OK design but very limited use. I prefer a good LCR meter with 3 1/2 digits accuracy.
Speaking from experience, not only does an LCR meter easily measure defective caps but ones going to be defective going from 10 to 100 milliohms where with large 10A ripple currents(rms), ( the eye squared R =10 Watts in a small thermally insulated electrolytic causing a bulge to appear with the next year after it has failed.Which is completely useless for testing ESR - and high ESR is by FAR the biggest cause of electronic faults in the 21st Century (and the latter part of the last one).
Speaking from experience, not only does an LCR meter easily measure defective caps
that's exactly how I fixed my SMPS in my 43" TV monitor in five minutes.
My Extech LCR meter measures C,Q, Rp, Rs and L of any cap with >3 digit accuracy.
Hy Les,Hi Nigel,
There was a design for an ESR meter in "Everyday Practical Electronics Magazine" September 2005 that works well testing capacitors in circuit. It uses a square wave current source through the capacitor and measures the voltage across the capacitor. I have built a slightly modified version (Added a lower range.) of this and found many high ESR capacitors. I have found it particularly useful around the line output stages of CRT monitors. It even found some tiny faulty electrolytics on a video camera module which got it working again.
EDIT.
Correction. The magazine was Elektor (Not EPE)
Les.
I know both Tony and Nigel have enough experience in the field, so my conclusion is that the type or quality of the meter(s) in question is different for each person. Tony obviously had good meters, while Nigel must have used the cheaper ones.
After reading your posts ( thanks) seems I still don't fully comprehend ESR that much. Test wise , I have an LCR, a couple of DMMs a DIY Freqency counter ( via ETO ) an old 2235 Techtronix Scope, that I had to repair.. no focus. I just wanted to have some idea of the caps I was using for PIC24 were the ESR money ( you can pay silly $ for a low ESR 10uF )(you never know theses days) and I have some caps that are decades old ! and I read somewhere they can become deformed over time .
My little black box seems to fit the bill.
Now what can I build with this.....
View attachment 98750
After reading your posts ( thanks) seems I still don't fully comprehend ESR that much. Test wise , I have an LCR, a couple of DMMs a DIY Freqency counter ( via ETO ) an old 2235 Techtronix Scope, that I had to repair.. no focus. I just wanted to have some idea of the caps I was using for PIC24 were the ESR money ( you can pay silly $ for a low ESR 10uF )(you never know theses days) and I have some caps that are decades old ! and I read somewhere they can become deformed over time .
My little black box seems to fit the bill.
Not really, Tony claimed that all you need is an LCR meter to test for faulty electrolytics - which is patently untrue. He later added the extra information that it tests ESR as well. A normal LCR meter wouldn't detect 95+% of faulty electrolytics.
Interesting post doc,I still have a psu I buitl 25 years ago with a a sprague powerlytic in it that I salvaged from a typewriter, still runs on for 20 seconds after power off.
My cap esr tester is a thrown together affair, mine has a ferrite from a pc psu to transform the test voltage right down below the conduction voltage of a silicon junction so I can test cap esr's in circuit, its been a really good tool, I didnt even bother callibrating the scale, I just go off experience with it.
This is the project I used to build mine, its more or less the same:
https://ludens.cl/Electron/esr/esr.html
Thanks Doc , I did see this design but had parts for build "In stock"This is the project I used to build mine, its more or less the same:
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?