Re: an interesting idea...

To: tesla-at-pupman-dot-com
Subject: Re: an interesting idea...
From: "Jim Lux" <jimlux-at-jpl.nasa.gov> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Sat, 22 May 1999 14:19:38 -0600
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme


> > Original Poster: "Jim Lux" <jimlux-at-jpl.nasa.gov>
> > 
> > vacuum spark gaps are a well known technology. I believe that several
> > people have used the core of a vacuum circuit breaker (from mfr's like
> > Joslyn, for instance) to make a static gap. The problem would be heat
> > dissipation and quenching.
> > 
> Jim
> 
> Richard Hull did this about 5 years ago, we used a single pole
> of a 12kV vacuum breaker.  We adjusted contacts open with a 1/4x20
> lead screw about 1mm at let it go.
> 
> It worked fine up to about 500W (Richard jump in if my memory is
> short  :^)  ) but ran HOT AS HEL...  If the vacuum contacts could
> be forced air cooled, and the contacts were large enough, you could
> be talking a decent gap to handle powers up to low kilowatt range
> (3 to 5 maybe).  Heating will quickly kill the vacuum seals if
> cooling can not be accomplished.

Makes sense.. a vacuum CB is really only designed for intermittent use. A
high power vacuum gap would probably need forced air or water cooling
through the back side of the electrodes. Also, as I recall, Fruengel talked
about high power vacuum gaps in his book (along with everything else under
the sun)