InCircuit ESR Meter

[janengelbrecht]

Im looking for an incircuit ESR meter that actually works: Which works at voltages low enough so they wont trigger any semiconductors on the PCB where one is meassuring ESR in a cap.

I have narrowed my search down to this: http://www.ebay.com/itm/Digital-ESR-Meter-Test-In-Circuit-Electrolyte-Capacitor-Resistance-0-01-30-Ohm-/261350478205

Anyone know this meter ?

[mathsquid]

I have a meter that looks mostly the same, but has red and black banana jacks on the side.  I don't have anything to compare it to, but it seems okay.  The attachments have pics that show the meter's test signal.  (How do you include pictures inside a post?)

[janengelbrecht]

Yir it looks much the same. Thx for the pics. I can see the voltage is okay for incircuit analysis

[zaoka]

That new version may be using 4 wire measurement method?

[janengelbrecht]

Seems legit..... something like this (only with a microcontroller instead):

[DanielS]

Im looking for an incircuit ESR meter that actually works: Which works at voltages low enough so they wont trigger any semiconductors on the PCB where one is meassuring ESR in a cap.

Unless you can isolate the component you want to test, you have to take your in-circuit measurements with a fistful of salt since your measurements will include effects from other components in parallel including alternate series paths between your measurement points. Not suitable for much more than sanity-checking - you are basically measuring the Thevenin/Norton equivalent of your circut as seen from your test points assuming active components are open-circuit.