I Make by combining materials and parts of ESR METER - Help Plz

[elbaz_elec]

Yes i used Kasper's firmware, so please what should i do to debug the code and add low pass filter?

thanks

[kinsa]

Use the original firmware. Kasper haas a copy of it in his archives.

Also, ripple in the power supply would cause this. Try using a battery when calibrating.

[elbaz_elec]

thank you kinsa,

i did your instruction and the circuit was more stable, i will finish its calibration and tell you what's happen to supprot me,


Thanks a lot again.
i wish the best for you
Osama Elbaz

[elbaz_elec]

hi Kinsa,

I asked why my full calibration starts with 1.25 ohms at location 0X0010

is this normal

thanks.
Osama

[kinsa]

if you are doing full calibration, replace the trimmer with 220 ohm resistor.

[elbaz_elec]

Hello Kinsa,

I already replaced the trimmer with 220 ohm, metal film, 1% tolerance but the 0X0010 appears at 1.30 ohm, is this normal?
another question please, I asked can I connect DMM directly to ESR meter while I do full calibration?
I saw your pictures I think you connect DMM (in resistor measure) directly to ESR meter while you calibrate it.
Or I must disconnect trimmer while measuring its resistance….

Thanks a lot....

Osama

[kinsa]

hello osama,

the result you are seeing is normal; the values that you will get depends a lot on the component tolerances and the components that you have used. your circuit has a lower gain compared to my original circuit.

if you want to increase the gain (improves the resolution at low ESR), reduce the value of R8. temporarily replace R8 with a trimmer to find the optimum value and then swap it with a fixed one.

the DMM can stay connected as long as there is no difference on the readout if you disconnect it from the circuit.

regards,

kinsa

[elbaz_elec]

Hello, Kinsa

I will replace R8 with 500 Ohm trimmer then tell you the results, and i'll try to improves the resolution at low ESR by decrease R8 as much as possible.

Best regards,

Osama
baztronics@yahoo.com

[elbaz_elec]

Hi Kinsa,

I decided to normal calibration and i've done it well, but when i connect the probes it wasn't work properly.
i connect 10.0 ohm through probes it measured 5.06 ohm, when i connect 0.15 Ohm resistor it measured above 1.00 ohm.

when i shorted probes and press zero button it flasher then read out some value then go to zero and back to flasher with values like 0.05>>>

What should i do??

Thanks

Osama

[kinsa]

when i shorted probes and press zero button it flasher then read out some value then go to zero and back to flasher with values like 0.05>>>

This could be due to noise. make sure your probe length is short. use a shielded wire like kasper had used.

also, a noisy power supply could cause this.

regarding your calibration, maybe there is a problem with your table; hex conversion?

can you post a graph of your values?

double check by measuring the values of your test resistors using the calibration mode to get the equivalent hex values (don't forget to zero the reading) and lookup the equivalent resistance using your graph. the code merely performs a linear interpolation based on your calibration table.

[elbaz_elec]

hello Kinsa,

I used Kasper's table and i did normal calibration. used 150 ohm resistor for R8.

waht do you recommend me?

Thanks...

Osama

[kinsa]

you need to update the table with the values you got from your calibration. did you do that?

[elbaz_elec]

Hello Kinsa.

No, I didn't complete my full calibration because my first resistance value at 0X010 is 0.91 ohm on LOW OHM ADAPTER even if i decrease R8 up to 100 Ohm, so i did normal calibration method instead updating table values ...

i am afraid if i did full calibration with same result, generally i will try to full calibration....

Thanks

Osama

[waterstrider]

yung smps transformer ng mga generic cp charger mas maganda.wag mo masyado sundin yung instructions nakaka ulol yun.tsaka mabusisi. tatlo winding nung nasa cp charger.gawin mong primary yung pinaka mataas resistance.kahit anung secondary gamitin mo dun sa dalawang natira.mas mataas ang output gain kc mas maraming turns yun kesa sa nandun sa instruction.nga lang di gasino reliable tong esr meter na to. shorted na cap good pa rin reading.. may leak na good pa rin.kakayamot

[Deantyne]

^waterstrider.. mga parener yann..digital esr ang kanilang pinag-uusapan, di yong analog na sinasabi mong "kakayamot" 

[turotoknis]

sis pwede ba yung sa meter ng sunwa baklasin ko ? tapos yung sa charger ng nokia (transformer)makakagawa na ko esr meter

[Deantyne]

^ di ko pa n-test na baklasi ang board then gagmitin yong meter niya.. ang kailangan kasi na meter d2 is 500ma.. ang ginawa ko lang set yong analog tester ko sa 500ma Settings then test mo siya sa 1 ohm and 10 ohms resistor if accurate..
^ yup ppwede rin xformer ng cp charger gmitin..


Ang gamit ko kc ay yong psu xformer ng smps ng DVD player..