Peak ESR60

[marc.hickling]

Hi all I have a peak esr60 esr meter. I also have the peak esr60+ meter which is the new version. If I take the identical capacitor on both meters I get different ESR readings (like significant). Any ideas why? I can only think its something to do with test frequency. I have tried this on multiple meters and multiple caps.

Furthermore I wonder if anyone can help me understand why I can have a bad electrolytic capacitor which doesnt read high esr but 100% causes the product to fail. Ive had this a bunch of times - esr meter shows no faults and then recapping the power supply gets it working again...

Just curious. thanks!

[wraper]

Furthermore I wonder if anyone can help me understand why I can have a bad electrolytic capacitor which doesnt read high esr but 100% causes the product to fail. Ive had this a bunch of times - esr meter shows no faults and then recapping the power supply gets it working again...=

Depends on what you mean by "doesnt read high esr". If it's something like 0.3 Ohm for 1000uF cap, it's completely enough to cause issues.

I get different ESR readings (like significant).

Again, no info of what you consider as significant. For someone it's 5%, for another 100% difference. Also at what resistance and capacitance value? Give some example.

[tautech]

You may find some info here and if not Peak's reps and contact details are there:
https://www.eevblog.com/forum/buysellwanted/special-offer-to-eevblog-forum-members/

[Specmaster]

Why a cap could cause product failure even though it passes an ESR test could be as simple as the capacitor is breaking down under the applied voltage in circuit, which can in some cases in the hundreds of volts, whereas that is not the case when using any ESR meter.

As to why you are getting conflicting ESR reads with what you describe as significant, I can't hazard a guess. I personally have 3 different ESR meters, but they all agree with each other within 0.1ohms.