5 Transistor ESR Meter Design

[Jay_Diddy_B]

JLLE21,
The frequency of the oscillator is not very critical. 100kHz is the industry standard for ESR measurement. When troubleshooting equipment the idea is to find bad capacitors.

If you don't have or unable to find the 1500pF capacitor you put 1000pF and 470pF in parallel. With SMD capacitors you solder them on top of each other.

The 555 timer will also work. Connect the output of the 555 timer to the base of Q3 with a 10k resistor.

If the capacitors are good they will not conduct dc, the resistance will be high. A good capacitor will have a low impedance at 100kHz. The short detector is to detect parts with a low dc resistance.

Regards,

Jay_Diddy_B

[JLLE21]

JLLE21,
The frequency of the oscillator is not very critical. 100kHz is the industry standard for ESR measurement. When troubleshooting equipment the idea is to find bad capacitors.

If you don't have or unable to find the 1500pF capacitor you put 1000pF and 470pF in parallel. With SMD capacitors you solder them on top of each other.

The 555 timer will also work. Connect the output of the 555 timer to the base of Q3 with a 10k resistor.

If the capacitors are good they will not conduct dc, the resistance will be high. A good capacitor will have a low impedance at 100kHz. The short detector is to detect parts with a low dc resistance.

Regards,

Jay_Diddy_B

Hello friend, it has been difficult to me this project, i'm stuck and feel ashamed about it.
started colecting the components following your schematic and thinking the anakiev board posted was exact to your design, but now looking closely is different, has 28R, an TP are different.
can you please post a non-SMD board view? (still missing components to find for mine)

i'll appreciate your help

best regards.

[Jay_Diddy_B]

Hello friend, it has been difficult to me this project, i'm stuck and feel ashamed about it.
started colecting the components following your schematic and thinking the anakiev board posted was exact to your design, but now looking closely is different, has 28R, an TP are different.
can you please post a non-SMD board view? (still missing components to find for mine)

i'll appreciate your help

best regards.

Forum user Anakiev posted a design in this message:

https://www.eevblog.com/forum/projects/5-transistor-esr-meter-design/msg5137590/#msg5137590

I have not made a thru-hole version myself.

Jay_Diddy_B

[Anakiev]

@JLLE21 I've uploaded the schematic in the original post.
R28 isn't something I've added this is the pot for calibration. All TPs are where my wires are coming from.

This is R28 in the original schematic:


Edit: Maybe you are looking an older schematic because all of my TPs match with the original ones.