RE: A new mini-coil competition winner!

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Lau, Gary" <Gary.Lau@xxxxxx>

Based on Karl's stated .06" gap separation, which is pretty close to
what I also have on my mini coil (I have closer to .07"), I can confirm
that his gap width has been properly set for a 4kVRMS NST.  If it was
breaking down at 15+kV, it would have to be much wider.

Regards, Gary Lau
MA, USA

> Original poster: Vardan <vardan01@xxxxxxxxxxxxxxxxxxxxxxx>
>
> Hi Karl,
>
> The resonant capacitor value for the modified transformer is:
>
> Cres = 0.038 / (2 x pi x 60 x 4000)  =  25.2nF
>
> so the 25nF capacitor in the coil is right at resonance.  Just like
> an NST system, the voltage at the gap can be pretty high and well
> over the rated voltage with a resonant size cap.  So instead of the
> firing voltage being 5524V it might be much higher.  I suspect it is
> closer to 15kV!
>
> There is an easy way to check.  Disconnect the cap and primary coil
> so "only" the transformer and gap are in circuit.  With just the gap
> as the load for the transformer, it should put out its rated
> voltage.  Then see if the gap fires.  If it does, then the gap is set
> to 5524.  However, if the gap does not fire and the electrodes need
> to be moved closer, then the gap was set for a higher voltage.  Once
> the gap is set for 5524V  I think the spark length will go way down
> :-(  Like 7 to 10 inches.  So set the gap back to where it was :-))
>
> Cheers,
>
>          Terry