To: rmp-at-cica.mlb.semi.harris-dot-com (Russ Pate)
Subject: Re: Help with Homemade Capacitors
In article <1994May2.201258.239-at-mlb.semi.harris-dot-com> you write:
: I am trying to fix an old
: Quack Medical Device that has a glass
: and foil stacked capacitor inside it.
: I have seen similar capacitors inside
: Leeds & Northrup equipment. Does
: anyone know how big (uFs), these
: capacitors tend to be and what the
: breakdown voltages might be? I hesitate
: to rebuild it.
Just a side note. I once build a capacitor out of a pane of
glass (about 10" x 12") with foil on each side, edges of foil
about 1" from all 4 edges of glass to keep arcing away. Sounds
silly, but I put 10,000 volts across it (oil burner ignition
transformer, 60Hz) and send a spark across a 1" gap. The shriek it
emits can raise the dead. Probably also lots of nice EMI/RFI.
Without my glass cap, the arc is just a soft hum. Have never
figured out what the cap is really doing, but it's interesting
to see. Makes plenty of ozone smell too.
I would also like to know what uFs rating this thing is. Probably
a book somewhere that you can calculate based on distance between
plates, type of dialectric used, (i.e., glass) and surface area and
shape of each plate.
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