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Re: Optimal Quenching Tests

Tesla List wrote:
> 
> > > Subject: Re: Optimal Quenching Tests
> > Subject: Re: Optimal Quenching Tests
> 
> Subscriber: harris-at-parkave-dot-net Mon Jan 13 22:11:12 1997
> Date: Wed, 23 Oct 1996 09:23:47 -0400
> From: Ed Harris <harris-at-parkave-dot-net>
> To: tesla-at-pupman-dot-com
> Subject: Re: Optimal Quenching Tests
> 
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> > > Subject: Re: Optimal Quenching Tests
<SNIP>
> > QNCHFFT - FFT view of the above near-optimal quenching case. Note the
> > absence of splitting, sidebands, etc. Also, the marked difference in
> > primary and secondary Q's can be seen in their bandwidths. 1:1 alignment
> > of peaks at 90 kHz.
> >
> 
> The neat thing here is that your primary current is NEARLY an impulse. This
> is brough out very clearly by the fact that the primary FFT is VERY
> broadband in its frequency spectrum. By quenching quickly you don't allow
> any interaction between the two tuned circuits and therefore there can't
> be any splitting. This should also happen to a greater extent if you quench
>  too soon or if your coupling increases (I think).
> 
> One question: for real circuits you've got a non-linear resistance due to
> the
> discharge arcs. Do you think these arc break-out before the calculated
> optimal quench time? If so, I wonder how much the quench time is changed
> by the presence of the secondary discharge arcs....
> 
> -Ed Harris
> 

Good question! Once we've heavily ionized the air around the toroid, the
arcs will most likely break out _before_ we would optimally quench. Ever
since you posted the Aryton/Nottingham material, I've been thinking
about how this could be input into either the primary gap or secondary
PSPICE simulations to see the impact. However, we certainly should see a
significant reduction in secondary Q as streamer current grows,
reflecting the impact of removing energy more rapidly from the
primary:secondary system. 

Under these conditions, it's not clear that the quenchtime would be
impacted to any great extent, but the peak secondary energy reached at
the first primary notch would certainly be lower for early breakout
case. The heavier the streamers, the lower the energy peak reached in
the secondary... If heavy enough, the peak would be reached at the point
of breakout, and would decline from there. In effect, energy coupled
from the primary goes directly into strengthening the streamers and no
longer adds to the reactive energy stored in the secondary. I know this
is what happens during a heavy ground arc. If there's not enough energy
coming back to reignite the gap, then I don't have to worry about
quenching - its done for me! :^) 

I really would like to be able to use a simple PSPICE model for the
non-linear gaps and arcs.. any ideas on how to tackle it?? Jim Fosse has
a rather complex model on his ftp site that he obtained from a German
professor, but neither he nor I have been able to get it to work (yet). 

Safe coilin' to you, Ed!

-- Bert --