RE: Optimum toroid size

["John H. Couture" <couturejh-at-worldnet.att-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Gary -

Note that the energy equation you show has two unknowns Csec and Vsec. This
equation cannot be solved without more information. One solution is to use
the graph with the two intersecting curves. This not only gives you both
unknowns but also optimizes the two variables for a sphere topload.
Variables like ROC are a consideration. This is for finding the unknowns at
the design stage before the TC is built.

Another method as you mention is to build the TC and test it by trial and
error. Using different toroids find the size that gives the longest
streamer. Variables like ROC are not a major consideration. This is the only
method at present for toroids.

John Couture

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-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Monday, October 09, 2000 10:14 AM
To: tesla-at-pupman-dot-com
Subject: RE: Optimum toroid size


Original poster: "Lau, Gary" <Gary.Lau-at-compaq-dot-com>

The discussion so far has been how to maximize top-load voltage prior to
breakout.  Increasing top-load size results in higher radius of curvature
(ROC), which increases breakout voltage, while increasing top-load size also
decreases maximum attainable secondary voltage by virtue of conservation of
energy Esec (0.5 CpriVpri**2) <= Epri(0.5CsecVsec**2).

I have to wonder though whether maximizing pre-breakout top-load voltage is
a necessary condition for optimum performance.  Many, if not most of us use
a breakout point on our top-loads.  They serve to direct the streamers to
where we want them, force breakout to occur, and also to concentrate all
available energy into (hopefully) one long streamer.  But it would seem that
the use of breakout points renders the ROC consideration a mute point.

If I have a toroid with a breakout point and streamers don't occur, then I
conclude that the top-load capacitance is too large.  If I have a toroid
with a breakout point and *multiple* streamers occur (I want only one), then
I conclude the top-load capacitance is too small.  But I don't believe ROC
of the top-load is a major consideration.  Is this thinking incorrect?

Gary Lau
Waltham, MA USA