Protecting Potential Transformers

To: "'Tesla List'" <tesla-at-poodle.pupman-dot-com>
Subject: Protecting Potential Transformers
From: Tesla List <tesla-at-stic-dot-net>
Date: Tue, 4 Nov 1997 20:50:12 -0600
Approved: tesla-at-stic-dot-net

From: 	Jeff W. Parisse[SMTP:jparisse-at-ddlabs-dot-com]
Sent: 	Tuesday, November 04, 1997 12:15 PM
To: 	Tesla List
Subject: 	Protecting Potential Transformers

All

I just landed a 100:1 Westinghouse potential transformer and
would like to gather some opinions on RF chokes.

The xformer is rated at 12kV with 15H kV insulation (whatever
the "H" means?) and a pulse test rating of 110kV. It is thermally
rated at 1.5kVA but, of course, I plan on running it hotter for short
periods. I'm using a 45A variac to limit current and it seems to work
quite well, kicking in a about half way around the dial and choking
down to a hundred milliamps or so at the end of the dial.

Question: I'll be feeding a 108kHz oscillator with this transformer.
What sort of RF choke (if any) should I apply on the HV side of
this trannie and can those chokes be on the tank side of the 
transmission lines as opposed to the transformer side?

I know when these questions have been raised in the past, the
threads seemed centered around protecting neon transformers.
I'm hoping to hear from those who have PT experience.

Jeff W. Parisse, Art Director
Digital Design Laboratories
www.ddlabs-dot-com