Re: TSG Troubles

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

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

At 07:52 AM 5/21/2003 -0600, you wrote:
>Original poster: "S & J Young by way of Terry Fritz <teslalist-at-qwest-dot-net>" 
><youngs-at-konnections-dot-net>
>
>Triggered Spark Gappers,
>
>I need some help.  I am having mediocre to miserable performance with my
>asynchronous triggered spark gap setup.  I have a MOT 4-pack with dual
>doublers providing up to 20 KV of smoothed DC.  This runs a resonant
>charging TC arrangement.  Inductor is three MOT secondaries and a de-Qing
>diode string in series.
>
>My TSG has two 3/16 inch diameter tungsten electrodes with an air blast to
>help with quenching.  I have tried a trigger electrode between the two main
>electrodes.  I have tried a needle point perpindicular to and spaced away
>from the axis of the main electrodes.  I have also tried annular rings -
>washers with 3/4 or 1 inch inside diameter with the inside edge ground
>sharp.  Best results for any of these seems to be around 180 BPS.  All
>configurations perform about the same.
>
>The TSG setup works great for power levels under about 700 DC watts.   But
>if I crank up the power, the TSG loses control and fires at a BPS of perhaps
>1500 or more, making wonderfully bright streamers, but drawing far too much
>AC power and generally stressing everything way too much.  Adjusting gap
>spacing, air velocity, trigger location, etc. does not improve the TSG
>performance at higher power.  I have not been able to run over 1 KW and
>retain triggering control of the gap.

Frungel and Marx's high power triggered gaps all had (supersonic) flow 
through a hole in the center of the electrode. This is probably necessary 
to keep the electrode surface cool enough that you don't get thermionic 
emission.

Fruengel also had a sealed triggered multigap running in Hydrogen for high 
rep rates.

What is triggering the gap?  Maybe you need BIG voltages to trigger, so the 
physical gap can be MUCH longer (of course, that will increase losses)...





>Has anyone used a TSG with a DC resonant charging reactor setup and had good
>performance?  Or, does anyone have any good engineering experience and ideas
>to improve my setup?
>
>In the meantime, it's back to my asynchronous RSG - heavy sigh . . .
>
>Steve Y.