Texas version of the Arizona OK corral shootout, ie, the Clanton's may have a secret they don't even know about

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

Original poster: "Dr. Resonance by way of Terry Fritz <teslalist-at-qwest-dot-net>" <resonance-at-jvlnet-dot-com>


If you are using a pole xmfr with external reactor you need to realize that
the pole xmfr, on very short pulsed cycles, will draw as much as 50 kVA for
very short current spikes.  These are not evident unless you use a storage
scope connected across the primary side.  The short high power spikes occur
just as the reactor tries to saturate.  A standard 10 kva pole xmfr may
operate at short pulses of 40-50 kVA when used with a standard non-saturable
reactor design.

This information was first drawn to my attention by John Couture, a retired
power company engineer.  I checked this with our TEK storage scope, and John
was correct.

In short, the very bright spark appearance with pole xmfrs is caused by some
of these spikes.  This is also the reason why you can not make 15 ft. long
sparks with a 1.5 kVA xmfr and claim it was only running at 3-4 kVA and
appears to be violating John Freau's equations.

Unless you use a scope across the input to see the "peak" power levels then
John Feau's equation holds up in strict accordance.  These peak power pulses
amount to a small "cheat factor" that would make one think he is only
running at 3-5 kVA when in reality the peaks may be much larger.

Magnifiers will produce very long sparks from small coils but the tradeoff
in constant maintenance headaches is not worth the trouble in my opinion.

"Racing sparks" are almost always caused by two factors:  improper coupling
and improper tuning.  In some cases the total tuning range (using the "scrap
wire" techniques I had described previously) is not fully explored and the
sec. is operating at some improper 1/4 lamba multiple.

Coupling on most large coils, example, one of our 18 inch dia. secondaries
requires sec. coil elevation to be at least 7 inches above the primary.  In
our 24 inch dia. sec the elevation jumps up to a full 9 inches!   Even small
3-4 inch dia. coils when wound with #28 AWG wire usually require 1-3 inch
elevations.

Proper tuning procedures require (1) finding the correct primary tap to work
with your cap, and then (2) adjusting the sec. coil elevation for best
coeff. of coupling.  This all has to be done at variac settings of 30-40%
max before any full power operation is attempted.  We have used this tuning
method for nearly 20 years and seldom encounter "racing sparks" when
carefully using these techniques.  It only occured once when we where in a
hurry and didn't use the scrap wire tuning method (our fault).

A third problem, though rare, can occur when using copper ribbon for the
primary in place of copper tubing.  The very sharp edges of the ribbon
provides a great disturbance of the electrostatic field and can lead to
breakdown.  This especially applies to coils operating with a 4 ft. or
greater spark output.  Smooth copper tubing with it's relatively larger
radius of curvature provides good field control between the copper tubing
and the toroid atop the sec. coil.

Take the time to carefully explore these areas before cranking the power up
and you will save a lot of sec. damage.

In summary, I agree completely with Bert.  Claims of extraordinary
performance are not valid unless careful monitoring of the power levels is
achieved.  John's equations may not apply to the OLTC which hold great
promise for future designs.

Dr. Resonance

Resonance Research Corporation
E11870 Shadylane Rd.
Baraboo   WI   53913


-snip-

   >It's hard to build a high performance coil as short as you describe and
not
 >  >have racing sparks or spark related break-downs.  You must have it tuned
 >  >very well!
 >