Re: Jim Lux Pipe Cap TSG

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

Hi Jim,

See answers below:
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, July 04, 2003 1:35 PM
Subject: Re: Jim Lux Pipe Cap TSG


 > Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<jimlux-at-earthlink-dot-net>
 >
 > How do you adjust the trigger electrode position relative to the pipe cap?
 > I assume you only move the non hole drilled electrode to adjust the gap,
or,
 > at least the trigger and its cap are locked together?

I could slide the trigger pipe cap as the rod is supported from the other
end of a PVC "T".  However, in the brief testing, it worked fine with the
end of the trigger rod just behind the cap inside surface, so I didn't mess
with it.  (My vacuum cleaner air supply went belly up so I had to quit tests
prematurely.  Will visit a thrift store tomorrow to find a replacement.)  I
only moved the non-drilled pipe cap.
 >
 > When it power arcs, I wonder what the mechanism is?  Is it the trigger
 > electrode getting hot or is it a hot spot on the main electrode?

I think neither.  If I quickly crank up the voltage, it will immediately
power arc before anything gets hot.  Since the gap voltage doesn't go
through zero like AC powered TSGs would, I think it just reaches a point
where the air flow can't extinguish the DC arc across it, the resonant
inductor saturates, and the result is a power arc.  Probably the same effect
as a RSG going too slow - makes trailing power arcs.  I am using 3 MOT
secondaries as the inductor.  I will try adding more inductance to see if it
delays the onset of power arcing.

 > An enhancement might be to drill holes in both pipe caps and force air
 > through from both sides.. this would prevent getting a hot spot in the
 > center of the  cap.

The thick copper caps conduct heat quite well, and they only get slightly
warm.  So I doubt there is much of a hot spot.
 >
 > I suspect that a bit of fiddling with the shape and size of the holes
might
 > have a big effect on the performance.  Even with a parallel tube gap,
small
 > changes in air flow and tube end finish had a huge effect.  Maybe
"punching"
 > the hole, so it doesn't have a sharp edge, but sort of curves back in,
might
 > be a good idea.  There's more than enough voltage on the HEI to bridge the
 > gap, so you don't need sharp edges on the gap.

I took care to smooth off the edges of the hole.  I would like to try a 3/4
inch hole, but I don't have a tool to do that yet, other than a file.
 >
 > Have you tried different polarities of trigger and what the "cold" side of
 > the hei coil is hooked to?

Not yet - vacuum blower quit.  The cold side goes to the center ground of my
quad mot dual doubler supply.  Hot side from HEI goes through a string of
0.001 mf 10 KV caps.  Bridging the trigger electrode & cap is a string of 40
1 meg resistors.  Thus between pulses the trigger electrode is at the same
potential as it's mating pipe cap.

--Steve Y.