RE: [TCML] Spark gap

["Lau, Gary" <Gary.Lau@xxxxxx>]

It was after reading a paper published by Terry Fritz that I first came to the opinion that multi-segment gaps have higher losses despite offering better quenching.  See http://www.hot-streamer.com/TeslaCoils/MyPapers/sgap/sgap.html.  Perhaps I'm reading it wrong, but it looks to me like the peak secondary voltage is significantly higher in the single-gap cases when the coupling is in the region where we typically use it.  And independent to that, I'm pretty sure that I've read that spark gaps are similar to zener diodes, in that they exhibit a near-fixed on-voltage independent of gap width.  (This is where Bert Hickman usually chimes in...)

There is no doubt that multi-gaps exhibit superior quenching over single-gaps, but contrary to what is often repeated on this list, quenching is not the primary determinant of gap performance.

Regards, Gary Lau
MA, USA

> -----Original Message-----
> From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
> Behalf Of bartb
> Sent: Friday, February 22, 2008 9:31 PM
> To: Tesla Coil Mailing List
> Subject: Re: [TCML] Spark gap
>
> Hi Gary,
>
> I'm undecided on the single segment versus multi-segment gap losses. The
> only possibility of lower losses is "if" the arc resistance is lower in
> a single segment gap. The voltage drop should be the same for both
> assuming identical pipes diameters, surface, and total gap spacing.
>
> Take care,
> Bart
>
>
> Lau, Gary wrote:
> > I'm similarly skeptical about a propeller gap's quenching.  The only thing that I
> can see superior quenching-wise is that the air flow over the gap may be better
> than in a cylinder gap.  But if that was all you need for superior quenching, then an
> air-blast gap should be the best solution of all.
> >
> > I would think that a mult-segment cylinder gap is the best at actual quenching,
> due to the fact that being divided into multiple small arcs, they would be easier to
> cool and extinguish.  But I also believe that multi-segment gaps exhibit higher
> losses (each gap represents a fixed voltage drop, and the more gaps in series, the
> greater the total gap voltage drop, and loss).
> >
> > The benefit of a propeller gap comes about in that it's a rotary gap.  If it's a sync
> gap, it's superior because the bangs can be engineered to be consistent in size and
> timing, rather than the chaotic mode inherent in static gaps.  If it's an async gap, it
> may be better than a static gap if the power supply is larger than what can be
> effectively handled with a static gap.
> >
> > Regards, Gary Lau
> > MA, USA
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