Re: Finished with Isolation Transformer.

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Stephen Conner by way of Terry Fritz <teslalist-at-qwest-dot-net>" <steve-at-scopeboy-dot-com>

At 07:51 25/02/03 -0700, you wrote:
>Original poster: "Richard W. by way of Terry Fritz <teslalist-at-qwest-dot-net>" 
><potluck-at-xmission-dot-com>
>
>Steve C,
>
>I tried that.
>
>
>Lesson learned:
>Be sure to wind ROUND coils for homebrew HV transformers. And use
>laminations to allow room for round coils.
>Square coils should be OK too but the idea is to be sure the forces applied
>to the first few layers aren't unequal and not great enough to deform them
>as more layers are added.

Thanks for sharing your hard-earned knowledge. I didn't realise how much 
more difficult it was to make an HV transformer compared to a LV 
transformer with HV isolation. I was under the impression that if you were 
able to do vacuum impregnation, and designed the HV winding to be a short 
fat pie shape (a la MOT) so that the voltage is distributed over a greater 
number of layers, and if you were careful to wind the layers evenly, you 
didn't need insulation between winding layers. I've never built a HV 
transformer, though.

A good plan for a HV winding might be a bunch of pies, each on its own 
thick insulating bobbin, all connected in series. It would be like four or 
six MOTs all on the same core. You could use a core from a dead 12/60 NST 
or something. What do you think?

Steve C.