Re: Triggered Spark Gap

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

Original poster: "Brian by way of Terry Fritz <twftesla-at-qwest-dot-net>" <ka1bbga-at-webryders-dot-net>

Hi, gang, it's good to be back after a change of ISP. Seems to me that i
worked on using uv to fire a gap at high speed for firing a TEA Laser at 40
cps. It took a lot of uv thru a lense to get reliable results. I can not
remember if we used a 5kw or 10kw magnetron to fire a mercury lamp for uv
and it was focused onto the gap thru a shutter and lense. That was back in
the 80's and its getting hard to remember! cul brian f.
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, November 10, 2001 4:02 PM
Subject: Re: Triggered Spark Gap


> Original poster: "Gregory Hunter by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <ghunter31014-at-yahoo-dot-com>
>
> I think UV radiation alone will get the job done. The
> notion of a UV triggered gap has been visited before
> on this list, but I never heard of anyone building a
> working example.
>
> Small, short wavelength "hard" UV lamps are available
> as replacement bulbs for EPROM erasers. I've seen them
> surplus for a few bucks. Likewise, and ordinary spark
> gap in air creates UV. Perhaps a small "trigger" spark
> gap and a main spark gap located physically near each
> other could do the job. UV from the "UV source" gap
> could illuminate the main gap, triggering the main
> discharge. This might allow a fairly small,
> low-powered spark gap to control a much larger,
> high-current main gap a short distance away.
>
> Another interesting idea is a rotating opaque disk
> with one or more holes in it. The disk would mask a CW
> UV source, allowing it to illuminate the main gap only
> when a hole lines up--sort of a rotary UV gap.
>
> Actually, the recently popular 3-terminal triggered
> spark gap is so simple and effective, I'm not sure
> what the benefit of a UV triggered gap would be.
>
> Regards,
>
> Greg
> http://hot-streamer-dot-com/greg
>
> --- Tesla list <tesla-at-pupman-dot-com> wrote:
> > Original poster: "Kelly & Phillipa Williams by way
> > of Terry Fritz <twftesla-at-qwest-dot-net>"
> > <kellyw-at-ihug.co.nz>
> >
> > Dear All,
> >
> > While reading my physics textbook this week I came
> > up with a really neat, if
> > fairly esoteric, idea for a triggered spark gap.
> >
> > All metals have a certain energy barrier preventing
> > electrons from leaving
> > the surface of the metal. (Analougous to a rounded
> > curb at the edge of a
> > flat road, it keeps a slow-moving soccer ball on the
> > road unless it is
> > kicked hard enough.) This energy can be provided by
> > heating the metal very
> > hot (thermionic emission),
> >
> > Or by bombarding the metal with photons (light) of a
> > high enough frequency
> > so that when an electron on the surface absorbs a
> > photon, it jumps off the
> > metal.
> >
> > Now suppose an enclosed spark gap in a box,
> > surrounded by an xenon
> > flash-tube or similar source of light.
> > The electrodes a slightly too far for the voltage to
> > jump alone, but when
> > the tube flashes and the electrons jump off the
> > metal they ionise gas and
> > fly across to the other electrode, thus initiating
> > the spark. I know this
> > effect occurs in a slight vacuum, but I would have
> > to investigate it's
> > effect in air.
> >
> > The only problem is that the cut-off frequency for
> > this emission for many
> > metals, and tungsten too I would imagine, is in the
> > ultraviolet range and
> > slightly above.
> >
> > Could those with a working knowledge of x-ray tubes
> > tell me whether an x-ray
> > tube can be PULSED at 100 (50 Hz)
> > or 120 (60Hz) to trigger a gap like this? Forced air
> > quenching may also be
> > necessary, although this technique could be applied
> > to a single static gap
> > all the way through a multi-gap-static-gap, provided
> > the metal of the gap
> > itself was exposed.
> >
> > I would very much appreciate knowing whether vacuum
> > tubes can be pulsed -
> > maybe a pulsed supply to the x-ray tranny, would
> > that work?
> >
> > Best Regards,
> >
> > Alan Williams
> >
> >
> >
>
>
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