From: "Terrell W. Fritz"
Date: Fri, 27 Sep 2002 18:54:36 -0600
Subject: Re: [TSSP] Top Voltage
Hi Paul,
At 06:33 PM 9/27/2002 +0100, you wrote:
>Terry wrote:
>
>> Good news. The fiber probe seemed to be working most of the
>> time so the previous data is fine.
>
>Well that's good. Those current signals looked too realistic
>to be an artifact. Hope the current probe is fit for battle.
I have spare parts and all. I "think" it is ok but the problem seems a little
intermittent. No worries though.
>
>Bert wrote:
>
>> Corona, and corona flashes (or streamers) are all "cold"
>> discharges, while leaders (what most coilers mistakenly call
>> streamers) are composed of hotter, highly conductive plasma
>> (actually more arc-like).
>
>So the leaders are plasma, but the streamers are un-ionised gas
>with the odd accelerated electron, insufficient in themselves
>to cause a bulk ionisation of the air, but enough when combined
>in their multitude to cause a leader to form?
>
>You see, in the back of my mind, I'm forming a hypothesis that
>Terry's topload is in fact breaking out rather earlier than
>the load current probe suggests. Could it be that streamers are
>forming at around the expected breakout voltage, but
>
>a) they are not bright enough to see,
>b) their large number plus their individual miniscule current adds
>up to a smooth average displacement current which is sufficiently
>smoothed by their large number to be indistinguishable from the
>displacement current that we can already see charging the rod and
>sphere.
>
>Perhaps the spikes we are taking to indicate breakout actually
>mark the formation of distinct, visible leaders, and that a much
>less visible (by eye or current probe) breakout is starting
>rather earlier.
>
>Malcolm has in the past reported a faint glow around his topload
>prior to obvious breakout.
That all does sound very possible!
>
>If this hypothesis were correct, then if we measured base current
>and rod+sphere+load current simultaneously (average or RMS values
>here, not scope traces) and plotted their ratio as a function of
>variac setting, then we would see a departure from a constant
>ratio. At low power, definately no breakout, the value would be
>set by the fixed capacitance of the rod+sphere. As the voltage is
>turned up and invisible streamers begin to form, the load current
>would increase disproportionately above the base current.
I think I see what you mean.
>
>Conveniently, Terry's rod+sphere is of quite small C, therefore it
>should be fairly sensitive to a small additional streamer current.
>
>> http://www.physic.ut.ee/~tomas/phd_plank.pdf
>
>Thanks Bert. www.physic.ut.ee is not letting me download at
>the moment, I'll try again later.
I have it at:
http://hot-streamer.com/TeslaCoils/OtherPapers/phd_plank.pdf
Looks like a great set of papers!!! At 168 pages, it will take a little time
;-)) He talks of the exact subjects we are dealing with now!
Cheers,
Terry
>I'm away this weekend at
>the final round of the British rally championship, so if anyone
>posts anything, don't worry if it doesn't come through until Sunday.
>
>Cheers All,
>--
>Paul Nicholson,
>--
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.