RE: Safety gap arrangements

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Gary.Lau-at-compaq-dot-com>

It you're using a static gap with the output of the filter network feeding
across the main gap, then it makes no sense to have the safety gap in
parallel with the main gap.  Whichever one is smaller will arc and the
other one won't.

Assuming that the safety gap is at the NST and is adjusted to fire at a
slightly higher voltage than the main static gap on the far side of the
filter, it's not clear by what mechanism a transient could occur that would
fire the higher-voltage safety gap and not the lower-voltage main static
gap.  But safety gaps are cheap and easy to implement and if there's any
chance that they might save our NST's, I'll keep 'em.  It has been
suggested that if there's any significant wire length between the NST and
the main gap, that transmission line effects might cause transients to
occur at the NST, but I've not studied this.

If you are using a rotary gap or a triggered spark gap, then it is very
important to have a safety gap directly in parallel with the main gap, to
fire in the event that the main gap is misadjusted.

Regards, Gary Lau
MA, USA


Original poster: "Michael J Strube by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <mjstrube-at-artsci.wustl.edu>

Hi

	I've noticed two basic arrangements for safety gap and filter units. Some
are arranged NST-Safety Gap-Filter. Others are arranged as
NST-Filter-Safety Gap. Does the arrangement matter and, if so, why?

Thanks,

Mike
arrangements