Q about deriving cap specs

[jazz]

Hi,

I've got a bunch of big old electrolytic caps lying around I want to use in the psu of some prototype builds. To try and have some understanding of what I'm doing and how to rate parts I want to try and simulate using psudesigner.

The problem is I have no specs on the caps other then what's printed on them. The print states the following:

33.000uF (-10/+50%)
UN 40V
-40/085/56 type1
Ieff. (100Hz) 30A (50deg.C)

Is there a way I can deduce the ESR from that?

Thanks,
Joris

[Tech]

You're wanting to see about checking if the capacitors are good? If so, I wouldn't worry about those old caps. I'd be more concerned about what your actual capacitance values are under that huge tolerance.

[Black Gate]

It may be overkill for your requirement but for anyone else reading this thread, I've found a capacitance meter such as the PEAK Atlas ESR Capacitor Analyser to be very helpful.

Here's the link: http://www.peakelec.co.uk/acatalog/jz_esr60.html

[jazz]

Hi,

Thanks for the responses. I don't worry about them being good or not as much. They work and that's enough for the purpose. I was just wondering about deriving esr from the printed specs for simulation purposes.

For the rest I just reformed them (leakage current check) and measured capacitance. Then I put them in the circuit and pressed 'fire'. Nothing blew up (unlike the first time when I used them without bypasses and blew up a few bridges...).

regards,
Joris