[Timothy Daniels]

"GregS" wrote:
"Timothy Daniels" wrote:
I've got 30 large electrolytic capacitors (like soup cans)
to sell (12,000 and 8,300 µfd, working voltage 100dc,
purchased as new surplus), and they've been sitting is a
cabinet for 20 years. Is there a simple way to test them
to see if they're still good? Any suggestions on where a
guy could sell a third of a farad of electrolytic capacitance?

*TimDaniels*

They are probably OK. They may need to be charged slowly
up to 100 vdc or higher to make sure. I have some over 40 years old.

Nothing simple for sure.


Measure the ESR.
Charge up to 100 volts and measure the discharge curve.
You can also see if they will hold a charge.

I think the key here is size, for those wanting a paticular mechanical
size replacement. Whats the brand and type ?

greg


Yeah, the problem has always been that I don't have a variable
voltage power supply to "form" them and no 'scope to watch their
discharge rate. The 12,000µfd caps were made by GE with nos.
92F308ALA, and the 8,300µfd caps were made by Mallory with
nos. CG832U100G1.

*TimDaniels*