Re: Future of Solid State Coiling?

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

Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>" <dhmccauley-at-spacecatlighting-dot-com>

 > What is the biggest spark length anyone has had from a SSTC so far? Justin
 > & Aron's 32" is the most spectacular claim I've heard yet.

My second SSTC gets 24" inch arcs continuously and can be run for long
periods of time without destruction (>30 minutes).  This is with 240VAC
input.
This same SSTC was pushed forward up to 480VAC input (using 480VAC to 120VAC
step down transformer run backwards) and 36"+ streamers were visible until
the entire SSTC failed spectacularly!!!!  It appears the schotkey diodes
failed first causing a chain reaction of failures throughout the device.
This 36"+ was only obtainable for
maybe 30 seconds before failure.  Justin claim they did get 32" arcs from
Arons SSTC for about 3 seconds before failure, but I think its only fair to
claim a maximum arc length when
a system can do so without failure for at least a few minutes.  (This was
debated awhile back for the minicoil contest)  So for my second SSTC coil,
I'm only going to claim 24" streamers.

My new MOT powered SSTC has thus gotten past the 30" mark easily although
there are still many bugs to fix and other modifications needed to make the
circuit more stable and reliable.
(I say this as during a test session after lunch I managed to blow 3 of the
4 FETs)  I'm attributing this so far to the induced voltage from the primary
coil inductance after the FET switch is closed.  Because the inductor
doesn't want current to stop instantaneously, it will cause a high voltage
transient condition to form.  (similar to boost converters etc...)

But the design is promising.  Much work ahead!!!

The Captain


 > What is the way forward to even bigger sparks? Just now, we have
 > MOT-powered hi-voltage SSTCs, DRSSTCs, OLTCs, regular SSTCs with IGBTs,
 > plus probably a bunch of others that I forgot about, all poised to invade
 > the mini/midi coil sector as soon as the NSTs run out... So far, in terms
 > of actual results, the MOT-powered coil (How about calling it a HVSSTC?)
 > seems to be most promising. But I'm sure everyone else has their own
 > favourite designs...





 > Steve C.
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