5 Transistor ESR Meter Design

[E_Pepegamer]

*** Edited the message because I had a proper look to the schematic and many answers to my questions could be found there ***

Hi, thx for this version Anakiev. I am trying to make this one without having much electronics knowledge, however I am struggling a bit to find the correct parts.
I have exported the BOM list from kicard board. This generates the attached Excel.

1- From the resistor sizes I think these resistors should be 0.25W ones. But not quite sure.
2- Condensers do not show the volts parameter, only for the electrolitic ones.
3- R22 value is set to 'X', in the photo it seems a 18K resistor but again not totally sure.

Anyone can help me a bit with this?

[sdouze]

Thank you for your time to reply.

I have one more question, probably my meter is not very good.

With μΑ scale out of the box I can get the needle to go at 0μΑ (with the screw on meter) some times show 10μα sometimes less ore more (sometimes if move the meter can change) and  when I short the leads goes far right 50μΑ so I turn the pot to have exactly 50μΑ (0 esr) sometimes can not keep the zero adjustments.

I think that you are right, I think you have a bad meter movement. You can test the meter with a power supply, or battery and a few resistors. Use a  9V battery and a 330 kOhm resistor, that should give you around 27uA or 55% of full-scale. A 9V battery and 1M Ohm should give 9uA or 18% of the scale.

Regards,
Jay_Diddy_B

Hello,
I repaired the meter, and now it is working properly. I used a 15K resistor.

[sdouze]

*** Edited the message because I had a proper look to the schematic and many answers to my questions could be found there ***

Hi, thx for this version Anakiev. I am trying to make this one without having much electronics knowledge, however I am struggling a bit to find the correct parts.
I have exported the BOM list from kicard board. This generates the attached Excel.

1- From the resistor sizes I think these resistors should be 0.25W ones. But not quite sure.
2- Condensers do not show the volts parameter, only for the electrolitic ones.
3- R22 value is set to 'X', in the photo it seems a 18K resistor but again not totally sure.

Anyone can help me a bit with this?

Hello,
1.Yes 0.25W resistors are enough.
2.Most of the capacitors are ceramic and the minimum(I think) ceramic capacitor voltage is 50V also your power supply is 9V battery so you are ok with common ceramic caps.
3.The R22 value it depends on the meter you have.Check reply 422 in this thread where OP answered my question on how to choose R22 value.