RE: Optimum toroid size

["Ted Rosenberg" <Ted.Rosenberg-at-radioshack-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Gary and friends:
 I hate to add my 2 cents to this mix but I think the toroid on my coil is
too large because:
1. without breakout points I get virtually zero breakout. One or two measley
streamers.
2. with breakout points, it is incredible---2-3 footers with a 15/60 NST.

When the Halloween gig is over, I will experiment with a smaller toroid. Now
I use a 6" duct and 22" diameter. Thinking of seeing what happens using 4"
diameter.

I get a feeling that toroid efficiency is to a degree hit and miss. I
originally went by Wintesla but I'm having second thoughts.

Ted AKA
Ted Rosenberg
Geek Group Member #1030
www.thegeekgroup-dot-org
Because the Geek shall inherit the Earth!


-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Monday, October 09, 2000 12:14 PM
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