir. :DD
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 06, 2010, 04:59:27 PM
kung di ako nagkakamali pin 3 E/A out is equivalent sa COMP(para sa 3842 na IC) pin na tinutukoy ko. FB ay pin 1 INV.

Quote
Kung tama po ung iniisip ko eh ung PWM input eh nagbabase siya sa out na ibibigay pagkatapos ng Soft Start? so kung hndi po mattrigger ng Soft Start ung mga input at wala pong lumabas na output eh continuous lang ung PWM na mag Soft Start so hindi gagana ung PWM.

yes partly correct, ang softstart ay nangyayari tuwing startup lang(unang beses nagpowerup yung chip at hindi pa fully charged ang capacitor at SS pin8).

protection ang softstart para maiwasan ang overshoot sa output during startup. ang ginagawa nito eh dahandahang inaangat ang duty cycle hanggang umabot sa max duty or hanggang magregulate na ang output.

pagfully charged na yung SS capacitor, expected natin eh max duty kung nakalow ang pin 1 and 3.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 07, 2010, 10:09:51 AM
Sir, ito na po yung mga data na nakuha namin gamit ang oscilloscope:

Pin 1: No Output Voltage
Pin 2: 5.16V
Pin 3: No Output Voltage
Pin 4: 4.76V
Pin 5: 3.08V
Pin 6: 2.92V with + triangle waveform
Pin 7: 2.92V with + triangle waveform
Pin 8: 5.40V
Pin 9: No Voltage Output
Pin 10: No Voltage Output
Pin 11: No Voltage Output
Pin 12: No Voltage Output
Pin 13: No Voltage Output
Pin 14: No Voltage Output
Pin 15: No Voltage Output
Pin 16: 5.16V

-yung back driving po na tinuro niyo yung ginamit naming method.

sorry po kung hindi na kami nakapag post/reply kahapon. Uwian na po kasi namin nun

tnx po na madami :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 07, 2010, 11:49:33 AM
Pin 1: Error Amp Inverting Input
(No Output Voltage) This is normal since ipinashort to ground ko tong input na to

Pin 2: Error Amp Non - Inverting Input
(5.16V) OK, Usually connected to Vref pin16

Pin 3: Error Amp Output/ Comp
(No Output Voltage)  This is normal since ipinashort to ground ko tong input na to

Pin 4: Clock
(4.76V) Output ng Oscillator with frequency based on Rt and Ct

Pin 5: Rt
(3.08V) OK

Pin 6: Ct
(2.92V with + triangle waveform) OK

Pin 7: Ramp Input (Rsense or Ct, probably Ct)
(2.92V with + triangle waveform) OK

Pin 8: Soft Start
(5.40V) OK

Pin 9: Shutdown/Ilim
(No Voltage Output) Active High OK

Pin 10: GND
(No Voltage Output) OK
Pin 11: OutA
(No Voltage Output) not OK

Pin 12: PGND
(No Voltage Output) OK

Pin 13: Vc
(No Voltage Output) Please connect to Vcc when backdriving

Pin 14: OutB
(No Voltage Output) not OK

Pin 15: Vcc
(No Voltage Output) I thought you supplied it with 15V already?

Pin 16: Vref
(5.16V) OK specs says it's 5.1V
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 07, 2010, 12:20:01 PM
Yes Sir may supply na po yan, sa oscilloscope po ang sabi eh pin connected to supply pero pag sinusukatan ko na po gamit ang Voltmeter 15V naman po.

Yung Vc lang po yung hindi ko nakakabit sa Vcc.

So sir san ko na po pwede tingnan kung bakit walang output yung PWM?

-tnx
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 07, 2010, 01:11:39 PM
Ok na po ung PWM IC sir. May output na pong lumabas at may Square Waveform na po.

San na po kaya may possible na sira ung power supply sir?

-tnx
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 07, 2010, 01:34:47 PM
ayos... yung Vc lang ang di napakabit kanina?
ayos ulet at may scope kayo ;D

check nyo ngayon yung FET na tinanggal nyo kung OK pa using continuity/resistance check.

next is kung kaya nyo supplyan ng voltage yung output using a DC source, supplyan nyo ng expected voltage nya then sukatan yung voltage at pin 1(make sure tanggal na pagkakashort ng Pin1 at pin3 before doing this)

next nito eh check nyo yung resistor na nasa baba ng mosfet kung ok pa.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 07, 2010, 04:22:39 PM
Sir ok naman yung mga MOSFET na tinangal namin bako mag back driving. Pati po yung mga resistor na nasa baba ng MOSFET.

Ang bago po naming ginawa ay yung nagsupply na kami ng AC source mismo sa Power Supply tpos eto po yung mga nakuha naming data/voltages using voltmeter sa PWM.

Pin 1: 0v
Pin 2: 5.06v
Pin 3: paiba iba yung voltages, 3.5v, 2.1v, 1.5v and 0 (yan po yung kadalasang kong nakikita)
Pin 4: hindi ko na po sinukat
Pin 5: hindi ko na po sinukat
Pin 6: hindi ko na po sinukat
Pin 7: may initialization voltage of 3.5v(blink lang po) tpos after noon eh 1.7v na lang po siya
Pin 8: paiba iba yung voltages 3.8v. 2.4v, 1.6v and 0v(yan po yung kadalasn kong nakikita)
Pin 9: hndi ko na po sinukat
Pin 10: ground
Pin 11: initially sir eh wla siyang Voltage pero pag tinaggal na naming yung plug eh dun nagkakaroon ng 2.5v tpos unti unting bababa yung voltage until mag 0v.
Pin 12: hindi ko na po sinukat
Pin 13: initially sir eh wla siyang Voltage pero pag tinaggal na naming yung plug eh dun nagkakaroon ng 2.5v tpos unti unting bababa yung voltage until mag 0v.
Pin 14: 15v
Pin 16: 5.1v
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 07, 2010, 04:54:57 PM
Quote
Pin 7: may initialization voltage of 3.5v(blink lang po) tpos after noon eh 1.7v na lang po siya
Pin 8: paiba iba yung voltages 3.8v. 2.4v, 1.6v and 0v(yan po yung kadalasn kong nakikita)

hindi ko pa masabi kung saan ang problema pero eto ang nakita ko abnormalities

sa pin7, pakicheck po kung sa rsense sya connected or sa Ct(sometimes may transistor pang kasama ito)

yung pin 8 ang normal na response nito eh magraramp lang hangang abutin yung vref, maganda kung makakapagprovide ka ng waveform.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 07, 2010, 04:58:50 PM
teka, tingin ko may pumapatay na signal na pumapasok sa pin9, maaring external protection circuit na may nadedetect na fault maaring yung primary current mismo ang pumapatay (rsense).

mas maganda kung makapagprovide ka schematic diagram at picture na rin nung power supply. nanghuhula lang kasi ako kung ano itsura ng design nyan and maaring iba sa nasa isip ko. ;D

kung current ang pumapatay sa power supply, pwedeng damaged ang FET or yung diode sa secondary or may short sa secondary side. wala kayong sound na naririnig pag binubuhay nyo PSU?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 07, 2010, 05:18:26 PM
Sir, sa Pin 7 nakaconnect po siya sa Pin 6(CT) pero wala pong nakaconnect na transistor at may nakaconnect na capacitor at may Thermostat na nakakabit din (AIRPAX 67F095P).

--> sa Pin 8 naman po eh wala pa po kaming mga waveforms, mga bukas na po namin ito maproprovide. uwian na po kasi.

Lahat po ng mga waveform na makukuha namin sa different pin ng PWM ay ipopost po namin sa inyo.

Sa ngayon po eh chinecheck po namin yung pinaka control board ng Power Supply. Ginagawa na po namin yung sinasabi niyong supplyan yung Output.

see you tomorrow sir.

thank you so much po ;D :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 07, 2010, 05:25:19 PM
kahit waveform ng pin 1,7,8,9 lang pwede na yun,

at saka 11 at 14 sa startup.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 07, 2010, 05:32:18 PM
Sir, yung pin 9 po ba ung rsense? ??? anu po ba un? ??? ;D

tapos po yun din po yung tingin namin na nangyayari, tingin din po namin may pumapatay din po dun sa signal. yung control board po yata yung sinasabi niyong external protection circuit. kung may pumapatay po doon sa signal na pumapasok sa pin 9, so sir maari pong sa mga papuntang input yung problem kaya hindi po nagkakaoutput? ???

bukas po try po naming ipost ung schematic..wehehe ;D ;D ;D

cge po sir, bukas na lang po ulit.. ;)

 -tnx po ulit
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 07, 2010, 05:34:22 PM
 ahh ok po sir , sige po bukas nalang po ,
 
uwi na po kasi kami hehe , thankyou so much ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 07, 2010, 05:43:23 PM
yung pin9 ang pangshutdown ng PWM pero maaring iconnect din sya sa Isense para patayin output kung sobrang taas na ng current.

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 08, 2010, 10:56:39 AM
sir ipapakita na po namin sa inyo yung waveforms ng PWM (supplied with DC source). Maya maya po eh ipapakita na po namin sa inyo yung waveform ng mga Pins ng PWM kapag may supply na po yung buong Power Supply.

-tnx
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 08, 2010, 11:31:44 AM
Sir, may naririnig po kaming sound after namin i-switch on yung PSU. Mga siguro after 1-2 sec. saka siya tumutunog, parang click siya na sobrang hina lang.

-tnx ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 08, 2010, 03:15:18 PM
Sir, si silent_clp na po ang magpopost ng Pictures ng waveform ng mga pins. Siya po yung kasam ko na gumagawa nitong PSU na ito

-tnx ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 08, 2010, 03:17:27 PM
ok abangan ko....
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: siLent_cLp on July 08, 2010, 03:50:45 PM
Sir, ako po yung kasama ni icarus08 sa pag-gawa ng PSU. Ito na po Yung mga waveform na nakuha namin sa PWM na may DC source po.

Pin 1:
(http://img101.imageshack.us/img101/7122/pin1pp.jpg) (http://img101.imageshack.us/i/pin1pp.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


Pin 7:
(http://img638.imageshack.us/img638/7913/pin7.jpg) (http://img638.imageshack.us/i/pin7.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


Pin 8:
(http://img149.imageshack.us/img149/1986/pin8.jpg) (http://img149.imageshack.us/i/pin8.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


Pin 9:
(http://img340.imageshack.us/img340/7743/pin9.jpg) (http://img340.imageshack.us/i/pin9.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)'


Pin 11 Start Up:
(http://img708.imageshack.us/img708/192/pin11startup.jpg) (http://img708.imageshack.us/i/pin11startup.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)



Pin 11:
(http://img413.imageshack.us/img413/3005/pin11.jpg) (http://img413.imageshack.us/i/pin11.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


Pin 14:
(http://img709.imageshack.us/img709/9065/pin14.jpg) (http://img709.imageshack.us/i/pin14.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


Pin 14 Shut Down:
(http://img534.imageshack.us/img534/8905/pin14shutdown.jpg) (http://img534.imageshack.us/i/pin14shutdown.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 08, 2010, 04:02:10 PM
yun lang, di ko makita,hehehe,

sige paguwi ko na lang tingnan to.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 08, 2010, 04:25:45 PM
Ipopost na din po namin sir yung waveforms ng PWM na may AC supply na yung buong PSU.

xenxa na po sir kung malaki po yung image ;D ;D ;D hindi po kasi kami alam kung pano iresize yung image sa ImageShack ;D

-tnx
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: siLent_cLp on July 08, 2010, 04:29:51 PM
ahehe, pasensia na po sir glutnix,
mejo malabo yung picture, hindi na po kasi masiadong naedit ;D

ahm, ayun po tinatry na po namin ung sinasabi niyo na suplayan yung mga output,
baka nga po ung sa control yung may tama,

 
yung sa naka AC supply po baka bukas na po namin ipost,

ayun sige po ty, :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: siLent_cLp on July 08, 2010, 05:12:18 PM
Sir ito na po yung Waveforms ng PWM kapag may AC Supply na po yung PSU.

Note: Yung Pin 8, Pin 9, Pin 11 and Pin 14 po eh merong parang Start up na waveform/pulse lang na sobrang bilis(mga .5 second lang siyang lumabas) tapos bigla na pong nawala.

Pin 1:
(http://img41.imageshack.us/img41/4383/pin14ac.jpg) (http://img41.imageshack.us/i/pin14ac.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


Pin 7:
(http://img824.imageshack.us/img824/6648/pin1ac.jpg) (http://img824.imageshack.us/i/pin1ac.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


Pin 8:
(http://img180.imageshack.us/img180/3626/pin7ac.jpg) (http://img180.imageshack.us/i/pin7ac.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


Pin 9:
(http://img638.imageshack.us/img638/5476/pin8ac.jpg) (http://img638.imageshack.us/i/pin8ac.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


Pin 11:
(http://img815.imageshack.us/img815/7165/pin9ac.jpg) (http://img815.imageshack.us/i/pin9ac.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


Pin 14:
(http://img823.imageshack.us/img823/337/pin11ac.jpg) (http://img823.imageshack.us/i/pin11ac.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

ayun po TY ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 08, 2010, 05:37:13 PM
Sir, iinform ka na lang po namin bukas  kung ano na pong nagyari doon sa pinapagawa niyo sa amin na lagyan ng supply yung output at i-trace kung saan na po mawawala yung signal.

Ipoprove na din po namin yung schematic diagram bukas, kasama na po yung mga data (voltages and waveforms).

sige po sir uwian na po namin ni silent_clp. bukas na lang po sir.

sobrang salamat po sir ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 09, 2010, 09:11:08 AM
Sis, ito na po yung Schematic diagram ng PSU namin.

(http://img191.imageshack.us/img191/5121/schematicdiagramtiboard.png) (http://img191.imageshack.us/i/schematicdiagramtiboard.png/)

Uploaded with ImageShack.us (http://imageshack.us)

-tnx ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 09, 2010, 09:26:13 AM
Sorry di ko na natingnan sa bahay kanina, tumba na ako pagkauwi ko mga 11pm,hehehe,

mamaya na lang siguro.

hindi ko kasi makita dito sa office...

paupload na lang siguro ng schematic dito...

http://www.mypixelspace.net/ (http://www.mypixelspace.net/)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 09, 2010, 09:42:32 AM
http://www.mypixelspace.net/imgs/img01/CZxZL4CiOP.bmp (http://www.mypixelspace.net/imgs/img01/CZxZL4CiOP.bmp)

 (http://mypixelspace.net/imgs/img01/CZxZL4CiOP.bmp) (http://www.mypixelspace.net/)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 09, 2010, 09:45:28 AM
Sis, ito na po yung schematic diagram nung PSU.

ah sis, sa mypixelspace na din lang po ba iuupload yung mga pictures ng wavveform?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 09, 2010, 10:01:53 AM
maski wag na muna. aralin ko muna yung schematic nyo.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 09, 2010, 10:03:23 AM
ok sis. antayin ka po namin ;D ;D ;D hahaha

sobrang Tnx po ng madami ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 09, 2010, 10:13:09 AM
open loop pala kayo, meaning walang knowledge(walang connection) yung PWM sa value ng output voltage,

nagpoproduce sya ng constant duty cycle na pulses regardless kung ano value ng output voltage mo. So dapat pag sinuplyan mo yung power supply eh may pulses ka na makikita sa outputA. Meron nga ba?

ang gagawin mo na lang eh itrace bakit hindi dumideretso sa FETs yung pulses. Push-Pull nga pala yung topology ng SMPS mo.

Di bale malalaman ko yan pagnakita ko waveforms.

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 09, 2010, 10:47:20 AM
sis, wala po kaming nakikitang waveform/pulses sa outputA kapag may supply na po yung PSU ng AC source. so sis ittrace po namin yung mga dinaanan ng Output A to FET?

 sis, tama po ba yung iniisip ko? so sis kung open loop siya eh walang connection yung PWM ko sa Output Voltage ng SMPS ko? at wala din pong feedbacks yung PWM Outputs ko sa input ng PWM ko na para gumana siya or hindi gumana?

 tsaka po pala, irerepost po ba namin yung mga picturs ng waveforms ng PWM kapag DC source yung supply sa PWM mismo at yung Waveforms ng PWM kapag may AC Supply na yung PSU?

-tnx sis
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 09, 2010, 11:02:54 AM
tama yun though designed talaga sya na ganun, parang engot yung PWM na pulse lang na pulse.

regarding PICs kung kailangan nyo masolve yan pakirepost, kung di naman kayo nagmamadali eh sa bahay ko na lang titingnan yan mamaya paguwi ko.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: siLent_cLp on July 09, 2010, 12:21:57 PM
Sir glutnix,

sige po try namin gawan nang paraan yung mga PICs..
di naman po kami nagmamadali ,hehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Macgyver on July 09, 2010, 12:51:02 PM
@icarus08 - kung gusto nyo paliitin yung photos, pwede itong free software http://www.faststone.org/FSResizerDetail.htm (http://www.faststone.org/FSResizerDetail.htm)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 09, 2010, 01:23:09 PM
thanks sir mcguyver kailangan ko rin nito, pogi point :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 09, 2010, 02:05:58 PM
@Sir mcgyver: maraming salamat po sir ;D

@Sis glutnix_neo: irerepost ko na po sis yung mga pics ng waveforms ng PWM sa AC at DC supply

(panu nga po pala nagkakaroon ng pogi/ganda points? at para saan po yun?)

-tnx so much ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 09, 2010, 02:24:15 PM
Sis glutnix, ito na po yung waveform ng PWM kapag may AC Supplyy na yung PSU. ;D



PIN 1:

(http://img594.imageshack.us/img594/6648/pin1ac.jpg) (http://img594.imageshack.us/i/pin1ac.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


PIN 7:

(http://img249.imageshack.us/img249/3626/pin7ac.jpg) (http://img249.imageshack.us/i/pin7ac.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


PIN 8:

(http://img266.imageshack.us/img266/5476/pin8ac.jpg) (http://img266.imageshack.us/i/pin8ac.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


PIN 9:

(http://img638.imageshack.us/img638/7165/pin9ac.jpg) (http://img638.imageshack.us/i/pin9ac.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


PIN 11:

(http://img251.imageshack.us/img251/337/pin11ac.jpg) (http://img251.imageshack.us/i/pin11ac.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


PIN 14:

(http://img580.imageshack.us/img580/4383/pin14ac.jpg) (http://img580.imageshack.us/i/pin14ac.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 09, 2010, 02:34:07 PM
Sis glutnix, ito na po yung waveforms ng PWM kapag may DC source po mismo sa Vcc at GND yung PWM.

PIN 1:

(http://img4.imageshack.us/img4/165/pin1n.jpg) (http://img4.imageshack.us/i/pin1n.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


PIN 7:

(http://img704.imageshack.us/img704/4617/pin7q.jpg) (http://img704.imageshack.us/i/pin7q.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


PIN 8:

(http://img715.imageshack.us/img715/1986/pin8.jpg) (http://img715.imageshack.us/i/pin8.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


PIN 9:

(http://img189.imageshack.us/img189/7743/pin9.jpg) (http://img189.imageshack.us/i/pin9.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


PIN 11 Startup:

(http://img594.imageshack.us/img594/192/pin11startup.jpg) (http://img594.imageshack.us/i/pin11startup.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


PIN 11:

(http://img341.imageshack.us/img341/8623/pin11i.jpg) (http://img341.imageshack.us/i/pin11i.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)


PIN 14 Shutdown:

(http://img97.imageshack.us/img97/8905/pin14shutdown.jpg) (http://img97.imageshack.us/i/pin14shutdown.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)



PIN 14:

(http://img294.imageshack.us/img294/9065/pin14.jpg) (http://img294.imageshack.us/i/pin14.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 09, 2010, 08:57:32 PM
Hmmm, OK, therfore I conclude gumagana naman ang PWM mo,

Pero pag AC wala sya pulse which is weird,

Napuna ko walang voltage yung pin8(Soft Start) pag supplied ng AC, isa lang ang magcocause nun,

malamang nakahigh above 1.4V ang pin9 mo.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 09, 2010, 09:01:02 PM
kung nakahigh ang pin9, isa lang ibig sabihin nun, hindi kumpleto yung schematic kasi wala yung circuit na nagcocontrol ng pin9  ;D ;D ;D

pwede rin palang yung Vcc is above 9V. check mo master kung may vref ka, nawawala kasi vref pag di tama ang supply
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 12, 2010, 08:16:16 AM
Sis, meron naman po kaming Vref n 5.1V
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 12, 2010, 09:02:41 AM
Sis, wala din po kaming nakukuhang voltage sa Pin 9 (I limit).
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 12, 2010, 09:08:47 AM
Sis, wala din po kaming nakukuhang voltage sa Pin 9 (I limit).

which is normal, hmmm, saan kaya problema nyan, normal naman lahat...

oakicheck naman po ng pin sa Vc(iba to sa Vcc), eto yung nagsusupply sa gatedrive circuit.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 12, 2010, 09:43:07 AM
Sis, may voltage naman po yung Vc namin 15.4V which is kapareho nung voltage ng Vcc namin. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 12, 2010, 10:03:21 AM
kumakamot na ako ngayon sa ulo, hehehe, review ko mga waveforms nyo,  ;D

compare nyo rin anong pinagkaiba ng conditions na powerup from AC againts dun sa backdriving nyo bakit walang pulse ngayon.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 12, 2010, 10:24:50 AM
Sir, send ko lahat ng files. penge po ng YM account nio sir ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 12, 2010, 10:29:58 AM
glutnix_neo sa yahu, nakablock din nga pala yahu dito,
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 12, 2010, 10:56:54 AM
sir glutnix, na add ko na po kau sa YM
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 12, 2010, 05:11:21 PM
sis, nasend ko na po sa mail niyo (glutnix_neo at yahu). ah sis pede po ba namin hingin yung YM account niyo para po sa mga private conversations about sa PSU.

 tnx ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 12, 2010, 05:33:01 PM
yan na rin ym ko, ang problema nga lang eh nakablock nga yahu dito.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 13, 2010, 09:06:46 AM
Sis, nakita niyo na po ba yung mga files na nasend ko po sa inyo?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 13, 2010, 09:19:16 AM
hindi pa, ano balita? naikumpara nyo yung difference ng back drive at yung supplied ng AC?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 13, 2010, 10:25:29 AM
Ayun po sis, kinukumpleto po namin yung schematic nung buong PS, tsaka pano pong icompare yung back driving sa AC Supplied? yung PWM waveforms at voltages po ba?  Tinatry din poi namin itrace kung bakit nawala yung papasok na signal papuntang PWM.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 13, 2010, 10:37:54 AM
Ayun po sis, kinukumpleto po namin yung schematic nung buong PS, tsaka pano pong icompare yung back driving sa AC Supplied? yung PWM waveforms at voltages po ba?  Tinatry din poi namin itrace kung bakit nawala yung papasok na signal papuntang PWM.

yup, waveforms and voltages
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 13, 2010, 11:57:00 AM
ok sis icocompare na po namin ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 13, 2010, 12:55:37 PM
kumpleto ba 'yung schematic na posted? open loop talaga? saan ba 'to ('yung PSU) nakakabit? ano gamit nung SW1? kapag nag-close kasi 'yun mamamatay talaga 'yung PWM niyo (connected to gorund 'yung soft start capacitor).

Note: Yung Pin 8, Pin 9, Pin 11 and Pin 14 po eh merong parang Start up na waveform/pulse lang na sobrang bilis(mga .5 second lang siyang lumabas) tapos bigla na pong nawala.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on July 13, 2010, 01:15:25 PM
how do you compute for the output capacitance of a buck converter?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on July 13, 2010, 01:19:08 PM
kumpleto ba 'yung schematic na posted? open loop talaga? saan ba 'to ('yung PSU) nakakabit? ano gamit nung SW1? kapag nag-close kasi 'yun mamamatay talaga 'yung PWM niyo (connected to gorund 'yung soft start capacitor).

Note: Yung Pin 8, Pin 9, Pin 11 and Pin 14 po eh merong parang Start up na waveform/pulse lang na sobrang bilis(mga .5 second lang siyang lumabas) tapos bigla na pong nawala.

minsan ginagamit yung softstart pin pag may fault na nangyayari(OCP,OVP,OTP depende kung anung fault)pag na ground(switch to ground) mamamatay na yung PWM para housekeeping or protection circuit nya.nilalagyan din ito ng delay(RC circuit) para di naman abrupt yung start-up ng PWM circuit.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 13, 2010, 01:33:26 PM
^ based kasi sa schem sis, merong switch to ground sa SS, then kapag may supply na (AC), sisindi sandali at mamamatay.

nakakita na ako ng similar dito, open loop para sa DC-AC then may pressure switch na pumapatay sa DC-DC stage. gamit siya sa dehydrator ng fiber optic cables. ang may problem talaga 'yung glue logic, hindi 'yung PWM stage.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 13, 2010, 01:33:59 PM
kumpleto ba 'yung schematic na posted? [/i]

hindi po sis. kinukumpleto pa po namin.

open loop talaga? s[/i]

ayun po ang sabi ni sis gutnix sa amin.

saan ba 'to ('yung PSU) nakakabit? [/i]

sa original po niyang PSU. part lang po kasi ng original PSU yung schematic na pinakita namin.

ano gamit nung SW1? kapag nag-close kasi 'yun mamamatay talaga 'yung PWM niyo (connected to gorund 'yung soft start capacitor).[/i]

thermostat po yung SW1.


Note: Yung Pin 8, Pin 9, Pin 11 and Pin 14 po eh merong parang Start up na waveform/pulse lang na sobrang bilis(mga .5 second lang siyang lumabas) tapos bigla na pong nawala.

Pin 8; different voltages po yung nakukuha namin, 3.8V 2.4V 1.6V .87V 0V
Pin 9: no Vout
Pin 11 & 14: initially, wala pong Vout. pero pag tinanggal na po namin yung AC source eh magkakaroon po ng 2.5V tpos unti unting bababa hangang sa mag 0V

tnx sis rdpzycho ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on July 13, 2010, 01:39:54 PM
how do you compute for the output capacitance of a buck converter?

it depends upon the ripple voltage you want in the output.the ESR of the output cap contributes ripple voltage in the output.link below might be help you.

http://focus.ti.com/lit/an/slva057/slva057.pdf (http://focus.ti.com/lit/an/slva057/slva057.pdf)

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 13, 2010, 01:41:22 PM
@icarus08: check niyo 'yung condition ng SW1 kapag sinindi niyo. posibleng hindi PWM ang problem niyo. kapag 'di kasi sumasagad sa Vcc 'yung SS pin ( pin 8 ), merong ibang pinupuntahan 'yung constant current sa kanya. kung papansinin niyo kasi sa block diagram nung UC3825, kapag low voltage ang pin 8, ma-inhibit 'yung error amp, na papatayin din 'yung buong PWM circuitry.

pwede niyong subukang kalasin 'yung SW1 at tignan kung aandar na siya. bale 'yung SW1 ang talagang feedback nung system na kinakabitan nito, controlling maximum pulse width by varying voltage sa SS.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 13, 2010, 01:50:20 PM
napakalaki po kasi nung power supply pra ma ischematic lahat sir,
ayun nirerevise lng po namin yung shematic nun, hehe sariling sikap lang po kami eh hahahaha ;D ;D ;D

minsan ginagamit yung softstart pin pag may fault na nangyayari(OCP,OVP,OTP depende kung anung fault)pag na ground(switch to ground) mamamatay na yung PWM para housekeeping or protection circuit nya.nilalagyan din ito ng delay(RC circuit) para di naman abrupt yung start-up ng PWM circuit.


ayun sis, yung SW1 is used as OTP. (thermostat)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on July 13, 2010, 01:52:08 PM
.... part lang po kasi ng original PSU yung schematic na pinakita namin.
....
i-torture nyo na lang si frank para ibigay na sa inyo yung buong schematic.. ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 13, 2010, 01:55:44 PM
oo nga,pinapahirapan kayo, hehehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: updated on July 13, 2010, 02:18:49 PM
ayoko sana sumali, kaso bistado na ako. alam n din nila account ko. pinapahirapan nga sila. kasi yung mahirap ng board yan. tapos yung ginagawa ko yung madali lang. :)

@ate yuri, ang ganda mo daw, mahal ka na ni icarus
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 13, 2010, 02:37:27 PM
mga sis, ok naman po yug SW1 (AIRPAX thermostat).

@rdpzycho: pwede po ba namin tangalin yung SW1 tpos susupplayan yung PSU? ??? ???? ???

@mga sis: so malaki pong possibility na may umiipit ng signal papuntang Pin 8 (SS) kaya hindi po nagloloop?

-tnx ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 13, 2010, 02:44:39 PM
pwede mong gawin 'yun, kung alam mo 'yung consequences na pwedeng mangyari. ;)

somewhere sa area ng pin 8 at pin 9 ang pwedeng i-check since may problem 'yung startup.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 13, 2010, 02:54:55 PM
mga sis, ok naman po yug SW1 (AIRPAX thermostat).

@rdpzycho: pwede po ba namin tangalin yung SW1 tpos susupplayan yung PSU? ??? ???? ???

@mga sis: so malaki pong possibility na may umiipit ng signal papuntang Pin 8 (SS) kaya hindi po nagloloop?

-tnx ;D ;D ;D

dalawa nakikita ko pwedeng pumatay SS or yung Ilim, mas maganda nga makita ng complete yung circuit.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 13, 2010, 03:06:37 PM
@rdpzycho: ok po check po namin lahat ng mga pinaggalingan ng Pin 8 at Pin 9.

@sir glutnyx: isesend ko po ulit sa inyo yung updated na schematic namin. mejo buo na po kasi schematic ng PSU. (mejo private daw po yung schematic ng PSU kaya wag daw po namin ipost dito sis)

-tnx ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 13, 2010, 03:08:36 PM
@rdpzycho: ok po check po namin lahat ng mga pinaggalingan ng Pin 8 at Pin 9.

@sir glutnyx: isesend ko po ulit sa inyo yung updated na schematic namin. mejo buo na po kasi schematic ng PSU. (mejo private daw po yung schematic ng PSU kaya wag daw po namin ipost dito sis)

-tnx ;D

ok no probs
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 13, 2010, 03:13:18 PM
may nakita po kaming parang fault sa control board ng PSU, walang Vcc yung Load share controller IC ( UC3902). may effect din po kaya yun?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 13, 2010, 05:36:05 PM
sir glutnix, bukas ko na po isesend yung 3/4 schematic ng PSU. Sorry po kung ngayon ko lang nasabi, kala ko po kasi eh matatapos ko ;D ;D ;D pasensya na po :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: pEN DoTA on July 13, 2010, 08:41:00 PM
hello po sa lahat. this is regarding smps ng dvd player. napansin ko  "no disc na ung display nya. when i checked madaling uminit ung heatsink ng mother IC, at meron +8, -8 and +5, -5 volts sa power supply section. during voltage testing ok nman ung 5V pero ung 8V , 10V ang nakuha kong voltage. sa tingin nyo ito kaya ang dahilan?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 14, 2010, 07:29:05 AM
tingin ko unregulated yung 8V nyo, kaya 10V ang nasukat nyo kase wala pa syang load, try nyo loadan ng kahit konte lang, observe nyo kung bababa. Normal pag ganito.




Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: pEN DoTA on July 14, 2010, 07:52:07 PM
tingin ko unregulated yung 8V nyo, kaya 10V ang nasukat nyo kase wala pa syang load, try nyo loadan ng kahit konte lang, observe nyo kung bababa. Normal pag ganito.





master neo, pag may load po ehh umabot sa 12V. ok lng po ba to? ung malaking IC madaling uminit. at ung cd tray nya mabilis namang umikot pero ung disc na e load hindi nya madala  sa pag ikot, so no reading ang labas.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pangasinan boy on July 14, 2010, 08:20:05 PM
hello po sa lahat. this is regarding smps ng dvd player. napansin ko  "no disc na ung display nya. when i checked madaling uminit ung heatsink ng mother IC, at meron +8, -8 and +5, -5 volts sa power supply section. during voltage testing ok nman ung 5V pero ung 8V , 10V ang nakuha kong voltage. sa tingin nyo ito kaya ang dahilan?

hello pedot!
china made ba yang repair mo?
minsan kasi iba ang nakalagay na voltage value sa board
mostly 5 volts at split 12v sir
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: / on July 14, 2010, 09:32:27 PM
diba pag niload mo ang cd sa player minamagnet nya eto pataas para sumama sa pag ikot?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 14, 2010, 10:49:38 PM
kung 5V ang regulated, mapupuna mo na habang tinataasan mo load sa 5V tataas ang voltage sa 8V.

nung niloadan mo ang 8V malamang may load din 5V kaya tumataas ang voltage instead na iniexpect natin na bumaba.

Yung paginit I think is normal din lalo na kung may metal tab yung IC na tinutukoy nyo.

malamang ang sira eh hindi madala sa pagikot yung disk?hindi ko lang maimagine  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 15, 2010, 08:32:03 AM
yung DVD player ko din ganyan. NO DISC lagi ang laging indication niya. Hindi ko po alam kung bakit ganun pero may nbapansin lang ako nung binuksan ko yaung player, pag ka on nung DVD eh iikot saglit yung Module na nagpapaikot sa CD tpos biglang titigil (NORMAL po kaya yun) tpos No DISC na siya.

san po kaya problem nun sis glutnix.


oo nga po pla sis glutbix. isesend ko na po ngaun sa inyo yung schematic ng PSU namin. 80% na po siyang buo.

-tnx ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 15, 2010, 08:54:43 AM
ok great, tingnan ko mamaya sa bahay...

naku hindi po ako expert sa mga player, SMPS lang alam ko and I think ok naman PSU ni kuya pedot.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 15, 2010, 09:11:54 AM
ok sis tnx ;D ;D ;D

hahahaha XD ok lang po yun sis ;D kala ko po kasi pareho kami problema ni sis pedot :D :D :D

-tnx ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 15, 2010, 01:42:50 PM
nasend ko na po sis glutnix yung 80% nung PSU pati po yung mga pictures  ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: pEN DoTA on July 15, 2010, 02:00:54 PM
kung 5V ang regulated, mapupuna mo na habang tinataasan mo load sa 5V tataas ang voltage sa 8V.

nung niloadan mo ang 8V malamang may load din 5V kaya tumataas ang voltage instead na iniexpect natin na bumaba.

Yung paginit I think is normal din lalo na kung may metal tab yung IC na tinutukoy nyo.

malamang ang sira eh hindi madala sa pagikot yung disk?hindi ko lang maimagine  ;D


thnks master gluttix_neo, parang good yata ung smps ko. ang problema ay ung disc. kasi po hindi nya madala ung cd na e loload sa pag ikot, napansin ko ung pag ikot nya pero ung cd hindi nya madala sa pag ikot until it reads no disc. ???
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 15, 2010, 02:03:38 PM
or yung pinagkakabitan ng disk, hindi kumakapit.

may mga belt pa ba yan?baka naman yung belt ang maluwag na?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: pEN DoTA on July 15, 2010, 02:47:07 PM
or yung pinagkakabitan ng disk, hindi kumakapit.

may mga belt pa ba yan?baka naman yung belt ang maluwag na?


ahhh oo nga. thanks master i will try pag uwi ko. pogi for u master. :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 15, 2010, 02:53:16 PM
ganyan palagi problema nung vintage sony walkman ko eh,  :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 16, 2010, 08:14:38 AM
sis glutnix, nakita niyo na po yung mga pictures at yung schematic diagram ng PSU?


