Help po Uminit yung PIC877A at Yung LM340

[0hñ33n]

 

waaaah uminit po ung 877A at LM340 Voltage regulator namin huhuhu bat ganun waaa???


Pahelp naman po...

ayan po ung schematic namin sa ibaba.....

Hope somebody can help me 

bili muna kami ng capacitor sa labas sna makapag post kayu agad hehe 

[maldihtah13]

waaaah uminit po ung 877A at LM340 Voltage regulator namin huhuhu bat ganun waaa???


Pahelp naman po...

ayan po ung schematic namin sa ibaba.....

Hope somebody can help me 

bili muna kami ng capacitor sa labas sna makapag post kayu agad hehe 

bka po baligtad ung lm340 nyo. Ksi ang technique nyan wag muna ikabit ang pic. Test nyo muna ung voltage source nyo bgo kabit pic.

[akosiikem]

bka po baligtad ung lm340 nyo. Ksi ang technique nyan wag muna ikabit ang pic. Test nyo muna ung voltage source nyo bgo kabit pic.

agree!!!

[0hñ33n]

Nacheck po namin lahat ng connections

and ung LM340 tinignan pa po namin ung Spec sheet

tama naman po sa tatlong pins ang connections except for the stabilizing
capacitors na di namin kinabit

tska, sobrang init po nun PIC at Voltage regulator (buti may heat sink ung regulator)

im hoping di natusta ung dlwang device 

nakabili n kami ng stabilizing capacitor and sna gumana to as we will retest it again....

f ever may mali sa schematic paki reply n ln gpo here.   

bka po baligtad ung lm340 nyo. Ksi ang technique nyan wag muna ikabit ang pic. Test nyo muna ung voltage source nyo bgo kabit pic.

yap yun po gingawa namin bago po ikabit yung pic 

[kinyo]

I think those 1K resistors are overloading you PIC. I would suggest using ULN2003 to drive the solenoids.

[RaffT]

to the original poster:

pag gumawa kayo ng ckt, dapat step-by-step.. power supply first then PIC.... sa tingin ko naka reverse yung connection sa PIC(umiinit lang yan pag neka reverse connection)...

[zer0w1ng]

I think those 1K resistors are overloading you PIC. I would suggest using ULN2003 to drive the solenoids.

Each I/O of the PIC can source or sink 25mA max.
1K load in-front of a transistor is I = (5-0.7)/1K = 4.3/1000 = 4.3mA only.

Nevertheless ULN2003 is very good for driving multiple common loads.

Regarding the heating problem, check for LM340 pin inversion.

Also, I don't see any capacitors on the regulator.
A capacitor at its input is *NEEDED* if it is far from the supply.
A capacitor also on the output is needed for transient.
Its datasheet should give the right values for these caps.

[0hñ33n]

I think those 1K resistors are overloading you PIC. I would suggest using ULN2003 to drive the solenoids.

hmmm even if its only connected to the base of the transistors?? You mean we will replace thos transistors with ULN2003?? Im looking at its Data sheet right now...  Uhm I hope youll reply again hehe.. tahnx 

to the original poster:

pag gumawa kayo ng ckt, dapat step-by-step.. power supply first then PIC.... sa tingin ko naka reverse yung connection sa PIC(umiinit lang yan pag neka reverse connection)...

yupp thats an SOP(standard operational procedure) for us electronic builders.. I didnt bypassed that step.. In fact lahat ng testing bago ikabit to the supply ginawa namin.. At saka un sa supply naman naghanap din kami at inayus ng maigi kaya napunta kami sa pag gamit ng LM340 Voltage regulator... Ung regulator nakumpirma namin na hindi naman baliktad ang
pag kaka-kabit.

Each I/O of the PIC can source or sink 25mA max.
1K load in-front of a transistor is I = (5-0.7)/1K = 4.3/1000 = 4.3mA only.

Nevertheless ULN2003 is very good for driving multiple common loads.

Regarding the heating problem, check for LM340 pin inversion.

Also, I don't see any capacitors on the regulator.
A capacitor at its input is *NEEDED* if it is far from the supply.
A capacitor also on the output is needed for transient.
Its datasheet should give the right values for these caps.

Yes before we connect the solenoids to the PIC we tested each solenoid using the LM340
the regulator did not heat up. Plus we didnt use the capacitors you are referring too.
Kaya sa previous posts ko dito sabi ko kanina bili muna kami ng Capacitor sa labas.
Ngayun nakabit n namin ung capacitors na nsa input and output ng Regulator.

Pero they both, PIC and Regulator, still heated up..

[RaffT]

bka may short -somewhere-

[0hñ33n]

bka may short -somewhere-

un din ang hinala namin

paulit ulit namin na tanggal kabit ung pyesa ganun p rin ngyayari..

