Re: spark gap spacing

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

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi Jeremiah,

At 01:03 PM 6/10/2001 -0500, you wrote:
>
snip...
>
>The transformer is a 12/30 NST controlled through a variac and i have only
>set it at 115 on the variac.  I didn't know how to calculate the peak
>voltage.  Is 1.414 a constant or an independent variable in an equation?

1.4142135... is actually the square root of 2.  It is a constant.  If you
have a sine wave (as most AC signals are), then the peak voltage is the
sine wave's RMS voltage multiplied by the square root of 2.

Thus, if you transformer is rated at 12000 Vrms output, the peak is 12000 x
SQRT(2) = 16971 volts.  You can set the main gap to fire at ~17000 volts,
or less, but not more.  You do not have to be super exact but reasonably
close is good enough.

>Now should i set gap so that it arcs dependably and then add the caps in
>their?  

Yes, the voltage should be set with just the NST and the main gap in
circuit.  Adding caps, inductors, etc. will effect the circuit and mess up
the voltage setting.

>If i set the gap this way is that going to be the peak voltage at
>that voltage setting?

The gap fires at a peak voltage, so it will fire around 17kV.

Cheers,

	Terry


>Thanks
>Jeremiah
>