Re: Re. HDPE found: check my capacitor, please

To: tesla-at-pupman-dot-com
Subject: Re: Re. HDPE found: check my capacitor, please
From: Mike Nolley <mnolley-at-mail.slc.edu> (by way of Terry Fritz <terryf-at-verinet-dot-com>)
Date: Sat, 24 Oct 1998 11:46:29 -0600
Approved: terryf-at-verinet-dot-com

Hi Mike,

I work with vacuum variable high power capacitors that have only about 0.05
inch of plate to plate clearence. However, they can easily stand off 15000
VAC.  They use a very high vacuum as the insulator.  The dielectric
constant is 1.000000 ;-)  Their construction is probably beyond our
capabilites.  The comerical ones are shockingly expensive.

Check out:

http://www.jenningstech-dot-com/

for additional info...

	Terry



>I meant fill with oil (but not fully) and leave some empty vacuum volume.

	Unless both your container and your vacuum pump could develop the kind of
incredibly high vacuum that insulates well, evacuating some of the air
would increase corona arc-over to a great extent- because the ions in an
evacuated environment are easier to ionize. Your capacitor would probably
break down in seconds if the vacuum touched any of the dielectric or
plates-- it would provide a less resistive current pathway than either oil
or air at regular pressure.  Vacuum is a somewhat misleading term in this
respect-- it doesn't mean the air molecules are absent. 
	On the other hand, I wonder if anyone has tried building a capacitor using
near-absolute vacuum?  It would insulate incredibly well-- since there
wouldn't be a current pathway to speak of-- but perhaps this is exactly the
problem-- it wouldn't be a dielectric in the same sense.  Does anyone know
if this would work theoretically?