-tnx
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 16, 2010, 08:25:40 AM
hindi pa po, late na ako nakauwi kagabi at medyo mabagal ang smartbro ko sa bahay ngayon.

baka sabado ko na matingnan yun.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 16, 2010, 08:42:18 AM
ah ok po sis hahahaha ;D oo nga po pala, pasensya na po kung nakakaabala na po kami sa inyo at sobrang thank you po sa lahat ng tulong niyo ;D ;D ;D

-tnx ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 16, 2010, 08:47:34 AM
ok lang, isa pang dahilan eh nawili ako sa pagpapalipad nung bagong RC helli ko, ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: hardcore misery on July 16, 2010, 08:24:41 PM
Sir Glutnix, pasilip naman nitong problema ko, hehe http://www.electronicslab.ph/forum/index.php/topic,18703.0.html (http://www.electronicslab.ph/forum/index.php/topic,18703.0.html)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 20, 2010, 02:19:39 PM
sir, natanggap niyo na po yng mga Files?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 20, 2010, 02:26:11 PM
Sir may bago po kaming observation. May unexplainable na waveform yung Soft Start. nstable po ying waveform nia tpos parang sine wave na nagpupumilit mag modulate.

-tnx sir ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 20, 2010, 02:55:42 PM
Sir may bago po kaming observation. May unexplainable na waveform yung Soft Start. nstable po ying waveform nia tpos parang sine wave na nagpupumilit mag modulate.

-tnx sir ;D

hindi ko pa rin naview files mo, sobra bagal ng internet sa bahay ngayon. so clue na yan n may pumapatay
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 20, 2010, 02:59:02 PM
so sir pwede pong may nasesense siyang over current sa Pin 9 which is Ilimit?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 20, 2010, 03:04:31 PM
so sir pwede pong may nasesense siyang over current sa Pin 9 which is Ilimit?

yes, very possible, at kung nangyayari nga ito, MOSFET or transformer ang sira nun, try nyo kaya palitan pansamantala ang lahat ng MOSFET, then powerup nyo, be sure walang load.

palitan nyo na rin yung sense resistor
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: updated on July 20, 2010, 03:51:53 PM
mukang meron problem ang transformer nyo. palagay ko yung gumagawa na ang may sira.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 20, 2010, 03:59:43 PM
Opo sir, ang layo ng inductance nila yung isa uH lang tpos yung isa eh mH na po ;D hahahah oo nga sir eh baka sa gumagawa na yan XD

-tnx ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Yo on July 20, 2010, 04:13:24 PM
ung transformer naayos!! ang kaso eh ung gumagawa kya maayos!!?
^^
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: siLent_cLp on July 20, 2010, 04:36:15 PM
Sa tingin ko nga din po yung gumagawa na talagayung may sira..haha! 8)



Ayun, Sir Glutnix, may npansin pa po kami, nagkaron po bigla nang noise yung dun sa transformer,
Tapos po mei isang part po dun sa transformer, anlayo po nung nasukat namin na inductance
kumpara dun sa isang Transformer, dalawang units po kasi yun.. parehas nang sira..


Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 20, 2010, 05:29:42 PM
hehehe,
a small crack sa core ng transformer would render it useless. kung uH na lang ang nasusukat saturation ang possible cause ng overcurrent na pumapatay naman ng PWM.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: updated on July 20, 2010, 08:23:03 PM
sir, yung mga yan naimpluwensyahan ko ng mag member. :)

@ icarus, post mo yung inductance na nasukat mo, para makita din ni master. palagay ko kapag nasolve nyo ang problem nyan madadalian na kau sa ibang powersupply na irerepair nyo :o :o :o
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: siLent_cLp on July 21, 2010, 08:50:44 AM
Sir glutnix,

eto na po yung mga inductance values na nasukat namin sa mga pins nung transformer,

Unit1-

pin1: 2.3uH
pin2: 2.5uH
pin3: 3.9uH
pin4: 3.9uH
pin5: 5.1mH
pin6: 5.1mH


unit2-

pin1: 2.3uH
pin2: 2.3uH
pin3: 3.1uH
pin4: 3.6uH
pin5: 298uH
pin6: 283uH

....


ttry po naming ioff-circuit yung transformer... mejo mahirap nga lang po tanggalin..hehe 8)


@ sir outdated, sana nga po sir, haha, pg ganun pwede na din kami maglagay nang karatula sa labas ng bahay....  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 21, 2010, 09:00:11 AM
saan sinukat to?with respect to where?nakapull out yung transformer sa board?
kelangan ko talaga makita yung schematic, try ko tingnan mamayang gabi, naubusan naman ako laod kagabi nung uwi ko eh, hehehe.

siguro ang significant dyan eh yung inductance ng primary windings.

aling unit nga pala sa dalawa ang sira?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 21, 2010, 09:17:43 AM
saan sinukat to?with respect to where?nakapull out yung transformer sa board?

siguro ang significant dyan eh yung inductance ng primary windings.

aling unit nga pala sa dalawa ang sira?

Sir glutnix, naka in-circuit po yung transformer nyan nung sinukat namin ang inductance. Ah sir pag masyado po bang maliit ang sukat ng inductance ng isang transformer eh sira na po ba yun o depende po yun sa design?

parehas pong sira sis yung unit. same problem.

ito na din po pla sis yung schematic ng secondary side ng transformer

(http://img51.imageshack.us/img51/4962/transformer2.png) (http://img51.imageshack.us/i/transformer2.png/)

Uploaded with ImageShack.us (http://imageshack.us)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 21, 2010, 09:23:23 AM
(http://img541.imageshack.us/img541/7963/transformer.png) (http://img541.imageshack.us/i/transformer.png/)

Uploaded with ImageShack.us (http://imageshack.us)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 21, 2010, 09:51:31 AM
Sis ito na po yung mga pictures ng transformer namin.


PCB: across po ang pagsukat namin ng inductance dito sis ;D ;D ;D


(http://img840.imageshack.us/img840/8665/trns2.jpg) (http://img840.imageshack.us/i/trns2.jpg/)


Transformer:

(http://img19.imageshack.us/img19/3295/trans1v.jpg) (http://img19.imageshack.us/i/trans1v.jpg/)



(http://img94.imageshack.us/img94/2843/transrj.jpg) (http://img94.imageshack.us/i/transrj.jpg/)


-tnx sis ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: siLent_cLp on July 21, 2010, 10:08:27 AM
Nung sinukat po namin yun, nasa board pa sir yung transformer...
yung mga shorted po na pins yung sinukatan ko nang inductance..
nagrarattle po kasi yung transformer pag sinusuplayan namin yung buong board. :o


ahm, yung dalawang unit po parehas na sira...hehe ;D

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 21, 2010, 02:15:49 PM
Sir glutnix, ito na po yung mga nakuha naming inductance ng transformer which is off circuit na po.

Transformer 1 (ito po yung transformer na may rattle kaming naririrnig)

Primary

Coil 1: 18.4 uH
Coil 2:  5.9 uH
Coil 3:  5.8 uH

Secondary

Coil 1: 27.7 uH
Coil 2: 10.7 uH
Coil 3: 10.5 uH


Transformer 2


Primary

Coil 1: 19.4 uH
Coil 2:  5.8 uH
Coil 3:  5.8 uH

Secondary

Coil 1: 29.8 uH
Coil 2: 11.2 uH
Coil 3: 11.2 uH

 ok pa po kaya yung transformer amin sis?


-tnx ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 21, 2010, 02:24:55 PM
try nyo kaya gamitin ibang transformer dun sa unit, pag hindi pa rin gumana, gawin nyo yung naunang binanggit ko na palitan mga FETs at sense resistor.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: siLent_cLp on July 21, 2010, 05:16:30 PM
ayun sir na try na po namin palitan yung transformer, ganun pa din po, nung inoff-circuit namin yung
mga transformer, parehas naman po sila nang inductance. . .

sige po ttry po namin na palitan yung mga FET's at yung sense resistor..


ty po.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 21, 2010, 05:32:57 PM
ayun sir na try na po namin palitan yung transformer, ganun pa din po, nung inoff-circuit namin yung
mga transformer, parehas naman po sila nang inductance. . .

sige po ttry po namin na palitan yung mga FET's at yung sense resistor..


ty po.

push pull circuit nyo no?check nyo rin nga yung dalawang malaking diode malapit sa FETs kung OK pa.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 22, 2010, 08:49:04 AM
(http://img709.imageshack.us/img709/9963/trans2e.jpg) (http://img709.imageshack.us/i/trans2e.jpg/)

sis glutnix, ito po ba yung diode na sinasabi mo? nacheck na din po namin to. ittry na din po naming palitan para mas sure ;D yung sinukat din po pla yung Vf nitong diode na to eh nsa 0.46V lang po yun (in circuit at off circuit) tpos ang Vf po niya ayon sa specs eh 1.25V

-tnx sis ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: siLent_cLp on July 26, 2010, 04:09:01 PM

sir,

ok lang po ba kung yung supply namin ay nagvavary?
pansin ko po kasi yung supply namin dun sa pwm at sa iba pang ic & components ay nagvavary mula 2.2v-14.6v,
nacheck na po namin lahat nung mga FET's, diodes, capacitors, pati po yung transformer...

mejo napapakamot na po kami nang ulo, wala pa din pong output... hehe
natry na din po namin mag swap ng transformer saka palitan yung resistor sa Isense...

t.y.  po... :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on July 26, 2010, 04:57:01 PM
sir,

ok lang po ba kung yung supply namin ay nagvavary?
pansin ko po kasi yung supply namin dun sa pwm at sa iba pang ic & components ay nagvavary mula 2.2v-14.6v,
nacheck na po namin lahat nung mga FET's, diodes, capacitors, pati po yung transformer...

mejo napapakamot na po kami nang ulo, wala pa din pong output... hehe
natry na din po namin mag swap ng transformer saka palitan yung resistor sa Isense...

t.y.  po... :)

baka naman kailangan ng preload bago mag output,ilan bang wattage ng PSU na yan mga master?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: siLent_cLp on July 26, 2010, 05:21:54 PM
 
baka naman kailangan ng preload bago mag output,ilan bang wattage ng PSU na yan mga master?


ahm, yung dc output po 300W... maximum po un...
@sir icefire, panu po ba  yung preload?hehe :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: siLent_cLp on July 26, 2010, 05:30:48 PM
-A sure way to avoid the resulting random-skipping/pseudo-hysteretic mode is to maintain a certain minimum external load on the converter output, i.e., a preload if necessary.

-eto po ba yun sir icefire? ??? hehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on July 26, 2010, 05:33:31 PM


ahm, yung dc output po 300W... maximum po un...
@sir icefire, panu po ba  yung preload?hehe :)

halimbawa 300W yan usually 10% to 20% ng full load, yung preload meaning may minimum load para gumana yung PSU.isa pa minsan may PS_ON yan,may pipindutin kapang switch or ishoshort para gumana yang PSU,try mo lang,20% of 300W = 60W,maglagay ka ng load na at least 60W.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on July 26, 2010, 05:34:43 PM
-A sure way to avoid the resulting random-skipping/pseudo-hysteretic mode is to maintain a certain minimum external load on the converter output, i.e., a preload if necessary.

-eto po ba yun sir icefire? ??? hehe


yan nga may mga modelo kaming kailangan ng preload yung iba may standby na load na yun yung mga bago naming modelo dito.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 26, 2010, 06:26:08 PM
(http://img709.imageshack.us/img709/9963/trans2e.jpg) (http://img709.imageshack.us/i/trans2e.jpg/)

sis glutnix, ito po ba yung diode na sinasabi mo? nacheck na din po namin to. ittry na din po naming palitan para mas sure ;D yung sinukat din po pla yung Vf nitong diode na to eh nsa 0.46V lang po yun (in circuit at off circuit) tpos ang Vf po niya ayon sa specs eh 1.25V

-tnx sis ;D

tama lang na mababa ang masukat na Vf ng diode, 'yung karaniwang Vf na stated e 'yung sa nominal current rating ung diode. merong graph 'yan. ;)

kaya meron akong nakikitang mga supply na overkill 'yung parallel diodes para 'di masyadong mainit (lower current through each diode, lower forward voltage), though pwede ring synchronous rectifiers na lang sana. una ko 'yung nakita sa lumang Nemic-Lambda supply, 27A, 'yung maximum rating nung parallel diodes lalabas sa >200A.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 27, 2010, 09:31:25 AM
thank you so much mga sir sa mga tulong niyo! ;D 8)  ::)  :o  ;)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: siLent_cLp on July 27, 2010, 09:42:05 AM
@ icefire
ahh...ok po sir,
thanks nang marami.. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 27, 2010, 09:51:24 AM
napuna ko mga master parang hindi lang isang power supply yung binabanggit nyo? medyo nakakalito po kasi itroubleshoot...

sensya nga pala di masyado makareply ngayon, 4projects na naman tinatrabaho ko with 2 MCU each project  :'( :'( :'(
hindi ko alam bakit ako paboritong tagasalo ng project ng nagreresign,hehehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on July 27, 2010, 10:13:42 AM
napuna ko mga master parang hindi lang isang power supply yung binabanggit nyo? medyo nakakalito po kasi itroubleshoot... baka nga nakaparallel,kailangan i-monitor yung current sense circuit at pareho sila ng parallel sensing output.

sensya nga pala di masyado makareply ngayon, 4projects na naman tinatrabaho ko with 2 MCU each project  :'( :'( :'(
hindi ko alam bakit ako paboritong tagasalo ng project ng nagreresign,hehehe

ganyan talaga master hehehe may bago kami tapos may mawawala hahaha,gusto nga namin mass resignation dito baka next year magkaroon kami ng mass resignation.  :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 27, 2010, 02:44:06 PM
@sis glutnix: d po sis ibaba ito. 2 lang po itong PSU na ito pero parehas na parehas pati problema parehas ;D pasensya na din po pla kung naiistorbo na namin kau hahahah ;D


tnx po ng madami sis ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 27, 2010, 02:48:43 PM
kahit parehas po ng senyales maaring magkaiba pa rin ng failures....
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on July 28, 2010, 12:16:19 PM
ok po sis ;D ittroubleshoot pa po namin ng husto ;D salamat po ng madami
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: iyo karpo on August 01, 2010, 09:55:26 AM
Bakit kaya tuwing marinig ko ung Switch Mode Power Supply sa mga contractors, harmonics mitigation kaagad ang pinag-usapan?

Mapilipatan tuloy akong maghanap ng K13 type transformer. Mapamahal pa ung customer ko.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on August 12, 2010, 09:06:12 AM
sis about nmn sa inductors, which is better, higher inductance or lower inductance? meron kais kaming nakitang magkaiba yung inductance ng coil, yung isa malaki yung isa maliit.

tnx
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on August 12, 2010, 09:36:09 AM
higher kasi mas napapaliit nya yung ripple...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Vhelt on August 16, 2010, 07:49:42 PM
Gud pm sir Glutnix magtatanong lang po regarding crt monitor smps before no power xa. trouble shoot s ko sa primary nakita ko walng b+ ung UC3842am ic hangang sa nakita ko rin ung dahilan may shorted na zener diode sa may start up malapit sa may switch pagkapalit ko 20v zener expected ko ok pero nagkaroon na ng output voltage sa secondary mababa kapag tinester ung output gumagalaw galaw ung needle hindi  stable walang ilaw ung power indicator.. Ano po ba posible na dahilan nito wala na kong makitang sira sa primary side....... Tia
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on August 17, 2010, 07:45:04 AM
try to do the test na ginawa ni wojou to check kung OK pa yung PWM nyo...

check nyo rin kung ok yung feedback path. baka kasi open loop na sya.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on August 20, 2010, 11:04:18 AM
sis, aabalahin na kita diyan sa PID controller seminar niyo,
ahm, yung sa dati pa pong PSU na tntroubleshoot namin eh halos lahat naman po ng piyesa na nandito sa PSu eh OK naman po. Yung tungkol naman po sa control board eh lahat ng posibleng sira eh napalitan na po namin, base po sa control board, pansin namin eh yung ibang IC doon (UC3902) eh hiwalay yung supply niya kaysa sa ibang mga IC na nandun sa board, assuming po eh  3 po yatang magkakahiwalay ang supply line ng Control Board, yung isa pong part eh nanggagaling yung supply sa Output part ng buong PSU, yung isa naman pong part eh sa Secondary part nanggagaling yung supply ..


bali po ganito po yung tingin namin sa loop ng ckt

AC Supply -  Full bridge Rectifier - PWM (Preregulator) - second PWM, Control Board,

2nd PWM - Secondary Side ng trans - Control board

sa tingin niyo po ba eh kailngan ng feedback ng PSU na ito galing sa makina ? kasi nga po kulang yng supply nung ckt a pinaka control niya... ung nga lang po sabi kasi samin eh yung natrace po namin na supply line nung isang part sa control board eh output na pla nung buong smps...


nagtry na din po kaming magsupply sa control board na po mismo, nung nalagyan na po ng supply eh marami po doon sa mga comparator tsaka doon sa ibang mga IC eh nagkaroon ng mga output, umilaw din po yung LED na nakakabit sa control board. Ok lang po ba na try namin supplyan yung Control board habang may AC supply yung buong PSU?


konti pong pasensya kasi magulo..  ;D


thank you!
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 'yus on August 20, 2010, 12:44:26 PM
....
Ok lang po ba na try namin supplyan yung Control board habang may AC supply yung buong PSU?
...
safe sya kung naka-OR yung external supply sa internal supply
(i.e. may naka-series na diode yung internal supply papuntang IC and magse-series din na diode sa external supply)


____________________________________

  available na nga pala yung latest version ng basag na PSIM dun sa s0ns1vr1..
     very usefull sa power electronics.. :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on August 22, 2010, 06:15:57 PM
assuming primary is OK time to check the secondary, possible cause kung bakit nagtitrip ang protection ng PSU is my short sa secondary.

A simple test you can perform is use a DC source set the current limit to few milliampere (<50mA), and then supplyan nyo yung output capacitor. pagnacurrent limit yung power supply malamang may short sa about.

Note: wag nyo supplayan ang AC while performing this test
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: HI-FI on August 22, 2010, 11:59:23 PM
Lesson 2.0    Why is There a Need for Power Supply   20080213

Introduction...

I am often asked by a question and even I asked it when I was a student, "Why do we need power supply?"...
That question is often followed by another question, "Can't we just use a voltage divider?"

Those are very good questions for beginners. Well, explaining why we can't use a voltage divider to have a stable

voltage source also explains why we need power supplies (because there's no other alternatives, hehehe).

In theory, if the voltage supplied by the input or the current drawn by the load does not vary with time,

definitely, a voltage divider computed for that specific load and input voltage is sufficient to keep the output

voltage fix on that level. But, in real applications the input voltage from battery and worst from AC line varies

with time. Switching loads such as micrcontrollers and digital circuits draws different amount of current from time

to time. Thus, the need for power supply arise.

What is a voltage divider anyway?...

It is a circuit commonly composed of two resistors in series that produces an output that is a fraction of its

input.
(http://upload.wikimedia.org/wikipedia/en/d/db/Resistive_divider.png)

the relationship of input and output becomes

Vout = vin * R2 / (R1 + R2)            eq. 2.1

I don't need to explain the derivation in detail but in case you're interested, you may refer to Mr. Wiki on the

link below

On the formula, R2 could represent a load (the effective resistance of the component supplied by the voltage

divider) or if you need to add load to it just compute the effective resistance of it and place them in parallel to

R2.


Very Simple Example...
Suppose we have a circuit that draws 5A and needs to be powered by 5V but our Vin is 10V, how are we going to have

this using a voltage divider?

Given are:
Vout = 5V
Vin = 10V
Iout = 5A

The effective resistance of the load (R2) can be calculated using Ohm's law (I = V/R) or R = V/I

R2 = 5V / 5A = 1 Ohm

Required is :
the resistance of R1 to form a voltage divider

Rearranging equation 2.1 we get

R1 = R2 * (Vin - Vout)  / Vout

R1 = 1 Ohm * ( 10V - 5V ) / 5V

R1 = 1 Ohm

Therefore 1 Ohm is the required series resistance to have a 5V output.

Effects if changing voltage on the voltage divider...

Supposed we are using the same circuit as mentioned on our "very simple example" and the voltage increased from 10V

to 20V, will our output remain the same?

Given:
Vin = 20V
R1 = 1 Ohm
R2 = 1 Ohm

Required:
V2 = ?

Again, using equation 2.1 we get

Vout = 20V * 1 Ohm / ( 1 Ohm + 1 Ohm )

Vout = 10V <<< Lumake!!!!

From the example we can conclude that in a voltage divider

1. As we increase the input voltage, the output voltage also increases
2. As we decrease the input voltage, the output voltage also decreases

Effects of loading a voltage divider...

Supposed we are using the same circuit as mentioned on our "very simple example" and two paralled 1 Ohm resistor

are used in place of R2 (same as increasing the load), will our output remain the same?

Given:
Vout = 10V
R1 = 1 Ohm
R2 = 1 Ohm // 1 Ohm = 0.5 Ohms

Required:
V2 = ?

Again, using equation 2.1 we get

Vout = 10V * 0.5 Ohms / (0.5 ohms + 1 Ohm)

Vout = 3.33333333333333333333333333333333333333333333V        <<< Lumiit!!!

From the example we can conclude that in a voltage divider

1. As we increase the input voltage, the output voltage decreases
2. As we decrease the input voltage, the output voltage increases

Conclusion...

Because of the limitations of the voltage divider on maintaining the output at a constant level on varying loads

and input voltages, the need for a better regulator became a necessity.

Karagdagang Babasahin...

http://en.wikipedia.org/wiki/Voltage_divider (http://en.wikipedia.org/wiki/Voltage_divider)


bat sa last po lahat voltage out?? walng in??
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on August 23, 2010, 10:19:24 AM
sorry typo, dun sa given yung vout should be vin,

see eq. 2.1
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: namzer0 on August 24, 2010, 12:22:41 PM
sers pasingit lang, basic question po sa flyback converter, ano po bang current path dito sa feedback winding? nagreverse engineer po ako ng nokia/cp charger tas gusto ko po i-modify... parehas lang ba current flow maski yung feedback e nasa outer winding ng xformer? (pri-sec-feedbk) (pri-feedbk-sec) parehas din po ba flow maski ibang isolated topology? thx po...
(http://i218.photobucket.com/albums/cc69/namzer0/IMG.jpg)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on August 24, 2010, 12:51:19 PM
basta may pumasok na current sa do ng transformer, palabas siya sa dot ng ibang winding.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: namzer0 on August 25, 2010, 09:28:36 AM
Ser, ganun lang po ba yun kasimple? ngyee... ;D
ang bopols ko...  auch...

pero ganda talaga ng mga SMPS... ang mamahal tas anglaki ng mga linear xformer lalo na pag high currents kase...
mejo complex nga lang...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on August 25, 2010, 10:33:13 AM
Ser, ganun lang po ba yun kasimple? ngyee... ;D
ang bopols ko...  auch...

pero ganda talaga ng mga SMPS... ang mamahal tas anglaki ng mga linear xformer lalo na pag high currents kase...
mejo complex nga lang...

actually din naman ganun ka kumplikado pero ang mahirap hanapin yung core at magnetic parts,nagiging kumplikado lang batay sa topology at requirements,sa commercial world kasi basta low current either buck/boost or flyback/forward topology madalas gamitin pero sa high current yung mga bridge topology na(half/full).

meron magandang ireverse engineer yung dvd players na smps at clone smps chargers.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on August 25, 2010, 03:36:10 PM
^ may nakita akong clone charger, clone na clone talaga 'yung kaha dahil may logo pa ng ASTEC, pero mali-mali 'yung spelling sa specifications. ;D ang laman nung charger 'yung self oscillating flyback.

maganda ring pag-aralan 'yung sa ATX kapag tapos na sa flyback at forward ('yung mga nabubuksan kong PSU ng Epson printer dati Forward ang gamit, hindi Flyback), half-bridge na merong gate drive transformer 'yung high side FET.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: namzer0 on August 26, 2010, 11:32:07 AM
oo nga pala, kaya ba ng mga yan(flyback/ forward/ bridge) yung bipolar supply? From the transformer mismo ng converter.

pang Audio Amplifier lang...

Try ko na lng kaya... (boom)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on August 26, 2010, 02:41:15 PM
oo nga pala, kaya ba ng mga yan(flyback/ forward/ bridge) yung bipolar supply? From the transformer mismo ng converter.

pang Audio Amplifier lang...

Try ko na lng kaya... (boom)

kayang kaya ng SMPS yan basta high amps,yung disadvantages ng SMPS yung EMI kaya tinitest eto ng maigi na walang interference sa mga delicate equipments sa noise,example sa mga hifi audio equipments.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: victor16 on August 29, 2010, 06:52:32 PM
sir ask lang po sa value ng FET sa smps ng HUG dvd player durado kasi. tia.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: updated on September 03, 2010, 04:10:04 PM
^ mas maganda sir kung may diagram ka. para ma analyze ni master ng maayos yung problem mo.

sa wakas nagawa ko na din yung nirerepair kong PSU!

@wojou, goodluck sau.

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on September 03, 2010, 05:33:45 PM
@victor
or kahit identify mo lang topology ng SMPS na ginamit

@updated
hindi pa rin ba tapos PSU ni wojou?  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: m@r on September 03, 2010, 07:44:53 PM
mga sir meron po ba kayong ebook tungkol sa smps and troubleshooting smps?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on September 09, 2010, 01:45:52 PM
@sis glutnix: d pa din po tapos eh

@sis updated: grats!!
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: gie62 on September 09, 2010, 09:17:32 PM
@sis glutnix: d pa din po tapos eh
sa anong machine yang psu na ginagawa nyo??
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: wojou on September 14, 2010, 01:52:58 PM
@sis gie62: d po namin alam kung parasaan to eh pero sa tingin ko lang po eh mukang sa mga Ball bonder.

thnx!
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: gie62 on September 14, 2010, 03:07:29 PM
alam mo ba kung anong brand at model ng ball bonder?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on September 21, 2010, 01:14:30 PM
Testing post ko lang ito mga sis & brod, Ok pla may smps section dito...
I play with some smps using old Computer choppers, can rewind it quite easy!

Welcome ba ako dito mga pards?

(http://img638.imageshack.us/img638/9483/fa5304.jpg) (http://img638.imageshack.us/i/fa5304.jpg/)

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on September 21, 2010, 01:54:29 PM
Testing post ko lang ito mga sis & brod, Ok pla may smps section dito...
I play with some smps using old Computer choppers, can rewind it quite easy!

Welcome ba ako dito mga pards?

(http://img638.imageshack.us/img638/9483/fa5304.jpg) (http://img638.imageshack.us/i/fa5304.jpg/)



welcome ka dito sir basta magtanong kalang.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on September 21, 2010, 02:12:45 PM
Testing post ko lang ito mga sis & brod, Ok pla may smps section dito...
I play with some smps using old Computer choppers, can rewind it quite easy!

Welcome ba ako dito mga pards?



Welcome Master, congratulations on your first post ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: pEN DoTA on September 21, 2010, 03:35:59 PM
Testing post ko lang ito mga sis & brod, Ok pla may smps section dito...
I play with some smps using old Computer choppers, can rewind it quite easy!

Welcome ba ako dito mga pards?

(http://img638.imageshack.us/img638/9483/fa5304.jpg) (http://img638.imageshack.us/i/fa5304.jpg/)





ang galing mo brod. 1 point ka sa akin :) :) :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: siLent_cLp on September 23, 2010, 09:43:03 AM
@ sir glutnix .. hehe ndi pa dn po namin npagana ni wojou ung Ps n nre2pair nmin.. haha

tingin po namin kialangan ng external supply nung psu galing dun sa makina.. :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on September 23, 2010, 09:52:26 AM
OK, basta compare nyo lang yung signal na normal at yung signal sa actual(while operating sa totoong setup). Kung hindi nyo pa rin makita, gawing nyo ang huling secret technique ko, let it smoke. hehehe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on September 23, 2010, 12:58:34 PM
^Lekat ganun pala technique dun  ;D  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on September 26, 2010, 02:19:53 PM
Welcome Master, congratulations on your first post ;D

He, he! Di naman ako master, hobbiest lang ng pagbubutingting for more than 2 decades. Kumusta na ba ang buhay dyan sa Pilipinas?

Nga pala baka may alam kayong sourse locally ng toroidal choppers approx "20mm thick x 60mm outer diameter x 20mm center hole" or nearest spec. I have something to design sana yung ibang klasing smps na capable of self sustaining energy from itself. Something stange pero may basic principle at very possible. Input of 1w and producing 60w of output! Sounds like crazy but it looks real! Don't look for normal theory because it's impossible there...

Tol, baka may powerfull design ka rin ng smps na flyback mode with a very less tolerance of fluctuation. Better to play with some tested design than starting from scratch to save time, busy masyado eh.

My previous testing of smps nga pala here:
(http://img34.imageshack.us/img34/3566/puttingoncompchassis.jpg) (http://img34.imageshack.us/i/puttingoncompchassis.jpg/)






Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on September 26, 2010, 05:17:34 PM


ang galing mo brod. 1 point ka sa akin :) :) :)

Shokran sa point sadik! Este salamat sa pontos, sa yo pala galing yun..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: siLent_cLp on September 30, 2010, 09:15:42 AM
@ sir glutnix.. hehe ok po , aun mejo nakatambak pa po siya dito eh.. mlayo ksi pgtetestingan..hehe

haha un po pla secret technique nio..  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on October 04, 2010, 06:23:28 PM
how do you compute for output cap of smps given output ripple voltage?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: patz11bullet on October 06, 2010, 09:28:21 PM
Good evening po, question po about sa buckboost converter. Ang input is 4 and 10 volts then ang output po eh 7 volts fixed. Ang design ko po eh yung conventional design po ng buckboost, but I can't start sa gate driver. Ano po magandang values for these to achieve the desired output? By the way, CCM po ang operation niya and driven at 40KHz po ang parameters. Thanks for your replies sirs/maams
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on October 07, 2010, 08:23:22 AM
^ conventional? like this?

(http://upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Buckboost_conventions.svg/800px-Buckboost_conventions.svg.png)

Ano master ang ginamit nyong switching element? N-Channel? P-Channel? BJT?


how do you compute for output cap of smps given output ripple voltage?

from the formula of capacitance to current relation...

I = C dv/dt

dv = the desired ripple,pk-pk
I = max output current
dt = is the Ton (D/Fsw)

ideally C = Iout * Ton / Vripple, but we have to account for the effect of ESR on output ripple voltage,
Microchip presentation below( Buck Converter design, slide 8 ) has a good discussion about it.

Normally we choose the capacitors with ESR as low as possible because there is a point that even if we add capacitance the ripple voltage can no longer be contained due to ESR.

Share ko sa iba....
Flyback Design (http://www.gotopower.net/article.asp?art_id=65)
Buck Converter Design (http://satcom.tonnarelli.com/files/smps/SMPSBuckDesign_031809.pdf)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on October 07, 2010, 01:45:01 PM
thanks. so how do you compute for max iripple?

max. iripple is proportional to cap physical size di ba?

derating ko for v and iripple is 90%. ok na yun?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on October 07, 2010, 02:09:33 PM
inductance po ang nagdidictate ng iripple,
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on October 07, 2010, 03:07:36 PM
para sa output cap
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on October 07, 2010, 04:08:04 PM
Ah I see, opo I think enough na yang 5%-10% of Iout_max, dun pala sa design example 30% ang ginamit nya.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on October 07, 2010, 05:02:46 PM
Iout = max output current, is this DC current? di ba walang Idc (=0) sa cap.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on October 07, 2010, 05:19:52 PM
Yup DC po yan, pero yung ripple current eh inassume lang out of the max Iout. Sa case ng microchip 30% of Iout_max yung allowed ripple nila sa design nila. Eto rin yung ripple current na nakikita sa inductor current na hindi nakikita sa output kasi inabsorb na na output capacitors.

Proper design ng inductors ang way para mareduce ito, then yung rest eh yung capacitors ang bahala.
Note na may rated ripple current din ang mga capacitors kaya di pwede masyado malaki.

Dun sa book ni Ned Mohan, energy/charge yata ang parameter na iniconsider sa pagcompute ng output caps instead of current(IIRC). :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on October 08, 2010, 09:27:21 AM
ok. so assumed yung iripple going thru the cap.

any way of computing for this instead of approximation?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on October 08, 2010, 09:51:23 AM

design parameter/requirement po ang Iripple so iaassume talaga ito sa simula,

kung actual ripple ang gusto nating hanapin based sa actual circuit. eto rin ang ripple sa inductor current.

v = L di/dt

v = is depende sa topology na ginamit pero may discusstion ako sa start ng thread nito kung paano makukuha, dun sa buck converter.
L = is yung actual na inductance na ginamit
di = hinahanap na Iripple
dt = ton, duration kung saan ang voltage v at persistent
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on October 08, 2010, 11:59:42 AM
aside from the ripple i, meron din very small dc component ang dumadaan sa output cap.

gusto ko sana i-compute thru equations itong dalawang ito; w/o resorting to approximations.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on October 08, 2010, 01:20:07 PM
^Probably due to esr,

Master bakit nyo kailangan ng ganung kaaccurate na value?

normal kasi eh we make approximations then calculate, then ichecheck sa actual at pag kulang eh dagdagan na lang ang value ng capacitance or pili ng mas mababang esr. pagnagpaparallel eh napapababa din esr.

minsan sa mga high power applications pati yung trace routing eh malaki epekto sa output ripple so kahit nacompute na natin ng accurate ang value ng capacitance nagiiba pa rin sa actual.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on October 08, 2010, 01:27:47 PM
para sa isang research paper...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on October 08, 2010, 02:03:58 PM
i see, kailangan natin magrefer sa mga books sir...

mukhang maganda research nyo ah, nagattempt ako mapropose ng research about power electronics hindi nila maintindihan sinasabi ko(mga prof ko), ang pinili nila topic eh yung pwede ko gawan ng prototype parang college thesis, yung iba nga basta tunog high tech approve agad, hehehe.

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on October 08, 2010, 02:29:20 PM
just getting some insight from you guys.

di lahat nasa books.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on October 08, 2010, 05:04:57 PM
v ripple is compensated by L
i ripple is compensated by C

but L and C should be at resonance w/ ripple freq.

thats what they call SMPS 90%+ effeciency.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on October 08, 2010, 06:20:25 PM
v ripple is compensated by L
i ripple is compensated by C

but L and C should be at resonance w/ ripple freq.

thats what they call SMPS 90%+ effeciency.


ano po relation ng efficiency sa resonance?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on October 08, 2010, 06:41:17 PM
with resonant topologies (switch parasitic capacitances in combination with magnetic's parasitic inductances), nakakadagadag siya sa efficiency, pero with output filter, I don't think nakakadagdag siya sa efficiency, and I believe it should be avoided.

as far as feedback control is concerned, resonant output filter will make the loop go wild, dahil magkakaroon ng oscillations. considered din 'yung 2nd order phase sa feedback design, dahil any noise at this part, malaki na ang oscillation. kaya madalas, malayo pa sa cut off ng filter, cut off na 'yung feedback.

as far as filter design is concerned, a low pass filter with resonance at the ripple frequency will never reduce the ripple frequency, hence the output will never approximate a flat DC.

one of the main reasons kaya mataas ang switching frequency (in effect ripple frequency) ng mga SMPS para kahit light filters lang (well below the switching frequency but well above few kHz) malaki na 'yung reduction sa output ripple.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ner1116 on October 08, 2010, 06:50:47 PM
OK here's a short explaination, I'll try to make it as simple as possible

Para sa new sa PSU technology, there are three(main types are only two) types of power supply
1. Linear Power Supply - The transistor is operated in active region mostly in linear region, effectively para xang potentimeter na        binabago ang resistance
2. Switched Mode Power Supply - In here the transistor is operated on cutoff and saturation (switching) kaya naderive ang name na "switched Mode"
3. Others - some say a zener regulator falls under this category but it is not a real regulated PSU

The simplest SMPS topology(circuit) is the buck converter, basically what it does is it converts a higher input voltage to a lower output voltage.

