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Re: 19 kV MOT stack? (fwd)

---------- Forwarded message ----------
Date: Tue, 17 Jul 2007 08:35:58 -0700 (PDT)
From: J. Aaron Holmes <jaholmes@xxxxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: 19 kV MOT stack? (fwd)


Straight away, the "19kV from 6 MOTs" bit sets off
every alarm, but getting back to the more fundamental
"NSTs as isolation transformers" idea:  Realize that
your isolation transformers must pass every bit of
power that your MOT stacks put out.


So, if you want 19kV at 500mA from your MOT stack,
that's 19kV * 0.5A = 8kVA.  8kVA would be eight or
nine 15/60 NSTs.  If you had eight or nine 15/60 NSTs,
you could just run them all in parallel for 15kV at
8kVA, right??  You won't pull much more from a NST
than its rated power; the cores are designed to
prevent it.  If you want, you can pry the NSTs out of
their cans and modify the cores for more power,
enabling you to use fewer of them.

MOTs are onerous as it is, but...

Aaron, N7OE

--- Tesla list <tesla@xxxxxxxxxx> wrote:

> ---------- Forwarded message ----------
> Date: Mon, 16 Jul 2007 22:43:43 -0400
> From: Scott Bogard <teslas-intern@xxxxxxxxxxx>
> To: tesla@xxxxxxxxxx
> Subject: 19 kV MOT stack?
> Hey everybody.
>      I read in the archives that somebody tried to
> parallel a MOT and NST to 
> get high voltage and current, but I have a slightly
> different idea.  What if 
> you took a center tapped MOT or OBIT, to get your
> volts up, and put the 
> outputs to the case of a MOT, to get oober current. 
> The first thing to come 
> to mind is shorting the MOT, but MOT stacks have
> been successfully extended 
> to 8 MOTS, 6 more reliably, and by doing something
> like this, you could put 
> the primary at a higher potential, reducing the
> chance of an arc over.
> http://www.altair.org/projects/MOTstack2.gif
> So If you have a 15 kV NST, each side is 7.5 kV and
> the MOT primary sits at 
> 2 kV, so the MOT primary is seeing 5.5 kV
> difference, just over what a 6 
> stack would see, and less than an 8 stack.  So you
> could get 19 kV with 6 
> MOTs and an NST, and you could float the  MOT cores
> from the secondary to 
> reduce stress further.  My biggest question is would
> excess current draw 
> from kill the NST or doesn't it work that way (would
> the current come from 
> the MOT, or does it have to be pulled from the
> ground in the center of the 
> NST or OBIT)?  Just a thought.
> Scott Bogard.
> http://liveearth.msn.com