Re: quench gap

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>" <evp-at-pacbell-dot-net>

Tesla list wrote:
> 
> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<FutureT-at-aol-dot-com>
> 
> In a message dated 8/15/01 2:46:04 PM Eastern Daylight Time, tesla-at-pupman-dot-com
> writes:
> 
> > Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<Kidd6488-at-aol.
> > com>
> >
> >  Hi everyone,
> >        Quench gap. Does anyone use these anymore? they sound like they
> would
> >  work pretty well.
> >
> >  Quench Gap - A special type of multi-electrode static spark gap sealed in
> an
> >
> >  enclosure filled with air. After a few seconds of operation, the oxygen
> >  inside the enclosure is burned away, leaving the gap to operate in a
> > Nitrogen
> >  atmosphere (air is 80% Nitrogen). The Nitrogen atmosphere makes the gap
> >  self-quenching without the need for mechanical assistance from fans or
> >  blowers.
> 
> Jonathon,
> 
> the true quench gap is a stack of special machined metal discs
> with insulating rings between their edges.  The metal is recessed
> so the sparking will not occur near the inner edge, which would
> burn the insulating material.  When teh gap is first run, the oxygen
> is burned up, leaving unburnable gases inside.  They do quench
> well, but I'm not sure how they are loss-wise.  To handle high
> powers they have to be quite large and robust or they'll overheat.
> A lot of work to build them properly.  I'm not sure how much
> testing has been done with them on TC's.
> 
> John Freau

	I have an ancient AMRAD quenched gap, 1 kW rating, built circa 1918.  I
have used it on a small coil (9 kV, 60 ma transformer, 0.009 mfd
capacitor, 14" by 3.17" secondary, resonant frequency about 280 kHz with
14" toroid).  The breakdown voltage is a little low (they didn't run
them at a very high voltage in the old days, and because the insulating
washers have gotten smashed thinner over the last 70 years), but it
works really nicely with 18" streamers at a pretty high rate (next time
I run it I'll measure that) and really hot arcs.  Best part is that the
gap is ABSOLUTELY SILENT!!!  Can send pix of the gap to anyone who is
interested.

Ed

Ed