? on old electrolytic caps

[Charlie+]

On Tue, 17 Jun 2014 16:50:40 -0500, "Dave" <db5151@hotmail.com> wrote as
underneath :

I have an LCR meter which shows the ESR for electrolytic caps, but I have no
idea how to interpret this number. How do you know if a cap is shorted or
boardering on that status? I mean, if it gives me a reading of zero Ohms,
that's obvious, but what if a small (4.7uF), medium voltage (35V) cap comes
up with a reading of, say, 3 Ohms? Is that too low, like I expect, or
should it be considered acceptable? I just don't know what a good cap would
likely register, and have been surprised in the past when a brand new cap
registered a lower ESR than the one I thought was bad. Where can I find
info on the subject? Any ideas are welcome.

Thanks...

Dave

This might be helpful to you - its a link to the Peak ESR meter
instruction manual which has a chart on page 9 uF/voltage/ESR approx
expected in average conditions.
http://www.peakelec.co.uk/resources/esr60_userguide_en.pdf
C+

 

[John Fields]

On Fri, 20 Jun 2014 06:57:50 +0100, Charlie+ <charlie@xxx.net>
wrote:

On Tue, 17 Jun 2014 16:50:40 -0500, "Dave" <db5151@hotmail.com> wrote as
underneath :

I have an LCR meter which shows the ESR for electrolytic caps, but I have no
idea how to interpret this number. How do you know if a cap is shorted or
boardering on that status? I mean, if it gives me a reading of zero Ohms,
that's obvious, but what if a small (4.7uF), medium voltage (35V) cap comes
up with a reading of, say, 3 Ohms? Is that too low, like I expect, or
should it be considered acceptable? I just don't know what a good cap would
likely register, and have been surprised in the past when a brand new cap
registered a lower ESR than the one I thought was bad. Where can I find
info on the subject? Any ideas are welcome.

Thanks...

Dave

This might be helpful to you - its a link to the Peak ESR meter
instruction manual which has a chart on page 9 uF/voltage/ESR approx
expected in average conditions.
http://www.peakelec.co.uk/resources/esr60_userguide_en.pdf
C+

---
That's a keeper! Thanks.