Re: Gap Dwell Times (formerly: Beating Solved)
> I did some research this weekend, pouring through a Corum brothers
> monograph and some old posts to this newsgroup and found out that the
> optimal dwell is 1/(k*Fr), *not* 1/(2*k*Fr). In other words, the spark
> gap should conduct for only 1/2 of the superimposed beat-frequency
> envelope. Primary current peaks at that point, and maximum energy is
> transferred into the secondary.
I started from k approx dF/F, and ringup time = 1/2dF so you can see
how I derived that. The problem when cutting the gap off (if you
could) when Ip is maximum is that with k<1, most of the primary
energy is coupled to the primary. I tried doing exactly this with the
MOSFET gap and the spikes hit the roof. Virtually none of that energy
was coupled to the secondary. The spikes in a real gap would have re-
ignited it anyway. I wonder if they have actually tried doing this?
I found the ideal dwell to be when the secondary was fully rung-up
and the primary had virtually nothing left. Even then, quenching at a
primary zero-crossing is a no-no because of spike generation. I sent
some photos I took of this process to several people.