Re: 43" First light! - Dead Transformers :-(

To: tesla-at-pupman-dot-com
Subject: Re: 43" First light! - Dead Transformers :-(
From: Mark Finnis <mefinnis-at-medicine.adelaide.edu.au> (by way of Terry Fritz <terryf-at-verinet-dot-com>)
Date: Sun, 20 Sep 1998 18:00:52 -0600
Approved: terryf-at-verinet-dot-com

At 07:12 19/09/98 -0600, you wrote:

>We did have a protection network in place but it was poorly
>constructed and "blew itself up".  We had been operating without it when we
>got
>the primary/secondary strikes.  Impatience :-(
>
>I am looking for suggestions for a good protection system for this coil.  I
>will
>have 4 more NSTs available so I should be able to operate with 4-7
(120-210ma)
>depending on how many I can repair.  I am considering unpotting them and
>puting them in oil.

I run  a similar system, two 15 kV / 60 mA NSTs.

I use a protection circuit as advised by Malcolm Watts

See:

	http://www.cobweb-dot-com.au/~dkfinnis/current_coil.htm

	scroll down to see both circuit & parts used ;-)

The original 1K resistors where rated at 50W (3 of 17W wire-wound).  I have
since replaced these with 100W versions mounted on heat-sink which are far
better (just be careful with insulation from heat-sink !!!).

Cheers,


Mark

http://www.cobweb-dot-com.au/~dkfinnis