Re: Spark Gap Questions

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 7/13/01 10:45:44 AM Eastern Daylight Time, 
tesla-at-pupman-dot-com writes:

> Original poster: "CJ Moore by way of Terry Fritz <twftesla-at-qwest-dot-net>" <
> wizard1234-at-home-dot-com>
>  
>  I have long been under the impression that the main spark gap should have a
>  larger space then the transformer(s) can breach on its(their) own, but 
that 
> the
>  combined power of the transformers and the capacitor(s) can break. 

CJ,

If you use a matched size cap at a low bps, the system may work
this way, but letting the voltage go higher like this is stressful on
NST's.  By using an LTR sized cap, the gap size can be kept smaller
and this protects the NST.  Wide gaps tend to destroy NST's and
OBIT's because they are feeble with poor insulation.  That said, I
do make my gaps a little wider than the NST can jump alone.  For
instance my safety gap is set at 1/4" on both sides for 1/2" total
for my 12/30 nst.  My safety gap is made from wires, so if balls
were used, the gap could be narrower.

> Is this 
> the
>  case only when using static gaps? 

The concepts apply to safety gaps and static gaps.

> In a RSG what is the "ideal" spacing 
> between
>  the flying electrodes and the stationary ones.

In a RSG, the gaps should be set as close as possible.  It's very
bad to make them wide, and this can destroy NST's very quickly,
and will give miserable performance.  I set my RSG gaps at about
0.015" or even closer.  

> If this depends on the rest 
> of
>  the coil, I will be using 9kv 120 ma and a .03 uf single cap. Also, should 
> the
>  safety gaps have a bigger gap than the ones in the main gap or a smaller
>  spacing? (or does this also depend on the type of main spark gap). 

With static gap, the safety gap setting will be maybe a little wider
than the main gap.  With a rotary, the safety gap will be much wider,
because rotary gaps must be set very close.

John Freau

>   
>  Thanks,
>  CJ Moore