Re: Doubling NST voltage? (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Gregory Morris <gbmorris@xxxxxxxxx>

Forgive me for being naive, but to me it seems that either way, 
whether you ground the centre or not you are going to see a 15kV 
difference between the outputs. In the centre-grounded situation one 
end is 7.5k above ground, and the other is 7.5k below, but in the 
floating situation you are still going to see the same differences 
between points in the coil, they can just be different relative to 
ground, but ground is arbitrary, is it not? Sorry if I'm missing 
something, but I'm just a student, as yet.

Greg

Tesla list wrote:
> Original poster: List moderator <mod1@xxxxxxxxxx>
>
>
>
> ---------- Forwarded message ----------
> Date: Sun, 29 Oct 2006 15:27:17 -0500
> From: Mike <mike.marcum@xxxxxxxxxxxx>
> To: Tesla list <tesla@xxxxxxxxxx>
> Subject: Re: Doubling NST voltage? (fwd)
>
> The reason most nst's 7500v and up are midpoint grounded is it 
> halves the insulation requirement (lowers cost). To series them this 
> would have to be moved to 1 of the ends, doubling the voltage stress 
> at the free end. Doable, but alot of work and wouldn't last long 
> (potting in oil instead of tar would help). If you really need 18kV 
> from a current limited source take a 15 kV nst and run it at 150v 
> from a  variac. Only trouble with this is right at the edge of core 
> saturation which could be a problem.