(http://www.daycounter.com/LabBook/BuckConverter/BuckConverterSchematic.gif)
From the diagram above, the switch represents a MOSFET na iniswiswitch natin on and off, pag ginawa natin to alam natin na square wave pulse ang lalabas sa output but the LC combination serves as a low pass filter na pinifilter nya ang high frequency at ang natira na lang sa output eh pure DC(average ng pulse).

Alam natin from integral calculus(naks math,hehe) na ang average ng pulse is equal to the area under the curve (Vin * ton duration of switch) divide by the Period (ton + toff duration of the switch)
in short

Vout = Vin ton / (T) = Vin * Duty Cycle

usually the switching frequency is very high(70kHz up) para hindi xa magrequire ng malaking filters.

you might ask para saan ang diode sa circuit? it prevents inductive kick? Or safe to say current path ng inductor current during toff

karagdagang babasahin...
http://www.powerdesigners.com/InfoWeb/resources/pe_html/ch07s1/intro.html (http://www.powerdesigners.com/InfoWeb/resources/pe_html/ch07s1/intro.html)
http://en.wikipedia.org/wiki/Buck_converter (http://en.wikipedia.org/wiki/Buck_converter)

wow... lufet... bro!
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on October 08, 2010, 07:02:49 PM
disadvantages lang ng resonant converters(ZVS or ZCS) ay mataas ang losses during light load(mataas ang switching losses due to may umiikot na energy sa LC tank) pero habang malapit na sa full load gumaganda ang efficiency kaya minsan denidesign yung resonant frequency sa full load or ginagawang variable frequency para lahat ng loading may resonant frequency.

sa output filter naman no need for resonant frequency,dapat low ESR ang gagamiting caps at damihan eto ng caps para lumiit ang effective ESR(parallel combination)at lalaki ang effective capacitance(gaganda ang output filter bababa ang ripple).

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on October 08, 2010, 07:07:04 PM
Quote
^Probably due to esr,

yup tama ka sis eto talaga culprit in theory kasi,pag walang load ang power supply walang ripple hehehe(meron explanations kay vatche vorperian yung ripple theorem for mathematical computations)

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on October 08, 2010, 07:08:29 PM
disadvantages lang ng resonant converters(ZVS or ZCS) ay mataas ang losses during light load(mataas ang switching losses due to may umiikot na energy sa LC tank) pero habang malapit na sa full load gumaganda ang efficiency kaya minsan denidesign yung resonant frequency sa full load or ginagawang variable frequency para lahat ng loading may resonant frequency.

sa output filter naman no need for resonant frequency,dapat low ESR ang gagamiting caps at damihan eto ng caps para lumiit ang effective ESR(parallel combination)at lalaki ang effective capacitance(gaganda ang output filter bababa ang ripple).

^ agree.

with resonant output filter, 90 degree phase + 180 phase = 270 degrees na, 90 degree random phase disturbance na lang, 'di na maglo-lock 'yung loop at magiging oscillator na siya. madali lang maabot 'yung 90 degree disturbance lalo na kung dumaan pa sa TL431 at opto.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on October 08, 2010, 07:20:16 PM
teka napalayo yata usapan... resonant converters na. hihihi...

anyway, kaya ako nagtaka wala naman relation ang efficiency doon sa resonance. :)

nalito ako dun a.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on October 08, 2010, 07:54:06 PM
ano po relation ng efficiency sa resonance?


we use pulses in smps (clarify ko lang, constant freq but variable pulse width) although it is a pulse meaning an abrupt change in current and voltage but still a change in magnitude . if we put only a inductor to attain a dc out, what will happen to current as one of the power component? if we can just see the v and i component, especially at no load (r) condition, it will be running at almost 90 degrees out phase with each other. to compensate this we put capacitor... at certain freq we can only put back together the v and i again, only at resonance, that is by equating both the inductive and the capacitive reactance based on the frequency used. theirs is a lot of advantage when the LC is only tuned to a certain freq....

old power supply using 60hz sine wave they call it a TUF or transformer utilization factor. (somebody posted this topic a week ago maybe, u can search for it, it may give some ideas on how it affects effeciency although it is in the 60hz type power supplies)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on October 08, 2010, 08:02:35 PM
so where do the losses occur? certainly, a phase lag or resonance doesn't contribute to power efficiency.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on October 08, 2010, 08:09:03 PM
so where do the losses occur? certainly, a phase lag or resonance doesn't contribute to power efficiency.

P (true power) = V x I x Cosine of the phase displacement of V and I
                    = V x I x Cosine +/-90 degrees = 0

try it in calculator....

in pure DC as in Batteries, Power is only V x I...  :)

but we are converting it from pulsating to pure DC   ;)

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on October 08, 2010, 08:28:14 PM
in pulsating dc,

inductive means your voltage on time is +90 degrees out of phase with the current on time, and -90 degrees for capacitive.  :)

we can see this theorytically and if you have a current probe in your scope u may see it graphically  ;)

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on October 08, 2010, 08:43:10 PM
 
Heyy, Engineer Atom i remember now u are the one hiring an smps engineer....if u will hire me   ;D  i will open-up this topic upto 1000watts  :D :D :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on October 08, 2010, 09:01:03 PM
disadvantages lang ng resonant converters(ZVS or ZCS) ay mataas ang losses during light load(mataas ang switching losses due to may umiikot na energy sa LC tank) pero habang malapit na sa full load gumaganda ang efficiency kaya minsan denidesign yung resonant frequency sa full load or ginagawang variable frequency para lahat ng loading may resonant frequency.

sa output filter naman no need for resonant frequency,dapat low ESR ang gagamiting caps at damihan eto ng caps para lumiit ang effective ESR(parallel combination)at lalaki ang effective capacitance(gaganda ang output filter bababa ang ripple).

in 60hz power supply sis, one important rule is also to avoid the 60hz LC filters. it may saturate everything.  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on October 09, 2010, 02:47:06 PM
going back to the topic, i'm working on a paper that identifies/calculates the dc & ac components going into an output cap of an smps (any topology). just need some inputs from other smps design engineers out there.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: panyero on October 10, 2010, 05:04:37 PM
sir high pitch tune from power supply ano kaya posible problem?tnx
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on October 10, 2010, 05:29:26 PM
^ posibleng sa magnetics (inductor or transformer), 'di na masyadong naka-dikit.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: j2sip on October 11, 2010, 09:08:50 AM
Sorry po pero mukhang OT. Pwede pong imodify ang pSu ng ng mga pc (which are, I understand,some kind of SMPS) para magoutput sila ng greater that 12V? Will it be possible to obtain 36 or 48v from a single psu, as opposed to daisychaining them?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on October 11, 2010, 12:07:43 PM
Sorry po pero mukhang OT. Pwede pong imodify ang pSu ng ng mga pc (which are, I understand,some kind of SMPS) para magoutput sila ng greater that 12V? Will it be possible to obtain 36 or 48v from a single psu, as opposed to daisychaining them?

baka mag float ang common ng feedback ckt ng regulator? pwede siguro dalawa lang pang +12=gnd=-12 split supply lang. yong universal laptop supply may 21V out ata ito pwede +21=gnd=-21 split supply 65w x 2 .
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on October 11, 2010, 12:23:17 PM
Sorry po pero mukhang OT. Pwede pong imodify ang pSu ng ng mga pc (which are, I understand,some kind of SMPS) para magoutput sila ng greater that 12V? Will it be possible to obtain 36 or 48v from a single psu, as opposed to daisychaining them?

pwede po sir, pero kailangang i-rewind 'yung transformer, rewind 'yung inductor, palitan 'yung output rectifier, at ibahin ng konti 'yung feedback loop. fixed power pa rin kung hindi papalitan 'yung frequency, kung 12V 10A 'yung original na design, sa modified pwedeng 48V 2.5A.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: j2sip on October 11, 2010, 01:20:15 PM
Quote
pwede po sir, pero kailangang i-rewind 'yung transformer, rewind 'yung inductor, palitan 'yung output rectifier, at ibahin ng konti 'yung feedback loop. fixed power pa rin kung hindi papalitan 'yung frequency, kung 12V 10A 'yung original na design, sa modified pwedeng 48V 2.5A.

Whew daming palitan. at bababa pa pla ang amperage nya.Zero ako sa electronics eh. Meron kayang mapagbilhan ng khit 36V 30amps na SMPS?

Thanks sa sagot guys.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on October 11, 2010, 03:15:31 PM
^ dati meron akong nabiling 24V 27A na supply sa e-gizmo (nasa Morayta pa sila noon), at napapa-abot ng 34V sa trimmer, tapos pwedeng i-bypass 'yung current shutdown, kaya pwedeng umabot ng 30A pero sobrang init na.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: j2sip on October 12, 2010, 09:25:41 AM
YUn sasa ang perfect sa purpose ko. Meron pa kaya sa stock nilang ganun?  Sir rdpzycho, nakikita ko name mo sa cnczone at sa cnc thread dito. Musta na yung CNC machine mo?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: leux29 on October 12, 2010, 04:21:24 PM
Hi! Mga master ask ko lng po pano ang solution sa mga smps n ngpplactuate n boltahi lalo n sa adaptor ng Laptop. Wlang output kc yong boltahi sa secondary ng pplactuate pati sa primary. regulator nya STR1414A, yong switching reg nya K3713. pno kya m pepermanent to! pls help. di nmn ako tech pro my kunting alam sa repair.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marleona on October 12, 2010, 11:35:06 PM
bakit ganun? may 7V na akong output sa PIC SMPS ko. 26uH, 330uf/16V, IRF503, 1N5401 tapos 50kHz 58% duty cycle ung design ko. kaso bumabagsak ung voltage once na magload ako ng voltage regulator. ano magandang solution para di bumagsak ung voltage?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on October 13, 2010, 07:51:32 AM
bakit ganun? may 7V na akong output sa PIC SMPS ko. 26uH, 330uf/16V, IRF503, 1N5401 tapos 50kHz 58% duty cycle ung design ko. kaso bumabagsak ung voltage once na magload ako ng voltage regulator. ano magandang solution para di bumagsak ung voltage?

nakaclose loop kayo? of constant lang ang duty?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marleona on October 13, 2010, 10:30:03 AM
di po kami nakacloseloop. constant duty cycle kami eh. 58% lang kasi simple generation lang ng pwm ung ginagawa ko sa pic. paano po kaya un??? need help.... huhuhu napapaiyak na ako dito sa smps.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on October 13, 2010, 10:44:00 AM
di po kami nakacloseloop. constant duty cycle kami eh. 58% lang kasi simple generation lang ng pwm ung ginagawa ko sa pic. paano po kaya un??? need help.... huhuhu napapaiyak na ako dito sa smps.

yun po ang dahilan, normal sa SMPS na bumagsak ang output once na niloadan, kung nakaclose loop ka automatic na nagaadjust ang duty cycle to compensate for that effect, kung open loop ka, taasan mo mano-mano ang duty cycle hanggang marating mo desire output. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on October 13, 2010, 11:51:09 AM
@marleona: dapat naka-compute yung duty cycle mo for that specific load. ano ba topology gamit mo?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marleona on October 13, 2010, 02:48:44 PM
buck topology kasi gamit ko eh. nacompute po namin ung duty cycle nun.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on October 13, 2010, 02:54:47 PM
tweak/adjust niyo yung duty to match your specific load.

more likely taasan kasi bumabagsak ang v.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: labgruppen on October 13, 2010, 03:09:45 PM
sa mosfet configuration po yata nila ang problema. non-logic level mosfet directly driven by  the mcu (pwm generated by the mcu) aggravated by the use on N-ch mosfet for high side switching. thus when the voltage at the source node starts to build-up, the mosfet is starved of Vgs. (their mosfet connection is Gate->mcu  Drain->12V Source->inductor node)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on October 13, 2010, 04:48:31 PM
Isa pang problem yan sa buck. Meron yatang circuit na inipost si Yus sa thread n ito na low side switched buck converter. try nyo yun.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on October 13, 2010, 04:57:51 PM
Isa pang problem yan sa buck. Meron yatang circuit na inipost si Yus sa thread n ito na low side switched buck converter. try nyo yun.

yung opto based buck?ok yun:-)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on October 13, 2010, 07:07:03 PM
kaya pala... need to check the specs of the switch. ts?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marleona on October 14, 2010, 01:07:05 PM
di ko po makita ung schematic ni sir yus. hahaha pwede mabigay po ung link.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on October 15, 2010, 10:22:57 AM
ano ba ang bus bar? paano i-compute yung parameters nito?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: emz_jereza on October 17, 2010, 11:43:11 AM
sir nid help..im trying to make a guitar effects power supply..im thinking to make a smps for a power supply..could someone help me with the circuit??vi = 220vAc  vo = 9vdc current is 2A
thanks
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on October 17, 2010, 12:14:53 PM
you can use this. just recompute the component values; specially the transformer.

http://datasheets.maxim-ic.com/en/ds/MAX5022EVKIT.pdf (http://datasheets.maxim-ic.com/en/ds/MAX5022EVKIT.pdf)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: emz_jereza on October 18, 2010, 09:24:57 PM
sir mdyu kulang d2 sa bacolod ung mga part. im planning 2 use parts for cellphone charger etc.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: zee on November 04, 2010, 11:54:14 AM
Mga sir, need help po..

Kailangan ko pa kasi ng battery power supply para sa Wireless Network Camera.. 5V/2.5A max po ung rating ng camera..
 
According dun sa mga nakagawa na, they used 12volts SLA battery tapos gumamit ng LM2576, or LM2676. Pero wala ng available sa Deeco, Alexan, at Egizmo..

Ano po bang pwede kong gamiting alternative? (Or baka meron po sa inyo na may stock jan, bilhin ko na lang.)

Thank you in advance! :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: gie62 on November 04, 2010, 12:53:22 PM
Mga sir, need help po..

Kailangan ko pa kasi ng battery power supply para sa Wireless Network Camera.. 5V/2.5A max po ung rating ng camera..
 
According dun sa mga nakagawa na, they used 12volts SLA battery tapos gumamit ng LM2576, or LM2676. Pero wala ng available sa Deeco, Alexan, at Egizmo..

Ano po bang pwede kong gamiting alternative? (Or baka meron po sa inyo na may stock jan, bilhin ko na lang.)

Thank you in advance! :)

http://www.newportelec.com/ic_l.html (http://www.newportelec.com/ic_l.html)
dyan meron..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on November 04, 2010, 01:09:14 PM
Mga sir, need help po..

Kailangan ko pa kasi ng battery power supply para sa Wireless Network Camera.. 5V/2.5A max po ung rating ng camera..
 
According dun sa mga nakagawa na, they used 12volts SLA battery tapos gumamit ng LM2576, or LM2676. Pero wala ng available sa Deeco, Alexan, at Egizmo..

Ano po bang pwede kong gamiting alternative? (Or baka meron po sa inyo na may stock jan, bilhin ko na lang.)

Thank you in advance! :)

try max1626; available sa e-gizmo. datasheet here (http://tinyurl.com/2w43m5h).

here's a sample circuit.

(http://www.maxim-ic.com/images/qv/1236.gif)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: DimaWari on November 05, 2010, 04:10:37 PM
Hi guys!!

Any idea on how to convert ATX PC Supply to high voltage inverter? lets say 220v ac to 10kv?

thanks in advance..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on November 05, 2010, 04:15:46 PM
errr... not possible. for one, the circuit as a whole is designed to step down the voltages.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on November 05, 2010, 04:24:52 PM
Hi guys!!

Any idea on how to convert ATX PC Supply to high voltage inverter? lets say 220v ac to 10kv?

thanks in advance..

para saan po ang gamit nito?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: DimaWari on November 05, 2010, 04:32:51 PM
Sayang, I have so many junk PC power supply unit.... Even if i change the no. of turns in power
transformer..?
plans ko sana for a gas discharge tube...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: DimaWari on November 05, 2010, 05:00:20 PM
Or maybe i will start from scratch? any diagram po that you would recommend? but using TL494 and C13007?
thanks po sa reply...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on November 05, 2010, 05:47:59 PM
Sayang, I have so many junk PC power supply unit.... Even if i change the no. of turns in power
transformer..?
plans ko sana for a gas discharge tube...

for neon lights?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: DimaWari on November 05, 2010, 06:53:20 PM
Yes and alike.. Lately i just found a circuit.. but could i replace those MOSFET with 2sc13007?
[richieburnett.co.uk/sstc01.gif]
[richieburnett.co.uk/sstc02.gif]

Thanks
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on November 05, 2010, 07:26:08 PM
ac multiplier po need niyo.

http://tinyurl.com/356h7d2 (http://tinyurl.com/356h7d2)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: zee on November 12, 2010, 06:21:19 PM

Nakabili n po ko LM2576 mga sir! Buti na lang sinubukan ko pa rin pumunta sa deeco ever commonwealth kahit sabi sa phone e ubos na. May kwenta rin pala ang pagiging makulit. Hehe.

Oks na sa breadboard, i-PCB ko n lng.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on November 12, 2010, 10:09:39 PM
Nakabili n po ko LM2576 mga sir! Buti na lang sinubukan ko pa rin pumunta sa deeco ever commonwealth kahit sabi sa phone e ubos na. May kwenta rin pala ang pagiging makulit. Hehe.

Oks na sa breadboard, i-PCB ko n lng.

tulungan kita dyan if ever may problema ka sa magnetics at caps.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Pro-Engineer on November 15, 2010, 11:49:28 PM
saan po nakakabili ng high-perm toroid cores?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on November 16, 2010, 02:45:53 PM
merong ilan ng e-gizmo, not sure if yun ang hanap mo...

merong thread na ginawa si tita born about designing inductor without LC meter, I think meron ang e-gizmo nun.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: zee on November 17, 2010, 03:00:40 PM
tulungan kita dyan if ever may problema ka sa magnetics at caps.

actually sir na pcb ko na. npka basic lng nung ginawa ko e. hehe.

ung inductor po binili ko lang din sa deeco, 100uH.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on November 19, 2010, 10:25:50 AM
actually sir na pcb ko na. npka basic lng nung ginawa ko e. hehe.

ung inductor po binili ko lang din sa deeco, 100uH.

oo meron sa deeco 100uH yung caps dapat low ESR,para konting ripple.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: j a y k e z on January 04, 2011, 10:28:53 AM
up ;D

sis sa pc psu pwede bang balitan ung mga output filter electric caps ng mas mataas na uf, karamihan kasi 1000uf 16v ang nakalagay change ko sana ng mga 4700uf 16V?

tsaka pwede pa kaya pataasin ung voltage nun ung +12V gawin ko sana mga +12.something or +13.something?

;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on January 04, 2011, 12:35:26 PM
^ 'yung output caps posibleng magkaroon ng instability kapag pinalitan, naka-compute kasi 'yun doon sa nakalagay na filter. plus, sa ATX specification, merong limit 'yung capacitor load na ilalagay, kaya kung itataas pa 'yung filter, lalong lalapit doon sa limit. though, kung hindi gagamitin sa PC, pwede namang subukan.

'yung 12V, pwedeng i-adjust 'yun sa resistor. though, sasabay din 'yung 5V at 3.3V dahil iisa lang ang regulation ng mga PSU, cross regulated lang.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: updated on January 04, 2011, 11:55:36 PM
kamusta sir yelong apoy? gusto ko matuto mag design ng power supply. SMPS.. output 80vac 1khz
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on January 05, 2011, 11:34:28 AM
kamusta sir yelong apoy? gusto ko matuto mag design ng power supply. SMPS.. output 80vac 1khz

inverte ata iyan hehehe,medo madugo yan need dsp to automatically convert 220Vac to 80Vac at 1kHz,pero base sa servo controlled pwede yan pero need to srep down din yang frequency
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on January 05, 2011, 12:43:29 PM
merong kilala ako gumawa ng discreet na inverter, ang pangalan ay rafft,  ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bytewise on January 05, 2011, 12:58:33 PM
merong kilala ako gumawa ng discreet na inverter, ang pangalan ay rafft,  ;D ;D ;D
oo nga pala sa electronic ballast(CFL) di ko alam kung modulated into 1kHz,iba naiisip ko programmable
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: updated on January 05, 2011, 01:38:44 PM
mga sir, inverter nga. hehe.. si si raft pala ang mahusay sa ganyan.. kelangan ko kasi matutunan..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nicasio on February 20, 2011, 12:18:46 AM
By the way mga bosing if you have questions feel free to ask po.

I'm thinking is I can extend discussion on buck converter design or should I go to other topologies na lang like boost converter,

ano po ba mas maganda? Anyway for the design may inisend na ko link before paano macompute values.

Hi mga BOOSING, Pwede po ba mag tanong ng fault condition ng buck converter design, ano po ba ang explanation bakit nasusunog ang mosfet? Pwede po ba rin lagyan ng sample computation or formula bakit nag breakdown ang device. ;D

Eg: 1. in rush current during start-up
     2. shoot-through current
     3. or pag sunog ang inductor after ng mosfet, masusunog din ang mosfet? ano po ba ang effect sa sunog na inductor doon sa mga mosfets (top at bottom mosfet).
     4. pag may open pin sa mosfet or sa PWM ckt. (LTC3850), possible po rin ba na sanhi ng pagkasunog ang mosfet?

Salamat po. :D

     
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 20, 2011, 11:02:05 PM
design nyo or existing equipment? sa mga baguhan sa pagdedesign ng buck converter malimit nakakalimutan nila eh ang mosfet(N-Channel) eh hindi bastabsata maidadrive sa high side.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: fantom_mayonaise on February 22, 2011, 05:09:57 PM
Sir Glutnix : meron kayong suggestion na circuit for a buck regulator from 12v to around 7volts. As high as 20~30ampere

if feasible lang? :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on February 22, 2011, 07:34:51 PM
^ pwede pa rin naman 'yung standard Buck regulator, lalagyan lang ng protections dahil mas mataas ang amperahe, mas malaki ang destructive power ng leakages.

pwede ring Polyphase Buck converters katulad nung mga gamit sa motherboard, pero hindi na siya basic. mahirap i-troubleshoot 'yung mga ganun ng walang oscilloscope.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 22, 2011, 07:49:12 PM
yan din unang pumasok sa isip ko kanina, interleaved...

tama same lang ng basic buck don't expect lang na kaya iimplement using a single MOSFET.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nicasio on February 22, 2011, 11:07:03 PM
design nyo or existing equipment? sa mga baguhan sa pagdedesign ng buck converter malimit nakakalimutan nila eh ang mosfet(N-Channel) eh hindi bastabsata maidadrive sa high side.

Existing equipment po. Taga debug lang kami M/B na may palaging putok na MOSFET at sunog na inductor.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 22, 2011, 11:16:05 PM
hula ko nauunang masira yung mosfet bago nasusunog yung inductor.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: fantom_mayonaise on February 23, 2011, 02:37:35 PM
sir rdpzycho / sir glutnix :

Mga anong switching frequency ang ideal? Anong frequency nagiging critical yung pcb layout? Meron na akong nakitang controllers na ang operating frequency nasa 100~500khz. Baka din meron kayong alam na source ng ferrite cores para sa 30amperes at this frequency ranges?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nicasio on February 23, 2011, 09:05:41 PM
hula ko nauunang masira yung mosfet bago nasusunog yung inductor.

May instance din po Sir na yong trace mismo ng Supply voltage, Vin ang sunog. Cguro nga yong in-rush start-up current ang sumunog sa mosfet. Or dahil shorted siya sa ground. Kaya ndi nakayanan ng trace.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on February 23, 2011, 09:59:29 PM
sir rdpzycho / sir glutnix :

Mga anong switching frequency ang ideal? Anong frequency nagiging critical yung pcb layout? Meron na akong nakitang controllers na ang operating frequency nasa 100~500khz. Baka din meron kayong alam na source ng ferrite cores para sa 30amperes at this frequency ranges?

kahit anong switching frequency critical ang PCB layout ng SMPS. 'yung sizes ng magnetics ang apektado ng switching frequency. 'yung sa CPU sa mother board, around 100A ang peak nun, greater than 500MHz switching frequency.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 24, 2011, 08:14:22 AM
switching losses are greater at higher freq din.

dapat kaya ng MOSFET mo.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: fantom_mayonaise on February 26, 2011, 06:12:52 PM
sir glutnix / rdpzycho  : should i still be concerned with proper air-gapping if I'm to use an ETD core? yung pinakamalaki sa e-gizmo. Parang mahirap yata magtantya ng air-gap
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 26, 2011, 06:41:08 PM
ano topology? kung flyback required na may airgap.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on February 26, 2011, 08:17:36 PM
tama, ano nga bang topology? kung as inductor, kailangan talagang may gap dahil hindi forced ang reset nung core plus sa gap din talaga nai-store 'yung energy.

hindi naman kailangang saktong-sakto 'yung gap, pero mag-iiba 'yung computed number of windings kapag mali 'yung sukat ng gap.

kung inductor lang talaga at high current, pwede pa naman 'yung toroidal cores. pwede ring multiple cores sa isang inductor. 'yun ang common setup na nakikita ko sa mga Telco rectifier at 30A and up.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: fantom_mayonaise on February 27, 2011, 01:12:17 AM
Buck converter topology po mga sirs.

Also, paano ang testing methodology nyo halimbawa para sa maximum current capacity? Okay lang masunog yung first attempt pero mas okay kung safe yung test. :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on February 27, 2011, 04:20:51 PM
^ nichrome or salt water. mas mura 'yung salt water, palit nga lang ng palit. babahayan kasi ng kung anu-anong insekto. :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: fantom_mayonaise on February 27, 2011, 08:10:34 PM
So if I use an ETD core in a buck converter, I should be concerned with the air-gap? In my case, a torroidal core would be preferable, and a stacked torroid would be better.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: raldski on May 05, 2011, 12:43:17 AM
galing naman! ang dami ng smps expert dito.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 1diyMARKET on May 05, 2011, 02:28:08 AM
Anong Approval Body or Certification ang ipasa para magaming ang SMPS sa mga electornics device :

1.  USA
2.  Europe
3.  Philippines
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 05, 2011, 07:45:33 AM
Safety(Marami to depende sa country pero most are based sa IEC60950, sa europe iba iba din per country dun)
-UL (US)
-TUV
-CCC (China)

EMI
- CISPR(nakalimutan ko na mga numbers, 1 for radiated and 1 for conducted)

Harmonics
- NEMA

Environmental Compliance
- 80Plus
- Energy Star
- Blue Angel

Yung tinatrabaho naming inverter may requirement din sa anti-ilanding kasi connected sya sa grid


Sa Philiphines meron tayong "PS" Mark, Hindi ito yung nakikita sa mohon ng lote natin ;D ;D ;D, Philippine standard daw pero hindi mandatory ang pagsunod dito, hindi rin specific sa power supply lang.

EC - European Conformity yata eh hindi kailangan ng certification, pwedeng kayo na mismo magdeclare base sa audit nyo.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: RaffT on May 05, 2011, 11:43:22 AM
I got a question:

very finicky circuit ba ang forward converter(yung may reset winding)?

kasi on mine, one I apply power, mabagal marating ang 'set' voltage ko, pero kapag inalisan ng power, biglang tataas yung output voltage nya,minsan LAGPAS pa sa set voltage...

anu kaya possible na problema nito?

im using uc3845 chip/single switch topology (my first forward converter project actually)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 05, 2011, 12:39:41 PM
I got a question:

very finicky circuit ba ang forward converter(yung may reset winding)?

kasi on mine, one I apply power, mabagal marating ang 'set' voltage ko, pero kapag inalisan ng power, biglang tataas yung output voltage nya,minsan LAGPAS pa sa set voltage...

anu kaya possible na problema nito?

im using uc3845 chip/single switch topology (my first forward converter project actually)


tama kaya mga polarity ng windings? parang buck converter lang kasi yan na may isolation.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: RaffT on May 05, 2011, 01:31:34 PM
tama kaya mga polarity ng windings? parang buck converter lang kasi yan na may isolation.

yes tama regarding polarity... my primary/reset is 7turns(primary wire heaver gauge compared to reset).. yung secondary naman nasa 250T, Im aiming for about 300mA output so about #27 ata ito(mga scrap ko)...

input voltage is about 12-14Vdc... goal output about 250Vdc
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 05, 2011, 02:10:05 PM
walang gap dapat ang transformer,

kung tama ang polarity ng mga windings, hindi dapat tataas ang output voltage kung nakaoff ang transistor kasi wala namang panggagalingan ng power papunta sa secondary unlike sa flyback na yung nakastored energy ang pumupunta sa load.

 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on May 05, 2011, 02:28:20 PM
Up!!!
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: RaffT on May 05, 2011, 05:05:21 PM
walang gap dapat ang transformer,

kung tama ang polarity ng mga windings, hindi dapat tataas ang output voltage kung nakaoff ang transistor kasi wala namang panggagalingan ng power papunta sa secondary unlike sa flyback na yung nakastored energy ang pumupunta sa load.

 

 nag wind ulit ako ng secondary ko.. interleaved (150t/150t) .... so OK na siya umaabot na ng P250V yung output ko (closed loop).. so meaning kulang lang pala yung secondary turns ko... :)

when I remove power, wala nang 'surge' or 'spike'.. nothing...drain nalang ng stored charge sa filter cap...

matanong ko lang.. bakit walang GAP?

Im using cores similar to ETD(bobbin is not square, sort of oblong)...may gap na 1.5mm ito... gamit ko lang UNGAPPED pag push-pull.. pero pag flyback topo, gapped tlga..


EDIT:
ok gets ko na :) basa mode (switching power supply design )
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on May 05, 2011, 09:55:52 PM
Ang mga flyback ay required na may gap kasi nagstore sila ng energy, ang energy ay napapastore sa gap daw.
Ang mga forward ay hindi dapat nagstore ng energy kasi totoong transformer yun, ang reset winding ang way para izero out ang stored energy kung meron man at idivert pabalik sa source para ready sya sa next cycle.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on May 10, 2011, 01:54:51 AM
Im using cores similar to ETD(bobbin is not square, sort of oblong)...may gap na 1.5mm ito... gamit ko lang UNGAPPED pag push-pull.. pero pag flyback topo, gapped tlga..

actually sis, 'yan 'yung ETD technically. ;D EI / EE core 'yung square ang center leg. ang main advantage nung ETD family is the winding area. mas optimum 'yung pwedeng i-wind kaysa sa square leg.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on May 10, 2011, 01:10:40 PM
actually sis, 'yan 'yung ETD technically. ;D EI / EE core 'yung square ang center leg. ang main advantage nung ETD family is the winding area. mas optimum 'yung pwedeng i-wind kaysa sa square leg.
this is true kaya common eto sa smps,yung ibang design naman PQ yung core na ginagamit,malaki kasi yung product area ng core.mas malaking product area,mas malaking energy to transfer.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Vhelt on July 12, 2011, 03:38:12 PM
Gud pm sir. Magtatanong lang po ko regarding sa smps ng tv using STRS6707 no power ang nakita ko lang na sira ung wasak na 3 pin ic se115 error amplifier ic sa secondary connected xa sa opto coupler. Ang tanong ko lang po anong function ng error amplifier ic na yan sa smps.Tia....
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 12, 2011, 04:29:28 PM
ang hula ko(hula lang kasi wala tayo schematic) eh sa kanya dumadaan yung feedback voltage information coming from the output going to PWM sa primary.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 18, 2011, 07:47:51 PM

papaano ba kukunin ang β ng isang ferrite core? pwede ba itong e measure (trial n error) using LCR meter tapos gamit nalang ng formula para makuha ang β nito?  okay kaya ang kalalabasan nito sa actual application para smps transformer?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 18, 2011, 07:53:14 PM
'yung maximum magnetic field ba? o 'yung permeability?

approximately, pwede sigurong makuha with a LCR (delta ng inductance with certain number of turns), though, para makuha talaga, pwedeng i-trace sa oscilloscope (makikita 'yung hysteresis curve). may mga notes at design ako niyan dati, medyo nakalimutan ko na rin kasi matagal na akong wala sa power. :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 18, 2011, 07:53:14 PM
isang tanong pa  ;D

applicable ba ang formulang ito para sa transformer ng smps?

