Lux Pipe Cap Gap

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

Original poster: "S & J Young by way of Terry Fritz <teslalist-at-qwest-dot-net>" <youngs-at-konnections-dot-net>

Jim & TSGers,

I did more experiments with Jim Lux's design of a copper pipe cap TSG with
my filtered
DC resonant charging setup.  Goal was to find a way to increase the DC power
without onset of power arcing.

Baseline performance:  180 BPS, 940 DC watts input.  TSG air flow came from
a vacuum cleaner blower running at 80 volts.  Streamer length between
two breakout points on twin TCs was set at 55 inches.  The charging choke is
somewhere between 30 and 50 Henry (3 MOT secondaries in series).

Problem:  If power is increased, it appears the
TSG power arcs, most likely causing the DC supply output filter to
completely discharge.  This causes
huge AC surges in the variac and MOTs as the cap then rapidly recharges.
Very
hard on all components.

1st Experiment:  Added another 48 Henry to the charging choke, thinking this
would delay the onset of charging choke saturation.  Surprisingly, this made
no difference.  Power arcing onset still occured at about 940 watts.

2nd Experiment:  I swapped the connections to the HEI coil primary,
reversing trigger pulse polarity.  This made interesting improvements.  At
the same BPS, power could go up 100 watts before power arcing.  The DC
voltage was about 2 KV higher and the current stayed about the same.  At 200
BPS, max power was about 1150 watts, 200 watts more than the baseline & was
the best I could squeeze out of the setup without frequent power arcs or
over-volting my MMC.

In all cases, increasing BPS and reducing DC power makes the situation
worse - more frequent power arcs.  Guess I  need the lower BPS to have time
to quench & blow the hot plasma out of the spark channel.

Conclusion:  TSG performance is improved, but still not as good as from a
RSG.  I may try two TSGs in series.  Anyone actually had good results with
magnetic spark gap quenching?

Steve Y.