RE: Doubling NST voltage? (fwd)

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Original poster: List moderator <mod1@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Sun, 29 Oct 2006 14:09:30 -0800
From: Jim Mora <jmora@xxxxxxxxxxx>
To: 'Tesla list' <tesla@xxxxxxxxxx>
Subject: RE: Doubling NST voltage? (fwd)

Hello Curt,

This would be nice if it were practical and SAFE. Consider the design beyond
what Dr R said they are intended to do. Since they are mid point grounded to
the case either side's insulation sees only half the total voltage thereby
reducing the voltage dialectric stress by 1/2: someone jump in and correct
me if I'm wrong.

Floating two big cases is a bit scary to me; furthermore, the voltage stress
would be 4X since the half point grounds are gone.

Jim Mora

If you figure out a safe way to do this without meltdown , I'd love to know
it, as I am working on a similar issue. My key point is my higher end
transformer's secondaries are floating and have a 95KV BIL rating.

My opinion: Neons are not good vehicles to higher then rated voltages both
in safety and material survival but do great in additive current output
until as Richard Hull said, "you run out of room to place them". Then a pig
is in order or other higher rated device.

Regards,
Jim Mora

-----Original Message-----
From: Tesla list [mailto:tesla@xxxxxxxxxx] 
Sent: Sunday, October 29, 2006 8:45 AM
To: tesla@xxxxxxxxxx
Subject: Re: Doubling NST voltage? (fwd)

Original poster: List moderator <mod1@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Sun, 29 Oct 2006 07:49:21 -0800 (PST)
From: C. Sibley <a37chevy@xxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Doubling NST voltage? (fwd)

It seems to me that if the cases were isloated and ungrounded this would
work, and the voltage across each NST wouldn't exceed their individual
output.  The higher voltage would only exist across both, and would stress
the individuals.  What am I missing?


Curt.


----- Original Message ----
From: Tesla list <tesla@xxxxxxxxxx>
To: tesla@xxxxxxxxxx
Sent: Sunday, October 29, 2006 7:04:18 AM
Subject: Re: Doubling NST voltage? (fwd)


Original poster: List moderator <mod1@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Sat, 28 Oct 2006 15:46:31 +0100
From: resonance <resonance@xxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Doubling NST voltage? (fwd)



No this will not work.

The tar-like insulation in the nsts will quickly break down.

NSTs are really only designed to operate at 12 kV for 1/4 sec to ionize the 
gas in a neon tube.  Then the voltage drops back to approx 500 volts and 
they serve as a constant current source to keep the gas ionized in the tube.

They are not designed to provide HV for a long period of time.  They do this

in Tesla coil service but are constantly being strained in this operational 
mode.  Double the voltage will not work.  Also, you can't hook them in 
series because the center is grounded --- you would need two xmfrs without a

center-tap grounded configuration to accomplish this task.

Dr. Resonance
>
> Is it possible to connect my NST's in series, for double the voltage? I've

> run them in parallel before for the ma's, but I'm wondering if setting 
> them in series is do-able. If this has been done before, is there anything

> I need to do re: grounding, connecting, or whatever with their cases? 
> FWIW, I'm thinking of using a couple of 9/30's. I don't have 220v 
> available at my workbench, so I'd have to stick with 110v, if that's an 
> issue. Thank you all in advance, for any info you might have.
>
> Neal.
>
>
>