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Re: Secondary CURRENT
Bert, Greg,
> Subscriber: lod-at-pacbell-dot-net Tue Feb 18 22:43:04 1997
> Date: Mon, 17 Feb 1997 20:17:33 -0800
> From: Greg Leyh <lod-at-pacbell-dot-net>
> To: tesla-at-pupman-dot-com
> Subject: Re: Secondary CURRENT
>
> Bert Hickman wrote:
>
> [snip]
>
> > The Q of the secondary system is a measure of its "lossiness". A number
> > of experimental measurements on operating coils have shown that the
> > secondary Q declines markedly once streamers are formed. One set of
> > experiments, for example, showed secondary Q dropping from about 150 to
> > the range of 10-20 depending upon the operational power level and how
> > "heavy" the streamers were. This was on a secondary & toroid with a
> > characteristic impedance at resonance of about 42000 Ohms. If we grossly
> > model this as leakage current due to the lossy dielectric (air) of the
> > secondary toroid cap, then this would represent an average "leakage"
> > resistance of about 420k Ohms under moderately heavy (Q=10) streamer
> > conditions. This implies that the "average" streamer current for this
> > coil was in the ballpark of about 1/10 of the reactive current covered
> > in the no-breakout case above or about:
>
> [snip]
>
> A thorough analysis as usual, Bert!
>
> I was considering using the secondary base current waveforms as a metric for
> judging how well the output impedance is matched to the streamer impedance.
>
> What do you think is the best loaded Q on the secondary for optimum power transfer?
> IMO, optimum energy xfer occurs as long as the loaded Q is low enough so that 90%
> of the secondary energy is gone within 1/2 of a beat cycle.
>
> -GL
It should be possible to measure this using the coil single-shot and
a grounded discharge rod. I can control the gap quench and secondary
loss very precisely by moving the rod closer and further away. I can
certainly make it meet this ideal condition using such tests. It
would be nice to know the V vs I combination and whether this is
power-variant. In my experiments, the optimum match always occurs
at longer spark distances as power is upped and with attached sparks.
In fact (buzzing with excitement), if we know Es and Idisch and
Tdisch, we might just about know Vout ?
Malcolm