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Re: Primary Resonance



Hi Jim,

>I'm finding a resonant beat between the neon leakage inductance, the
>primary cap, and the  mains line frequency. (I'm using my numbers, I
>don't have yours)

That's exactly what we thought it was. As the variac is turned up the core
saturates and this changes the beat freq.

>given this level of modeling, the neon secondary voltage reaches
>120kV.  This type of modeling  also matches, using a separate ballast
>inductor, the measured results for my pole pig -- 75kV.

I measured the output (projected of course) to be about 130kV so your
modelling is excellent. It is also very similar to what I saw on the scope
when I was testing it. I have found a way around this although it is not the
best. I have 4 15kV 30mA trannies which should require 20nF. If I overload
it and put 30nF I don't get the beat and can crank up the variac to full
power and get 40"-50" white hot discharge. I don't run it for very long
becasue it's drawing a little too much current.

I built a nice air quenched static spark gap which has improved performance
considerably. But anyway, thanks for the reply it was good to see that it's
not just my bad circuit that's causing this!

Graham