E / N = 4 x f x βmax x A x 10^-8
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 18, 2011, 07:55:56 PM
^ hindi sis dahil ginawa 'yan for sine waves.

http://www.smps.us/magnetics.html (http://www.smps.us/magnetics.html)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 18, 2011, 07:56:53 PM
'yung maximum magnetic field ba? o 'yung permeability?

approximately, pwede sigurong makuha with a LCR (delta ng inductance with certain number of turns), though, para makuha talaga, pwedeng i-trace sa oscilloscope (makikita 'yung hysteresis curve). may mga notes at design ako niyan dati, medyo nakalimutan ko na rin kasi matagal na akong wala sa power. :D

sis rd, wala nabang ibang factor na e consider? i mean straight lang ba yong computation tapos apply na sa formula?

nakagawa kasi ako noon pero lahat given na e  ;D  ngayon may mga cores ako pero hindi ako sigurado sa β ng mga ito  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 18, 2011, 07:59:47 PM
alin? kung makuha 'yung max B? dine-derate pa rin kasi magbabago rin siya with respect to temperature at kung may residual DC na dumadaan. ang typical max, IIRC, nasa 2000, pero ang ginagamit ko is 1200 to 1400.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 18, 2011, 08:00:16 PM
^ hindi sis dahil ginawa 'yan for sine waves.

http://www.smps.us/magnetics.html (http://www.smps.us/magnetics.html)

para pulse daw yong 4 sis, yong 4.44 ang para sine wave daw sabi nila  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 18, 2011, 08:02:01 PM
ah, 4 na pala 'yung naka-post. hehe. yup, 'yan nga, * duty cycle pa.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 18, 2011, 08:03:22 PM
alin? kung makuha 'yung max B? dine-derate pa rin kasi magbabago rin siya with respect to temperature at kung may residual DC na dumadaan. ang typical max, IIRC, nasa 2000, pero ang ginagamit ko is 1200 to 1400.

so mag-apply ng 65% derating factor sa core βmax sis?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 18, 2011, 08:06:01 PM
^ depende na sa designer sis. 'yung mga advance designs (merong mga monitoring), sinasagad 'yan para mapaliit 'yung size ng supply.

push-pull 'yung mga ginagawa ko dati kaya may tendency talaga maging unbalnced dahil 'di madaling lagyan ng DC blocking. kaya halos half lang ng Bmax ginagamit ko.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 18, 2011, 08:08:21 PM
ah, 4 na pala 'yung naka-post. hehe. yup, 'yan nga, * duty cycle pa.

duty cycle in t sis? o convert ko yong f sa  1 / f = t / 2 = duty cycle ?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 18, 2011, 08:09:14 PM
^ pecentage na.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 18, 2011, 08:11:05 PM
^ pecentage na.

ah okay sis...50% ba o pwede upto 60% max duty cycle ang smps? at max load.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 18, 2011, 08:13:20 PM
50% max, pero with advanced controls (typically sa papers lang makikita) pwedeng umabot hanggang almost 100%.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 18, 2011, 08:15:27 PM
^ depende na sa designer sis. 'yung mga advance designs (merong mga monitoring), sinasagad 'yan para mapaliit 'yung size ng supply.

push-pull 'yung mga ginagawa ko dati kaya may tendency talaga maging unbalnced dahil 'di madaling lagyan ng DC blocking. kaya halos half lang ng Bmax ginagamit ko.

a okay sis.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 18, 2011, 08:18:34 PM
50% max, pero with advanced controls (typically sa papers lang makikita) pwedeng umabot hanggang almost 100%.

hhmm tindi nong almost 100% a!  ;D

sis, at no load condition ilang % lang ba dapat ang duty cycle?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 18, 2011, 08:21:07 PM
mababa 'yan. minsan nasa 2% to 5% lang, lalo na kung malaki 'yung capacitor.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 18, 2011, 08:27:50 PM
mababa 'yan. minsan nasa 2% to 5% lang, lalo na kung malaki 'yung capacitor.

so typically pwede maglaro ang pulse width from 2% upto 50% depende sa load.

okay sis thanks!

limang points sana bigay ko sa yo pero indi pala pwede  ;D


Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 18, 2011, 08:30:12 PM
yup. makakabuo 'yun ng subharmonic waveform. kapag 'di optimized 'yung feedback path, mag-oscillate siya. kaya kung fixed load tapos malikot ang duty cycle, may control loop instability.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 18, 2011, 08:40:57 PM
yup. makakabuo 'yun ng subharmonic waveform. kapag 'di optimized 'yung feedback path, mag-oscillate siya. kaya kung fixed load tapos malikot ang duty cycle, may control loop instability.

hhmm...sis yong secondary feeback to primary ba ay para controlin lang ang width ng pulse? o pati na yong amplitude ng primary ? para regulated yong out at any rated load.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 18, 2011, 08:42:41 PM
pulse width lang sis. bale 'yung averaged secondary amplitude ang kino-control.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 18, 2011, 08:48:29 PM
pulse width lang sis. bale 'yung averaged secondary amplitude ang kino-control.

a okay, so pulse width lang to control output amplitude at any given rated load. kaya pwde itong gumalaw at mag osc.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 18, 2011, 08:58:00 PM
tanong uli  ;D

i was given this TNY280 PN a 5w smps ic and somebody wants me to amplify the output to 200w  ;D posible kaya ito?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 18, 2011, 09:02:56 PM
TinySwitch? medyo mahirap 'yan sis, highly integrated kasi 'yan, pati 'yung current sensing resistor nasa loob (which is part of the control loop and current limiting function). kung isa 'yan doon sa kailangan ng external resistor, baka pwede pa kabitan ng external FET.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 18, 2011, 09:10:54 PM
TinySwitch? medyo mahirap 'yan sis, highly integrated kasi 'yan, pati 'yung current sensing resistor nasa loob (which is part of the control loop and current limiting function). kung isa 'yan doon sa kailangan ng external resistor, baka pwede pa kabitan ng external FET.

ganon nga nakikita kong problema sis papaano makalagay ng external drive sa tny280 kung ang gagamiting control loop ay siya pa rin  :(
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 18, 2011, 09:48:45 PM
pwede kaya ratio and proportion dito? ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 19, 2011, 09:58:57 AM
tanong uli aki  ;D

sa transformer formula na  E = 4 x f x N x βmax  x A x 10^-8  constant na po kasi yong 4 = na quarterwave,  N = no. of turns,  βmax = core flux density , A = area ng core at saka yong factor na 10^-8 pagnagawa na yong transformer di ba?

ang ibig bang sabihin nito na ang regulator ng amplitude o voltahe ng smps ay ang variable f = frequency? at ang nagbibigay ng current sa variable load ay ang variable pulse width? kaya tinatawag itong pwm o pulse width (frequency) modulated supply?

solly kung natanong na ito hindi ko lang mabasa lahat ng pages ng thread nasa 48 pages na kasi ito inaantok na ako sa limang pages palang  ;D

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 19, 2011, 11:21:04 AM
^ 'yung pulse width lang sis. ibang classification pa 'yung Frequency Controlled Supplies (meron ding ibang supply na nagva-vary ng Frequency not to control voltage but to limit emission levels para pumasa sa EMC Qualifications).

bale doon sa equation, kasama 'yung Duty Cycle, hindi talaga constant. kaya variable talaga 'yung Bmax depende sa duty cycle.

Bmax = VpkD10^8/4NAcF
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 19, 2011, 01:58:06 PM

kung rearrange ko ang equation nyo sis magiging ganito:

E = 4 x f x N x βmax  x A x 10^-8
                       D


wow... everything will depend sa on time ng pulse.

thanks sis.   
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: jenny diaz on July 24, 2011, 04:18:37 PM
mga sir, me nirerepair po akong power supply,sa handspree lcd tv baka matulungan nyo po ako. FSP212-3F01 REV:1 Dead set,no standby power. sana po me schematic diagram. na search ko na sa google, sabi sa isang forum madalas masira ung transistor,Q7,at zener diode, ZD4. nung chineck ko sira talaga.15v ung zener diode pro ung Q7 di ko matukoy number nya,pro npn sya. triny kong palitan ng  C815  nung tinest ko me standby 5v na pro after few minutes namatay din. nadamay tuloy ung Q11 nasira narin. baka nagkamali akong ikabit ung mga pins,ECB.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: randy80 on September 26, 2011, 06:50:44 PM
hello mga sirs,. mahirap po ba e troubleshoot ang smps pag walang feedback circuit o optoisolator?napansin ko mga sirs yung smps ng tv na philips walang optoisolator. sabi ng iba pag ganito daw ang design kailangan ko daw ng load mga sirs? hindi daw ako maka measure ng exact value pag walang load. tanung ko lang mga sirs toto ba yung sinasabi nila?pls help mga sirs kailangan ko ng tulong nyo mga sirs.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Topaklong on October 11, 2011, 01:38:14 PM
Pa help naman dyan mga experts kung sino meron ferrite transformer winding calculation para push pull configuration smps. Tagal ko na naghanap nito para sa project ko. Thanks.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on October 11, 2011, 02:27:43 PM
^ marami 'yan sa SMPS cookbooks ng TI.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Topaklong on October 12, 2011, 07:21:33 AM
@rdpzycho

^ marami 'yan sa SMPS cookbooks ng TI.

Thanks sa info. Downloaded and convert to pdf. Ang daming pages. Sarap basahin mga ito. ;)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nicasio on November 13, 2011, 05:17:41 PM
Mga Sir,

May discussion po ba kayo kung paano gumagana yong short voltage protection gaya ng LTC 3810-5. Ibig sabihin po ba nito na pag i-short  physically yong output to ground ay ndi masisira ang I.C. hanggat nawala yong short circuit at gagana ulit yong I.C.?

Sana marami akong matutunan pa dito. More power sa inyo.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on November 13, 2011, 05:28:51 PM
merong set current 'yung controller ('yung iba voltage dependent), kapag naabot 'yun at na-detect nung current sense nung controller, mamamatay siya pulse-by-pulse, then 'yung iba ibababa 'yung pulse rate para mas lumiit 'yung power consumption.

gagana ulit 'yun, though merong rare cases na nasisira kapag heavy transient talaga.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: alyas on November 22, 2011, 10:42:14 PM
UP UP UP  SUBSCRIBING ulit

Meron na akong LC Meter  ... it can measure up to 70mH inductance.  Ano ba yung mga typical inductance sa mga ATX power supply?  Would the 70mH suffice.

I have a dead ATX PSU.  I want to experiment first using the ac line filter inductors.  Can this be used as the main inductor in a buck config?

Kaya ba ng mga typical 877a mcu ang pwm or do we need dedicated pwm ic?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on November 22, 2011, 10:45:12 PM
^ kung kasama ang feedback algo sa 877 sir, 'di kakayanin, mas ok pa gumamit ng PWM IC.

maliit lang ang typical inductor dito sir, madalas nasa 10mH na ang pinakamalalaking nae-encounter ko.

'yung line filters na toroidal sir? o 'yung EI type? kapag line filter kasi sir mataas ang permeability, kailangang i-gap para maka-store ng charge at hindi mag-saturate sa DC.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: alyas on November 22, 2011, 11:19:43 PM
Yup yung line torroid sa ac input  ... so hindi pala pwede as is.  Sana pala di ko na unwind and use it as is na lang. 

There is a couple of transformers sa primary side (or hot side ba tawag dito) and then one big torroid sa secondary (or cold side ba tawag dito).   So I guess I'll start with that big torroid core on the secondary side instead.

Medyo cheap ako ngayon ....  wala akong pambili ng pwm ic, will an atmeg8515 or atmega8 running at 16MHz suffice for the pwm including the feedback algo?


Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on November 22, 2011, 11:42:17 PM
mas masasagot kayo nina glutnix sir. pero based on the rectifiers we've been working on, kung hindi PWM IC (mostly Eltek, AcBel, Delta, Siemens, Ericsson), DSP ang gamit - dsPic or TMS320, karaniwan naman 'to galing ng Emerson. 'yung mga PWM IC based, meron pa ring mga microcontroller na assistance para sa initialization, safety, etc.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on November 23, 2011, 01:06:48 AM
yup merong PWM ang 877a but its just for producing a PWM signal (Duty Cycle).

Ang closed loop SMPS PWM ay may mas complex na PWM which is better implemented using dsPIC na designed talaga for SMPS.

closed loop SMPS PWM ay typically are implemented with 2 feedback. 1 for output voltage and the other is for the inductor current.
Eto yung tinatawag na current mode control which gives better response sa transients.

It is better described sa binanggit ni sir rdpzyho ...

merong set current 'yung controller ('yung iba voltage dependent), kapag naabot 'yun at na-detect nung current sense nung controller, mamamatay siya pulse-by-pulse,

ngayong ang limitations kung gagamit tayo ng MCU are...

1. una yung processing speed ng MCU, ilang MCU cycles ba natin kayang iprocess ang PID at every PWM Cycle interval? Typical frequency is between 75kHz-100kHz sa mga natrabaho ko na na SMPS. so dapat every 10uS eh nagagawa nya matapos ang pagcompute pa lang ng PID, kasama na mga latency sa interrupts nun.
2. another limitation is we have to sample voltage and current at every PWM cycle. I think setup time pa lang ng sample and hold circuit yung 10uS na yun sa mga common MCU, (not sure with atmel, PIC user kasi ako).

sa pagupdate ng PWM duty eh wala naman akong nakikitang problem sa 877a, yun nga lang limitations aove ang nakikita kong problema.

sa dsPIC merong way sa hardware PWM i-implement yung current mode control(pagbasa ng current then patayin PWM signal cycle by cycle) na output voltage na lang ang babantayan mo.

maganda rin pagexperementuhan sir ang fast ADC at CPLD as PWM.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: updated on November 23, 2011, 01:10:33 AM
gumamit ka ba ng PWM nung monday night ;D?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: insomartin on November 23, 2011, 01:18:48 AM
HIJACK!!!
 ;D ;D ;D ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: alyas on November 23, 2011, 07:16:44 AM
ok sir glutnix at rd,  mukhang di kakayanin ng avr kasi although mabilis sa processing, mabagal ang adc ng mga avr na nasa around 15ksps.  Yung mga pic16/18 naman medyo mabilis ang adc pero mabagal naman sa processing.

Meron akong pic24hj32gp202,  40MIPS at adc 1.1 Msps@10-bit or 500Ksps@12-bit.  Pwede na siguro ito pero addditional learning curve na naman.

I'm not after industrial/commercial grade smps design.  Gusto ko lang gumawa ng simple smps tracking pre-regulator for a linear PSU para di uminit masyado yung linear regulator.

Would a simple buck converter suffice  for that purpose?  If I am to use the torroid core sa atx psu, does that mean I have to work in the range of 100KHz pwm? 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on November 23, 2011, 08:55:09 AM
Quote
Medyo cheap ako ngayon ....  wala akong pambili ng pwm ic, will an atmeg8515 or atmega8 running at 16MHz suffice for the pwm including the feedback algo?
madaming 3842 dito  ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on November 23, 2011, 01:07:06 PM
kung meron kayong ATX PSU sir, meron na rin 'yang PWM IC, typically, TL494 nga lang kung 'yung generic. mabagal 'yung internal transistors niya kaya kapag ginagamit ko 'yan, gumagawa ako ng external na totem pole or kahit pampabilis lang ng turn off time.

baka medyo kakapusin pa rin 'yan sir, 40MIPS for 100kHz = 40 instructions per cycle lang nung PWM, at 20kHz, pwedeng marginal at 200 instructions per cycle, kailangan optimized lahat ng instructions ng PID. medyo madali 'to sa DSP dahil MMAC's sila rated (millions of multiply-accumulate per second), 'yung operation na kailangan mismo nung PID. pwede rin sa CPLD as suggested ni sir glutnix dahil pwedeng gumawa ng parallel operations at hindi limited ng MIPS.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: insomartin on November 23, 2011, 01:15:38 PM
Gusto ko lang gumawa ng simple smps tracking pre-regulator for a linear PSU para di uminit masyado yung linear regulator.

baka naman pwede na... since pre-regulator lang? ummmmm di naman din kailangan na uber precise.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on November 23, 2011, 01:57:59 PM
Gusto ko lang gumawa ng simple smps tracking pre-regulator for a linear PSU para di uminit masyado yung linear regulator.

baka naman pwede na... since pre-regulator lang? ummmmm di naman din kailangan na uber precise.

pwede sir sa buck regulator them kahit hiccup mode yung OVP and OCP
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on November 23, 2011, 03:50:30 PM
^ sabagay pwede nga sir dahil meron namang secondary regulator.

kulang pala ng 0 'yung computation ko ng instructions per PWM cycle sa taas kanina, 400 for 100kHz at 2000 for 20kHz dapat. ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: alyas on November 23, 2011, 07:54:35 PM
unfortunately, yung pwm ic ng sira kong atx psu, ayun yung nasunog, naka mount yung chip sa isang daughter board.  Kaya laking gulat ko, buo yung main mosfet.  Nakalimutan ko na yung part number at natapon ko na but I remember cearly when I checked the part number, it was a current-mode pwm ic.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on November 23, 2011, 08:26:31 PM
Gusto ko lang gumawa ng simple smps tracking pre-regulator for a linear PSU para di uminit masyado yung linear regulator.

baka naman pwede na... since pre-regulator lang? ummmmm di naman din kailangan na uber precise.

ganito rin gusto ko sa smps dapat pang reg lang. yong total isolation kasi sa primary ang nawawala smps at saka delikado at walang silbi yong line filters nito pagwalang proper earthing yong 3 prong plug.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: insomartin on November 23, 2011, 09:09:29 PM
ganito rin gusto ko sa smps dapat pang reg lang. yong total isolation kasi sa primary ang nawawala smps at saka delikado at walang silbi yong line filters nito pagwalang proper earthing yong 3 prong plug.

back read po...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on November 23, 2011, 09:12:58 PM
back read po...

ooppps magkaiba nga
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on November 23, 2011, 09:16:09 PM
ganito rin gusto ko sa smps dapat pang reg lang. yong total isolation kasi sa primary ang nawawala smps at saka delikado at walang silbi yong line filters nito pagwalang proper earthing yong 3 prong plug.

hindi rin naman sir, nakaka-filter pa rin siya kahit wala 'yung earth, mas maganda lang talaga kapag earthed. part 'to ng trabaho ko dait kaya may idea ako sa laki nung nababawas na line noise dahil doon sa filters, also as verified by ASTI-DOST EMC Equipment. improper placement nung X caps ang malaki ang contribution sa noise.

kaya sa preliminary design nung line filter, kailangan ding i-consider kung gagamitin ba siya sa non-earthed plugs. maraming discussion nito sa EMC books. at maraming author ang nagsasabi na mas madali siyang i-filter dahil mas maliit 'yung chances na may pumasok na common mode noise sa earthing.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: alyas on November 25, 2011, 06:02:51 PM
(http://i1138.photobucket.com/albums/n540/alyasngelab/powersupply_schematic.gif)
From http://www.smps.us/12volt-powersupply.html (http://www.smps.us/12volt-powersupply.html)

Yung TL431 ba ang nagdidictate ng output voltage?  Pwede ba mamodify ito to make the output variable from 0~30VDC?

Punta akong Raon at bili ako ng mga atx psu sa bangketa, baka may mabili ng tig 100~200 petot lang.  Magkano ba bentanhan ng mga surplus 350W atx psu?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on November 25, 2011, 06:11:25 PM
^ yup sir. pwede niyong gawing trimmer or pot 'yung R15 at R14 para gawing variable 'yung voltage, 'yung lang dapat i-compute 'yung inductor sa extremes sir kasi posibleng maging DCM (discontinuous) siya sa ibang condition.

kung current mode naman 'yung control, medyo kakayanin niya kahit nasa DCM na 'yung inductor.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on November 25, 2011, 06:17:27 PM
(http://i1138.photobucket.com/albums/n540/alyasngelab/powersupply_schematic.gif)
From http://www.smps.us/12volt-powersupply.html (http://www.smps.us/12volt-powersupply.html)

Yung TL431 ba ang nagdidictate ng output voltage?  Pwede ba mamodify ito to make the output variable from 0~30VDC?

Punta akong Raon at bili ako ng mga atx psu sa bangketa, baka may mabili ng tig 100~200 petot lang.  Magkano ba bentanhan ng mga surplus 350W atx psu?

yung R14 and R15 ang nagdidikta ng output(voltage divider)bale 2.5V yung reference na yung pin 1 ng TL431 w/c is error amp and stable voltage reference in one,delikado ding baguhin 0-30VDC short circuit na kasi yung 0V,i think pwedeng i modify yan gawing variable yung R14 and R15 to make it variable but sa circuit above baka 5V-12V lang pwede kasi magdedepende sya sa duty cycle ng 3844 kung kaya pa, kapag papaabutin mo ng 30V baka magrerewind ka ng transformer to compensate yung output.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 25, 2011, 06:20:54 PM

Yung TL431 ba ang nagdidictate ng output voltage?  Pwede ba mamodify ito to make the output variable from 0~30VDC?

Punta akong Raon at bili ako ng mga atx psu sa bangketa, baka may mabili ng tig 100~200 petot lang.  Magkano ba bentanhan ng mga surplus 350W atx psu?

Kung sa TL431 ka mag adjust malabo mong mkuha ang zero volt, pwede yung iniisip mo pero limited output lang at yung max voltage na target mo depende sa (OVP) over voltage protection makikita m sa isang pair ng optocoupler pwede mong maniubrahin yun. make sure lang na kaya ng MOSFET ang power na kailangan mo then maglagay ka ng resistor sa auxilliary supply patungo sa modulator IC, nagawa ko na yan dati. Meron ako ditong adjustable 9~30V out at autovolt In.

(http://i41.tinypic.com/mjolxt.jpg)

edit attachement no value yung una.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on November 25, 2011, 06:28:34 PM
Kung sa TL431 ka mag adjust malabo mong mkuha ang zero volt, pwede yung iniisip mo pero limited output lang at yung max voltage na target mo depende sa (OVP) over voltage protection makikita m sa isang pair ng optocoupler pwede mong maniubrahin yun. make sure lang na kaya ng MOSFET ang power na kailangan mo then maglagay ka ng resistor sa auxilliary supply patungo sa modulator IC, nagawa ko na yan dati. Meron ako ditong adjustable 9~30V out at autovolt In.

(http://i43.tinypic.com/o71wmx.jpg)
malabo nga sir kasi reference mo 2.5V malamang hanggang doon nalang 2.5V,pwedeng gawing zero yan kung maglagay ka ng active preload using MOSFET then kapag 2.5V na saka si output ang magsasalo lahat ng power.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: alyas on November 25, 2011, 06:35:26 PM
Thanks Pinoy Tech, master RD at basura_man.

Pwede na yung 9~30V.  Gusto ko lang gawing tracking pre-regulator.  Main regulator eh Linear Regulator pa rin.

@ pinoy_tech, yung transformer T2 mo ba eh yung torroid core din lang na galing sa atx psu ang gamit mo?  Do I have to rewind or is it the primary transformmer sa hotside?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on November 25, 2011, 06:42:37 PM
Thanks Pinoy Tech, master RD at basura_man.

Pwede na yung 9~30V.  Gusto ko lang gawing tracking pre-regulator.  Main regulator eh Linear Regulator pa rin.

@ pinoy_tech, yung transformer T2 mo ba eh yung torroid core din lang na galing sa atx psu ang gamit mo?  Do I have to rewind or is it the primary transformmer sa hotside?
di ko makita yung posts ni sir pinoy_tech so i can't comment,hint dito is remember energy transformer ang flyback(yung ETD core ang itsura ng main xformer not toroid),magpapalit ng turns ratio ng main xformer then adjust sa divider using pot like sir rd said basta covered yung voltage divider yung output sa recompute sa OVP(yung isang opto CN17,recompute sa zener voltage usually ang OVP is 120% ng output voltage)for safety purposes.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 25, 2011, 06:50:52 PM
Thanks Pinoy Tech, master RD at basura_man.
Pwede na yung 9~30V.  Gusto ko lang gawing tracking pre-regulator.  Main regulator eh Linear Regulator pa rin.
@ pinoy_tech, yung transformer T2 mo ba eh yung torroid core din lang na galing sa atx psu ang gamit mo?  Do I have to rewind or is it the primary transformmer sa hotside?

Pwedeng toroid kaso medyo malaki ng konte sa ordinary toroid ng atx, malaki kase ang role nun. Sya ang magbibigay ng half swing sa forward mode pati yung secondary diode na kung titingnan mo ay naka reverse bias, akala ng marami walang silbi pero nandun yung half part ng power. Pwede mong gamitin ang dalawang old transformer ng atx, mag rewind ka. Use heavy gage para di uminit ang coil. Ganito ang perspective ko sa 2nd version ko, kasya pa rin sa casing ng pc psu. T2 is another trafo sis. Forward mode sure akong walang voltage dropping kahit heavy loads.

(http://i42.tinypic.com/r02ydu.jpg)

My old version :
SMPS.mpg (http://www.youtube.com/watch?v=Eu4ebKall64#)

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on November 25, 2011, 08:37:54 PM
hindi rin naman sir, nakaka-filter pa rin siya kahit wala 'yung earth, mas maganda lang talaga kapag earthed. part 'to ng trabaho ko dait kaya may idea ako sa laki nung nababawas na line noise dahil doon sa filters, also as verified by ASTI-DOST EMC Equipment. improper placement nung X caps ang malaki ang contribution sa noise.

kaya sa preliminary design nung line filter, kailangan ding i-consider kung gagamitin ba siya sa non-earthed plugs. maraming discussion nito sa EMC books. at maraming author ang nagsasabi na mas madali siyang i-filter dahil mas maliit 'yung chances na may pumasok na common mode noise sa earthing.

kuya Rd, tanong ulit  ;D mabuti at nakapag work na pala kayo nito, nalilito kasi ako sa filters ng smps, saan ba ito nakaharap sa line side o sa load side?

kung titingnan ko ito sa electrical side dapat kasi filter ito para sa line para walang pumasok na hi freq harmonics sa linya ng bahay, pero kung titingnan ko naman ito sa electronics side dapat e filter nito ang noise/transients na galing sa main line para wag masira yong components na directly connected sa main line.  :-\  

o bidirectional ang filter na nito dahil both sides yong caps ng L? pero i doubt it is in line side dahil usually yong Y-caps ay nasa load side nakalagay.

ang usuall na ginagawa ko para tumahimik itong smps dalawang series na line filters ang inilalagay ko to double the Y-caps  :(  pwede isa lang pero kailangan yong pang-medical equipment na line filters ang gagamitin dahil both sides ang Y-cap nito.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on November 25, 2011, 09:06:46 PM

ay can really see, na laking problema nito sa mga EE kapag hi power smps na lahat ang gagamitin natin para sa appliances ng mga bahay  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on November 25, 2011, 09:15:29 PM
kuya Rd, tanong ulit  ;D mabuti at nakapag work na pala kayo nito, nalilito kasi ako sa filters ng smps, saan ba ito nakaharap sa line side o sa load side?

kung titingnan ko ito sa electrical side dapat kasi filter ito para sa line para walang pumasok na hi freq harmonics sa linya ng bahay, pero kung titingnan ko naman ito sa electronics side dapat e filter nito ang noise/transients na galing sa main line para wag masira yong components na directly connected sa main line.  :-\ 

o bidirectional ang filter na nito dahil both sides yong caps ng L? pero i doubt it is in line side dahil usually yong Y-caps ay nasa load side nakalagay.

ang usuall na ginagawa ko para tumahimik itong smps dalawang series na line filters ang inilalagay ko to double the Y-caps  :(  pwede isa lang pero kailangan yong pang-medical equipment na line filters ang gagamitin dahil both sides ang Y-cap nito.


bidirectional talaga 'yan sir, pero meron kasing mga nagtitipid ng konti na basta pumasa lang sa regulation ok na kaya typically nasa galing ng load side 'yung Y caps. normally kasi ok naman sa load na tumanggap ng harmonic at 'yung transients 'yung varistor naman ang sasalo. meron din kasing susceptance test na papasukan ng interference 'yung device at mas madali 'yung ipasa kaysa doon sa interference test.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: insomartin on November 25, 2011, 09:17:19 PM
ay can really see, na laking problema nito sa mga EE kapag hi power smps na lahat ang gagamitin natin para sa appliances ng mga bahay  ;D

"laking problema" ganun ba. try mong lahat nang gamit mo sa bahay eh de transformer. mas madali mag repair nang SMPS kesa mag rewind nang same spec transformer.

i can't imagine HOW big would a PC, Cellphone or a LAPTOP power supply kung transformer ito. and how inefficient it is.

wala din negosyo sa repair at service centers kung perpektong di nasisira ang item. lahat magsasara na.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on November 25, 2011, 09:41:06 PM
bidirectional talaga 'yan sir, pero meron kasing mga nagtitipid ng konti na basta pumasa lang sa regulation ok na kaya typically nasa galing ng load side 'yung Y caps. normally kasi ok naman sa load na tumanggap ng harmonic at 'yung transients 'yung varistor naman ang sasalo. meron din kasing susceptance test na papasukan ng interference 'yung device at mas madali 'yung ipasa kaysa doon sa interference test.

so bidirectional pala talaga dpat yong input filters, k thanks.

"laking problema" ganun ba. try mong lahat nang gamit mo sa bahay eh de transformer. mas madali mag repair nang SMPS kesa mag rewind nang same spec transformer.

i can't imagine HOW big would a PC, Cellphone or a LAPTOP power supply kung transformer ito. and how inefficient it is.

wala din negosyo sa repair at service centers kung perpektong di nasisira ang item. lahat magsasara na.

parehas lang po ang laki ng 500W na transformer at over-all casing size ng 500W na smps, try nyo pong e size up ito smps ng pc nyo, yong bigat lang po parang 100 times yata.

anyway i think the conveniences always equates with sacrifices  ;)

EEs are now suffering from harmonics due to hi-capacity motor switching drives.  :(
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: insomartin on November 25, 2011, 09:46:35 PM
^ some company even hotels (nakita ko lang sa tv) are putting harmonic filters and power conditioning sa systems nila. di maiiwasan yun sa madaming motors and switchmodes.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on November 25, 2011, 09:48:15 PM
parehas lang po ang laki ng 500W na transformer at over-all casing size ng 500W na smps, try nyo pong e size up ito, yong bigat lang po parang 100 times yata.

depende rin sa design sir (power density), marami akong nahahawakan ngayong 1500W SMPS na halos kasya sa palad ko ang laki, at kasing taas lang ng CDROM drive. 3x smaller kaysa doon sa 2000VA na transformer. dahil 'to sa advancements sa efficiency (lossless topologies) kaya 'yung mga heatsink ng iba wala ng fins pero malamig pa rin.

mas madaling makita 'yung size difference pagdating na sa higher powers, 'yung 15kVA, halos kasing laki lang ng PC.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on November 25, 2011, 09:54:01 PM
^ nakalimutan kong i-note, 'yung 1500W, may kasama pa palang Power Factor Correction preregulator.

sa regulation kasi (CE and FCC) kasama rin 'yung harmonics, merong given curve 'yun. kaya lang ang problema, 'yung curve limits para lang naman sa isang device, kapag marami ng parallel, doon na may problema. :D

kung nahihirapan na sa harmonics, dapat ipa-mandate na gawing standard ang PFC preregulator sa greater than xxxW na SMPS. halos lahat ng nahahawakan ko ngayon may PFC na.

ang isa pang pwedeng gawin ng establishments, gumawa ng PFC regulated na DC outlet tapos doon kokonekta lahat ng SMPS naman ang supply. naalala ko tuloy nung nasa design pa ako ng SMPS (Portable Inverters), merong ilang bansa pa na DC ang outlet sa bahay.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on November 25, 2011, 09:56:53 PM
yah we can integrate it all in one ASIC smps IC, but if we try to put it into test as rigid as the transformers at same power rating again it will size up to transformer size  ;D

 EEs are now finding ways to size up their cores because of hi-cost, hope they come-up with lighter materials they want to size it down but the problem is the increase in weigth.  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on November 25, 2011, 10:08:14 PM

1-2 mils na gold wire + 32 x 32 x 5mils na Si versus AWG#8 na copper wire + santambak na bakal  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on November 25, 2011, 10:10:43 PM
^ it's as rigid and as heavy duty as the iron cores. kahit mahulog 'di nabibiyak 'yung ferrites sa loob. industrial SMPS 'yung mga 'yun, not ordinary household ones, sa cellsite ginagamit, at as is na 'yung size niya, diretso na sa cabinet.

little known fact, isa rin sa pinakamaliit na SMPS 'yung katabi ng CPU sa motherboard. it's rated to run at 200W (with 100A or more peak current rating) at that small size. 'yung mga mas bago, mas maliliit pa. sobrang liit nila kasi nasa MHz region na ang switching nila. power density at efficiency ang primary concern sa design nila.

1-2 mils na gold wire versus AWG#8 na copper wire  ;D

kung gagamit kaya ng iron core transformer ang mga LCD TV gaano kaya sila kalaki?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on November 25, 2011, 10:13:19 PM
^ it's as rigid and as heavy duty as the iron cores. kahit mahulog 'di nabibiyak 'yung ferrites sa loob. industrial SMPS 'yung mga 'yun, not ordinary household ones, sa cellsite ginagamit, at as is na 'yung size niya, diretso na sa cabinet.

little known fact, isa rin sa pinakamaliit na SMPS 'yung katabi ng CPU sa motherboard. it's rated to run at 200W (with 100A or more peak current rating) at that small size. 'yung mga mas bago, mas maliliit pa. sobrang liit nila kasi nasa MHz region na ang switching nila. power density at efficiency ang primary concern sa design nila.

kung gagamit kaya ng iron core transformer ang mga LCD TV gaano kaya sila kalaki?

pwede kuya Rd kasing nipis ng LCD TV medyo malapad nga lang siguro sa smps pcb nito.....iron cores tranformers are not always made square or circle, it can also be made thin.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on November 25, 2011, 10:18:02 PM
^ I mean the 1-inch thick panels na latest models. gaanong kalaki na ang iron core trafo nun?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on November 25, 2011, 10:20:32 PM
yes kuya Rd as thin as LCD TV @ 100W medyo malapad lang to compesate the needed area. special cores sizes na po ito ko gugustuhin lang talaga.

we can made transformers square, circle or rectangle as long ang needed area are meet with some compensation due to shapes.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on November 25, 2011, 10:26:10 PM
pero gaanong kalaki? kasing-size lang din ba ng cellphone? remember the raison d'etre of a 400Hz aircraft electrical system is the size and weight advantage over 60Hz, albeit, at the cost of efficiency.

kapag dumating 'yung time na common na 'yung low loss cores at high frequency, magiging mas maliit pa sila. siyempre as of now, sa can afford na industries pa lang sila makikita.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on November 25, 2011, 10:32:07 PM
i'm also really surprise how they do that in smps, they downsize the transformer by increasing the frequency right? a very wise move, but oh my! their are hundreds of components around the transformer  ???

it will automatically increase the failure probabilty by 100X  ::)

 ;D ;D ;D

let it be nalang and let the future solve its problems  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on November 25, 2011, 10:50:05 PM
hindi rin naman lahat 'yung additional components liability sa failure sir, depende na rin sa design. meron na akong mga na-encounter na sobrang dami ng failure modes at protection niya doon sa modes na 'yun, napupunta lang sa amin dahil nasisira 'yung fan, napupuno ng alikabok. ;D majority ng nare-repair naming rectifier (na SMPS) 'yung basic lang ang protection at mas konti ang components, 'yung halos basic circuit topology lang na given sa datasheet.

parang sa eroplano rin, hundreds of devices na 'yung naidagdag which we cannot say na directly nag-contribute sa 100x more failure probability dahil habang tumatagal pakonti nang pakonti ang aircraft accidents dahil dito sa mga dinadagdag.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: alyas on November 26, 2011, 12:30:25 AM
Pwedeng toroid kaso medyo malaki ng konte sa ordinary toroid ng atx, malaki kase ang role nun. Sya ang magbibigay ng half swing sa forward mode pati yung secondary diode na kung titingnan mo ay naka reverse bias, akala ng marami walang silbi pero nandun yung half part ng power. Pwede mong gamitin ang dalawang old transformer ng atx, mag rewind ka. Use heavy gage para di uminit ang coil. Ganito ang perspective ko sa 2nd version ko, kasya pa rin sa casing ng pc psu. T2 is another trafo sis. Forward mode sure akong walang voltage dropping kahit heavy loads.

(http://i42.tinypic.com/r02ydu.jpg)

My old version :
SMPS.mpg (http://www.youtube.com/watch?v=Eu4ebKall64#)


gagana din ba sir, w/o any modification if I frist try to feed around 30VDC instead of the rectified 230V mains.  Medyo takot ako maghandle ng mataas na voltahe for something I'm not so familiar with.  Kakayanin pa ba ng autovolt-in yung ganung kababang input?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 26, 2011, 03:05:24 AM
gagana din ba sir, w/o any modification if I frist try to feed around 30VDC instead of the rectified 230V mains.  Medyo takot ako maghandle ng mataas na voltahe for something I'm not so familiar with.  Kakayanin pa ba ng autovolt-in yung ganung kababang input?

No sis, di na uobra. Pag autovolt kase may limitation din at sa testing ko mga 90VAC ok pa.
San mo ba gagamitin, baka pwede na yung simpleng flyback mode lang like self exciting,
madali lang yun at kahit sino kayang gawin. Pag gumawa tayo puro praktikal lang lahat para di
maging masalimuot ang project ala batang kalye na 12yr old na nagko convert ng mga japanese
tv tuner thru guidance ng parents.

Pag nasanay na tayo thru practical way, kahit anong flyback mode psu madali na lang gawin,
later-on makakaya na rin nating mag modify ng mga surplus 110v tv to 220v without major parts. 
Sorry di ko nasundan ang mga previous posts kaya tanong na lang kita.

Here kung gusto mo ng simpleng flyback mode with dual output.  Masinop ka, sure kaya mo yan.

My SMPS_Dual-Output_Presentation 115VDC & 20VDC.mpg (http://www.youtube.com/watch?v=v6hmyI6EVAM#)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 26, 2011, 03:17:49 AM

Much more simplier at very afforadable sa budget tapos available pa ang mga parts.
Kahit kumatay ka lang ng mga diode sa lumang tv pwede.

(http://i39.tinypic.com/2yx1wyc.jpg)

(http://i42.tinypic.com/2pzy2c3.jpg)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 26, 2011, 03:38:20 AM
Medyo takot ako maghandle ng mataas na voltahe for something I'm not so familiar with.  Kakayanin pa ba ng autovolt-in yung ganung kababang input?

Kung gusto mong mag try muna sa low voltage, siguro yung step-up muna ang subukan mo.
Sikat dyan ang SG3525 at uPC494, mga mosfet na IRF540 at IRFZ44. Let say 12VDC to 50VDC,
pwedeng pang car stereo amp psu, kaso lang kailangan mo ng high current source like 12V or 24.

