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Re: an interesting idea...




> > 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)