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Re: rotary gap question



In a message dated 4/12/99 2:49:15 AM Pacific Daylight Time, tesla-at-pupman-dot-com 
writes:

> 
>  Chris, all,
>  
>  That's a good question.  A non-sync rotary is not always better than
>  a static gap.  In a small coil, or using an NST, a static gap may give
>  better results.   A rotary can be best for an NST system, but it has to
>  be a sync rotary.
>  
>  In very high powered systems, a static gap may overheat, and fail to
>  quench, or it may fire too often.  The rotary is a timed switch, it sets
>  the firing rate as needed or desired.  It may also help to quell some of
>  the chaotic firing characteristics of static gaps.
>  
>  Another distinct advantage of the rotary, is that it permits somewhat
>  independent control over the firing voltage and break rate.  This can
>  be achieved with a static gap, but requires an adjustment of the gap
>  spacings for each change.  This may be one of the greatest 
>  advantages of a rotary gap.
>  
>  John Freau
>  
Chris, John,

In addition, a rotary gap must be used once the primary supply current gets 
much over 150 ma.  I used a cylindrical static gap with a 12 kv 120 ma neon 
sign transformer supply and it performed well.  With a 5 kva 14.4 kv 
distribution transformer, the static gap would not quench (as in go out) 
regardless how much ballast I tried in the primary control circuit.  I then 
built an asynchronous rotary gap and it worked fine.  I have read comments 
from others that the upper limits of a static gap are around 1.5 kva to 2.0 
kva.  Comprssed air or vacuum quenched static gaps should take this limit to 
some higher number but I have no direct experience with those.

Ed Sonderman