On this vid, I'm using 3 types of smps. Yung 1st version ko ng forward mode na autovolt with fixed
24VDC output (no V dropping din yun), then 24VDC to something step-up to about 200VAc using
uPC494 running at 62Khz. Ito yung sinasabi ko... Yung HV smps some other purpose yun for resonance,
not part of the issue.   

My 1st step to SR device.wmv (http://www.youtube.com/watch?v=rVXN8wtzBvU#)

    
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: alyas on November 26, 2011, 01:04:53 PM
Salamat pinoy_tech for your simplified and easy to understand schematics ng smps.  Parang ang dali gawin.  Pogi points for you. 

I guess I was a bit carried away but honestly I dont know anything about smps yet.    Baby steps muna ako.  I will be using a trafo with a 24VAC secondary so need ko lang ay simple variable output buck converter design that will act as a tracking pre-regulator sa main linear regulator.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 26, 2011, 06:56:36 PM
OT: Okey yan sis, syempre lahat naman nag umpisa sa wla then step by step lang to learn.
      Pag nasa taas na, Keep It Simple!

Btt: Di ako masyadong naglalaro sa mga low B+ smps pero may simple schema ako ng
      buck boost ckt gamit sa wireless transmitter, may pagka joule thief lang naman
      ang mga yan. Pwedeng I core lang, toroid, or ordinary EI type basta high frequency
      core. Yung huling play ko sa smps walang core nga eh kaso mainit ang power drive!
      Ang ibang alternative ko is yung kabelya ng bahay, running on high freq din yun based on
      my testing. Sounds crazy pero walang nawala sa akin sa mga experimento ko, instead gaining!

Ah eto pala yung simpleng ckt ko. Pwedeng scaled up yan for higher power. Di ko maharap
baguhin sa ngayon daming ginagawa. Yung frequency variation sa R1/C1, voltage chopping
sa D4 pwedeng variable output using trimpot. Actual experiment will guide you to do so.

(http://i42.tinypic.com/34i0h81.jpg)   

 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 27, 2011, 02:26:04 AM
^Ah! Correction pala! Di na umabot sa modifying time. Part lang ng buck-boost ckt
yung attached ckt ko. DC Boosting Converter lang ito, as in walang buck ckt tapos
yung C2 di naka tapped sa base ng Q2, shorted sana ang oscillation. Nandun yun
sa anode ng Zener D.


Corrected Boost converter:

(http://i43.tinypic.com/e8517c.jpg)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: your most RIDICULOUS man :) on December 08, 2011, 10:44:51 AM
Ayus! Pasubscrayb! :) Point sau sir pinoy_tech!
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: amadjo01 on January 31, 2012, 11:16:22 AM
mga sir patulong po sa DC to DCconverter using LM 22678 5.0 kailangan ko po kasi ng 10.0 to 36.0 volts wide Voltageinput tapos 5.0 volts output @ 5.0 amperes.

nakita ko po sa National Semicon sa Web Bench nila na suggested design...

http://www.national.com/webench5/power/webench5.cgi?lang_chosen=en_US&VinMin=10&VinMax=48&O1V=5.0&O1I=5.0&op_TA=30 (http://www.national.com/webench5/power/webench5.cgi?lang_chosen=en_US&VinMin=10&VinMax=48&O1V=5.0&O1I=5.0&op_TA=30)

any help mga sir... kailangan ko po ng inductor.. na 6.5 uH may nakita ako sa RS...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on January 31, 2012, 11:53:00 AM
pwede kitang iwind dito ng gauge 18 na inductor ithink sa e-gizmo meron silang inductor dun at blank ferrite
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on January 31, 2012, 12:19:56 PM
Nakatuwaan ko likutin yung sa cp charger. Naghanap ako ng walang optocoupler or feedbacking galing ng secondary to primary circuit. Wind additional turns to secondary output. Pwede palang pataasin boltahe o pababain, hindi naman nagiinit yung core.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on January 31, 2012, 12:44:12 PM
Kung simple ckt may isa ka pang option para pataasin or pababain ng konti yung sec.
Dun sa pri ckt usually may zener diode, yun yung pinaka correction. Increasing value
will increase the output and vice versa, of course with limitations. Kung ginamitan naman
ng pwm controller ibang way naman. 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on January 31, 2012, 12:54:47 PM
Nakatuwaan ko likutin yung sa cp charger. Naghanap ako ng walang optocoupler or feedbacking galing ng secondary to primary circuit. Wind additional turns to secondary output. Pwede palang pataasin boltahe o pababain, hindi naman nagiinit yung core.
zener reference ba yan master or divider lang? nagbabaklas din ako pag aarlan yung winding ng transformer nila
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on January 31, 2012, 01:11:53 PM
Wala itong feedback from secondary papunta ng primary. Bale meron siyang hiwalay na feedback circuit, I think zener reference sya. Pero mas mahirap at mahal ang zener dito samin kesa sa winding. Tira galing sa pagrewind ng speaker. Kasukat kasi.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on January 31, 2012, 01:17:41 PM
Wala itong feedback from secondary papunta ng primary. Bale meron siyang hiwalay na feedback circuit, I think zener reference sya. Pero mas mahirap at mahal ang zener dito samin kesa sa winding. Tira galing sa pagrewind ng speaker. Kasukat kasi.
palitan mo ng mas mataas na value tataas din pero same power laang so bababa yung output current
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on January 31, 2012, 01:21:16 PM
Napansin ko kasi minsan kung ano yung zener reference niya yun ang rated output voltage sa output niya.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: amadjo01 on January 31, 2012, 01:22:31 PM
pwede kitang iwind dito ng gauge 18 na inductor ithink sa e-gizmo meron silang inductor dun at blank ferrite

salamat po sir... tsaka pa turo nalang rin sa inductor...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on January 31, 2012, 01:30:23 PM
salamat po sir... tsaka pa turo nalang rin sa inductor...
depende kasi sa core material basta may specs kana nun pwede ng simulan isang important specs ay ang Al ng core material to compute kung ilang turns gagawin mo
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: malamig on January 31, 2012, 10:21:55 PM
pa subs po dito
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: lloydi12345 on February 10, 2012, 10:20:55 AM
Nice meron palang pang SMPS na thread :D sorry di ko na binasa ang buong thread sobrang haba talaga eh. Anyway, I'm building a power supply of 220vac to 12vdc at least 1A yung tulad ng mga cellphone charger or wallwart. May nakagawa na ba? May nakita kasi akong link ito http://bbs.dianyuan.com/bbs/u/30/1118463481.pdf (http://bbs.dianyuan.com/bbs/u/30/1118463481.pdf) problema lang yung ibang components walang values tulad ng transformer tska inductor. Any suggestions? :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on February 10, 2012, 11:16:24 AM
Bka malito ka sa oscillating coil inilayo sa diagram, part pa yun ng trafo.
Mag customize ka na lang ng trafo using pc psu babad sa thinner 24hrs.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: lloydi12345 on February 10, 2012, 01:01:35 PM
Bka malito ka sa oscillating coil inilayo sa diagram, part pa yun ng trafo.
Mag customize ka na lang ng trafo using pc psu babad sa thinner 24hrs.

Anu yung trafo?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 10, 2012, 02:23:48 PM
traditional folitician... ;D ;D ;D

seriously, transformer
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on February 10, 2012, 02:35:08 PM
dapat may specs muna before mag wind kung ilang power ihahandle ng trafo,then saka pipili ng ferrite trafo to cater the energy will deliver
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: lloydi12345 on February 10, 2012, 03:19:04 PM
Lol transformer pla. Nosebleed na ako :( My plan is 12V catering 1A estimating 12W of power. Hindi ko magets yung PC PSU what do you mean Pinoy_Tech?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on February 11, 2012, 12:45:59 PM
Sa mga lumang computer power supply may makukuha kang transformer dun mostly EI33 type ungapped,
pwede mong mapaglaruan. Ma dismantle mo ang core pag binabad mo sa thinner for about 24hrs kasi malulusaw yung pinaka varnish at matatanggal mo ng maayos ang core pero wag mong pupukpukin baka madurog.   
 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: roberthegyes123 on March 11, 2012, 05:37:26 PM
in reality, developing smps goes like this:

1. record down the input/output requirements
2. identify the appropriate topology accd. to 1
3. style the attractive areas i.e. transformer, result chokes, etc.
4. magic size and test
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on April 07, 2012, 03:19:13 PM
mga sir, may plano po akong mag DIY ng SMPS.
ung input . 12VDC or 24VDC (optional na lang ung 24VDC). (para kasi sa jeep namin)
output = 27-0-27VDC (para ito sa TDA8920BTH na nabili ko sa 1diy.)
ang tanong.
posible ba akong makagawa galing lang sa mga sirang ATX PSU? (coil, tx, diodes etc..)
meron pa akong ibang sources. etc etc...
salamat.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on April 07, 2012, 03:36:19 PM
backread backread ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on April 08, 2012, 02:07:42 PM
Naka try na ako nyan dati at ok naman. Pwede kang gumamit ng IRF530,540, IRFZ44 pero
mas malakas yung IRF3205. Mas mainam kung mag custom trafo ka para masunod mo yung
gusto mong output. Tapos di maganda sa split smps yung lalagyan ng feedback regulator
kung ang application ay sa amplifier kasi unbalance load yung amp unless gagawin mo syang
bridge type or tri-mode bridging.

Di pala lahat ng parts ay available sa old pc psu kaya bibili ka pa rin.

(http://i42.tinypic.com/bhlvp.jpg)

(http://i40.tinypic.com/21b4r2b.jpg) 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: RaffT on April 08, 2012, 02:56:23 PM
un-gapped cores good for push-pull oscillator (TL494/LM3524/5)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on April 08, 2012, 03:41:05 PM
Naka try na ako nyan dati at ok naman. Pwede kang gumamit ng IRF530,540, IRFZ44 pero
mas malakas yung IRF3205. Mas mainam kung mag custom trafo ka para masunod mo yung
gusto mong output. Tapos di maganda sa split smps yung lalagyan ng feedback regulator
kung ang application ay sa amplifier kasi unbalance load yung amp unless gagawin mo syang
bridge type or tri-mode bridging.

Di pala lahat ng parts ay available sa old pc psu kaya bibili ka pa rin.

(http://i42.tinypic.com/bhlvp.jpg)

(http://i40.tinypic.com/21b4r2b.jpg)  

pde po patingin sa schem??
ok lang sir kahit wala sa mga lumang PSU, basta wag lang ung mga mahihirap na IC. ung may SG**** siguradong wala yan dito sa amin. ;D

un-gapped cores good for push-pull oscillator (TL494/LM3524/5)
huh? ;D ;D paturo nman sir kung ano maganda. :D


-kahit mga 100 - 150watts. kakayanin na ba ? :D
-backread again.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on April 08, 2012, 04:04:08 PM
cdr king inverter seems to be interesting. :D
cdrking + torroid traffo = looks like inefficient?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on April 08, 2012, 09:35:41 PM
pde po patingin sa schem??
ok lang sir kahit wala sa mga lumang PSU, basta wag lang ung mga mahihirap na IC. ung may SG**** siguradong wala yan dito sa amin. ;D
Di ko na yata mahagilap yung ginawa kong shematic dati, drawing kamay lang kasi yun  :(. Subukan kong gawan ng panibago throught e-cad or hanapin ko yung guide manual ng Sencor Car Amp, andun lahat yun. Matagal ko na kasing nagawa yun, di pa uso ang net nun. Chenik ko kanina kung operational pa at ok pa rin naman. So sad lang, di maka upload ng vid sa YT.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on April 08, 2012, 09:39:49 PM
Di ko na yata mahagilap yung ginawa kong shematic dati, drawing kamay lang kasi yun  :(. Subukan kong gawan ng panibago throught e-cad or hanapin ko yung guide manual ng Sencor Car Amp, andun lahat yun. Matagal ko na kasing nagawa yun, di pa uso ang net nun. Chenik ko kanina kung operational pa at ok pa rin naman. So sad lang, di maka upload ng vid sa YT.
hehe ok sir, ill be waiting... :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on April 09, 2012, 12:49:35 PM
Hirap mag upload ah! Nabago na yata yung sa mediafire, not sure! YT rejected vid ako also, hmmm!

Wait mo na lang dito, uploading pa yung Diagram titled "DC-DC Converter" at
"testing DC-DC Converter". Yung pcb dyan ay sa ibang application ko pero pwede
yan dyan sa DC-DC Converter lagyan lang ng trafo gagana na.

http://www.4shared.com/folder/SyCO-bGC/Dc-Dc_Test.html (http://www.4shared.com/folder/SyCO-bGC/Dc-Dc_Test.html)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on April 09, 2012, 12:54:27 PM
ok sir ty in advance.
+1 po muna :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on April 09, 2012, 01:32:27 PM
mas gusto ko ung push pull pwm na yun sir.
;D simple lang
ung size nung PCB na nasa pdf, as is na po ba sir??
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on April 09, 2012, 01:51:31 PM
^Actually, yan na mismo yung ginawa kong dc-dc na nasa testing ko ngayon. Yung orig na ckt yun mismo yung Sencor design pero marami akong tinoli dun kaya naging simple na lang. Sure will work yan, remember my vid sa 1st attemp to SR193 device? Yan yung ckt control na ginamit ko, gumamit lang ako ng tesla coil sa output. Make sure lang na sabay na mag off ang B+ ng IC at supply ng trafo para di bumading yung mosfet. Pwede kang maglagay ng 2.2uF ecap sa pin 13,14 & 15 to pin 4 para sa soft start ng IC. Pin 4 is for dead-time control and can use for short ckt protect.

PCB size? As-is na pero sa toner making pcb yan.

Tnx pala sa pnt. Work muna me  ;D!
  
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on April 09, 2012, 01:58:22 PM
ok sir noted.
tanong ulit sa transfromer po, ung primary center tap, nakaconnect na sa B+ ?
or yung P GND?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on April 09, 2012, 09:32:17 PM
May two options ako:

1. P.gnd direct na always sa supply at control na lang ang B+. Mas mainam na lang siguro na mag ON/OFF control tayo sa pin 4 para di ka hirap sa high power switch. 150W ba ang target mo? Around 12Ampere na DC switcher! Gawin na lang nating ganito siguro>>> Connect na lang yung P.G at center Tap sa supply sabay na rin yung supply ng IC. Tapos yun pin 4 na sabi ko sa yo na lagyan mo ng 2.2uF na ecap for soft start, instead na naka tap from vref to pin 4 lagay mo na lang from pin 4 to gnd pero increase the value to 100uF. Now ang magiging ON/OFF control natin is >>> applying supply to pin 4 will OFF the IC, we can take it from vref pin 13,14,15. We can use around 100ohms or so then pass through low current switch, yan yung ON/OFF control mo. Pag OFF ang switch at nag discharge na yung ecap sa pin 4 to gnd, yan yung soft start natin.

2. Direct ang p.gnd at ct ng trafo sa supply tapos ON/OFF yung B+ ng IC through switch pero "babaan m konti yung ecap sa B+. Imbes na 470uF gawin mong 100uF tapos lagyan mo ng 2.2uF yung sinabi ko dati sa pin4. Pag mataas ang ecap sa B+ magiging graceful discharge ang supply ng IC at in danger ang mosfet sa threshold signal, lot of mosfets ang nasira ko dyan.   

 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on April 09, 2012, 10:04:51 PM
Try ko ibang hosting site. Yung ginawa kong shematic yung R1 dapat 1K hindi 10K pero di naman problema yun. If ever, magiging early trigger lang sya at stop ang operation pag uminit konti yung heatsink.

http://www.freeimagehosting.net/zgig1 (http://www.freeimagehosting.net/zgig1)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on April 10, 2012, 06:30:11 AM
May two options ako:

1. P.gnd direct na always sa supply at control na lang ang B+. Mas mainam na lang siguro na mag ON/OFF control tayo sa pin 4 para di ka hirap sa high power switch. 150W ba ang target mo? Around 12Ampere na DC switcher! Gawin na lang nating ganito siguro>>> Connect na lang yung P.G at center Tap sa supply sabay na rin yung supply ng IC. Tapos yun pin 4 na sabi ko sa yo na lagyan mo ng 2.2uF na ecap for soft start, instead na naka tap from vref to pin 4 lagay mo na lang from pin 4 to gnd pero increase the value to 100uF. Now ang magiging ON/OFF control natin is >>> applying supply to pin 4 will OFF the IC, we can take it from vref pin 13,14,15. We can use around 100ohms or so then pass through low current switch, yan yung ON/OFF control mo. Pag OFF ang switch at nag discharge na yung ecap sa pin 4 to gnd, yan yung soft start natin.

2. Direct ang p.gnd at ct ng trafo sa supply tapos ON/OFF yung B+ ng IC through switch pero "babaan m konti yung ecap sa B+. Imbes na 470uF gawin mong 100uF tapos lagyan mo ng 2.2uF yung sinabi ko dati sa pin4. Pag mataas ang ecap sa B+ magiging graceful discharge ang supply ng IC at in danger ang mosfet sa threshold signal, lot of mosfets ang nasira ko dyan.  

  
option 1 nlang ata sir.
nakakatakot namn ung 2 naninibak ;D ;D ;D
pa rewrite ng schema sir kung ok lang po sa inyo :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on April 10, 2012, 12:44:46 PM
^may nakita akong little consideration sa option 1. Baka medyo mahaba ang wire na
i tap natin sa pin 4 mag cause sya para maka pick ng elect noise at magka problema
sa operation ng IC. I go for option 2 at nag quick check me last night at ok naman.
I increase the value of delay cap to 47uF.

(http://www.freeimagehosting.net/t/7yzxe.jpg) (http://www.freeimagehosting.net/7yzxe)

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on April 10, 2012, 01:56:50 PM
My latest testing :

(http://www.freeimagehosting.net/t/bijwg.jpg) (http://www.freeimagehosting.net/bijwg)

(http://www.freeimagehosting.net/t/g1xsq.jpg) (http://www.freeimagehosting.net/g1xsq)

(http://www.freeimagehosting.net/t/ci35l.jpg) (http://www.freeimagehosting.net/ci35l)


Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on April 10, 2012, 02:05:38 PM
waw :D
+1 muna sir. hanap pa me monar pambili ng mga mosfet :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on April 10, 2012, 09:13:38 PM
Try mong ring maghanap nung mas mataas na mosfet na IRF3205 or IRF3808. Yan ang
madalas na ginagamit sa mga forklift drive. Imagine yung bigat na dinadala ng mga yun,
ganyan lang ang mga parts sa ginagamit dun. 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Ikasamoko on April 10, 2012, 10:08:54 PM
Sir baka may simple design ka dyan na SMPS?

Input: 12VDC
Output1: +5VDC @ 1.5A
Output2: -12VDC @ 250mA


TIA

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: e-tronix on April 10, 2012, 10:33:52 PM
subs
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on April 11, 2012, 01:01:36 PM
Sir baka may simple design ka dyan na SMPS?

Input: 12VDC
Output1: +5VDC @ 1.5A
Output2: -12VDC @ 250mA

TIA

I recommend flyback mode sir sa multi out. Chk mo yung reply 1003 bka type mo.
Dagdag na lang ng additional coil sa sec pero observe polarity.

OT: I'm 14dys countdown to smell the Philippines, might be very busy next few days  ;D .
      Yung LCR reserved ko sir, still noted pa ba?  
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Ikasamoko on April 11, 2012, 09:27:23 PM
Try ko yung post mo sis...


EDIT: Sis wala ba 12VDC input?


OT:
igagawa kita bukas sis...;D

medyo may time pa naman tayo..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on April 14, 2012, 12:35:49 PM
Ah, oo nga. 12V input pala he he. Chk ko mga files ko kung melon hik!
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on April 14, 2012, 12:41:29 PM
Sis Rkendu, nag try akong mag new pcb layout, i max natin  yung ibang features
tapos kung nakagawa ka na ng dating pcb good for soldering iron yan sa mga Jeep
tested ko na from 12V to 220V/60W soldering iron >>> http://www.freeimagehosting.net/jkbph (http://www.freeimagehosting.net/jkbph)

Wait u na lang dito yung kompletong layout, uploading now pero bagal eh!
http://www.4shared.com/folder/eYEX1bjA/DC-Dc_Converter_2.html (http://www.4shared.com/folder/eYEX1bjA/DC-Dc_Converter_2.html) 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on April 14, 2012, 02:32:54 PM
waw nice :D
+1 sir
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Ikasamoko on April 14, 2012, 03:08:58 PM
Sir any info sa transformer?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on April 14, 2012, 09:04:43 PM
Alin sir?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Ikasamoko on April 14, 2012, 09:29:12 PM
yung winding details ng trafo sa ckt above sir..;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on April 15, 2012, 12:36:12 AM
Ah, ha ha ha! Actually, sa pc trafo yung kadalasang available na ferrite core na nakakatay natin at
kung may mabibili importante yung details ng trafo. Since wala tayong actual source ng kung anong
materials ang ginamit sa pc trafo, ang ginagawa ko na lang is count yung number of turns ng primary,
huwag sa secondary. Kung makuha mo na ang number of turns sa pri, pang divide natin yun sa given
supply natin.

Since alam natin ang topology ng pc psu na half bridge makukuha na natin yung turn per volt. Let say,
220V ac, to make it into Dc it will become approx 310VDC. Now divide it into half for half bridge mode,
magiging 155V na lang ang Vin. Kung ang bilang ng pri trafo na binaklas mo ay sabihin na nating 38T total,
ayon na ang T/V natin 4.07T/volt. So, kung gagamitin mo ito sa 12V input, approx 2.9T or 3Turns primary.
Sa output let say gusto mong 50V output without feedback regulation, near about 12T. Please consider
tolerance like 1 to 2 turns. Kung may feedback naman dagdag ng konti para sa extra Vout para sa chopping
voltage.

For me, I prefer 4T x 2 sa primary at 12T x 2 sa secondary.   

Above parameter ay similar lang naman sa internal oscillator ng uPC494 kaya wala tayong problema sa T/V.
Kung magbago tayo ng oscillating frequency, iba ang magiging combination ng turns per volt natin. The best
pa rin is, we need to observe actual experiment.     
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Ikasamoko on April 15, 2012, 01:23:08 AM
+1 sis!

try ko connect pullout na trafo without any modification then measure yung output nya..;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on April 15, 2012, 12:48:14 PM
Tnx, clarify ko lang volt per turn pala  ;D ! Kung sa soldering iron ang application, ok
na yan sa pc psu kahit di tamperin at kahit di gumamit ng diode sa secondary. Di rin pala
makukuha ang accurate na voltage reading sa secondary hangga't di nacoconvert into DC. False
reading pa yung unrectified.

We can use other formula pala:
Np is equal to Vin x 10 to the power of 8, divided by 4 x F x Flux density of Core x Cross sectional Area of core.

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Macoy8932 on April 18, 2012, 03:30:18 PM
http://www.taobao.com/view_image.php?pic=Wx0GGlFDXA1VUwMBWx0SCwkNGRFcVxxQW1UcCxMFRBkDCFdVV1cRRhpXRDhHKnx2U2tRAGsxKgtcDwVKYmsDAUdaQV1FBgYV&title=1K3XsCA2ODMyMTM4NTAwLTAxIFBUQi0xMzg1ICC159S0sOU%3D&version=2&c=ODY4YzNlZjNmNGVhNTVmOWJhODMxZTAyNTlmM2IwZmQ%3D&itemId=10321270782&shopId=65339205&sellerRate=4204&dbId=&fv=9 (http://www.taobao.com/view_image.php?pic=Wx0GGlFDXA1VUwMBWx0SCwkNGRFcVxxQW1UcCxMFRBkDCFdVV1cRRhpXRDhHKnx2U2tRAGsxKgtcDwVKYmsDAUdaQV1FBgYV&title=1K3XsCA2ODMyMTM4NTAwLTAxIFBUQi0xMzg1ICC159S0sOU%3D&version=2&c=ODY4YzNlZjNmNGVhNTVmOWJhODMxZTAyNTlmM2IwZmQ%3D&itemId=10321270782&shopId=65339205&sellerRate=4204&dbId=&fv=9)

pahelp naman po dito.. di po nag o on ee
thanks sa guidance, IBM thinkVision LCD po ito
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Ikasamoko on April 19, 2012, 09:00:24 AM
^^ Please create your own thread about dito...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on May 06, 2012, 02:46:54 PM
Gumawa ako ng MC34063-based buck converter set to about 3A. I have to put an external boost transistor. TIP41C ang nilagay ko. with switching frequency of about 68kHz.

Question: Can you suggest a particular transistors that is designed for this application?

I think mabagal ang TIP41C...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: insomartin on May 06, 2012, 02:47:58 PM
Gumawa ako ng MC34063-based buck converter set to about 3A. I have to put an external boost transistor. TIP41C ang nilagay ko. with switching frequency of about 68kHz.

Question: Can you suggest a particular transistors that is designed for this application?

I think mabagal ang TIP41C...

nag babaklas lang ako sa lumang motherboard nang mosfets.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on May 06, 2012, 02:56:04 PM
nag babaklas lang ako sa lumang motherboard nang mosfets.

yeah! oo nga ano! heheh ;D
thanks... :D
++point for you! :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on May 06, 2012, 10:20:52 PM
can i use IRFZ460N (http://pdf1.alldatasheet.com/datasheet-pdf/view/68628/IRF/IRFZ46/+475_9U.OE/1pyHcYC+/datasheet.pdf) -  a power mosfet?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: insomartin on May 06, 2012, 11:09:24 PM
pwede i-simulate sa proteus yung MC34063 and IRFZ460N
altho di ako sure kung pwede. but i think pwede since switching lang naman.
... gulp!
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on May 07, 2012, 12:34:13 AM
tested it by directly replacing the TIP41C by IRFZ64N. worked just as it should be... :)

next question: how do we make those high frequency transformers?
;D ;D ;D


EDIT: opppss.. sorry, back read kaya ako!  heheh ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: drin20 on May 15, 2012, 11:10:53 PM
pwedi ba i-reversed engineer ang PC power supply para gawin power inverter?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on May 15, 2012, 11:28:56 PM
sa available components lang ng PC PSU, nope. though, magagamit yung trafo.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Ikasamoko on May 15, 2012, 11:39:32 PM
Baka may reference kayo dyan conversion ng PC PSU to variable power supply...yung tested nyo na po...marami ako nakita sa net pero gusto ko yung tested ng impakta...;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: drin20 on May 29, 2012, 12:27:50 AM
NOOB question po sa boost converter

input: 12vdc
output 330vdc @ 1 ampere

pwede ko ba gamitin ang TL494?
ano po dapat mag simula pagaralan? salamat
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on May 29, 2012, 02:05:28 AM
medyo malaling boost yan, mas madali yan gawin sa flyback.

yup, pwedeng gamitin ang TL494.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Ikasamoko on May 29, 2012, 01:22:34 PM
I'm planning gumawa ng universal driver..;D

TL494 based para kabit ko na lang hand-wound ferrite trafo for trial and error...;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: min on June 16, 2012, 10:48:15 AM
naitanong ko na ito dati pero wala sumagot, so itatanong ko uli ,tungkol naman ito sa SMPS kaya dito ko nlng i post.

(http://img708.imageshack.us/img708/70/capres2.png)

obviuosly kahit wala yan mag wo work ang PS so para saan yan? protection sa Chopper? ???
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on June 16, 2012, 11:23:49 AM
yung resistor alam ko bawal yan sa safety. yung capacitor pwede iallow provided na safety rated yung gagamitin (Y-Caps na Y2 yata kung di ako nagkakamali) kung saan ang failure mode eh laging open lang.

tingin ko ilan lang to sa mga magic ng mga design engineers para imanipulate yung EMI emission para pumasa sa EMI testings
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: min on June 16, 2012, 11:29:45 AM
Ah OK noted sir. ;D

Ung resistor nga parang nag provide pa ng path para ung AC main (hot) eh makatawid sa secondary ground. he,he
pero mataas nman ang value ussually na gamit nila.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: drin20 on June 16, 2012, 09:43:05 PM
ah. hehe. typical kasi sa Sine Wave Inverter merong DC Link. kung from 12V (or any lower voltage) to 220Vac for example, merong stage na 12Vdc to 330Vdc or sa case ng AC to AC inverter merong AC rectification to DC. after nung Higher Voltage DC Link merong chopper to create the sinusoidal output. sa 12V battery case, 2 stages siya lumalabas.

merong designs na instead of 2 stages from 12V, gagawing 1 stage na lang. 'yung technique, hindi diode ang gagamitin as output rectifier after ng transformer. back to back MOSFET ang gamit (as active rectifier) that can serve as bidirectional switch ('yung configuration dapat blocked 'yung body diode ng MOSFET). sa positive half-cycle ng output Sine, sa isang direction pinadadaan 'yung half-wave sine tapos sa negative half-cycle sa kabila naman.

'yung isa namang method, ang output ng transformer at ng rectifier niya ay puro positive half-cycles pero after nung half cycle merong output H-Bridge na pwedeng i-invert 'yung direction.

ano po ba yung chopper?

saan po part ng schematic ang chooper?

(http://a3.sphotos.ak.fbcdn.net/hphotos-ak-snc6/205405_3283472849231_1810770183_n.jpg)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on June 16, 2012, 10:00:00 PM
Ah OK noted sir. ;D

Ung resistor nga parang nag provide pa ng path para ung AC main (hot) eh makatawid sa secondary ground. he,he
pero mataas nman ang value ussually na gamit nila.

madalas ko 'tong ma-encounter sa mga supply na mataas ang output like inverters or para sa 48V bank. typical 'yung capacitor na Y-cap.

pinatatawid niya talaga 'yung ground in small current para parehas sila ng potential. common problem kasi sa hotplug 'yung minsan malayo from mains ground 'yung potential ng secondary ground tapos isasaksak, madalas merong madadali ng discharge.

tapos tulad rin ng sabi ni sir glutnix, minsan dito dinadaan 'yung daya para sa limiting ng common mode conducted noise.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: drin20 on June 17, 2012, 06:01:32 PM
hello!
para saan po ung OCP at OCP-G?
sa feedback po simpleng voltage diver lang naman un diba?

pwedi po ba gawin itong 330vdc?
modify ko na lang ang turn ratio ng transfo?

(http://a3.sphotos.ak.fbcdn.net/hphotos-ak-prn1/525921_3286456363817_1059888635_n.jpg)


edit: pinalaki ang imahe
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: j a y k e z on June 17, 2012, 06:20:27 PM
di ba OCP stands for Over Current Protection?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: motion55 on June 17, 2012, 06:29:22 PM
OCP = Over-Current Protection ata. Hindi complete ang view ng schematic kasi.

Here is my analysis:

Pag ang voltage sa OCP-P (positive) ay tumas w.r.t. OCP-G (ground), then mag ON si  C945 and also turning ON A1015. This will shutdown uPC494 through pin 4. At the same time, the transistor C945 will remain ON (latched like an SCR) until power is turned OFF.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: drin20 on June 17, 2012, 06:52:14 PM
OCP = Over-Current Protection ata. Hindi complete ang view ng schematic kasi.

Here is my analysis:

Pag ang voltage sa OCP-P (positive) ay tumas w.r.t. OCP-G (ground), then mag ON si  C945 and also turning ON A1015. This will shutdown uPC494 through pin 4. At the same time, the transistor C945 will remain ON (latched like an SCR) until power is turned OFF.


salamat sis.

pwedi pala naka hung lang yon. :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on June 17, 2012, 11:48:35 PM
Tama sila pareho at tama ka rin kahit walang connection yung ocp pwede pa rin, yun nga lang wala ka ng margin for safety. Pwede kang kumuha ng current sensing sa source ng mosfet, mag add lang ng resistor na low value like used in yamaha smps or yung small toroid core na nakakatay sa pc psu.

Kung gagamitin mo yung trafo ng pc psu, yung output mo is almost closed to what you need.   
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on June 18, 2012, 08:28:28 AM
actually yung OCP pwedeng up to 120% ng full load current
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: drin20 on June 19, 2012, 12:15:22 AM
salamat po sa inyo

eto pa po tanong ko.

para saan po ang R5 at R7?

hindi ko maintindihan lalo na ung R5. bakit pa kailangan un? edi mababawasan lang ang voltage from Vref after ng dividing network.

(http://a2.sphotos.ak.fbcdn.net/hphotos-ak-ash3/532841_3290893234736_1435330348_n.jpg)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on June 19, 2012, 12:59:03 AM
pang-set ng gain nung opamp. EA gain = R7 / R5 = 100. typically, linalagyan pa 'yan ng compensating capacitors depende sa topology at actual values ng LC filter.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on June 19, 2012, 08:36:29 AM

may nag-alok sa akin na gumawa ng portable 125Vdc, 10A na smps psu, i want to pass this project to anyone who wants to make it. the budget could be as hi as php 20k - 30k. wala nalang akong time akong time may pending pa kasi akong dalawang electrical projects and i am currently working with this 1 to 2 months project, kaya gusto ko nang itong ipasa sa iba.

anyone who wants it, just pm me.  
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: drin20 on June 19, 2012, 06:26:33 PM
pang-set ng gain nung opamp. EA gain = R7 / R5 = 100. typically, linalagyan pa 'yan ng compensating capacitors depende sa topology at actual values ng LC filter.

salamat sir Rdpzycho
kaya pala meron non-polar capacitor sa design ni Pinoy Tech.

EA gain = 1 + (R7/R5) = 101

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: drin20 on June 26, 2012, 02:55:21 PM
(http://a3.sphotos.ak.fbcdn.net/hphotos-ak-ash3/582140_3318909175117_1436440069_n.jpg)

(http://a2.sphotos.ak.fbcdn.net/hphotos-ak-ash3/532426_3318909295120_1748508648_n.jpg)

(http://a7.sphotos.ak.fbcdn.net/hphotos-ak-ash4/229869_3318908855109_416251595_n.jpg)

(http://a5.sphotos.ak.fbcdn.net/hphotos-ak-ash3/540920_3318908975112_716183089_n.jpg)


una 400 and output tapos biglang tataas ng 600 VAC. wala pa po rectifier at load.

gamit ko core, power mosfet, ay sa nakatay ko APC ES-500

kabit ko meya ung rectifier na MUR460 na galing din sa UPS ng APC.

may klase na kasi kami. hehehe.

thanks po sa inyo. sir RD, sir motion, sir jikkks, sir Rafft, at sir Pinoy_tech
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: RaffT on June 26, 2012, 03:00:51 PM
400Vdc pala ang rectified output? pwede ka naman mag lagay ng 2u2/400V elcap sa output, then sukat ulit para mas stable ang reading. :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: drin20 on June 26, 2012, 03:05:48 PM
400 vac po una output. after 2 seconds biglang tataas ng 600 vac. meya ko ikabit ang rectifier at caps. :)

kailangan ko din pala ng pot para sa feedback.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: j a y k e z on June 26, 2012, 03:11:22 PM
wow nice sis, abangan ko toh

ayos mini molex connector as transistor pin connector  :D

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on June 26, 2012, 03:23:58 PM
makagawa na nga nito.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: RaffT on June 26, 2012, 03:26:53 PM
teka, paanong naging AC? DC ang output nyan, hindi AC

baka tumataas output nyan kasi wala ka nilagay na voltage feedback..delicado yan pag nag lagay ka caps sa output
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on June 26, 2012, 09:23:17 PM
Wala pa raw syang diode na naka kabit sa output kaya AC daw. He read the output without rectifier pero medyo false reading pa yun kasi high F. Pag na DC na yun na yung ma read an actual then compute sa given data na 1.41 or 0.707. Either of the two pwede. Yung isa divide sa nasukat na dC, yung isa naman times o baka nakalimutan ko na, kulang na sa tagay he he, hik! 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on June 26, 2012, 09:40:14 PM
last year, sir tony gave me mur860 diodes . looks like this
(http://sigma.octopart.com/8901767/image/ON-Semiconductor-MUR860.jpg)
pde po ba to sa output side?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on June 26, 2012, 10:13:53 PM
deleted
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on June 27, 2012, 05:36:26 AM
MUR? Wow! Pwede yan pero sayang naamn kung low voltage lang ang paggagamitan.   

