Re: Jim Lux Pipe Cap TSG

["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>

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?

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?

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.

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.

Have you tried different polarities of trigger and what the "cold" side of
the hei coil is hooked to?


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, July 04, 2003 11:47 AM
Subject: Jim Lux Pipe Cap TSG


 > Original poster: "S & J Young by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<youngs-at-konnections-dot-net>
 >
 > Coilers,
 >
 > A few months ago, Jim Lux posted a link to his design for a triggered
spark
 > gap made of copper pipe caps.  I built one and finally tested it today.  I
 > can testify it is a good design, and very cheap too!
 >
 > Here is what Jim posted:
 >
 > "I have an idea (untested for now) on a way to build a blown triggered gap
 > that is low cost, adjustable, etc.
 >
 > It uses two copper pipe caps as the electrodes. A hole is bored in one,
and
 > the trigger electrode is mounted in that hole.  Air flows through the cap,
 > through the annular hole around the trigger electrode, and then, out
 > radially through the gap. The trigger electrode can most anything, but
 > something like a TIG electrode might be the best thing.
 >
 > Write up at http://home.earthlink-dot-net/~jimlux/hv/captrig1.htm
 > Diagram at http://home.earthlink-dot-net/~jimlux/hv/images/triggap1.gif "
 >
 > My design uses 1.25 inch copper caps, which make a good fit over 1 inch
PVC
 > elbows and Ts.  Caps are spaced about half an inch apart, but can be slid
 > back and forth on the PVC fittings to change the gap spacing.  The
triggered
 > cap has a half-inch hole with the trigger electrode being a 3/16 brass
 > threaded rod.  The end of the rod is roughly flush with the back side of
the
 > pipe cap.  It is triggered with a variable pulse rate generator driving an
 > HEI coil.  This is used with a DC resonant charging setup, but the Lux
 > design should work just as well with an AC supply, provided the trigger is
 > synched with the 50 or 60 Hz mains power.  Cooling/quenching air is from a
 > small vacuum cleaner blower, running at about 3/4 its normal input
voltage.
 >
 > Performance seems a bit better than my other TSG using tungsten rods and
an
 > annular ring trigger electrode.  Pipe caps only get a bit warm with 1 KW
DC
 > supply.
 >
 > At 1 KW DC power and 200 BPS, I get 66 inch sparks between twin coils with
 > breakout points.
 >
 > Good as this design is, I still cannot crank up the power beyond 1 KW DC
 > without the gap power arcing.  Thus for my resonant charging setup, my
ARSG
 > can out-perform (72 inch streamers) the Lux TSG, but the Lux setup is
safer
 > and more fun to play with than the RSG.
 >
 > The Lux design is great for using lower voltage supplies.  With the gap at
 > about 1/4 inch, it will fire reliably at only 4 KV.
 >
 > Bottom line:  try it - you'll like it!
 >
 > --Steve Y.
 >
 >