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Re: Vortex gap loss measurements
Off hand, I think you are in the right ball park. The resistance is
inversely proportional to the arc column area (all plasmas being of about
the same resistivity). The arc column area is going to be determined by
the arc current and the surface area of the column (i.e. how much can it
keep hot enough to keep ionized). If the arc radius were proportional to
current, area would be proportional to current squared, so resistance would
be proportional to 1/I^2. Voltage drop would be k* I * 1/I^2 or = k/I...
as opposed to a resistor, which would be = k I. I'll have to go look up
the arc equations, but I'll bet that some form of constant voltage drop
(which is dependent mostly on the metals in the electrode and the gas) + a
nonlinear resistance would do it.
----------
> 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 6:20 PM
>
> Original poster: "Lau, Gary" <Gary.Lau-at-compaq-dot-com>
>
> 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"
> <couturejh-at-worldnet.att-dot-net>
> >
> >
> > Gary -
> >
> > Many thanks for providing us with your test data. More of
> this type of
> test
> > information is needed because there are still many secrets
> of TC
> operation
> > we need to know.
> >
> > You mentioned that at times the dampened wave appeared to
> be logarithmic.
> I
> > found this to be true in some of my tests using a standard
> scope.
> However,
> > 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
> of
> > my single vacuum gap, and my new single vortex gap. To do
> so, I scoped
> the
> > 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
> to
> > record the results. I have not yet accurately calibrated
> the voltage
> > readout, so for now, the results are just relative to each
> other.
> >
> > With no secondary in place, the ringdown is a linearly
> decrementing
> > waveform, not logarithmic. As such, the slope of the
> ringdown indicates
> the
> > 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
> the
> > initial voltage, but the ringdown slope is a constant,
> independent of
> Vgap.
> >
> > 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,
> the
> > 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
> the
> > bang-to-bang gap breakdown voltage is not as consistent as
> one might
> hope.
> >
> > The slope decrement figures are assuming that my probe is
> accurately
> > calibrated for voltage, though I suspect it may not be, so
> the figures
> are
> > 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
> at
> > 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
> >
> >
> >
> >
> >
> >
>
>
>
>
>