Sa tingin nyo kaya un suggestion ni kinyo...

im thinking about it...

 

sana mag reply din po mga masters jan huhuhuh

salamat tlga sa mga nag popopst ^_^

[RaffT]

un din ang hinala namin

paulit ulit namin na tanggal kabit ung pyesa ganun p rin ngyayari..

Sa tingin nyo kaya un suggestion ni kinyo...

im thinking about it...

 

sana mag reply din po mga masters jan huhuhuh

salamat tlga sa mga nag popopst ^_^

i try nyo nga muna i power ang PIC LANG...walang ibang naka kabit..try nyo kun uminit pa.. measure na rin yung mga PIN/s for the PS connection

[0hñ33n]

i try nyo nga muna i power ang PIC LANG...walang ibang naka kabit..try nyo kun uminit pa.. measure na rin yung mga PIN/s for the PS connection

uhm nasubukan po namin yun.. wherein LM340 ang pinaka supply ng PIC tapos we tried measuring the outputs from our set ports. Wala nakukuha na output sa set prts namin at saka ganun pa rin umiinit ung bot PIC and LM340.

Since wala output(suppose to be meron) sa programmed port namin ung solenoids di napalo.

Im wondering if it is program related kaya uminit pero malamang hindi un.
Hinala rin namin baka hindi gumgana ung 20MHz xtal na kinabit namin.. We are currently testing ang confirming them..

[RaffT]

uhm nasubukan po namin yun.. wherein LM340 ang pinaka supply ng PIC tapos we tried measuring the outputs from our set ports. Wala nakukuha na output sa set prts namin at saka ganun pa rin umiinit ung bot PIC and LM340.

Since wala output(suppose to be meron) sa programmed port namin ung solenoids di napalo.

Im wondering if it is program related kaya uminit pero malamang hindi un.
Hinala rin namin baka hindi gumgana ung 20MHz xtal na kinabit namin.. We are currently testing ang confirming them..

try nyo nag i-power up with ONLY the PIC connected then measure nyo yung supply.. it should be in the vicinity of +5v....

[akosiikem]

PAno bang mainit, yung hindi mo halos mahawakan?
Hindi ba normal lng sya kasi nag run cya in high speed?

[RaffT]

PAno bang mainit, yung hindi mo halos mahawakan?
Hindi ba normal lng sya kasi nag run cya in high speed?

na actual ko na ang PIC running @ 20MHz ... its only around 20mA or so...sa PIC side..

[anthonydp]

talaga ba na walang clamping-diode yung mga solenoids? it is possible na nagproduce na ng voltage kick yung mga solenoid when those switched on and off at nadale na yung regulator and mcu.

i recommend that you remove the PIC from the board.

then measure the voltage coming from the regulator -- it should be as what is expected (5v).
let's ascertain that the regulator is still functional by giving it a dummy load -- a 4.7ohms/5watts would do.
measure the output voltage while being loaded by the dummy load -- it should still be 5v.

now that we are certain that the regulator is good, revise your circuit by putting diodes across each solenoids' coil.
you can use 1n4002. each is oriented with the cathode connected to the solenoid's pin that's connected to the unregulated 16v.

after that, you should test each solenoid's transistor driver by connecting the base resistor to 5v -- see if the solenoid activates whenever you apply 5v to each resistors.

once everything checks fine, try connecting the PIC again.  of course, power must be off when doing this.

if the pic and the regulator still heats up, you may have a busted PIC there.  try replacing it.
maybe the PIC died from the flyback voltage of the solenoid/s.

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Tama si Zero1ng 4.3mA lang sa isang pin, kaya lang anim yong load mo sa PIC.

Try using darlington transistor o di kaya mosfets, saka soleniod (coil) yong load mo kaya lagyan mo ng reverse diode bawat soleniod.

Yong heating mo sa LM340, laki kasi ng input 16V tapos 6V lang ang out mo, try mo heatsinks o di kaya babaan mo ang input .

[RaffT]

Tama si Zero1ng 4.3mA lang sa isang pin, kaya lang anim yong load mo sa PIC.

Try using darlington transistor o di kaya mosfets, saka soleniod (coil) yong load mo kaya lagyan mo ng reverse diode bawat soleniod.

Yong heating mo sa LM340, laki kasi ng input 16V tapos 6V lang ang out mo, try mo heatsinks o di kaya babaan mo ang input .

AND another posibility, bka pati soleniods eh nasa 5V supply...

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Baka busted narin yong mga transistors o di kaya yong LM340 o di kaya yong PIC mismo dahil sa reverse voltage ng anim na solenoids...

[RaffT]

Baka busted narin yong mga transistors o di kaya yong LM340 o di kaya yong PIC mismo dahil sa reverse voltage ng anim na solenoids...

di natin alam...d na yata nag post ang OP..  baka sira na ang project..