Re: Solid Toroid Beneficial?

To: tesla-at-pupman-dot-com
Subject: Re: Solid Toroid Beneficial?
From: "Gary Johnson" <gjohnson-at-ksu.edu> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Thu, 16 Mar 2000 18:47:23 -0700
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

Alan:

Thanks for the note.  The shorted turn effect that has been very steady and
reproducable for the past two weeks disappeared today.  Might have been a
high impedance connection, but I can't be sure.  Now I see no effect one way
or the other.  

I am writing up my research notes, which could easily come to 200 pages.  I
will make them available for the cost of photocopying and postage.  I could
have them finished in the next two or three months if I can figure out
theoretical explanations for some of the observations I am making.  Like
your observation that raising the toroid improves performance.  I noticed
that today also, that raising the toroid lowers the input impedance and
raises the top voltage.  It is not a classic frequency or current
distribution effect.  I used two toroids, one slightly larger than the
other.  The larger toroid had the same frequency sitting on the coil as the
smaller toroid had when 8 inches up.  The current distribution should be the
same.  But the smaller, raised toroid had 20 percent higher voltage on it.
If you could think of a reason this might be so, I would appreciate it.

My interest is more in the area of explaining Tesla coil operation than in
making long sparks.  I have equipment to make a classical coil with
potential transformers, but may never get around to doing it.

Gary Johnson

At 08:20 PM 3/15/00 -0700, you wrote:
>Original Poster: "Alan Sharp" <AlanSharp-at-compuserve-dot-com> 
>
>Gary,
>
>I read your post with great interest. And your paper on
>input impedance some time ago.
>
>I've also experimented a lot with solid state coils -
>but I've been discourage by poorly performing circuits -
>and the number of fets I've blown.
>
>My stuff is at.
>http://ourworld-dot-compuserve-dot-com/homepages/alansharp/
>
>I didn't see this shorted turn effect. I noticed that my top
>toriods were getting hot and so I raised them further away from the coil
>and performance increased slightly. But I was running at lower powers -
>under 1kw probably 5kW peak. 14" discharge and very different geometry..
>
>http://ourworld-dot-compuserve-dot-com/homepages/alansharp/
>
>I have a lot of questions about your circuit and coils. I see with
>interest that you are direct driving - no output transformer. 
>
>Could you be persuaded to post more details and the schematics -  I'ld be
>delighted to
>host your material on my site.
>
>At present I'm building a conventional coil. It is amusing that the 
>humble spark gap can still produce much better results than our hitech
>semiconductor stuff. 
>
>Alan Sharp (UK)
>
>