Re: Triggered spark gaps for coils

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

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-uswest-dot-net>" <jimlux-at-earthlink-dot-net>

A gentleman by the name of Marx (hmm.. high voltage? Marx? how odd?)...
actually developed a series of air blast triggered gaps about a century ago.
An interesting design.. the electrodes are basically conical, and have holes
in the center through which the air flows (at supersonic rates, typically).
Either you can pressurise the centers and blow radially out through the gap,
or you can pressurize the outside and blow radially in.  A center pin in one
of the electrodes (coaxial with the main electrode) provided the triggering.
Of course, back in the 19th century, they didn't have nifty HV pulse
generators to generate the repetitive trigger pulses, so Marx used, of all
things, a rotary spark gap to fire the trigger pulse.  The idea was that the
wear on the RSG would be much less because it switched a lot less power than
the main gap.

By the way, getting supersonic flow in air is pretty easy.  100 psi through
a 1/8" hole will easily get supersonic.  A regular old (pre-OSHA) blow gun
will go supersonic as well.  If the weather is right, you can see nice Mach
diamonds.

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, March 16, 2001 5:08 PM
Subject: RE: Triggered spark gaps for coils


> Original poster: "Basura, Brian by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <brian.basura-at-unistudios-dot-com>
>
> Gary/all,
>
> I had a discussion with Jim Lux and Kevin Ottilini last year and the
> conclusion was a trigatron would probably need gas flowing through it to
> quench properly at a significant break rate.  I plan to try it on a DC
coil
> (When I get back to my DC coiling activities and get those bugs worked
> out). With a DC coil and a Trigatron I should be able to make my coil go
> from single shot mode up to ??? break rate. Flowing a gas through it may
> make it impractical though. Time will tell...
>
> Preemptive response - A Trigatron is a triggered spark gap. You have two
> electrodes similar to a standard spark gap then you introduce something
> between the electrodes to trigger a breakdown. The trigger can be a
smaller
> arc, laser, etc. The ones I built use a motorcycle spark plug in the
center
> of one electrode as a trigger. I have some pictures posted at the
following
> url but they aren't directly related to Tesla Coils (although my long term
> plan is to use one in a Tesla Coil application).
> http://fp2.hughes-dot-net/brianb/pulse_discharge.htm
>
> Regards,
> Brian B.
>
>  -----Original Message-----
> From: Tesla list [mailto:tesla-at-pupman-dot-com]
> Sent: Friday, March 16, 2001 10:22 AM
> To: tesla-at-pupman-dot-com
> Subject: Triggered spark gaps for coils
>
> Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-uswest-dot-net>"
> <Gary.Lau-at-compaq-dot-com>
>
> >From my recent web searches and technical paper readings, there appears
to
> be a large variety of commercially available 3-terminal triggered spark
> gaps.  And it seems that these can easily be home-made as well.  These
would
> seem to be ideally suited for use as replacements for rotary spark gaps,
but
> I've not been able to find any reference to this obvious application.  The
> only reference I've seen towards "amateur" applications is in can and
> quarter shrinkers.  While RSG's do have relative simplicity on their side,
> it seems as though there ought to be some worthwhile benefits to using a
> triggered static gap.  Has anyone attempted this?  Or am I attempting to
> invent a square wheel?
>
> Gary Lau
> Waltham, MA USA
>
>
>
>