San kaya nabili ni sir Tony yang ganyang diode? Nilibot ko na yung Raon last
month pero wala akong matyempuhang ganyang type. MUR810 lang tested na
ng marami sa +/-50VDC application. 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: RaffT on June 27, 2012, 06:32:30 AM
heheh dapat talaga ang MUR sa output side na, sayang pagka hv nun.baka sa RS may benta sila.

@drin,
rather than following blindly for schematics on net(no offense pinoy_tech), i-google mo kung paano gumagana ang chip. sa g**gle marami ka makukuhang info nyan.

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on June 27, 2012, 07:15:00 AM
ok thanks +1 po sa inyong dalawa.
di ba ung KA7500C = TL494?
ung mur kasabay yan nung LM3875 :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on June 27, 2012, 01:01:00 PM
^Ano na naman ang niluluto mo sis?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on June 27, 2012, 02:16:00 PM
secret ;D
 

Q: paano tanggalin ung EI core na hindi nabibiyak? ibabad sa thinner?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on June 27, 2012, 02:45:39 PM
EDIT
ilang turns ung para sa EE 33? ung nakukuha sa PC PSU
input : 12vdc
output : ppde ba 35-0-35?
or pde na rin 27-0-27.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on June 27, 2012, 03:45:22 PM
Q: paano tanggalin ung EI core na hindi nabibiyak? ibabad sa thinner?

yup.

EDIT
ilang turns ung para sa EE 33? ung nakukuha sa PC PSU
input : 12vdc
output : ppde ba 35-0-35?
or pde na rin 27-0-27.

kung same frequency ang gamit, retain mo lang yung orig na 12V winding then compute the ratio for 35V or 27V at your desired duty cycle target. otherwise, kung ibang frequency, kailangan i-recompute lahat.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on June 27, 2012, 05:29:17 PM
hala. binaklas ko na lahat :(
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on June 27, 2012, 09:54:26 PM
ok nagawa ko na kaso naghihingalo ung supply.
kung papalakasan ung volume eh babagsak ( from 50 down to 20 ~ 30 ).
1 pair of mosfet palang.
kung 2? mas lalakas ba ung current?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on June 28, 2012, 04:10:08 PM
ok nagawa ko na kaso naghihingalo ung supply.
kung papalakasan ung volume eh babagsak ( from 50 down to 20 ~ 30 ).
1 pair of mosfet palang.
kung 2? mas lalakas ba ung current?
you have this already, add ko na rin dito. The previous one is designed for 200W.
This one is intended for 600W car audio >>> http://i50.tinypic.com/2j2ia8o.jpg (http://i50.tinypic.com/2j2ia8o.jpg)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on June 29, 2012, 03:48:49 PM
break... break!  ;D  may tanong lang (attn:G-neo) sa mga smps designers ;D

i'm converting standalone tny268 10w smps to 1kw, ano ba ang problerma sa diagram kong ito?

(http://i46.tinypic.com/cl4wm.jpg)

this is just a concept dagram. the target is to make the simplest hi power smps in the world!  :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: drin20 on July 01, 2012, 10:23:37 PM
may katanungan po ako.

1. sa na katay ko transformer sa PSU ay

primary : 4 turn center tap
secondary : 19 turn center tap

kung ang input voltage ko po ay 12 volts (push-pull topology po gamit ko SMPS)
114 volts lang po ba dapat output ko sa secondary?

2. pwedi na po ba gawin power supply ng mga CFL and 310 VDC? kahit high frequency? diba 60hz lang input ng CFL? after rectification po ba. parang battery na rin ba ang mga power supply? at wala ng frequency?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: TinTopHack on July 02, 2012, 01:40:43 PM
break... break!  ;D  may tanong lang (attn:G-neo) sa mga smps designers ;D

i'm converting standalone tny268 10w smps to 1kw, ano ba ang problerma sa diagram kong ito?

(http://i46.tinypic.com/cl4wm.jpg)

this is just a concept dagram. the target is to make the simplest hi power smps in the world!  :D

From 10W to 1KW - do not expect it to be a simple upgrade. The topology for 10W more often than not will not work for hi power apps.

For example simple SMPS circuits for 10W may get away without snubbers for MOSFETS and rectifiers like the ones shown on your circuit. But at hi power applications you will need snubbers or your mOSFETs and rectifiers will fail.

To go from 10W to 100W will already be challenging enough considering the modifications required. To go from 100W to 1KW will not be just 10 times more challenging it could 100 times more challenging. The challenge and complexity can grow exponentially.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 02, 2012, 01:50:53 PM
^ ang hirap nga  ;D lalo pat ang kailangan ay simply lang but w/ all the hi end specs  ;D

i'm still here reminiscing the past  ;D

(http://i46.tinypic.com/2cp85sk.jpg)

i cannot switch squarewave without garbage!!   :o :o :o

 ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 03, 2012, 07:58:40 AM
the hardest part of hi-power smps is switching the power transformer on and off at hi-speed which is very illegal in electrical eng'g point of view.  ;D ;D ;D

...solution could be waveshaping or a special transformer that is design for this insanity  :D :D :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 03, 2012, 08:33:28 AM
sample captured problem  ;D

(http://i45.tinypic.com/i6j9yr.jpg)

switching the power transformer on and off at hi-speed!  :o :o :o

bogbog sarado ang x-f  ;D

@ g-neo ano ba ang latest na remedy dito?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: RaffT on July 03, 2012, 09:52:46 AM
:D simple design AND high-end specs usually don't MIX.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 03, 2012, 01:43:41 PM
sayang lang 'yung double trafo kung booster type ang gagawin. single trafo with the same number of MOSFET's kayang-kaya na 'yan. mas mahal magpagawa ng trafo for these designs kaysa bumili ng bagong controller at MOSFET. nakakita na ako ng designs with stacked cores at 1kW levels, special 'yung bobbin niya. though, mas madalas 'yun sa toroid, wala ng special bobbin. ang typical na nahahawakan namin sa opisina is 1kW minimum, 5kW to 8kW 'yung malalaki.

'yung spikes, nagagawan ng paraan 'yan. snubbers ang pinakamadali. parasitic capacitances ang cause niyan then realistic turn on and turn off times (example 'yung rectifier na kailangang i-charge 'yung capacitance niya sa transition from turn on to reverse bias), discharging in the transitions. kung babagalan 'yung transition, mababawasan din 'yan. pwede ring i-damp lang.

pwede ring resonant topologies, mga zero voltage crossing switchers. medyo iba nga lang ang trafo design nito. pero doon sa mga ginagawa namin, 'di pa ako nakakakita ng completely resonant topologies, mostly, intelligent controls lang, may additional DSP controller bukod pa doon sa PWM controller.

kapag na-solve na lahat 'yan, pwede pang i-push 'yung design to use higher frequency para lumiit 'yung magnetics. sa mobo design, hindi uncommon ang 500kHz to 1MHz switching frequency. 'yung lumang mobo ko (circa 2006), 250kHz na ang switching frequency sa CPU, 'di ko pa nasukat 'yung sa mga bago.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on July 03, 2012, 04:02:30 PM
break... break!  ;D  may tanong lang (attn:G-neo) sa mga smps designers ;D

i'm converting standalone tny268 10w smps to 1kw, ano ba ang problerma sa diagram kong ito?

(http://i46.tinypic.com/cl4wm.jpg)

this is just a concept dagram. the target is to make the simplest hi power smps in the world!  :D
mas ok yung resonant dito using half bridge or fullbridge kaso lossy sa mababang load due to energy na umiikot sa resonant tank, i think magandang gawin yung LLC resonant topologies basta amit na gamit yung full loads para mababang losses, mataas yung efficiency.

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 03, 2012, 05:41:00 PM
:D simple design AND high-end specs usually don't MIX.

simplify the hi-end lang sis.

sayang lang 'yung double trafo kung booster type ang gagawin. single trafo with the same number of MOSFET's kayang-kaya na 'yan. mas mahal magpagawa ng trafo for these designs kaysa bumili ng bagong controller at MOSFET. nakakita na ako ng designs with stacked cores at 1kW levels, special 'yung bobbin niya. though, mas madalas 'yun sa toroid, wala ng special bobbin. ang typical na nahahawakan namin sa opisina is 1kW minimum, 5kW to 8kW 'yung malalaki.

'yung spikes, nagagawan ng paraan 'yan. snubbers ang pinakamadali. parasitic capacitances ang cause niyan then realistic turn on and turn off times (example 'yung rectifier na kailangang i-charge 'yung capacitance niya sa transition from turn on to reverse bias), discharging in the transitions. kung babagalan 'yung transition, mababawasan din 'yan. pwede ring i-damp lang.

pwede ring resonant topologies, mga zero voltage crossing switchers. medyo iba nga lang ang trafo design nito. pero doon sa mga ginagawa namin, 'di pa ako nakakakita ng completely resonant topologies, mostly, intelligent controls lang, may additional DSP controller bukod pa doon sa PWM controller.

kapag na-solve na lahat 'yan, pwede pang i-push 'yung design to use higher frequency para lumiit 'yung magnetics. sa mobo design, hindi uncommon ang 500kHz to 1MHz switching frequency. 'yung lumang mobo ko (circa 2006), 250kHz na ang switching frequency sa CPU, 'di ko pa nasukat 'yung sa mga bago.

torroid with inter winding and layer miracle could be an answer  ;D  i just dont know how  ;D  core damping through special winding, sis?

whats really wrong is the x-f was switch on/off, so the solution is to make a x-f that can be switch on and off  ;D ;D ;D thanks for the input sis!!

core damping and interlayer and winding damping would be nice but how?  ;D


mas ok yung resonant dito using half bridge or fullbridge kaso lossy sa mababang load due to energy na umiikot sa resonant tank, i think magandang gawin yung LLC resonant topologies basta amit na gamit yung full loads para mababang losses, mataas yung efficiency.



ok noted thanks!

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 03, 2012, 05:47:11 PM
sa mga ginagawa namin, sa inductor lang ginagamit ang toroidal cores, EE or ETD cores pa rin ang gamit sa trafo.

nakakita na ko ng trafos used as high as 200kHz sa mga high power supplies na ginagawa namin, nothing special with the windings or the materials, sa topology at snubber ang mga sikreto. meron ding gumagamit ng Controlled Snubbers, depende sa load (current sensing) 'yung activity nung snubber.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 03, 2012, 05:49:33 PM
:D simple design AND high-end specs usually don't MIX.

baka high power sis. :D

kahit 'yung mga lumang design na nakikita ko, lahat merong secondary controllers. 'yung mga luma na talaga, hindi MCU or DSP ang gamit, puro mga logic IC's. ang pinaka-purpose nila is to try to make the unit survive when something goes wrong like fluctuating lines or loads, etc.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 03, 2012, 05:57:30 PM
sa mga ginagawa namin, sa inductor lang ginagamit ang toroidal cores, EE or ETD cores pa rin ang gamit sa trafo.

nakakita na ko ng trafos used as high as 200kHz sa mga high power supplies na ginagawa namin, nothing special with the windings or the materials, sa topology at snubber ang mga sikreto. meron ding gumagamit ng Controlled Snubbers, depende sa load (current sensing) 'yung activity nung snubber.

i hope i can resolved the transformer problem without any external components involve sis  :D i hope thier are no transformer principles conflict in doing it  ;D   the tny268 uses fixed frequency transistion at 130khz and damped some pulses depende sa load nito its a bit simple kaya ito napili ko  ;D

torriod core could be the best but still some problem persist  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 03, 2012, 06:01:18 PM
^ kung mapapadaan niyo rin sa kanya 'yung load pulses sa output magagamit 'yung functions niya. from the diagram kasi sir, hiwalay ng current path 'yung palabas talaga ng output.

MOSFET's easily die without snubbers or any other way to limit switching losses. almost always a given na merong external circuitry bukod pa doon sa main topology pagdating sa high power supplies.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 03, 2012, 06:13:06 PM
plano ko talaga sis is to use a little hi-speed transformer as feedback to solve problems sa hi-voltage output. this could be safe and a simple remedy. protection could be like gfci techniques.

at hi power your right sis, mosfets has a very sensitive input component, i just dont khow yet how to take care with it specially when it is sorrounded by hi-power signals  ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on July 03, 2012, 08:41:48 PM
pwede ding gumamit ng active clamps sa mosfet sa mga forward derives topologies
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 05, 2012, 11:25:38 AM
shock absorbers works at the expense of 6 diodes and 2 capacitors  :(

(http://i49.tinypic.com/bva81.jpg)

no ferrite cores yet kaya laro muna sa ckt  ;D ;D ;D


sayang lang 'yung double trafo kung booster type ang gagawin. single trafo with the same number of MOSFET's kayang-kaya na 'yan.

how do you intend to do it sis?

(the first trafo was placed to isolate the tny268 from the hi-power switcher and second trafo is to isolate the load)

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: centOS on July 05, 2012, 01:35:17 PM
pa time in po dito... ganda ng discussion/tutorial

basa mode......
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 05, 2012, 03:27:51 PM
how do you intend to do it sis?

(the first trafo was placed to isolate the tny268 from the hi-power switcher and second trafo is to isolate the load)

gamit ng standard na controller, 'di na 'yung TNY. ang design kasi niyan (physical and internal) para sa small adapters. hindi siya tested para sa mas malalaking EM sa paligid niya. meron din silang levels depende sa type ng adapter at kung may ventilation o wala. medyo marami ako niyan dito sa opisina. ;D

isa pa, ang majority ng design ng mga 'yan ay based sa Flyback. kailangan baguhin 'yung compensation kung sa forward topology gagamitin. may provision kasi sa RHP zero ang mga 'yan. way back my first job, na-encounter ko 'yun nung ginamit ko siya labas sa Flyback. unfortunately, 'yung mga unang versions niyan, walang provision sa compensation.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: TinTopHack on July 05, 2012, 03:55:33 PM
sa mga ginagawa namin, sa inductor lang ginagamit ang toroidal cores, EE or ETD cores pa rin ang gamit sa trafo.

nakakita na ko ng trafos used as high as 200kHz sa mga high power supplies na ginagawa namin, nothing special with the windings or the materials, sa topology at snubber ang mga sikreto. meron ding gumagamit ng Controlled Snubbers, depende sa load (current sensing) 'yung activity nung snubber.

As you go up the power scale, switching freq and magnetics become more and more important thus your choice of core materials becomes critical, switching losses become more and more significant thus your choice of switching devices and snubbers become critical too.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 05, 2012, 04:13:35 PM
na experience ko minsan ang dc-to-dc upto 500W hindi masyadong problema yong switcher dahil lo voltage lang 13.8Vdc using totem pole switch.  itong switching sa 350Vdc ang nakakalula ang spikes wala yatang magsusurvive na components dito  :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 05, 2012, 04:23:26 PM
same case lang 'yan sir, parehas lang ang energy requirements sa same power, meron pa ring spikes.

sa TI maraming discussions, marami ring cookbooks.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 05, 2012, 04:37:41 PM
ok i'll try flyback switching if i cannot do it in the transformer  ;D    
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 09, 2012, 01:11:20 PM
gamit ng standard na controller, 'di na 'yung TNY. ang design kasi niyan (physical and internal) para sa small adapters. hindi siya tested para sa mas malalaking EM sa paligid niya. meron din silang levels depende sa type ng adapter at kung may ventilation o wala. medyo marami ako niyan dito sa opisina. ;D

isa pa, ang majority ng design ng mga 'yan ay based sa Flyback. kailangan baguhin 'yung compensation kung sa forward topology gagamitin. may provision kasi sa RHP zero ang mga 'yan. way back my first job, na-encounter ko 'yun nung ginamit ko siya labas sa Flyback. unfortunately, 'yung mga unang versions niyan, walang provision sa compensation.

i read yesterday about conventional smps topology, i found out that my switcher is in the two switch flyback topology. i just use this class b switch to reduce components,  more reliability (transformer) and glitch free switching (follow through inrush and transients).

here:

(http://i46.tinypic.com/mac8qo.jpg)

approaching 2kw without any switching problem. (at least in the sims hehehe)  :D

 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 09, 2012, 04:24:17 PM
so good to be true  :D :D :D

(http://i45.tinypic.com/2mrrtyc.jpg)

whack tahh...zero transients and zero displacement  :o :o :o
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bryanwizard30 on July 09, 2012, 04:57:34 PM
galing po ah
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 09, 2012, 05:10:01 PM

laro muna ala pa yong core ko  ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: insomartin on July 10, 2012, 08:10:03 PM
nag dredremel nang ferrite.. :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 11, 2012, 12:36:21 PM
pahenge.... ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on July 11, 2012, 01:18:59 PM
nag dredremel nang ferrite.. :D
ingat sis,pero pwede naman lagyan ng polyester tape para may gapping kono
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 11, 2012, 02:58:12 PM

ellppp!! dumadami na sila   :o

(http://i50.tinypic.com/2nk7x5h.jpg)

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 27, 2012, 02:03:08 PM
ano po ba ang nangyari dito?  :o

(http://i49.tinypic.com/27zkjt4.jpg)

sobra x3 ang input  (7kw, pf 0.70) kaysa output (2kw, pf 1.0)  :o :o :o
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on July 27, 2012, 04:31:09 PM
masyadong mababa ang efficiency sir kaya siguro ganyan.

noong nasa SMPS design pa ako, 'di namin ginagamit 'yung Transformer model mismo, gumagawa kami ng sariling mutually coupled inductor plus 'yung parameters ng core. mas realistic ang simulation kapag ganun, pero madalas umaabot ng ilang oras.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: @badoy on July 29, 2012, 05:41:12 PM
Tanong lang. pede bang e-modify ang SMPS multi output to single output and then increase voltage and current output?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on July 30, 2012, 08:05:35 AM
masyadong mababa ang efficiency sir kaya siguro ganyan.

noong nasa SMPS design pa ako, 'di namin ginagamit 'yung Transformer model mismo, gumagawa kami ng sariling mutually coupled inductor plus 'yung parameters ng core. mas realistic ang simulation kapag ganun, pero madalas umaabot ng ilang oras.

 :o

 iron core nga pala ang sa sim!!!    ??? ??? ???


thanks rd.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 30, 2012, 02:09:51 PM
Tanong lang. pede bang e-modify ang SMPS multi output to single output and then increase voltage and current output?

pwede...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: @badoy on July 30, 2012, 08:12:48 PM
pwede...
what things first to modify? and how
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on July 30, 2012, 09:11:11 PM
what things first to modify? and how

para sa increased voltage yung output capacitor, tataasan ng voltage rating. secondary windings dadagdagan ng turns and yung voltage divider sa feedback babaguhin ang ratio.

sa primary side since gusto mo taasan output current yung fets dun eh tataasan din ang current rating pati yung rectifier diodes at secondary rectifier diodes. kung may fuse ka syempre tataasan din ang current rating nun.

Bulk capacitors may need to be changed also if you observed increased ripple voltage.

check mo rin kung di nahihit yung power limit kung current mode control ang PWM mo, baka kailangan ding babaan value ng sense resistor mo.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: drin20 on August 07, 2012, 08:04:40 PM
medyo na lilito lang po ako. sa push pull. kapag 12 volts dc input at 320 dc volts output.

What should be the ratio of transfo? 1:27?

diba sa primary ay center tapped? kung 4 turns + 4 turns sa primary. 108 turns po ba sa secondary?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on August 08, 2012, 10:25:25 PM
^ may consideration pa 'yung PWM ratio and some other derating factors sir kaya 'di lang 'yan 1:27.

'yung secondary naman sir depende sa rectifier niyo, kung full wave bridge, tama 'yan, kung full wave center-tapped, bale 108 + 108.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: drin20 on August 09, 2012, 01:05:55 AM
^ may consideration pa 'yung PWM ratio and some other derating factors sir kaya 'di lang 'yan 1:27.

'yung secondary naman sir depende sa rectifier niyo, kung full wave bridge, tama 'yan, kung full wave center-tapped, bale 108 + 108.

ayun, salamat po. nalinawagan ako.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Macoy8932 on August 10, 2012, 03:50:04 PM
(http://i1060.photobucket.com/albums/t454/Macoy8932/SP_A0079.jpg)(http://i1060.photobucket.com/albums/t454/Macoy8932/SP_A0080.jpg)
need help po kung pwede po itong 220AC? 120uF 240V po ang Capacitor nnito?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on August 10, 2012, 05:06:20 PM
400V yong rating ng primary filter cap (black) na nakikita sa pics nyo, pero kung yong "Y" cap ang ibig nyong sabihin (blue) nakaseries yan kaya 240Vx2 ang actual nito.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Macoy8932 on August 10, 2012, 05:12:47 PM
ibig posabihin pwede kung tatangalin yong cpacitor na Y? ano po yong Y?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: drin20 on August 10, 2012, 05:37:58 PM
ibig posabihin pwede kung tatangalin yong cpacitor na Y? ano po yong Y?

diba sabi mo papalitan mo? yung color blue na cap.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: @badoy on August 13, 2012, 08:33:37 PM
what is the possible problem in my PC power supply? every time kasi bago bumigay kelangan pa ako mag hintay ng 5 mins na nakasakasak sa 220v bago mag on ang PC ko. ngayun tuluyan nang bumigay. ayaw na mag on kahit naka short na ang green at black wires. TIA
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: j a y k e z on August 13, 2012, 09:43:28 PM
buksan na yan at ivisual check baka may buntis na ecaps ;D

check mo din standby voltage nya ung kulay violet 5 volts iyun ;D
kahit di nakaon basta nakasaksak kung buhay pa ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: @badoy on August 14, 2012, 08:10:31 AM
wala pong busted ecaps at walang sign of damaged. maliban lang sa alikabok...hehehe pero nalinis ko na. ayoko muna katayin kung di ako sigurado kung saan ko ayusin. may 350V DC naman.

try ko sa sunday yung violet kung may 5V.  Tnx sa reply..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bluetooth on August 20, 2012, 10:32:37 PM
good eve mga master, :) mga nasa magkano po kaya ang ic na to L6599D? Bagsaka kasi ang boltahe ng vcc nya 15v suply bumababa ng 2v,.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on August 21, 2012, 11:00:51 PM
good eve mga master, :) mga nasa magkano po kaya ang ic na to L6599D? Bagsaka kasi ang boltahe ng vcc nya 15v suply bumababa ng 2v,.
Ot yata, nasa P120 yan.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: bluetooth on September 03, 2012, 05:06:49 PM
mga master, anu po ang pwedeng pamalit sa L6599d at L6562d? Ito po ang mosfet 2pcs (9D0N50F) Para po sa psu ng lcd tv.. Thanks poh :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: MonDU1FV on September 20, 2012, 10:49:31 AM
Hello! Saan kaya makakabili ako ng schottky diode 60A 40V stud type (DO-5)? Nagrerepair ako ng isang lumang nemic lambda.
Tnx.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Macoy8932 on November 23, 2012, 09:08:35 AM
(http://img853.imageshack.us/img853/3741/12dcto9dc.png)
Pahelp naman po kung may piyesa nito dito sa ph at kung tama ang Diagram.. thanks for correction and help.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on November 23, 2012, 09:36:13 AM
tama ang diagram, standard circuit to ng series pass voltage regulator. at may pyesa nyan dito, maybe not the exact transistor pero check mo transistor with same current and power rating and hfe.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Ron_wrong on February 06, 2013, 10:08:00 PM
pasub muna..meron pla nito :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on February 06, 2013, 11:59:51 PM
2n3055 baka pwede na sa requirements mo? Or baka MJE2955 kung npn parang t0-220, cmiiw. check mo na lang.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: chungkitos on February 22, 2013, 03:16:38 PM
Mga Sir's,

Ano pa kaya ang possible problem nitong power supply ng samsung LCD tv. bigla na lang nag-off habang nanonood kame, then binuksan ko busted yung isang fuse. then pinalitan ko ng fuse same amp., pumutok ulit..

Mahilig lang po ako magbutingting kaya gusto ko itry palitan kung ano po yung posibleng sira.

Thank you..

(http://i95.photobucket.com/albums/l125/chungkitos/DSC_9483_zpsf3fa2b52.jpg)

(http://i95.photobucket.com/albums/l125/chungkitos/DSC_9485_zpsc174e327.jpg)

(http://i95.photobucket.com/albums/l125/chungkitos/DSC_9484_zpsc22c8a74.jpg)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 22, 2013, 04:21:56 PM
pumutok ang fuse kasi possibleng may nasirang component, so kahit palitan palagi ang fuse puputok at puputok palagi yan.

after mo palitan ang fuse nagOn pa ba ang TV kahit konte?wala ba kayong narinig na tunog? or naamoy na nasusunog?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: chungkitos on February 22, 2013, 07:13:48 PM
Boss glutnix_neo, pagsaksak pa lang sa outlet e putok na agad...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on February 22, 2013, 08:11:58 PM
Check mo kaya yang mga T0 220 na component sa heatsink.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 22, 2013, 09:33:02 PM
Boss glutnix_neo, pagsaksak pa lang sa outlet e putok na agad...

ok, great, mas madali nga itrouble shoot yan putok agad kaysa sa mabubuhay pa muna ng matagal bago pumutok.

tama si question marks, check mo kung shorted yung switching mosfet ng primary.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: @badoy on February 23, 2013, 07:39:35 PM
sa kabila dre may expert doon sa mga lcd
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on February 23, 2013, 07:46:07 PM
LCD yun hindi power supply  ;D ;D ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on February 23, 2013, 11:26:54 PM
power supply ng lcd
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on August 06, 2013, 08:06:53 AM
buti pa mag-aral ng SMPS...

question po:
Alin dito sa schematic ang nagdedetermine ng voltage output? ... current output?

(http://i179.photobucket.com/albums/w313/kiashee/elab_dot_ph/PMP1533_zps237d5d47.png)
http://www.ti.com/lit/ml/slor090b/slor090b.pdf

Maari ba nating gawin nalang yung transformer? or imodify yung dati na?

Ilang beses na kasi ako nakakita ng ganito. baka pwedeng mamodify...
supply ng mga printers, similar dito.


eto, came from an HP printer. it has an output of +32V@625mA

(http://i179.photobucket.com/albums/w313/kiashee/elab_dot_ph/IMG_0056_zpsba20db24.jpg)


Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on August 06, 2013, 09:38:00 AM
buti pa mag-aral ng SMPS...

question po:
Alin dito sa schematic ang nagdedetermine ng voltage output? ... current output?

(http://i179.photobucket.com/albums/w313/kiashee/elab_dot_ph/PMP1533_zps237d5d47.png)
http://www.ti.com/lit/ml/slor090b/slor090b.pdf

Maari ba nating gawin nalang yung transformer? or imodify yung dati na?

Ilang beses na kasi ako nakakita ng ganito. baka pwedeng mamodify...
supply ng mga printers, similar dito.


eto, came from an HP printer. it has an output of +32V@625mA

(http://i179.photobucket.com/albums/w313/kiashee/elab_dot_ph/IMG_0056_zpsba20db24.jpg)



R20 at R23 sir yung Voltage output(Vref kasi 2.5V for TL431), R14 naman sa current(1V sir yung Vref naman to detect current)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on August 06, 2013, 09:53:51 AM
R20 at R23 sir yung Voltage output(Vref kasi 2.5V for TL431), R14 naman sa current(1V sir yung Vref naman to detect current)

thank you... I will have to try that when i get home.

alin ang determinant ng maximum current? Q2?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on August 06, 2013, 10:27:06 AM
thank you... I will have to try that when i get home.

alin ang determinant ng maximum current? Q2?
sa primary current sir let say 2A(120%)=2.4A  sa sec output OCP at 0.80 efficiency,so Pout=Pin(0.80)
24(2.4A)=(85Vac*sqrt(2))*Ipri*(0.80);Ipri=0.6A;
1V(Vref)=0.6A*Rsense;
Rsense=1.67R
kapag gusto sir lakihan ng output current babaan lang yung Rsense but dapat kaya ng Power Transformer yung power deliver at kaya din ng Q2 yung peak current habang switching.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on August 06, 2013, 10:51:48 AM
sa primary current sir let say 2A(120%)=2.4A  sa sec output OCP at 0.80 efficiency,so Pout=Pin(0.80)
24(2.4A)=(85Vac*sqrt(2))*Ipri*(0.80);Ipri=0.6A;
1V(Vref)=0.6A*Rsense;
Rsense=1.67R
kapag gusto sir lakihan ng output current babaan lang yung Rsense but dapat kaya ng Power Transformer yung power deliver at kaya din ng Q2 yung peak current habang switching.

ah yes, nakalimutan ko ang transformer....  try ko nalang.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on August 06, 2013, 11:23:41 AM
tita marce, roughly same power sa ibang voltage makukuha mo diyan. or pwede i-adjust ng konti frequency kung kaya sa controller, magiging mas mainit lang.

kung ire-rewind trafo, mas maganda kung makukuha orig na ratio, pwedeng doon magbase kasi computed na 'yun.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on August 06, 2013, 03:50:25 PM
sir pinoy_tech pde po pa pasa ulit nung TL494 based pwm.
try ko gawan ng PCB.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on August 06, 2013, 07:08:03 PM
yun bang nakuryente ka tapos halos ayaw mo nang hawakan!!! heheh ;D

ano mga sis ang ginagawa nyo para mawala kaagad ang charge sa malaking caps... except ishort. medyo takot na tuloy ako!! ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on August 06, 2013, 07:26:10 PM
mga 22 ohm to 100 ohm 5W resistor sis ang gamit ko pang-short. linalagyan ko ng clip kasi may mga design na umiikot ang charge (normally 'yung doubler types tulad sa PC PSU na may 110V switch). pwede rin maglagay ng LED with proper resistor across sa cap habang nangangalikot para makita kaagad kung may charge pa. warning. :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on August 06, 2013, 07:31:01 PM
Sabi ni ati dikitan mo ng plug ng soldering iron. Maganda mga 1 minute.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on August 07, 2013, 01:58:24 AM
yun bang nakuryente ka tapos halos ayaw mo nang hawakan!!! heheh ;D

ano mga sis ang ginagawa nyo para mawala kaagad ang charge sa malaking caps... except ishort. medyo takot na tuloy ako!! ;D ;D ;D
220V bulb ang gamit ko.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on August 07, 2013, 08:52:07 AM
yun bang nakuryente ka tapos halos ayaw mo nang hawakan!!! heheh ;D

ano mga sis ang ginagawa nyo para mawala kaagad ang charge sa malaking caps... except ishort. medyo takot na tuloy ako!! ;D ;D ;D
yung 10W sir at magparallel ka ng madaming 1R resistor marami sir sa Deeco iyan pero pag wala screw driver nalang basta insulated yung handle.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on August 07, 2013, 09:20:25 AM
Thank you sa mga comments ninyo... ++pogi kayong lahat!

itinigil ko muna kagabi kasi masakit talga. bibili muna ako ng resistors... ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on August 07, 2013, 09:28:21 AM
neon bulb.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on August 07, 2013, 09:33:32 AM
Thank you sa mga comments ninyo... ++pogi kayong lahat!

itinigil ko muna kagabi kasi masakit talga. bibili muna ako ng resistors... ;D ;D ;D

Wag mo kasing gamitin ang touch tester mo. ;D Mas maganda sis ang soldering iron load. Or 220V filament lamp. No worry sa spark ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on August 07, 2013, 10:53:56 AM
Wag mo kasing gamitin ang touch tester mo. ;D Mas maganda sis ang soldering iron load. Or 220V filament lamp. No worry sa spark ;D

actually, sa SMPS lang ako nakukuryente lately. lagi akong nakakalimot!  ;D

natandaan ko pa, 2 years ago, may nakuha akong lumang printer... epson yun. MC34063 based ba yata yun. madali lang eedit... ganun din, feedback resistors and babaguhin.

naitapon ko, basag ang ferrite core! ;D ;D ;D
nagwork pa yun, pero maingay na pagmayload.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on August 07, 2013, 11:13:06 AM
Hmm you give me an idea.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on August 07, 2013, 11:40:45 AM
Ilang beses na rin akong nakuryente sa pagmamadali pero ang di ko makalimutan yung nagyari sa akin lately dahil
surprise, nahagis ko nga yung board  (nasa baba). Akalain mong after 5days na naka unplug yung machine eh may
matitira pa palang charge yung capacitor. After tracing the board eh nakita ko na wala palang bleeder R across cap.
How come na makalimutan ng designer na lagyan yung psu na yun?

BTW, kung lamp discharge. Two actions kaagad ang magagawa nun. Actual discharge (very quick) and the visual light
will tell us that the cap is already fully discharged. I found out na ito rin pala ang method na ginagamit ng taga diy smps.


        (http://i41.tinypic.com/1z3w5cy.jpg)


   (http://i44.tinypic.com/2qva0lc.jpg)
   
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on August 07, 2013, 12:41:20 PM
How come na makalimutan ng designer na lagyan yung psu na yun?

BTW, kung lamp discharge. Two actions kaagad ang magagawa nun. Actual discharge (very quick) and the visual light
will tell us that the cap is already fully discharged. I found out na ito rin pala ang method na ginagamit ng taga diy smps.


        (http://i41.tinypic.com/1z3w5cy.jpg)


   (http://i44.tinypic.com/2qva0lc.jpg)
   

marami na akong nakitang ganyang design sir sa mga rine-repair naming telco rectifiers. karamihan mga top known brands pa ang gumagawa. :D

pinaka-important 'yung last na warning doon sa post niyo sir, kaya maganda 'yung may malayong extension na merong switch or any control. exploding large caps, shorted MOSFET's, at shorted MOV's (varistors) ang mga pinaka-delikadong nakita ko, malakas talaga umapoy. 'yung malalaking varistor kaya pang sunugin 'yung kurdon na gamit minsan lalo na kapag 'di na-trip 'yung breaker or fuse.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on August 07, 2013, 12:43:41 PM
in addition, sa opisina, linalagyan namin ng takip bago i-test. para kung meron ngang sasabog hindi na lilipad at baka may madamay sa sunog.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on August 07, 2013, 03:08:51 PM
Nyahaha uso rin pala sa inyo sir ang "fire in a hole".  :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on August 07, 2013, 06:22:59 PM
lalo na kapag mga 2kW to 5kW units ang tine-test. :D 'yung mga 3 phase na 15kW to 30kW units ang nakakatakot i-test kapag first time. :
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on August 07, 2013, 06:32:24 PM
noted yan mga sis... ituro ko yan sa mga students ko. hehe :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on August 25, 2013, 06:28:40 AM
experience ko dito yong splinter ng mosfet TO-220 package, ng pumutok ito, butas yong salamin ng bintana namin parang tinamaan ng bala, walang masyadong cracked pero butas ito. mula noon tigil na ako sa smps  ;D

maganda yang mga pre-cautions posted above para iwas disgrasya.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on August 26, 2013, 12:07:12 AM
Pwede ba dito itanong yung sa mga ferrite core? Like this one

(https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTcFIR7Cvrv8ZvPGcV30T-Vg5d9ukKNBjsRU2bOw9tQYgZGObM3khK1Wg)
from google

Paano gumawa neto. Inductance at ampere at wire size niya paano gawin.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on August 26, 2013, 07:39:11 AM
Pwede ba dito itanong yung sa mga ferrite core? Like this one

(https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTcFIR7Cvrv8ZvPGcV30T-Vg5d9ukKNBjsRU2bOw9tQYgZGObM3khK1Wg)
from google

Paano gumawa neto. Inductance at ampere at wire size niya paano gawin.

may mga ganyan akong nakita sa e-gizmo(I mean yung core).

