[TCML] Re: Spark gap Resistance

[Barton B. Anderson]

0.65 ohms is significant! I have to assume that 0.65 was an averaged 
value? It is still relatively small and I don't think reflects the gap 
losses associated with spark gaps. I wonder if those gap losses included 
the primary losses as part of the mix?

Take care,
Bart

Lau, Gary wrote:
> 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 at pupman.com [mailto:tesla-bounces at pupman.com] 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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