TSSP: List Archives

From: Bert Hickman
Date: Fri, 27 Sep 2002 08:10:19 -0500
Subject: Re: [TSSP] Various

Paul,

Just a quick note before going to work...
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). Leaders
are "fed" by the sum of the displacement currents coming from the
multitudes of streamers at the tips of the leaders, so current levels
are higher in leaders than streamers. Streamers tend to be much briefer,
and are harder to see than leaders, and are thus more difficult to
capture in images.

A good discussion of  corona and streamers can be found in the following
Ph.D. dissertation:
http://www.physic.ut.ee/~tomas/phd_plank.pdf

Best regards,

-- Bert --
--
Bert Hickman
Stoneridge Engineering
"Electromagically" (TM) Shrunken Coins!
http://www.teslamania.com


Paul wrote:

> Hi All,
>
> It's been a while since I posted anything so I thought I'd
> better say hello, and apologise to the several people who
> have sent me emails and not had replies.  They've all been
> read and acted upon, but I've just not had the time to respond.
>
> Work has been pretty busy, as usual.  Haven't had much time
> for TC work, the odd bit of coding, that's all.
>
> I'm still reeling from our initial observations of breakout
> voltage.  I can't fault Terry's measurements and we're forced
> to face the fact that his sphere seems to be breaking out at
> between 2 and 5 times higher potential than we thought it would.
> I'll have to go back over the surface field calculations to make
> sure nothing's messed up in there.
>
> Before going any further,  I think it's time for me to try
> to understand just what the difference is between streamers
> and leaders, which I'm not at all clear on.  I just use the
> word 'streamer' to cover everything.
>
> As regards the quiz, I've had quite a few positive comments
> and several people have lodged answers with me, although I
> haven't officially launched the quiz.  I'm hanging on until
> I get a spell in which I can cope with the correspondence!
> Don't let that discourage anyone from sending in answers,
> they will be saved at this end, but I need to check a few
> things first, and also disambiguate the rules a bit.
>
> Greg Leyh wrote:
>
> > Awhile back I was toying with the idea of connecting a
> > capacitor across the lower 1/6th or so of the secondary
> > turns, in order to convert the coil into a kind of
> > 'hybrid' coil -- somewher e between a standard and a
> > magnifier configuration....
> > ...I'm now wondering if this hybrid arrangement might
> > help smooth out the secondary voltage stress factor,
> > as well.
>
> That's an interesting idea.  Perhaps downward going
> transients resulting from step changes in top voltage will
> be swallowed by such a capacitor, thus protecting the
> already well-stressed lower part of the coil.  That sounds
> well worth trying to model, and we have the technology.
> As soon as I get the chance I'll setup a model of that and
> see how it responds.  At the very least it might make a
> kind of 'safety gap' for the secondary - a deliberate
> weak point for controlled secondary breakdown.
>
> Well, that's all for now,
> --
> Paul Nicholson,
> --






Maintainer Paul Nicholson, paul@abelian.demon.co.uk.