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Re: Capacitor charge, were is it?



Water has a dielectric constant of only 80, and apparently
a pretty low breakdown voltage.  Some of the titanates run
up to 4000 + and have reasonable breakdown voltage.  The
"doorknob" capacitors made by Sprague and others are just
a solid cylinder of titanate, perhaps 1/2" thick and 2.5"
in diameter.  Capacitance of the order of 3000 uufd, somewhat
lossy and very temperature dependent, breakdown voltage 
well above 20 kV.  Use some here with my small coil and they
work OK as long as I don't let the thing run long enough to
get overheating.  Have the advantage of small size and low
inductance, disadvantage of high temperature coefficient,
fairly high loss, and easily destroyed by leaving the power on.
Ed Phillips