[sdiy] old epoxy-sealed electrolytic capacitors

[Ken Stone]

>I know it's folly but they LOOK so cool. I suppose I could pepper circuits 
>with dummy caps for show but no go.

As already mentioned, some salvaged caps are usable. I use a primative test.
LED 9V batter, 200R in series - i.e. my continuity tester. Electro across it
the correct way. Led should light, then fade to nothing. How fast depends on
the cap, and can be a mere flicker on small electros. Reverse the cap, and
the same thing should happen. If the LED remains on, reverse it again, then
again etc until the LED goes out when connected backwards. If it doesn't
ever go out, toss the cap in the bin. Basically, this is a very crude way of
testing and re-forming. Don't do it with any greater current than indicated
above, or you may well be wiping the cap off the opposite wall.

>Oh and what about tantalum caps? 

Throw them in the bin. All of them. I have had way to many of these @#$%s go
short circuit, followed by smoke emitting for me to EVER use one again.
CRAP. In the case of salvaged ones, DOUBLE CRAP. They do appear to have a
relatively short valid life span, and salvaged ones are very near end of life.

Ken

_______________________________________________________________________
Ken Stone   sasami at hotkey.net.au or sasami at cgs.synth.net
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
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