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Re: Calculating Capacitor currents



At 12:26 AM 2/7/97 -0700, you wrote:
>Subscriber: Rodney.Davies-at-anu.edu.au Fri Feb  7 00:04:34 1997
>Date: Wed, 5 Feb 1997 23:49:09 +1100 (EST)
>From: Rodney Graham Davies <Rodney.Davies-at-anu.edu.au>
>To: tesla-at-pupman-dot-com
>Subject: Re: Calculating Capacitor currents
>
>Hi Richard,
>
>On Tue, 4 Feb 1997, Tesla List wrote:
>
>> Rod, 
>> 
>> There is absolutely no way to know the  peak current in the tank, ABSOLUTELY!
>> A close first order pass or stab at it would be to apply the Surge impedance
>> equation.
>> 
>> Z surge = square root of L/C
>> 
>> This will not take into account any form of circuit loses at all, such as
>> resisitve and gap losses.  The actual current will always, 100% of the time,
>> be much less.
>> 
>> The only way to determine the actual peak current value is to measure it
>> with a current transfomrer while the thing is throwin' arcs!
>
>Yeh, having analysed and experimented a little further as to how the 
>current is behaving across the spark gap, you're very much correct in 
>saying it's virtually impossible to know what the peak currents are doing 
>and when they're occurring...
>
>Well, luckily enough, I know just where to get a current transformer 
>from, I'll give it a go, but I'm expecting extreme fluctuating values...
>
>Thanks Ruchard,
>
>Cheers,
>Rod
>
>Rod,

Thanks for the return.  You must make sure that the C.T. that you use is a
wideband C.T.!  The 60-400 hz power C.T.s will not follow the rapid response
needed.  The waveform will be a normal ringing, decremented, damped wave but
its peak value will be related to the surge impedance and input voltage but
be attenuated by the losses distributed around the circuit and the gap.

Richard Hull, TCBOR