Re: Newbie question

To: tesla-at-pupman-dot-com
Subject: Re: Newbie question
From: Tesla List <mod1-at-pupman-dot-com>
Date: Tue, 14 Oct 1997 21:30:45 -0600 (MDT)
Approved: mod1-at-poodle.pupman-dot-com


---------- Forwarded message ----------
Date: Tue, 14 Oct 1997 18:41:15 +0500
From: "Alfred A. Skrocki" <alfred.skrocki-at-cybernetworking-dot-com>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Newbie question 

On Tue, 14 Oct 1997 11:16:46 -0400 (EDT) student_of_agoshtas
<ceg4760m-at-cs.wright.edu> wrote;

> Hello all.  I'm new to coiling and I have a few basic questions regarding
> coil construction.

Welcome to the world of coiling!

> 1.  What are some good products for coating Tesla secondaries?  I've seen
> acrylic-based dielectric sprays out there, but they're 3x the price of
> your run-of-the-mill spray on acrylic from the hardware store.  In
> particular, I don't want to use a product that will attack the enamel on
> the wire.

What you want to look for in a coating is something that is 
nonhygroscopic, has as high a dielectric strength as you can get and 
has as low a power factor as you can get. This will minimize 
breakdown as well as minimize power loss to dielectric heating of the 
coating. In theory you would want something with as low a dielectric 
constant as possible to make the secondary distributed capacitance as 
small as possible. This is because the ratio of transformation in a 
Tesla coil is determined by the ratio of primary to secondary 
capacitance(or conersely to the ratio of secondary to primary 
inductance). I said in theory because no one has yet actualy 
documented whether it noticibly effects the output or not. As to some 
actual product suggestions, I use polyurethane on all my medium to 
large coils. A favorite brand is Zar, clear high gloss since it has 
the least other additives. On small to medium coils I like glyptol 
and corona dope but these are too expensive for me on the bigger 
coils. I am not in favor of 'acrylic' since this is typicaly the same 
as mylar and mylar has high dielectric losses. One of the worse I 
might add.

> 2.  Has anyone built a HV switching supply for a Tesla?  I'd like to build
> a 15 kVDC supply using an off the shelf switching controller IC from
> National Semiconductor.  The tricky part will be the boost-transformer.  I
> thought I'd use a U or toroid core of 77 type ferrite wound with a 1:125
> ratio.

Many of us are experimenting with various solid state supplies 
including swithing supplies. I will step aside and let those with 
more experience in this area comment. 

                               Sincerely

                                \\\|///
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                           Alfred A. Skrocki
                   Alfred.Skrocki-at-CyberNetworking-dot-com
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