[sdiy] Tube amp cap discharge tool?

[R. D. Davis]

Quothe Ken Stone, from writings of Thu, May 19, 2005 at 01:06:24PM +1000:
> The problem with the cheap screwdriver trick is you need a new screwdriver
> each time you try it :)  I've blown a huge chunk out of one doing this ONCE.

Hmmm... screwdrivers from Sears, Roebuck and Co. have, or had, a
lifetime warranty.  I didn't see any disclaimer about not using them
to discharge large caps. :-) I'm thinking about the largest one that I
have with a square 1/2" thick shaft and doubt that it would be damaged
too badly by discharging 200uf, 450V caps, if at all.  All joking
aside, with Sears selling tools made in the U.S.A., and
U.S. manufacturers being in a tight spot with the China problem, I
wouldn't attempt to return a screwdriver damaged by using it to
discharge capacitors, even if the warranty would cover it.

Way back when, in high school... ok, very late 70's to very early
80's, not really that long ago, the electronics instructor would
discharge caps far larger than that. They were big and heavy.  I think
some were in a capacitor bank, and one was a big square oil-filled
capacitor, about a foot tall and at least eight inches square.  He
needed to wheel them into the room on a cart.  Anyway, the noise was
quite loud when they were discharged.  I think that he may have used a
crowbar with an insulated handle rather than a screwdriver.  At the
moment, I can't remember if we looked at the sparks.  Here's my vote
for keeping a large crowbar with an insulated handle on hand in one's
lab. :-)

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