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RE: Vortex gap loss measurements

Hi Jim:

I've not thought this all the way through but I'm guessing that the reason
for the non-logarithmic decrement is a non-linear arc resistance.  If the
arc resistance went down as the current went up, would it yield what I
observed?  If so, it's still remarkable that it was non-linear in such a way
to produce a linear result!

Regards, Gary Lau
Waltham, MA USA

		-----Original Message-----
		From:	Tesla list [mailto:tesla-at-pupman-dot-com]
		Sent:	Saturday, September 02, 2000 5:22 PM
		To:	tesla-at-pupman-dot-com
		Subject:	Re: Vortex gap loss measurements

		Original poster: "Jim Lux" <jimlux-at-jpl.nasa.gov> 

		You might also get a linear decrement if your gap is acting
as a constant
		voltage drop instead of a constant resistance.  A resistance
would give a
		log decrement, in the classic RLC circuit.

		> From: Tesla list <tesla-at-pupman-dot-com>
		> To: tesla-at-pupman-dot-com
		> Subject: RE: Vortex gap loss measurements
		> Date: Saturday, September 02, 2000 12:48 PM
		> Original poster: "John H. Couture"
		> Gary -
		> Many thanks for providing us with your test data. More of
this type of
		> information is needed because there are still many secrets
of TC
		> we need to know.
		> You mentioned that at times the dampened wave appeared to
be logarithmic.
		> found this to be true in some of my tests using a standard
		> the traces were very irregular. Could it be that the
storage scope is
		> affecting the results by sampling more than one trace?
		> John Couture
		> ---------------------------
		> ---Original Message-----
		> From: Tesla list [mailto:tesla-at-pupman-dot-com]
		> Sent: Friday, September 01, 2000 6:17 PM
		> To: tesla-at-pupman-dot-com
		> Subject: Vortex gap loss measurements
		> Original poster: "Lau, Gary" <Gary.Lau-at-compaq-dot-com>
		> Today I found some time and performed a comparison between
the gap losses
		> my single vacuum gap, and my new single vortex gap.  To do
so, I scoped
		> primary ringdown with no secondary in place.  I used a
Terry Fritz fiber
		> optic voltage probe across the primary coil and a digital
storage scope
		> record the results.  I have not yet accurately calibrated
the voltage
		> readout, so for now, the results are just relative to each
		> With no secondary in place, the ringdown is a linearly
		> waveform, not logarithmic.  As such, the slope of the
ringdown indicates
		> losses in the circuit and is independent of the gap firing
voltage.  I
		> performed ringdown slope measurements at a variety of gap
widths to vary
		> initial voltage, but the ringdown slope is a constant,
independent of
		> The power to the blower motor is varied through a lamp
dimmer and I tried
		> varying the motor speed to see what effect that had.  At
very low speed,
		> linearly decrementing waveform became slightly
logarithmic-looking, but
		> still predominantly linear.  The gap breakdown voltage
appeared to change
		> slightly at low speed, but this was hard to measure as it
was slight and
		> bang-to-bang gap breakdown voltage is not as consistent as
one might
		> The slope decrement figures are assuming that my probe is
		> calibrated for voltage, though I suspect it may not be, so
the figures
		> useful only for relative comparison purposes.
		> The pressurized vortex gap decremented at 200V/usec.
		> The vacuum gap decremented at 235V/usec (17.5% faster).
		> The vortex gap breakdown voltage is about 20% higher than
the vacuum gap
		> the same gap distance.
		> Vortex gap web page:
		> http://people.ne.mediaone-dot-net/lau/tesla/vortexgap.htm
		> <http://people.ne.mediaone-dot-net/lau/tesla/vortexgap.htm>
		> Vacuum gap web page:
		> http://people.ne.mediaone-dot-net/lau/tesla/onegap.htm
		> <http://people.ne.mediaone-dot-net/lau/tesla/onegap.htm>
		> Regards, Gary Lau
		> Waltham, MA USA