May "AL Value" na tinatawag ang mga core na ginagamit na multiplier sa number of turns squared.
Quote
L = n2 x AL

regarding sa current rating, depende sa frequency yun at size ng wires, normally you can refer to sa table like this...

you might find a table current capacity of wires at DC, expect na mas mababa capacity nito @ High Freq AC due to skin effect.

http://www.powerstream.com/Wire_Size.htm

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&ved=0CEQQFjAD&url=http%3A%2F%2Fwww.pulseelectronics.com%2Fdownload%2F3121%2Fg033&ei=m5QaUrXsMomCrAf48IAY&usg=AFQjCNE6VPoTl93WkMZG0ArlL4hTjnD8Tw
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on August 26, 2013, 04:52:01 PM
Pwede kaya ito as info?
hxxp://www.ece.ucsb.edu/~long/ece145b/Lab2_145b/INDUCTOR_w02.pdf

about AL value.


Ilan kaya Al value ng nasa eguessmo?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on August 26, 2013, 04:58:03 PM
mahirap masabi, kailangan alam mo kung sino manufacturer ng core at anong exact part number nun.......

With regards sa AL value nung nasa e-gizmo, pwede ka siguro humingi ng tulong sa kanila sa pagdetermine nun, kumpleto naman sila ng equipments dun...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on August 26, 2013, 05:18:43 PM
Masubukan nga bago makabili para hindi masyadong hulahula.

Saan naman sir dito pwedeng mapasok yung term na saturation niya? May nababanggit kasi kay google?



Pwede kayang style ay ganito? Making 10 turns tapos sukat ng inductance value then maybe ratio and proportion na lang din. Meron bang bearing yung wire size niya? Just to confirm kung meron man.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on August 26, 2013, 05:31:42 PM
nasa number of turns 'yan at 'yung current na ipapasok sa inductor, plus 'yung property ng core.

pero 'yung ganyang core, medyo matagala mag-saturate dahil hindi buong core 'yung magnetic loop, which is, kasama 'yung air. kaya normally, for filtering at oscillator purposes lang sila ginagamit, hindi sa energy storage.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on August 26, 2013, 05:43:18 PM
Paano kung gamit sir sa dcdc boost? 

Like this one

Paano ba ito? (http://dics.voicecontrol.ro/tutorials/mc34063/step_up.jpg)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on August 26, 2013, 05:47:40 PM
kung maliit lang ang power consumption nung load, kaya 'yan ng ganyang core. common examples nito 'yung mga joule thief.

pero kung malakihang load, ferrite cores with discrete gap or distributed gap ang kailangan. 'yung gamit na toroid sa PC PSU, medyo malaki na rin ang kaya niyang i-handle.

isa pang problem sa ganyang core na gagamitin sa energy storage circuit, malakas siya gumawa ng noise dahil kasama 'yung air sa magnetic loop.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on August 26, 2013, 07:13:33 PM
Salamat mga sir. Back to testing again.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on October 22, 2013, 06:05:44 PM
sir pinoy tech,
ano kaya ang magandang pang drive dito?
(http://i1145.photobucket.com/albums/o509/hengilbert/Untitled_zps923d5a8e.png)
na try ko na ung tl494 tapos ung core ng ATX PSU ung gamit.
then back to back trafo config.
(http://i1145.photobucket.com/albums/o509/hengilbert/IMG-20131021-00458_zpsfebcb377.jpg)
para sa 40" LCD TV po to.
ung load niya ay 20pcs EEFL
mga 1500Vrms 50mA ung nakasulat sa board na output ng inverter
search niyo na lang po ung mapa sa google.
bn44-00134a ung board number.

eto ung ginamit ko.
(http://i1145.photobucket.com/albums/o509/hengilbert/pwmpush-pulldrive_zpsfde59811.jpg)
kung napapansin niyo po ay may line na red, ibig sabihin niyan naka hang o putol.
kapag tinanggal ko po yan from traffo while leaving the other one connected ay gumagana pa rin.
kapag kinabit naman ay gumagana pa rin.
 eto ung tanong ko:
di po ba kapag naka hang yan ay di gagana? guess ko lang po.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on October 22, 2013, 07:21:43 PM
Gagana pa rin naman kaso hindi na nga lang ganun kalakas. Parang magiging flyback mode
na lang bale sya at mareset ang pri coil sa body diode ng nakakabit na mosfet.

Sa tanong mong drive, alin ang ida drive ba? Yun na bang input ng Hi / Lo drive IC?
DL ko muna ang mapa sa opis mamaya. Eating time & rest muna, duty mamaya...

At 102 + 18K osc, ang reading ko sa scope is 42Khz. The diag shows 62Khz, that is based on
datasheet calculation ng wala pa akong scope...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on October 22, 2013, 07:30:56 PM
Paano kung gamit sir sa dcdc boost? 

Like this one

Paano ba ito? (http://dics.voicecontrol.ro/tutorials/mc34063/step_up.jpg)

Baka kursunada mo ito sir at sa iba pang naghahanap ng DC boosting na namumroblema sa low voltage input like 3V.
Modified version ko na yan (natuli na)... I discovered na pag ganyan ang ckt di umiinit ang power trans kahit TIP41C lang.

Edit...resized

(http://i44.tinypic.com/sw3k7l.jpg)

(http://i43.tinypic.com/34dsb5i.jpg)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on October 22, 2013, 07:46:09 PM
Gagana pa rin naman kaso hindi na nga lang ganun kalakas. Parang magiging flyback mode
na lang bale sya at mareset ang pri coil sa body diode ng nakakabit na mosfet.

Sa tanong mong drive, alin ang ida drive ba? Yun na bang input ng Hi / Lo drive IC?
DL ko muna ang mapa sa opis mamaya. Eating time & rest muna, duty mamaya...

At 102 + 18K osc, ang reading ko sa scope is 42Khz. The diag shows 62Khz, that is based on
datasheet calculation ng wala pa akong scope...
ung transformer mismo ang i ddrive pero mas maganda ung dun sa lo at hi (mosfets) :D
iniisip ko ngayon ung topology ng ATX PSU na may similarity sa post ko.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on October 22, 2013, 07:52:06 PM
Patingin nga sir PT baka lang makursunahan gawin at experiment mabuti na maraming reference.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on October 22, 2013, 09:29:51 PM
ung transformer mismo ang i ddrive pero mas maganda ung dun sa lo at hi (mosfets) :D
iniisip ko ngayon ung topology ng ATX PSU na may similarity sa post ko.

Ah, got you... dapat talaga katulad ng sa atx kasi half bridge mode na to, may prob kasi tayo sa high drive.
Di ka ba naka sub sa self-osc smps intended for audio amp? Ay, may query pa pala si sir dorime, nakaligtaan ko na...

We can customize output trafo depending on our votage need, 1~2kw is possible (costly nga lang kung bibili)...

Drive:

Pwede rin upc494 + totem trans + GDT then mosfet or 494 + IR2110 then mosfet

Or SG3525 + GDT then mosfet or 3525 + 2110 then mosfet


 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on October 22, 2013, 09:33:12 PM
Ah, got you... dapat talaga katulad ng sa atx kasi half bridge mode na to, may prob kasi tayo sa high drive.
Di ka ba naka sub sa self-osc smps intended for audio amp? Ay, may query pa pala si sir dorime, nakaligtaan ko na...

We can customize output trafo depending on our votage need, 1~2kw is possible (costly nga lang kung bibili)...

Drive:

Pwede rin upc494 + totem trans + GDT then mosfet or 494 + IR2110 then mosfet

Or SG3525 + GDT then mosfet or 3525 + 2110 then mosfet

 
ngek, walang available na 3525 at 2110 dito sa amin :D
ok na ata to (upc494 + totem trans + GDT then mosfet)
so this will serve as a replacement for FAN7380?
di ako naka sub sa thread na un sir :D
what if i mods ung "oscillator" ng ATX para mapasok ung traffo ng inverter?
since half bridge din naman un, ung gagamitin na output ay yung nasa ATX at hindi ung mosfets.
300V naman ung + supply ng inverter traffo. ewan ko sa ATX.
possible? o might be a fail? :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on October 22, 2013, 09:51:57 PM
sa current setup ko kasi ngayon na back to back traffo ay malaki ang kinakain sa 12v,
almost 4-5A base sa tester.
pero ung ATX psu traffo ay di naman umiinit at ung mosfets (irf540) need lang ng fan kasi maliit lang ung heatsink.
wala rin akong makunan na 12V na mataas ang current sa board ng tv.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on October 22, 2013, 10:35:21 PM
Yan na ba yung current na nasusukat mo pag may load, yun ba yung nas pict above? Sabi mo nga nasa 1.5KV/50mA ang load specs. That is nasa range 75W na. So kung sa source natin na 12 for 75W power, more or less 6A na agad plus eff pa. Kukuha ka ba sir sa 12V source, why not from 310VDC?   
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on October 22, 2013, 10:47:52 PM
yes loaded na po yan.
un na nga sir ung plan :D
sa 310 kukuha ng source.
pde ba?
tanong ko nlang din kung ano ung pinakamababang frequency ang kaya ng EI33?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on October 22, 2013, 11:45:34 PM
Not really sure kung gaano ang aabutin, depende pa rin kasi sa windings natin kasi pagbaba pagdami naman ng ikot. Sweet spot na nya yung 30~50Khz, 42K is the middle choice sa material at spacing nya... Kung mapapansin mo sa orig winding ng atx, more or less nasa 22 + 22 yung winding ng pri....Ganito yun, 22T Pri >>> sandwich the 7T + 7T sec >>> then another 22T Pri. This winding is almost occupying space of EI33 at 42khz. So kung pabababaan pa freq, mas dadami ang turn.

Fell free to visit... http://www.elab.ph/forum/index.php?topic=40245.0

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on October 23, 2013, 04:17:42 PM

what if i mods ung "oscillator" ng ATX para mapasok ung traffo ng inverter?
since half bridge din naman un, ung gagamitin na output ay yung nasa ATX at hindi ung mosfets.
300V naman ung + supply ng inverter traffo. ewan ko sa ATX.
possible? o might be a fail? :D

May singyales na yata sa mapasok >>> mapausok  ;D  ;D  ;D

Nakita ko na ang full schema, may PFC ckt pa pala ito, syempre para mas effective ang autoV.

Pero Diac na DB3 ba meron sa store dyan? Pwede yung Base Drive Trafo na lang ng ATX wala ng IC
plus diac at few passive...

- Ano kayang operating Freq ng orig design nya? May mabuso kaya sa pcb?
- Gaano pa ang free space sa loob ng unit kung sakaling mag add ng parts?
- sa output, may indication ka ba dyan sa pcb na pwedeng makita ang Vdc?
- gaano kalaki ang mosfet?
- Ano ang pulutan, este... wala pala

Pero bago ang lahat, ano ba ang prob ng unit pala? Baka naka latch mode
lang sa error correction dahil may failure sa out, di kaya?

Pag nag mod tayo baka ma bypass ang short ckt, pano pag may trouble sa load?

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on October 23, 2013, 05:37:06 PM
db3 meron isa sa mga cfl.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on October 23, 2013, 06:39:40 PM
May singyales na yata sa mapasok >>> mapausok  ;D  ;D  ;D

Nakita ko na ang full schema, may PFC ckt pa pala ito, syempre para mas effective ang autoV.

Pero Diac na DB3 ba meron sa store dyan? Pwede yung Base Drive Trafo na lang ng ATX wala ng IC
plus diac at few passive...

- Ano kayang operating Freq ng orig design nya? May mabuso kaya sa pcb?
- Gaano pa ang free space sa loob ng unit kung sakaling mag add ng parts?
- sa output, may indication ka ba dyan sa pcb na pwedeng makita ang Vdc?
- gaano kalaki ang mosfet?
- Ano ang pulutan, este... wala pala

Pero bago ang lahat, ano ba ang prob ng unit pala? Baka naka latch mode
lang sa error correction dahil may failure sa out, di kaya?

Pag nag mod tayo baka ma bypass ang short ckt, pano pag may trouble sa load?


- Ano kayang operating Freq ng orig design nya? May mabuso kaya sa pcb?
yan din ang iniisip ko ngayon kung ano ung operating frequency nito.
Gaano pa ang free space sa loob ng unit kung sakaling mag add ng parts?
sobrang lawak sir. kaya pa ung motherboard ng PC.
sa output, may indication ka ba dyan sa pcb na pwedeng makita ang Vdc?
meron sir, nakasulat sa pcb. check link:
http://assets.shopjimmy.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/s/j/sjbn4400134a.jpg
gaano kalaki ang mosfet?
2 pcs FQPF11N50CF  TO-220F

Pero bago ang lahat, ano ba ang prob ng unit pala?
bangungot na kasi to sir, sira ung LX1691a. pahirapan makahanap ng board dito. sa pinas.
at pumayag naman ung tumer na i mods to.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on October 23, 2013, 06:42:24 PM
db3 meron ata sir dito sa amin.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on October 23, 2013, 07:29:19 PM
Mukhang hiwalay yung pri sa sec ang winding nito. Masilip kaya sa loob kung gaano kataba ang kabuuan ng pri winding nito? Tapos wire thick kung masilip din ...

Parang style TV flyback core din yata sa silip ko lang... Paki tantya kung gaano kalaki ang center diameter ng core or yung kung di masilip kahit yung gilid lang na "thick x width". C-type core ba?

Di tayo pwedeng may rely sa DC ng ibang chopper. Yung sa HV inverter ang pinaka naging DC is patungo sa comparator...

Yng preliminary test mo using 494, saan mo ipinasok ang output supply? Umilaw na ang display di ba? Sa tingin ko 494 na lang + driver pasok sa same orig GDT. Last option ang self-osc drive trafo...

(http://i44.tinypic.com/2ch8a9t.jpg)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on October 23, 2013, 07:40:45 PM
Mukhang hiwalay yung pri sa sec ang winding nito. Masilip kaya sa loob kung gaano kataba ang kabuuan ng pri winding nito? Tapos wire thick kung masilip din ...

Parang style TV flyback core din yata sa silip ko lang... Paki tantya kung gaano kalaki ang center diameter ng core or yung kung di masilip kahit yung gilid lang na "thick x width". C-type core ba?

Di tayo pwedeng may rely sa DC ng ibang chopper. Yung sa HV inverter ang pinaka naging DC is patungo sa comparator...

Yng preliminary test mo using 494, saan mo ipinasok ang output supply? Umilaw na ang display di ba? Sa tingin ko 494 na lang + driver pasok sa same orig GDT. Last option ang self-osc drive trafo...

(http://i44.tinypic.com/2ch8a9t.jpg)
Masilip kaya sa loob kung gaano kataba ang kabuuan ng pri winding nito?
upload nlang ako ng pic bukas sir.
di ko kilala ung C type :)
hindi single wire pero stranded siya.
Yng preliminary test mo using 494, saan mo ipinasok ang output supply?
bale ganito ung naging setup ko.
(http://i1145.photobucket.com/albums/o509/hengilbert/Untitled_zps123d4d17.png)
umilaw na ung display pero di gaanong mailwanag, hinala ko mahina ung 12v.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on October 24, 2013, 04:27:26 AM
Lumalabas kasi dyan na parang same lang din ang Vout sa Vin naging AC lang... Sa pcb nakasulat dun, 1.2kV/80mA RMS... Di mo ba nasubukan yung walang next trafo as in yung out na mismo ng 1st trafo patungo sa load? May variable psu ka ba? upc494 can run as low as 6V, datasheet said 7V but as tested 6V is still stable.   
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on October 25, 2013, 11:39:09 AM
Lumalabas kasi dyan na parang same lang din ang Vout sa Vin naging AC lang... Sa pcb nakasulat dun, 1.2kV/80mA RMS... Di mo ba nasubukan yung walang next trafo as in yung out na mismo ng 1st trafo patungo sa load? May variable psu ka ba? upc494 can run as low as 6V, datasheet said 7V but as tested 6V is still stable.   
na try ko po i direkta ung 494 sa traffo ng inverter, hindi umiilaw.
TMS91003CT ung core.
http://www.datasheetarchive.com/dl/Datasheets-SW21/DSASW00406560.pdf
wala po akong variable psu dito.

nag try po ako gumamit ng working ATX psu as replacement for battery.
ung 11.3v naging 9.8 - 10v nalang.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on October 25, 2013, 03:02:45 PM
Roughly nasa 34T ang primary... sayang walang details sa cross effective area ng core... ayon sa specs, 1:7:7 ang turns ratio. Our Vin is 385/2 = 192VDC. So roughly mataas talaga ang out nito...

Ganito sana yung sinasabi ko. Yung tapping ng 12Vin ay sa dulo-dulo muna ng ATX trafo, or the so called 12-0-12 tapos yung out direct sa load na pero mas prefer ko sana kung gagamit ng adjustable psu sa input para makontrol muna ang Vout.

May consideration pa yung orig ckt kasi may electronic switch ON/OFF at dimmer adjustment din which is kakailanganin talaga na IC control. I guess, you're targetting to just power-up the backlight on fix mode. Ok lang daw ba sa tomer?

(http://i42.tinypic.com/fkv41t.jpg)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on October 25, 2013, 06:39:30 PM
wala akong variable psu sir.
ok lang naman sa tumer ung fixed.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on October 25, 2013, 08:00:54 PM
Ilan bali ang F-lamp nya? Ba't parang unbalance lumen yata sa pre-test mo using back to back atx trafo? Darker sa left ba?

Test mo pa rin yung sinasabi ko kahit walang adjustable psu. I just want to see the effect muna kung may flicker yung fluorescent.

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on October 25, 2013, 08:10:08 PM
Ilan bali ang F-lamp nya? Ba't parang unbalance lumen yata sa pre-test mo using back to back atx trafo? Darker sa left ba?

Test mo pa rin yung sinasabi ko kahit walang adjustable psu. I just want to see the effect muna kung may flicker yung fluorescent.


10 per side.
pero 10 lang dinadrive yang inverter
ung left, may ibang circuit siya.
may 12v at sa feedback kumukuha.
ma individual traffo din per lamp
try ko mag upload ng pic bukas o samakalawa.
Test mo pa rin yung sinasabi ko kahit walang adjustable psu
ok sir try ko kung may oras ako.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on October 27, 2013, 05:55:28 PM
update ko lang, try ko na sa 9v,
imbes na full light, hanggang kalahati lang ung ilaw.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on October 28, 2013, 02:47:56 AM
Ibig sabihin mas humina kesa dun sa may back to back na trafo na dating test mo?
May inductance meter ka ba? Kung meron paki measure yung small drive trafo (EE16), open ckt.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on October 28, 2013, 10:04:12 PM
wala me inductance meter dito sir.
maiba po muna tayo sir kung ok lang.
how about i rewind ko nlang ung EE33 na transformer para ung out niya ay approx. 1500V.
kaso nakakadalawang palit na ako ng mosfet kasi minsan nag shoshort.
sa unang test using FL ng LCD monitor without rewinding the transformer ay umilaw nang sakto.
nung i transfer ko na sa TV w/ 10 eefl, nangalahati ung ilaw. test ko ulit using only LCD Monitor FL, nangalahati nlang.
nang i rewind ko. 4 turns 4 turns sa primary at 80 turns sa secondary, ok umilaw na. maya maya'y nangalahati na naman at sinira ung mosfet hehe :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on October 29, 2013, 12:20:20 AM
Di ako naka focus sa ganyang solution kasi may prob tayo sa DC source kung saan kukuha ng para sa custom trafo. Imagine kakain sya ng more or less 100W, means additional load sa other DC source kung yun ang target.

Ang target ko is buhayin ang dating psu using pwm control na meron ka. If di pa sira ang Hi/Lo driver IC na nakakabit sa mosfet, di tayo masyadong magtatamper ng orig ckt. 

Wait for sometime, medyo nagki clearing operation pa ako sa opis, after few days maaga na uli ako makauwi sa housing pag nabalik na ako sa field work.

For now, my plan is >>> upc494 + 4 trans in totem config then feed to input of orig GDT. Other is, 494 + mosfet then custom trafo then feed to input of orig GDT. Similar case when I'm checking TV/FBT, I just connect the input terminals of FBT from its own smps (before diode of course) but with some safety cautions like adding series lamp.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on October 29, 2013, 03:04:45 AM
Kung may ready dismantled EI33 ka na pala dyan, pwede na siguro tayong mag test again. Customized wind mo yung EI33 trafo para pang inject natin dun sa EE16 trafo. Make that EI33 in almost 1:1 ratio, 5 + 5 turns sa primary at single out sa secondary pero gawin mong style multi tap para pwedeng mag adjust ng level, let say 3T, 5T, 6T. Yung out, inject sa input nung EE16 pero try adding series resistor like 10R tapos tap muna sa low turns sec. Wala tayong masyadong info kasi sa LX1691 kung yung A&B out ckt ba nya ay naka source sa VDDA. Ano yung read mo sa VDDA, 12V ba? 

As-is muna yung pwm ckt natin na dinadrive ng same IRF540 mosfet at same 12V source. Ang naiba lang bale ay yung out na imbes na mataas gagawing low level AC lang para ma inject direct dun sa input ng T1803... Pag ok, scale down natin ang parts...     
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on October 29, 2013, 04:46:04 AM
^ Hold muna pala ito! Subukan kong sukatan muna ng waveform... I'm afraid about sa dead-time, pag dumaan na kasi ng trafo lumiliit or totally nawawala na yung dead-time. Baka magka problema tayo sa final stage, possible na magkaron ng cross conduction. Wait !!! Di rin pwedeng basta lakihan ang dead-time sa pin4, nagiging spike na lang sa output at magiging double shot signal in supposed to be one pulse...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on October 29, 2013, 06:19:23 AM
Di ako naka focus sa ganyang solution kasi may prob tayo sa DC source kung saan kukuha ng para sa custom trafo. Imagine kakain sya ng more or less 100W, means additional load sa other DC source kung yun ang target.

Ang target ko is buhayin ang dating psu using pwm control na meron ka. If di pa sira ang Hi/Lo driver IC na nakakabit sa mosfet, di tayo masyadong magtatamper ng orig ckt. 

Wait for sometime, medyo nagki clearing operation pa ako sa opis, after few days maaga na uli ako makauwi sa housing pag nabalik na ako sa field work.

For now, my plan is >>> upc494 + 4 trans in totem config then feed to input of orig GDT. Other is, 494 + mosfet then custom trafo then feed to input of orig GDT. Similar case when I'm checking TV/FBT, I just connect the input terminals of FBT from its own smps (before diode of course) but with some safety cautions like adding series lamp.
im not sure about sa FAN7382 kung ok pa.

ok sir, maraming salamat po sa tulong
+1 muna

Kung may ready dismantled EI33 ka na pala dyan, pwede na siguro tayong mag test again. Customized wind mo yung EI33 trafo para pang inject natin dun sa EE16 trafo. Make that EI33 in almost 1:1 ratio, 5 + 5 turns sa primary at single out sa secondary pero gawin mong style multi tap para pwedeng mag adjust ng level, let say 3T, 5T, 6T. Yung out, inject sa input nung EE16 pero try adding series resistor like 10R tapos tap muna sa low turns sec. Wala tayong masyadong info kasi sa LX1691 kung yung A&B out ckt ba nya ay naka source sa VDDA. Ano yung read mo sa VDDA, 12V ba? 

As-is muna yung pwm ckt natin na dinadrive ng same IRF540 mosfet at same 12V source. Ang naiba lang bale ay yung out na imbes na mataas gagawing low level AC lang para ma inject direct dun sa input ng T1803... Pag ok, scale down natin ang parts...     

sa ATX pa rin ba ako makakakuha ng EE16?
un ba ung pang drive ng 13007?
eto ung mapa sa LX1691
http://www.alldatasheet.com/datasheet-pdf/pdf/151953/MICROSEMI/LX1691.html

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on October 29, 2013, 12:43:00 PM
As much as possible yung orig pa rin nyang EE16 ang gagamitin natin wala ng babaguhin. Modulator na lang ang gagawin tapos kakapain yung freq.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on October 29, 2013, 05:34:42 PM
ok sige sir.
so the idea is, assuming that FAN7382 is working?

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on October 30, 2013, 03:19:56 AM
Yes... yan ang gusto kong malaman sana kaya gusto kong inject > kan ng input pulse yung orig EE16 trafo para malaman natin kung ok pa yung next stages. Medyo bago sa paningin ko itong FAN7382, not sure kung may ibang function sya kompara sa mga common IR2110. Majority sa schematic nitong FAN7382, ang recomendation is may input trafo talaga, but if nothing so special baka pwede ng pasukan lang ng logic signal na 0/1 while measuring the output pin (of cource no mosfet yet). If sira na, shift tayo for another plan, self-osc or royer ckt.

Mukhang di maganda ang result ng waveform test ko using trafo as our signal injector lalo na yung nilakihan ko ang dead-time sa IC, may spike sa pagitan ng single pulse. Sa 2nd stage trafo, di na lumalabas ang dead-time kung walang heavy resistive load. Kung mag add naman tayo ng heavy load, not good idea. Kung walang load, no way dahil lalong disaster. Di rin makatulong ang snnuber. No wonder na dapat sabihin talaga na kung magbabalak mag design ang individual ng high power smps without high freq oscilloscope, medyo bangungot ang aabutin.

http://i41.tinypic.com/14dm22u.jpg

   
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on October 31, 2013, 05:26:37 AM
Ok na yung waveform sa totem pole ckt. Prepare your pairs of trannies plus 2pcs resistors. 
Ang ginamit ko lang dito ay tig 2pcs na C945 & A733 pero itaas pa natin sa C2655 & A1020.

2pcs 2SC2655
2pcs 2SA1020
2pcs 2k2 1/4w
1pc 474/100V mylar

waveform after making totem pole drive:

(http://i41.tinypic.com/aoaz9z.jpg)

orig atx GDT_no load:

(http://i42.tinypic.com/5b78t1.jpg)

orig atx GDT_with load:

(http://i39.tinypic.com/qq4eoi.jpg)

custom GDT_no load:

(http://i40.tinypic.com/1z2pr21.jpg)

after main trafo_no load:

(http://i43.tinypic.com/28j8rx1.jpg)

after main trafo_with load:

(http://i42.tinypic.com/2dac360.jpg)
 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on October 31, 2013, 06:31:13 AM
wowowow ;D
cge sir wait ko nlang ung diagram.
+1 sir.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on October 31, 2013, 07:43:52 AM
Ganda.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on October 31, 2013, 06:38:39 PM
As-is, walang babaguhin.... forgot to tell you, pag sira yung FAN7382
saka pa lang natin gagamitin yung additional totem ckt. Observe kung
iinit maigi yung power mosfet, if ever tataasan natin ang freq.

http://i40.tinypic.com/16if68k.jpg
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on October 31, 2013, 08:02:27 PM
pwede ba kumuha ng Vcc FAN7382 para sa 494?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on October 31, 2013, 08:05:19 PM
try ko gawin bukas. sir
+1 ulit.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 01, 2013, 03:17:35 AM
pwede ba kumuha ng Vcc FAN7382 para sa 494?
Kung pag babasehan natin sa orig ckt magkaiba sila ng grounding kaya mukhang di pwede dun. Ang nakikita ko ay yung 12V sa QI808. Itaas mo pala ng konti yung 10Ω  sa output or mag series ka pa ng tig 10Ω bawat pin out.

(http://i41.tinypic.com/hwfkef.jpg)

 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 01, 2013, 02:46:21 PM
sir negative ung result, ayaw pa rin umilaw.
followed your diagram and 12v source, still no light.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 01, 2013, 03:23:36 PM
~edit.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 01, 2013, 03:45:38 PM
di ko na ma edit ung last post.
may output na ung HIN at LIN
(http://i1145.photobucket.com/albums/o509/hengilbert/Capture-2_zps3803bed6.png)
mga 1v both pero taas baba.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 02, 2013, 01:55:30 AM
Ba't kaya 1V lang, I'm expecting at least 5V or so. Yung custom GTD ko dito 1:1:1 using EI33. Ang output is 12VAC, kaya nyang mapailaw ang 12V/5W bulb. If gusto mo ganito na lang ang gawin nating set-up sa pict below. Nag quick & dirty setup ako kanina using whatever parts I gathered from my bin. I increased the operating frequency from 42khz to 55kHz by reducing RT (18k to 10k), plus added soft-start at pin4 by placing 2.2uf from pin14 vref toward pin4. Let me know your opinion.

My quick & dirty SMPS setup using upc494:

(http://i44.tinypic.com/2iide1h.jpg)

My quick & dirty SMPS setup, running continuously for several hrs:

(http://i43.tinypic.com/5w9h5y.jpg)

my quick & dirty SMPS setup using upc494_adding 12V_55W load:

(http://i43.tinypic.com/1z6xje8.jpg)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 02, 2013, 06:45:08 AM
Ba't kaya 1V lang, I'm expecting at least 5V or so. Yung custom GTD ko dito 1:1:1 using EI33. Ang output is 12VAC, kaya nyang mapailaw ang 12V/5W bulb. If gusto mo ganito na lang ang gawin nating set-up sa pict below. Nag quick & dirty setup ako kanina using whatever parts I gathered from my bin. I increased the operating frequency from 42khz to 55kHz by reducing RT (18k to 10k), plus added soft-start at pin4 by placing 2.2uf from pin14 vref toward pin4. Let me know your opinion.

My quick & dirty SMPS setup using upc494:

(http://i44.tinypic.com/2iide1h.jpg)

My quick & dirty SMPS setup, running continuously for several hrs:

(http://i43.tinypic.com/5w9h5y.jpg)

my quick & dirty SMPS setup using upc494_adding 12V_55W load:

(http://i43.tinypic.com/1z6xje8.jpg)
cge sir game ako diyan,
basta mapagana lang tong mga EEFL :D
still the topology is half bridge?
and still using the orig traffo?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 02, 2013, 12:13:42 PM
update:
still working on this.
(http://i40.tinypic.com/16if68k.jpg)
mukhang gumagana ung FAN7382.
may error pala ung pcb na ginawa ko, shorted ung isang out. papuntang ground.
base sa obserbasyon ko, kapag walang supply ung 494, malamig.
kapag meron naman, umiinit.
ill try to hang the fets just to check if there is an output at the HO and LO of FAN7382


but i'm still open for the new circuit sir pt :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 02, 2013, 12:31:29 PM
update ulit.
internally shorted ung LO ng FAN7382,
looking forward sa totem pole or new.

2nd update:
may nasusukat na ako sa EE16 secondary,
mga 8 vac both.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 02, 2013, 07:13:27 PM
Di kaya sira na yung 494 natin? In case nasira yung kabilang side, magkakaron pa rin ng output sa trafo dahil sa may
input pulse pa rin kaso nga lang  unbalance waveform na (very danger yan sa next stage). Pwede mo bang ma confirm
muna sa previous ckt mo using push-pull topo? If ok, ba't umiinit yung IC? Dito sa akin ok lang yung IC kahit drive nya
yung EI33 na tig 12Turns lang lahat. Are the zeners umiinit din ba pati yung dropping 10ohms na naka series? Since iba
bypass na natin ang  Hi/Lo driver IC, di na kailangan ng zener sa input ng trafo. For sure, mag custom trafo ka na
lang using EI33 or EE16. Gawin mong 1:1:1 pero make sure of the output polarity. Tiknik, pag nagkaron na ng output
oscillation sa trafo, iseries mo ang dalawa output at sukatin mo ang dulo-dulo. Dapat zero potential sya, tha't means
nagkaron sya ng contrary sa isa't-isa, also called subtractive polarity of coil. Other option, i wind mo yung EE16,
gawin mong same 1:1:1 pero at least tig 20/20/20T, gauge #34 or kung anong close size na meron kang
magnetic wire dyan. Lakihan mo yung PNP drive...

ito ang sundan mo...

(http://i40.tinypic.com/2dgqlqd.jpg)

 

 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 02, 2013, 07:35:06 PM
ok pa ung 494 sir, meron ako dito mga scavenged 494s from different psu(s)
also changed A1018 (pnp drive) to BD140
hindi umiinit ung 10ohms pati zener.

nahulog ko ung EI33 , meron pa akong isa dito pero mukhang mas maliit sa EI33, EE ung core.
try ko 12t 1:1:1 pero 1v lang lumalabas,
kakatakot i dismantle ung EE16 :D
meron ako dito #30 na magnet wire.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 02, 2013, 08:14:07 PM
gawa nlang ulit ako nang bagong 494 para walang issues.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 03, 2013, 12:00:00 AM
Sayang yung EI33 mo, sa tingin ko dumami ng mahulog  ;D  ;D. Ok yung #30, kakasya siguro yung
60T sa EE16 kasi yung orig ATX, ang turns ay 30+30/10/10/1T. Kung EI33 kahit #22 ok lang, gamit ko
ngayon ay solid tel wire lang. Use other EE16, as much as possible don't tamper the orig parts for
future servicing.

Yung new trafo mo ba't low V output lang? Baka iba ang material nya, dapat no gap din. Wala na bang makatay
na ibang atx trafo, sa akin sana 3 kahon ang mga smps collection  ko dito kaso malayo ka eh  :'( . 

Mukhang overkill na yung BD140, wala bang A1020 lang or similar 92MOD type?

Ito ang testing ng pwm controller. Dapat sureball tayo dito bago ikabit ang mosfet.

   Run test with low wattage load then observe:

(http://i42.tinypic.com/msnd08.jpg)

  See the effect if one of the outputs of pwm stays low:

(http://i41.tinypic.com/2uy0htx.jpg)
       



 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 03, 2013, 06:24:58 AM
imbes na transistors ung uminit sir eh ung 494 ang umiinit,
tried both configuration but no luck. umiinit tlaga :D
hold ko lang muna for a few days kasi mag eenrollment na dito :)
how about ung maliliit na traffo sa ATX? pde bang un nalang?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 03, 2013, 01:06:13 PM
ilang volts po ba dapat sir ung lalabas sa emitter ng PNP?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 03, 2013, 04:15:57 PM
ok back on track :D
got a working KA7500c again.
tried EE16 from ATX 20T pri/30T sec x2 = 8vac both unloaded.
using #30.

need pala walang gap. kaya pala nag iiba voltage
ok lang ba #30 on EE33?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: djkingchristian on November 03, 2013, 08:15:03 PM
basa basa muna ako dito
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 03, 2013, 08:29:35 PM
hehe nag try ako using 2n60 putok ung low side pati 22ohms na naka series.
(http://oi40.tinypic.com/2dgqlqd.jpg)
ok lang ba na magsimula muna sa low voltage?
like 12v?

btw sir, sure po bang 12v ang Vcc ng 494?
sa 15~18v nakakakuha na ako ng 12vac.

sira na naman ung 7500c :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on November 03, 2013, 09:33:27 PM
Sipag ni master. :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 04, 2013, 03:52:06 AM
ilang volts po ba dapat sir ung lalabas sa emitter ng PNP?
With respect to gnd, more DC out pa sya nasa 5V pero kung out to out terminals same sa Vin pero in AC form na.

ok back on track :D
got a working KA7500c again.
tried EE16 from ATX 20T pri/30T sec x2 = 8vac both unloaded.
using #30.

need pala walang gap. kaya pala nag iiba voltage
ok lang ba #30 on EE33?

Sabi ko nga lately no gap... now na alam na natin ang result pag may gap, avoid using gapped cores.
There are ways to use that, but in normal applications better to choose cores without gap.

