Actually, since power is I-squared * R, peak power in the gap is 1316 MegaWatts, or 1.3GW. But that's a peak value, for a very brief interval - good for bragging rights, but little else. The RMS current value for the duration of the gap on-time is a small fraction of the 4200A (sorry, no estimate, but <<4200A). And when you average that over a duty cycle (picking numbers out of the air) of ~ 10usec/8msec or 0.125% that the gap is actually on, you'd arrive at a more realistic figure for the amount of energy that's actually dissipated in the gap.
Regards, Gary Lau
MA, USA
-----Original Message-----
From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
Behalf Of David Rieben
Sent: Wednesday, December 05, 2007 1:42 PM
To: Tesla Coil Mailing List
Subject: Re: [TCML] Re: Spark gap Resistance
Hi Greg, all,
Maybe I'm missing something here. 4200 amps (peak) across
0.65 ohms translates to 11.466 MEGAwatts peak power loss!
I know the SG is the culprit for the biggest waste of power in
the primary circuit (the heat associated with the SG electrodes
and their associated mounting hardware verifies a significant
power loss) but this seems like a rather large sum of
lost power, even for peak levels.? Even with the really low
0.005 ohms for the silicon switch there would still be over 100kW
peak power loss at 4500 amps peak. I'm not that great on the higher
math but this seems to suggest that with an assumed 80% effeciency,
the primary circuit's peak power must be on the order of >50
MW? I suppose with the size of coils that Greg builds, 50
MW isn't that unthinkable for peak power levels, though.
David Rieben
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