Peter L. Peres wrote:
>
> > corrosive supercaps
>
> That's new to me Roman. Most supercaps have a solid dielectric. Can you
> quote a make that does not ? The main failure mode is by increased leakage
> afaik. This is 'helped' by the long (100ft or more) length of very thin
> (10 microns) tape dielectric in them. The slightest material fault causes
> leakage or breakdown (at ridiculously low voltages - like 1.5V). Afaik
> they don't age electrically, only material breakdown does them in.


Hi Peter, I replace a lot of the "goldcaps"
in 1F and 3.3F sizes, metal can units with
black epoxy end seal.

Yep they're corrosive, some corrode through the
pin internally, going OC, some corrode right
through the pin and the corrosive comes out the
hole where the pin was and damages the board.

Anyone who repairs 10-yr old VCRs fixes these
regularly. Often I see a VCR with the memory
still working, but corrosive salts on the base
of the goldcap. I tell the customer the memory
will go in a year or so and give them the option
of replacing the cap with a small NiCd pack, which
is the manufacturers recommended repair.
-Roman

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