Re: RSG and NST's

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Harold Weiss" <hweiss@xxxxxxxxxx>

Hi,

Syncronous rotories can be used with NSTs.  Having a good filter after the
NST will prevent death normally.  An LTR sized cap will also reduce
problems.  My old 6" coil ran with a resonant sized capacitor and was able
to break down 10" of canvas phenolic across the filter outputs due to
resonant rise of a missed firing.  The filters kept the spike from reaching
the NSTs, and as a result something else had to give.  A Terry filter
combines MOV spike suppression, RF filtering, and safety gaps all in one.

There is a modified version of this filter that was suggested to me by Dr.
R, that moves the safety gaps to the halfway point of the 1K 100W filter
resistor.  The added resistance in the safety gap path will cause the main
gap to want to fire first before the safety fires.  It will also provide a
current limited path for the capacitor to discharge thru instead of dead
short.  In operation the gap will look more like a spark plug firing instead
of a welding arc.

Pictures of this filter can be found at Terry Blake's website at www.tb3.com
under the latest Cheesehead Teslathon.

The filter schematic link can be found in the archives.

http://hot-streamer.com/TeslaCoils/Misc/NSTFilt.jpg

David E Weiss

> Original poster: "rb" <randyaz@xxxxxxxxxxxx>
>
> Several posts lately are discussing the use of rotary spark gaps with
NST's.
> I was under the impression that a RSG was not for use with NST's as they
> cause them to fail.  Is this not right?
>
> randyaz
>
>
>