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RE: www.drsstc.com massive update!
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- Subject: RE: www.drsstc.com massive update!
- From: "Tesla list" <tesla@xxxxxxxxxx>
- Date: Wed, 05 Jan 2005 08:10:26 -0700
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Original poster: "Steve Conner" <steve.conner@xxxxxxxxxxx>
>We need to figure out a John Freau style formula for DRSSTC spark
>length...
I make it around 2.1*sqrt(p) at the moment. Although I have heard some
people say that the exponent should be slightly different to 0.5. (Square
rooting a number is the same as raising it to the power 0.5.) If it were
changed to say 0.4, this would better model the observation that bigger
coils work more efficiently than small ones.
>At say 300Volts
>and 3600 peak amps, they could push over 1,000,000 peak watts!!
Are you using (Vpeak*Ipeak) for peak power? I tend to use Vpeak*Ipeak/2
which is the average power over one half-cycle. The cycles are so short
compared to the thermal time constants that I think this is the more
meaningful figure. I know this sounds crazy, using averaging to work out
peak power. But there is no such thing as a true instantaneous power
measurement- whenever you measure power it's always average power over some
(possibly very short) interval.
Of course Vpeak*Ipeak is the more impressive one- I can claim 5 megawatts
peak power from my OLTC2 as the switch sees 1kV in the off-state and passes
5000A in the on-state. But in fact the actual power delivery to the
resonator, averaged over the time the IGBTs are on, is only about 150kW, so
I quote this figure as the peak power.
This is the same method used in radar where the "peak power" is the output
of the magnetron averaged over the pulse length (or the average RF output as
measured by a bolometer, divided by the duty cycle, which works out to the
same thing and is probably how they measure it in practice?)
Steve C.