RE: vacuum spark gap (not exhaust fan type)

Hi Ed & List

Thanks for the reference. 
Here is more on the book:

High Voltage Engineering Fundamentals, 
E. Kuffel Engr Dean U of Manitoba, W.S. Zaengl EE Prof Zurich

This is a college text with theory, graphs, formulas AND nice HV apparatus Pictures,
a must for any serious HV'er !

ISBN 0-08-024212-X (soft cover)
ISBN 0-08-024213-8 (hard cover)

2.) The Jennings & Kilovac vacuum relay contacts DO NOT CLOSE the way I use them.
If they do, they are likely to stick. (been there...)
I run ~600A pk though the arc /gap / contacts !!

I charge a 10uF AL electrolytic to ~65V then mechanically 
via pneumatic air bulb, switch it across the 26v relay coil

producing a "Jog" of the armature, decreasing the gap distance encouraging conduction.
Once the gap is bridged by an arc, the full charge is delivered quite efficiently.
Good for Single Shot mode.

3.) It will work for fixed electrodes, if electrode spacing is adjustable to various V's.
I have vacuum contactors whose bellows allows precise gap distance 
adjustment that yields the same performance as the jog technique.

Regards, Dale
Redondo Beach, Calif

-----Original Message-----
From: Tesla List [mailto:tesla-at-pupman-dot-com]
Sent: Tuesday, May 02, 2000 4:30 PM
To: tesla-at-pupman-dot-com
Subject: Re: vacuum spark gap (not exhaust fan type)

Original Poster: "Ed Phillips" <evp-at-pacbell-dot-net> 

Check the text "High Voltage Engineering" (don't recall author-I'll ck &
> I recall a good chapter on arcs in a vacuum, Pashcen sp? law/curves vs.

	Paschen's law. circa 1910

> I use Jennings & Kilovac vacuum relay spark gaps for all my single shot
> and achieve very good results (contacts come close but don't contact - jog
> to arc).

	Any idea how close they come before breakdown?  I assume you throw the
contacts all the way using electrical input to the actuator coil.

> My efficiency is very high, even with voltages as low as 7kVdc.
> I do take advantage of moveable vs. stationary electrodes, however.

	Obviously excellent for single-pulse work (extremely low switch
resistance, controlled time of breakdown)  but as mentioned in another
post, don't think  the idea will work at all for fixed electrodes.