cap testing

[pete g]

hi all, I recently built a esr meter. I need clarification on two of the parameters it measures. 1) memory effect. 2)sz value. also what values of these two would render a capacitor defective? thanks.

[Agent24]

Re: cap testing

I have never heard of an ESR meter which measures anything other than, well, ESR.

Can you post photos of what you've actually built?

[pete g]

Re: cap testing

hi, the meter I built is a Hungarian design. it measures memory, leakage and tan delta along with esr. great meter but kind of tough to get built. has some very critical components. anyway I'm adding an attachment where you find details. use google to translate.
https://www.microsofttranslator.com/...eg_oldal1.html

[vinceroger69]

Re: cap testing

This thread maybe worth a read if you have not seen it already
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/

[pete g]

Re: cap testing

hi, does it measure in circuit. under 300mv output?

[Agent24]

Re: cap testing

The 'memory' they speak of is likely dielectric absorption. I have not heard of this parameter changing due to a failure in the capacitor, at least nobody had mentioned it here that I'm aware of.

Usually, a capacitor will fail totally; going shorted or open-circuit (these can also be intermittent faults), or, its ESR will become too high, leakage may become too high, capacitance may drop, or it may start breaking down under full voltage.

For all these parameters, you can check the datasheet and see if your measurements are within the specified values. I imagine dielectric absorption is either listed there too, or can be calculated.

As for 'sz value' I am not entirely sure what they are referring to (EDIT: looking at the photos, the meter displays Csz when showing measured capacity, so they probably mean capacitance), but in 99% of cases, capacitor faults will be found by checking ESR, leakage, capacitance, or voltage breakdown. If a capacitor passed all those tests, but you still had reason to suspect it as faulty, then at that point it would be faster/easier to just replace it.

[pete g]

Re: cap testing

hi, I think sz is referring to leakage. the lcm meter I built shows memory on a scale of 1-99. is the lower value indicative of a better cap. if not important parameter why show it?

[Agent24]

Re: cap testing

The meter shows "Csz" when displaying capacitance. I didn't see a photo where it displayed a leakage current.

I don't know anything about the dielectric absorption. You will have to do some Google research... I have never seen anyone using it as a test to identify a bad capacitor. It may only be useful to know when designing a circuit, perhaps.

[pete g]

Re: cap testing

hi, I thought sz might mean series impedance? I think your correct about memory being important in design.

[Agent24]

Re: cap testing

I don't know. This is the only place I could find 'sz' mentioned, and it's clearly referring to capacitance. Where did you see it in the article?

[pete g]

Re: cap testing

let me say there are literally hundreds of pages (forums) written about this meter. I thought somewhere I read that what it was. i'am probably wrong. it can't be series z. what do you think of this meter? worth the effort?

[rugger]

Re: cap testing

Only problem with these LCR meters is that they don't work well for faulty capacitors.

They are sorta/kinda OK for capacitors in good condition. But no good for faulty or capacitors in otherwise poor condition.

My main tester is the peak atlas tester: https://www.peakelec.co.uk/acatalog/jz_esr60.html

[pete g]

Re: cap testing

hi rugger, being an ex service tech for Philips, I accumulated a bunch of defective caps. I saved them. my experience has been that this cap checker lcm3 caught everyone of them. both for hi esr and low capacitance.

[vinceroger69]

Re: cap testing

lcm3
http://www.electronics-lab.com/proje...nced-lc-meter/

[pete g]

Re: cap testing

hi, I made that one too. but for some unknown reason couldn't get it to work right. if anyone makes a successful build plz let me know.

[rugger]

Re: cap testing

hi rugger, being an ex service tech for Philips, I accumulated a bunch of defective caps. I saved them. my experience has been that this cap checker lcm3 caught everyone of them. both for hi esr and low capacitance.

I probably should be clearer and state the right problems, as I was recalling from memory why I bought the expensive meter.

The main reason to get the more expensive meter is that you can often do ESR testing in-circuit with the expensive meter, so you don't have to unsolder the cap to do basic testing.

This meter is also a good design for in-circuit ESR testing, even though you build it yourself: http://www.altronics.com.au/p/k2574-esr-meter-kit/

[pete g]

Re: cap testing

nice meter. $90 bucks, ouch!!!!