#30 is fine for EE16 with 20/20/20T @ 55khz 12V source.
Core area is (Ae = 4mm x 5mm = 20mm^2 or 0.2cm^2)
pero sa EI33 kakalug-kalog yan.

 
        (http://i42.tinypic.com/3rgxj.jpg)

hehe nag try ako using 2n60 putok ung low side pati 22ohms na naka series.
ok lang ba na magsimula muna sa low voltage? like 12v?

btw sir, sure po bang 12v ang Vcc ng 494?
sa 15~18v nakakakuha na ako ng 12vac.

sira na naman ung 7500c :D


Sad to hear that! Baka nagkamali ka sa polarity, malamang nag switch ON sabay yung mosfet. Did you follow
my advice at the output of Gate Drive Trafo. Connect them in series tapos sukat sa dulo-dulo. Kung naging zero
ang output nasa tamang pwesto ang para sa Hi/Lo drive. To confirm kung ok pa rin ang out, CT to either end
dapat may tamang output pa. Mosfet can switch ON kahit 5V lang, pero mas ok kung close sya sa tamang
trigger voltage para di masyadong uminit. 

Sure ang 12V supply sa 494. Dropped pa nga yung supply ko sa 11V. Basically our supply voltage
for 494 ic is the input for the primary of GDT because the final output of our pwm is basically configured in
totem pole already (through internal tranny towards 4148 diode then extrenal PNP. Since gdt is 1:1:1 ratio,
practically our Vin is the same as our Vout.

Napabilis ka yata sa pag test. Yes, I'm about to tell you to use 12V psu muna sa entire ckt before final testing sa
orig supply. You'll see that there is enough output to measure. Just an indication that setup is ok.


(http://i44.tinypic.com/wmmn0g.jpg)

EE16 drive trafo on test:

(http://i41.tinypic.com/2077otg.jpg)
 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 04, 2013, 02:38:34 PM
got it running now! woohoo :D :D :D
using IRF530 and k2662 as temporary.
(http://i1145.photobucket.com/albums/o509/hengilbert/IMG-20131104-00499_zps495d280c.jpg)
3leds = output
1led = driver

nag series ako ng 24v bulb sa Vcc as a fuse. in case na mag baliktad, iilaw lang at hindi maninibak.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 04, 2013, 07:52:22 PM
ok lang ba na 2n60b muna ung gamitin ko pang test?
try ko na bukas sa 300VDC.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 05, 2013, 12:32:24 AM
got it running now! woohoo :D :D :D
using IRF530 and k2662 as temporary.

3leds = output
1led = driver

nag series ako ng 24v bulb sa Vcc as a fuse. in case na mag baliktad, iilaw lang at hindi maninibak.

Good, +1....

ok lang ba na 2n60b muna ung gamitin ko pang test?
try ko na bukas sa 300VDC.

Mataas ang Rds ON at hamak na mababa din ang current handling. Kung pang test lang at di nya
ida drive ang orig load pwede pero kung ilalagay sa orig ckt na may same load, mukhang di
kakayanin. Ang nakikita kong mas close na common sa market ay IRF740 or 840.   

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 05, 2013, 03:06:10 AM
Pasukat pala ng Core Cross Area.

  (http://i41.tinypic.com/v49eyo.jpg)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 05, 2013, 07:08:58 AM
Good, +1....

Mataas ang Rds ON at hamak na mababa din ang current handling. Kung pang test lang at di nya
ida drive ang orig load pwede pero kung ilalagay sa orig ckt na may same load, mukhang di
kakayanin. Ang nakikita kong mas close na common sa market ay IRF740 or 840.   


ok sir +1 rin.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Sirkito on November 05, 2013, 12:08:21 PM
Ilan microfarad yun naka series na cap sa primary ng power transformer?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 05, 2013, 06:52:23 PM
^ at least 0.1uF/400V ~600V, or parallel 0.1uF x 2, 3, 4, or single 1uF/400V depende sa load.
Kung meron kang lumang ATX psu meron dun, direct pick lang. If naka split ang DC input at
walang DC offset, pwedeng wala ng output DC blocking cap, connect lang sa common gnd.
See the principle of ordinary audio amp in Output Capacitor Less (OCL) design. Pwede rin
yung 2 series e-cap na let say 220uF or 470uF/250V, sa center tap dun i connect direct
ang 1 line ng input trafo.  I'm sure all of these............. 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 05, 2013, 08:08:53 PM
sir pause ko muna ung project, mag reready pa kasi ako dito may parating kasing malakas na bagyo. :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 06, 2013, 04:51:40 PM
sir quick and dirty setup.
flyback core gagamitin ko for 12v to 220V.
ilan po ung turns sa primary at sa secondary?
using push pull topology. 12vdc input.
load is about 2 cfl. 18W
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 06, 2013, 05:19:56 PM
ops di ako sure kung push pull un :D
kung di pde, plan b nalang muna, ATX PSU core
 nlang.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 06, 2013, 07:10:22 PM
Push/pull, half or full bridge same calculation....

Kailangan ko ng Core Effective Area...  pati operating F ng pwm (Rt + Ct)

e.g. F = 42kHz, Ae = 0.69cm^2, Vin = 12V, Bmax = 1400Gauss

In this case;  Pri = 7.3T + 7.3T or simply 7T, Sec = 134T

Wire size, chk ampacity table but give some extra tolerance....

V/T = 1.64

(lunch break, sleep muna!)

(http://i43.tinypic.com/rw1imb.jpg)


Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 06, 2013, 07:30:09 PM
maraming salamat sir! +1 and god bless.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 06, 2013, 09:45:22 PM
mukhang type ko ung flyback core ;D
andar kaagad walang problema.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 06, 2013, 10:44:52 PM
Good, very improving......pogi point for you....  Yes, I found also na ang material na ginamit sa FBT core ay maganda and I can say most of them are similar dahil kung ang pagbabasihan natin ay ang common application na ang preset operating frequency ng HOT ay 15,750Hz, possible na they are using identical materials.

Correction; My mistake for Cross Effcetive Area Calculation ng sample ko above. I multiplied it to 1.41 instead of 3.1416  ;D  ;D. That must be 1.53cm^2. By then, we can lower the value of Bmax to 1200Gauss instead of 1400G so that Ferrite core will be much more relax.

Ae or Ac = 14mm/2 = (7^2) x Pi

              = 49 x 3.1416

         Ae = 152mm or 1.53cm

Assuming same specs; f=42kHz, Vin=12V, Ae=1.53cm, target Bmax reduced to 1200G

Pri = 3.8T or 4T @ 12V

Sec = 73T for 220V out

our V/T then is = 3volts per turn.



 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 06, 2013, 10:48:37 PM
thanks again for the support sir.
right now im currently playing with the core :D
nag lagay muna ako ng TDA7294 for fun :D
also followed this one for 220V
Quote
In this case;  Pri = 7.3T + 7.3T or simply 7T, Sec = 134T
but Sec = 140T
using 11N50CF galing sa power board. ill change it tomorrow with irf540 2 pairs
(http://i1145.photobucket.com/albums/o509/hengilbert/IMG-20131106-00501_zps5069b311.jpg)
di tatalab ung common na bridge diode.
MUR860 ginamit ko.
(http://i1145.photobucket.com/albums/o509/hengilbert/IMG-20131106-00500_zpsec2c79ce.jpg)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 06, 2013, 11:07:18 PM
You mean ba na 140 ang turns para maging 220V? We can't rely on dig tester kasi depende kung supported yan ng high frequency reading. Most of the time it will give wrong output reading dahil sa D/A ckt na di supported sa higher freq. And one thing more, never measure the output without enough resistive load.

Di tatalab? Ibag mo bang sabihin di uubra? Yes dahil low speed lang yung mga common rectifiers, kailangan ng fast recovery or UFRD.

Avoid too much lengthy wires particularly flyover.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 06, 2013, 11:12:39 PM
You mean ba na 140 ang turns para maging 220V? We can't rely on dig tester kasi depende kung supported yan ng high frequency reading. Most of the time it will give wrong output reading dahil sa D/A ckt na di supported sa higher freq. And one thing more, never measure the output without enough resistive load.

Di tatalab? Ibag mo bang sabihin di uubra? Yes dahil low speed lang yung mga common rectifiers, kailangan ng fast recovery or UFRD.

Avoid too much lengthy wires particularly flyover.
no, just a guess though on the 140.

testing ko lang sir ngayon :D
try ko i shorten as close as possible.

btw DC na po ung sinukatan ko papuntang TDA7294.

how about sa 24v? x2 lang ba ung windings from 12v?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 06, 2013, 11:31:28 PM
mukhang matutuloy na yung project ko para sa car ampli ;D ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 07, 2013, 12:09:24 AM

how about sa 24v? x2 lang ba ung windings from 12v?
Yes, primary turns lang ang babaguhin. Exactly x 2 ang number of turn kung 24V, but kung direct
sa jeep gagamitin, expect the sudden changes of voltage during engine running & engine OFF. The
voltage will rise to 28VDC during engine running while 24VDC during off, that is at 24V jeep/bus/truck,
while 14V at car or the similar.

mukhang matutuloy na yung project ko para sa car ampli ;D ;D ;D ;D
Kung medyo mamumroblema ka sa other parts like fast rec diodes, pwede tayong mag switch sa
low freq switching like 60Hz using same ckt. By then you can use ordinary rectifiers. Likewise,
madali na lang i scale-up ang power dahil very common na ang parts locally using classic trafo.

 




Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: tranqspogi on November 07, 2013, 01:49:36 AM
Ba't kaya 1V lang, I'm expecting at least 5V or so. Yung custom GTD ko dito 1:1:1 using EI33. Ang output is 12VAC, kaya nyang mapailaw ang 12V/5W bulb. If gusto mo ganito na lang ang gawin nating set-up sa pict below. Nag quick & dirty setup ako kanina using whatever parts I gathered from my bin. I increased the operating frequency from 42khz to 55kHz by reducing RT (18k to 10k), plus added soft-start at pin4 by placing 2.2uf from pin14 vref toward pin4. Let me know your opinion.

My quick & dirty SMPS setup using upc494:

(http://i44.tinypic.com/2iide1h.jpg)

My quick & dirty SMPS setup, running continuously for several hrs:

(http://i43.tinypic.com/5w9h5y.jpg)

my quick & dirty SMPS setup using upc494_adding 12V_55W load:

(http://i43.tinypic.com/1z6xje8.jpg)


mali lang sa gawa ko hindi ko tinuli yong EIcore sa PSU hehehe sa Car amp ko din ilagay
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 07, 2013, 02:33:45 AM
Maghintay ka ng Byarnes Santo marami dyan nagku kwan  ;D  ;D  ;D...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 07, 2013, 05:12:51 PM
Good, very improving......pogi point for you.... 


Pag may nakakalimutan ako iniisip kong maigi, at ito pala yun...

for Disabled, 359 + 1 = 360

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: DJFEL on November 21, 2013, 09:02:12 PM
abang nalang ako nito....ok na yata to..
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 22, 2013, 02:08:13 AM
He he, baka inanod eh...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: Hengilbert on November 22, 2013, 02:23:41 PM
inanod na ung sakin ;D
pati ung mga nakatago.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 22, 2013, 06:37:05 PM
Sayang na test muna sana bago inanod  :( ...

Yung nakatago ko paminsan-minsan inaanod din ;D  ;D  ;D ...
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on November 24, 2013, 08:00:57 PM
maganda rin yong kombinasyon ng TNY280 saka SG3525, na try ko na ito up to 500W sa mosfet push-pull driver.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on January 11, 2014, 10:51:30 AM
Point of query lang. Probably may gumawa na nito (paki point naman po ako).

I'm thinking of reusing most parts of an ATX PSU for other applications. For instance audio application.
Napaisip ako gawa nung thread ni    576Pinoy_Tech: Self-oscillating SMPS intended for your audio amp or other applications (http://www.elab.ph/forum/index.php?topic=40245.0).

Isa pa kung bakit ko ito naisip kasi mura lang ang ATX PSU. as low as 300Php. Yun nga lang, substandard yung ganung prices.

Thanks.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on January 11, 2014, 07:31:03 PM
nasagot na pala yung query ko. nagback-read ako ng konti.

nweis, nakuha ko na ang idea. pwede pala, madami din makukuhang parts. pero madaming babaguhin especially sa main transformer. also, much simpler kung gagamit ng power mosfet. ATX uses power BJT.

may nakita ako, SG3525 based.
http://320volt.com/wp-content/uploads/2012/08/50khz-4n25-sg3525-smps-ir2110-smps-700w-50v-power-supply.png
(pakiclick nalang, medyo malaki kasi ang image)

naipapakita dito ang basics ng naisip ko. gawin ko ito, someday.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: ネ㑟㑯㑠 on January 12, 2014, 03:52:47 PM
nagandahan ako sa link na ito:

http://www.digikey.com/Web%20Export/Supplier%20Content/Wurth_732/PDF/Wurth_CookbookforTransformerDesign.pdf?redirected=1

share ko lang.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on January 22, 2014, 10:14:08 AM
nasagot na pala yung query ko. nagback-read ako ng konti.

nweis, nakuha ko na ang idea. pwede pala, madami din makukuhang parts. pero madaming babaguhin especially sa main transformer. also, much simpler kung gagamit ng power mosfet. ATX uses power BJT.

may nakita ako, SG3525 based.
http://320volt.com/wp-content/uploads/2012/08/50khz-4n25-sg3525-smps-ir2110-smps-700w-50v-power-supply.png
(pakiclick nalang, medyo malaki kasi ang image)

naipapakita dito ang basics ng naisip ko. gawin ko ito, someday.

first look, akala ko push pull converter, half bridge pala ang topology sis... :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on January 22, 2014, 11:15:24 AM
first look, akala ko push pull converter, half bridge pala ang topology sis... :)

pwede ba yan i-modify para maging push-pull?

natuwa lang kasi ako sa circuit na yan (although na realized ko, parehas lang ng iba) kasi nakita ko kaagad yung basics ng conversion configuration. Ibig kong sabihin, nakita ko kaagad yun rectification of the AC input to supply to the switching circuit that also generate an AC signal based on the controller's configuration and the feedback that controls the duty cycle.

Sa tingin ko nga, ang challenge sa DIY ay yung materials like custom transformers.  hindi rin available sa lahat ng electronic shop ang mga high power MOSFETs.

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on January 22, 2014, 11:28:12 AM
tanong ko na din sis, di ba pwedeng gamiting yung power transistors sa ATX? yung pinost ko, very similar yung half-bridge converter sa ATX. pero nangangailangan pa syempre ng driver.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on January 22, 2014, 11:33:25 AM
ang special sa kanya compared sa flyback at forward eh yung secondary nya makikita mo full-wave rectifier sya,

This is because alternating na positive and negative DC signals ang lumulusot sa transformer(same sa push-pull at full bridge).

para maging push-pull kailangan mong baklasin yung transformer at magcenter tapped dun sa primary. Ang problema yata eh normally nasa loob yung primary winding... ;D ;D ;D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on January 22, 2014, 11:35:38 AM
tanong ko na din sis, di ba pwedeng gamiting yung power transistors sa ATX? yung pinost ko, very similar yung half-bridge converter sa ATX. pero nangangailangan pa syempre ng driver.

anong klaseng power transistors? BJT? Problems with BJT eh mas mabagal sya compared sa MOSFETS
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on January 22, 2014, 12:13:41 PM
ang special sa kanya compared sa flyback at forward eh yung secondary nya makikita mo full-wave rectifier sya,

This is because alternating na positive and negative DC signals ang lumulusot sa transformer(same sa push-pull at full bridge).

para maging push-pull kailangan mong baklasin yung transformer at magcenter tapped dun sa primary. Ang problema yata eh normally nasa loob yung primary winding... ;D ;D ;D

ok lang magrewind uli ng transformer. kasama na yan sa pag-aaralan. :)

anong klaseng power transistors? BJT? Problems with BJT eh mas mabagal sya compared sa MOSFETS

Yeah, BJT nga.
nagtataka lang ako kasi bakit kinakaya ng mga ATX PSU.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on January 22, 2014, 12:46:10 PM

Yeah, BJT nga.
nagtataka lang ako kasi bakit kinakaya ng mga ATX PSU.
mababa yung switching frequency kaya kinakaya,kaso mas malaki trafo pag mababa switching freq
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: rdpzycho on January 22, 2014, 01:32:15 PM
relatively mabagal yung generic ATX, at dahil mura sila sa mass production kaya main choice. isa pa, madali siya pumasa sa mga standards against fire dahil sa worst case scenario, sabog ang BJT, whereas MOS, apoy. :D di na masyado kailangan ng additional investment sa protection.

isa pang advantage ni BJT sa hi-voltage, linear lang ang loss niya IVsat, si MOSFET, I^2Rds. kaya merong IGBT's, best of both worlds. pero relatively, mabagal din.

meron akong CoolerMaster na supply, MOSFET ang gamit plus merong PFC. 150kHz ata switching frequency, IIRC.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on January 22, 2014, 02:19:23 PM
Pero yung high na tinutukoy ni ate RDP na high voltage ay in range of KVs while ang mga appliances natin operated from AC eh upto 400-600VDC(nominal). Mas economical pa rin ang MOSFETs due to its switching speed sa ganitong voltage range.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on January 24, 2014, 10:55:51 PM
question nanaman ako! hehe ;D

pondering on tube amps, preamp to be exact. 12ax7 requires 12V and a 260V.
Kinoconsider ko ang usage ng SMPS (para sa 260V) vs rewinding transformer for tubes (220V secondary).

critical ba ang size ng core sa boost converter na ito?
(http://diyaudioprojects.com/Tubes/12AX7_Preamp/F02psschematic.jpg)
http://diyaudioprojects.com/Tubes/12AX7_Preamp/

pwede ko bang irewind nalang ang transformer sa ATX PSU (eto kasi ang madami ako)?
Kung pwede, ano ba ang sizing ng magnetic wires?
mahal din kasi ang ETD29, im thinking of alternatives.

sabi ni sir tony, maliit lang naman daw ang kailangan na current sa 260V (150mA per tube, so 300mA for 2 channels).
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on January 25, 2014, 08:50:58 PM
paanong rewind sis,you mean gagamitin mo sa 60hz?hindi pupwede.magsasaturate ang core
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on January 25, 2014, 09:09:25 PM
paanong rewind sis,you mean gagamitin mo sa 60hz?hindi pupwede.magsasaturate ang core

no, i mean, since sa circuit sinusuggest na etd29 (which is mahal), pwede ko bang gamitin anc core ng transformer sa atx?
base sa schematic about 25kHz ang switching frequency ng TL494.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on January 25, 2014, 10:20:37 PM
unfortunately magnetics is not my forte, but I'm guessing it is possible pero lalagyan ng gap yung core(grind the center).


Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on January 25, 2014, 11:29:14 PM
question nanaman ako! hehe ;D

pondering on tube amps, preamp to be exact. 12ax7 requires 12V and a 260V.
Kinoconsider ko ang usage ng SMPS (para sa 260V) vs rewinding transformer for tubes (220V secondary).

critical ba ang size ng core sa boost converter na ito?

pwede ko bang irewind nalang ang transformer sa ATX PSU (eto kasi ang madami ako)?
Kung pwede, ano ba ang sizing ng magnetic wires?
mahal din kasi ang ETD29, im thinking of alternatives.

sabi ni sir tony, maliit lang naman daw ang kailangan na current sa 260V (150mA per tube, so 300mA for 2 channels).
Medyo pasok yung 33 sa power requirement mo pero sa totoo lang inaabuse ko ang IE33 sa ibang application at ok naman di ko makitahan ng kakaibang abnoy.

Direct batt ba sir? Confusing yung ckt kasi may 7812 pag ginamit sa ibang source. Eh ano ba ang Imax ng 7812, 1A? So, @12V, approx 12W Pmax. Mangangailangan ka konwari ng at least 80W psu, at least 7A/12V wala pang transfer eff.

Ito ang nakuha ko, base na rin yung iba sa EI33 datasheet......

Operating frequency range of IE33 daw ay = 15khz ~ 120Khz

@ 25khz, Pmax = 75Watsss
@ 50Khz,Pmax = 125W
@ 100Khz,Pmax = 179W

Core Cross Area = 1.18cm

@ 12Turns + 25Khz, Bmax is 900Gauss

At 75W Pmax/12V, primary wire size = 5 strands #20, or 7strands #22, or 22strands #27

At 260V sec, = single strand #27 (not included tolerance).
 

 
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on January 26, 2014, 08:12:02 AM
^ thanks sis...

pero si ko gets yung about sa sinabi mong power efficiency. :D

once again, sa tube preamp ito gagamitin. and 12V ay sa heater ng tube gagamitin. honestly, di ko din alam kung sufficient na ang current na yan (1A), but based sa website (http://diyaudioprojects.com/Tubes/12AX7_Preamp/), parang very confident naman. at binibenta pa nga ang PCB.


@ 12Turns + 25Khz, Bmax is 900Gauss

At 75W Pmax/12V, primary wire size = 5 strands #20, or 7strands #22, or 22strands #27

At 260V sec, = single strand #27 (not included tolerance).
 

So sis, kung gagamitin ko ang IE33, yan na ang number of turns na gagamitin ko (instead of 12T:80T sa etd29)?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on January 26, 2014, 06:07:38 PM
^ thanks sis...

pero si ko gets yung about sa sinabi mong power efficiency. :D

once again, sa tube preamp ito gagamitin. and 12V ay sa heater ng tube gagamitin. honestly, di ko din alam kung sufficient na ang current na yan (1A), but based sa website (http://diyaudioprojects.com/Tubes/12AX7_Preamp/), parang very confident naman. at binibenta pa nga ang PCB.

So sis, kung gagamitin ko ang IE33, yan na ang number of turns na gagamitin ko (instead of 12T:80T sa etd29)?

Naka optional dashes sa schema na "link to run from battery". Ang pagkakaintindi ko ay paggagamitan ng battery parang ibabypass ang regulator IC. Pano bale ang magiging setup mo sir? From 220V mains down to 12V (PSU) tapos itong bossting ckt na 260V? Why not build flyback mode smps na may 12V at 260V na tapos direct na sa 220?

Sa snap shot ko sa pre-amp, naka idle sya sa 1mA (260V-250V/8.2k = 0.0012A). Duda talaga ako sa power requirement ng tube pre-amp sir, baka low current lang naman sya. Pwedeng mag assume na let say bring na natin yung tube into saturation mode, at some given V test points makukuha na dun yung current requirements... 

Sa tantya ko sa bossting nasa 40mA siguro o baka less pa. Una yung source ng boosting ckt eh ginamitan lang ng 7812 kaya lalabas na 12W lang ang Pmax supply nya sa input. Kung let say makatransfer tayo ng sabihin na natin na 70~90% effeciency mababawasan pa yung 12W natin sa output. Kung ang target ay 260V minus effeciency, magiging  8.4W ~ 10.8Watts na lang in total. So konwari 10W/260V = 38mA na lang ang makukuha nating juice sa out. Kung magkakaganun, pwede ng single strand na #22 sa primary pati secondary. Why bother to buy 2 different sizes of wires kung kakasya naman na sa core window, importante wag ma under size, masusunog pag maliit.

Same turns combination pa rin 12T/80T, mako correct naman ng feedback yung votage looses. Medyo na puzzle lang ako ba't ginamitan pa ng 7812 eh yung ic naman very wide V range ang supply, tapos sa output naka configured na sa auto correction.

Sa ETD29 vs EI33 kung titingnan natin ang material grade same specs sila na 3C90, naiba na lang ang cross sectional area, mas malaki pa nga ang EI33 kaya mas ok sya, not sure about window.



 

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on January 26, 2014, 08:41:31 PM

Quote
Naka optional dashes sa schema na "link to run from battery". Ang pagkakaintindi ko ay paggagamitan ng battery parang ibabypass ang regulator IC. Pano bale ang magiging setup mo sir? From 220V mains down to 12V (PSU) tapos itong bossting ckt na 260V? Why not build flyback mode smps na may 12V at 260V na tapos direct na sa 220?

yes tama. from 220Vac to 12Vdc then boost nalang. sa totoo lang, nagtitipid kasi, may available na akong 12V/2A transformer. But, yes, ikoconsider ko yan suggestion mo. pero siguro next time na. This is my first tube project anyway. lots to learn... pero iniiwasan ko ang paggawa ng custom transformer para sa linear.

Quote
Sa snap shot ko sa pre-amp, naka idle sya sa 1mA (260V-250V/8.2k = 0.0012A). Duda talaga ako sa power requirement ng tube pre-amp sir, baka low current lang naman sya. Pwedeng mag assume na let say bring na natin yung tube into saturation mode, at some given V test points makukuha na dun yung current requirements... 

Sa tantya ko sa bossting nasa 40mA siguro o baka less pa. Una yung source ng boosting ckt eh ginamitan lang ng 7812 kaya lalabas na 12W lang ang Pmax supply nya sa input. Kung let say makatransfer tayo ng sabihin na natin na 70~90% effeciency mababawasan pa yung 12W natin sa output. Kung ang target ay 260V minus effeciency, magiging  8.4W ~ 10.8Watts na lang in total. So konwari 10W/260V = 38mA na lang ang makukuha nating juice sa out. Kung magkakaganun, pwede ng single strand na #22 sa primary pati secondary. Why bother to buy 2 different sizes of wires kung kakasya naman na sa core window, importante wag ma under size, masusunog pag maliit.

ngayon ko lang binasa yung datasheet ng gagamitin ko na tube (12ax7), 150mA pala ang kukunin kay 12V (so 300mA for stereo), tapos yung boost (which is connected to the cathode plate), nasa 1.2mA (at 250V) ang bawat channel.
But, I will have to verify this on the other thread.

Quote
Same turns combination pa rin 12T/80T, mako correct naman ng feedback yung votage looses. Medyo na puzzle lang ako ba't ginamitan pa ng 7812 eh yung ic naman very wide V range ang supply, tapos sa output naka configured na sa auto correction.

Sa ETD29 vs EI33 kung titingnan natin ang material grade same specs sila na 3C90, naiba na lang ang cross sectional area, mas malaki pa nga ang EI33 kaya mas ok sya, not sure about window.

Buti naman at same number of turns lang.
may 7812 kasi, hanggang 12.6 lang ang heater ng 12ax7.

Maraming salamat sis.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on January 26, 2014, 08:48:17 PM
irerecommend ko sana silipin ang inductor current kapag naassemble na para tingnan kung nagsasaturate yung core before loadan ng full load, kaso wala yatang sense resistor yung circuit(Voltage Mode Control lang).

Kung may current probe ka walang problema.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on January 26, 2014, 09:10:53 PM
irerecommend ko sana silipin ang inductor current kapag naassemble na para tingnan kung nagsasaturate yung core before loadan ng full load, kaso wala yatang sense resistor yung circuit(Voltage Mode Control lang).

Kung may current probe ka walang problema.

wala akong current probe. any alternative suggestion sis?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on January 26, 2014, 09:19:32 PM
wala akong current probe. any alternative suggestion sis?

magseries ng resistor?maliit na value. <1v dapat ang mapoproduce sa max current.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: insomartin on January 28, 2014, 11:36:26 PM
http://elm-chan.org/works/lchk/report.html
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on January 29, 2014, 07:52:46 AM
http://elm-chan.org/works/lchk/report.html
1


like!

++ganda point to you! :)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on February 07, 2014, 06:35:32 AM
may natry ako na solution para di mabasa ang mga cores... initin mismo ang core. i use hot air rework station.
kapag nainit kasi, yung varnish natutunaw, kusang naghihiwalay na sa bobbin. di naman na susunog ang bobbin kasi parang ceramic (di ko alam ang materials).  amazingly, matagal bago lumamig ang core once nainit na. kaya, ingat sa handling. kasi baka mahulog. hehehe :D

got this from crt monitor (in the quest for flyback core, nakita ko din ito).
(http://i179.photobucket.com/albums/w313/kiashee/elab_dot_ph/2014-01-29194039_zpse861e697.jpg)

at mabilis ko lang nalinis.
(http://i179.photobucket.com/albums/w313/kiashee/elab_dot_ph/2014-01-30163109_zpsefb3ba37.jpg)

also tried removing the flyback transformer core in this manner. mas matagal ang retention ng init nung flyback cores.
ano nga pala ang tawag dun sa insulating tape na ginagamit sa mga ito? saan makakabili?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on February 07, 2014, 02:10:07 PM
polyester tape meron ata sa egizmo sis
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on February 07, 2014, 08:26:09 PM
polyester tape meron ata sa egizmo sis

salamat sis...

unti-unti ko itong inaaral during free time ko. eventually, matututo din tayo nito. :D
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on February 22, 2014, 01:44:12 PM
question uli...

pwede bang gawing variable workbench PSU ang SMPS?

Most ng SMPS controller (IC) ay binabago lang ang output based dun sa resistors sa output. Consider, simple switchers from TI/National, may mga adjustable versions sila, which in a way parang tulad lang nung LM317. Of course, magkaiba ang pamamaraan kung papano binabago ang output voltage.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on February 22, 2014, 02:15:05 PM
Are you referring sa mga flyback and the similar smps? Pwede sir pero kailangang i consider yung supply ng IC kung kumuha sya ng supply sa sarili nyang trafo. Depende rin sa IC kung anong min & max V supply na kaya nya, at dahil dun pwedeng maging narrow range lang ang variable output. Mas mainam kung yung IC mismo ay ihiwalang ang supply para mas wide ang Vout range.     
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on February 22, 2014, 03:09:06 PM
sis, i'm refering to something like this:
http://www.ti.com/lit/ds/symlink/lm2596.pdf


Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on February 22, 2014, 03:52:57 PM
Mas pwede yan  ;) .
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: _basura_man() on February 24, 2014, 10:13:56 AM
question uli...

pwede bang gawing variable workbench PSU ang SMPS?

Most ng SMPS controller (IC) ay binabago lang ang output based dun sa resistors sa output. Consider, simple switchers from TI/National, may mga adjustable versions sila, which in a way parang tulad lang nung LM317. Of course, magkaiba ang pamamaraan kung papano binabago ang output voltage.
basta covered yung duty cycle kaso basta wag labg zero ang output mag specify ka ng limit sis(e.g. from 24V-12V)
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: drin20 on April 22, 2014, 07:13:16 AM
design by tahmid

(http://2.bp.blogspot.com/-IGrcj4RjyYs/UOqa9ISSgXI/AAAAAAAAAYY/PpmE6sGtLck/s1600/circuit+50kHz.png)

http://tahmidmc.blogspot.com/2013/01/using-sg3525-pwm-controller-explanation.html (http://tahmidmc.blogspot.com/2013/01/using-sg3525-pwm-controller-explanation.html)


share ko lang matagal na kasi tambay ang sg3525
(https://fbcdn-sphotos-a-a.akamaihd.net/hphotos-ak-frc3/t1.0-
9/10291774_10201952476397079_1053523991348956120_n.jpg)

(https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-frc3/t1.0-9/10301362_10201952477717112_8765634196591095229_n.jpg)

(https://fbcdn-sphotos-e-a.akamaihd.net/hphotos-ak-prn2/t1.0-9/1538763_10201952486637335_6661210795459276170_n.jpg)

(https://scontent-a-hkg.xx.fbcdn.net/hphotos-ash3/t1.0-9/10246341_10201952487957368_5476938405035052766_n.jpg)

(https://fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-prn2/t1.0-9/1888627_10201952471196949_2447461802529293950_n.jpg)

thank you
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: >>>^^<<< on April 22, 2014, 09:26:22 PM
Hmm minimal components.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: drian on April 22, 2014, 11:33:19 PM
subscribing
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: nice_apprentice on January 19, 2015, 04:51:24 PM
Hi mga master,

Meron ba kayo suggestion for car inverter na controller????
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on November 10, 2015, 08:31:40 AM
gandang araw....

paclarify naman. confused ako sa transformer sa schematic na ito.

(http://danyk.cz/iz350.png)

galing yan dito: http://danyk.cz/iz350_en.html

Hindi ko gets yung another 40 turns near the gnd sa primary. Hindi ba pagForward mode, sa itaas lang ng MOSFET ang primary?

At another question, talaga bang dapat 800-1000V ang MOSFET ? Di ba ako pwede gumamit nung 500V rating lang?
Nasa 500V rating lang ang nakikita ko sa mga PSU's.

At clarify ko na din, I will have to determine my own number of turns, depende sa available ko na xformer. Tama, di ba?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: motion55 on November 10, 2015, 10:33:57 AM
^^^Actually this design is similar to the Apple II power supply. Ang purpose ng coil sa baba is to return to the supply the excess magnetic energy in the form of flux na di na transfer sa secondary. Kung walang return then the excess flux will be converted to high voltage during fly-back (turn off ng MOSFET). The high voltage will have to be absorbed by the transistor.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: motion55 on November 10, 2015, 10:50:54 AM
Googling here is a reference to the Apple II design.

http://www.righto.com/2012/02/apple-didnt-revolutionize-power.html

Na patent ng Apple ang so called "clamp winding" design. Although the author sa link claims may prior reference sa clamp winding design sa applicatiion notes ng Motorola, etc.

Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: glutnix_neo on November 10, 2015, 11:02:41 AM
ate marce, we call it the reset winding, naiipon kasi yung energy sa transformer on every cycle kung wala yan and possibly magcause ng saturation sa loob. gaya ng sinabi ni ate motion, inidadump nya yung excess pabalik sa source or inirereset nya to zero yung energy sa transformer.
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: 576Pinoy_Tech on November 10, 2015, 11:21:14 AM
gandang araw....

paclarify naman. confused ako sa transformer sa schematic na ito.

(http://danyk.cz/iz350.png)

galing yan dito: http://danyk.cz/iz350_en.html

Hindi ko gets yung another 40 turns near the gnd sa primary. Hindi ba pagForward mode, sa itaas lang ng MOSFET ang primary?

At another question, talaga bang dapat 800-1000V ang MOSFET ? Di ba ako pwede gumamit nung 500V rating lang?
Nasa 500V rating lang ang nakikita ko sa mga PSU's.

At clarify ko na din, I will have to determine my own number of turns, depende sa available ko na xformer. Tama, di ba?

* Hindi ko gets yung another 40 turns near the gnd sa primary.
Yes sir tulad ng sabi nila sa itaas, for resetting nga yan ng primary coil para ready uli for the next fire.
Pwede mo rin syang i configure sa ordinary soft clamp na tulad ng ginagamit sa flyback RCD type snnuber


*Hindi ba pagForward mode, sa itaas lang ng MOSFET ang primary?
Yup, forward mode yan.. ang quick basis ay yung dots, Tr2, at yung free-wheeling diode sa sec.

*At another question, talaga bang dapat 800-1000V ang MOSFET ?
Usually ganyan ang nakikita ko sa mga psu namin ito ang dati kong ginagamit K1342.
Pwede rin naman yung 500V pero medyo mainit nga lang konte.

*At clarify ko na din, I will have to determine my own number of turns, depende sa available ko na xformer. Tama, di ba?
yup pero i consider mo rin sir yung Tr2, nasa 50% ng energy ng secondary ay dyan kumukuha at dahil dyan need talaga yung free-wheeling diode.

hmm, late na ako sa work  ;D  ;D..












Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: marcelino on November 10, 2015, 12:28:14 PM
@motion55
@glutnix_neo
@576Pinoy_Tech

++pogi!

Maraming Salamat. May bago nanaman akong natutunan. :D

Clarification pa.
Sabi dun sa link, ang Tr1 ay hinati sa dalawang parts. Akala ko, yun dalawang 20z ang hinati nya.
So, 40z-40z nya pala hinati?
Title: Re: Lahat ng questions related sa Switched-Mode Power Supply (SMPS)
Post by: motion55 on November 10, 2015, 12:35:23 PM