Re: TC Output Voltage

To: tesla-at-pupman-dot-com
Subject: Re: TC Output Voltage
From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
Date: Wed, 13 Nov 1996 10:20:11 +1200

Hi Greg,

> How did you estimate Zarc?  Do you think that it can be determined by 
> watching the decrement of the current waveform at the base of the
> secondary coil?

Now you've got me thinking. I don't remember exactly what I did. I 
don't recall using the base current (certainly not alone) as the arc
resistance is going to be length dependent as well I think. Also,
the arc is divorced from the driving circuit by 90 degrees odd at 
least when initiated. I do know that the primary rate of energy unload
is dictated by k and it can do no better so it would be the same or
worse under loaded conditions IMO.
 
> If I remember correctly, a resonant tank ckt is critically damped 
> when SQRT(L/C) = 2R, and max power xfer occurs at SQRT(L/C) = R.
> TC secondaries seem to ring for quite a few cycles, indicating that
> the typical Zsec is actually much _lower_ than Zarc.  If this is the 
> case, how does adding a toroid help with spark production?

I've scoped the secondary waveform under arc conditions and it is 
dampened very considerably (much more so than corona). I've recorded
the arc sucking power out of the system almost to completion in as 
little as 11 cycles in the machine here at work. I think the topload
is a balance between holding off until the resonator energy is near 
max and drgging the final voltage down. The other point (an excellent
one first suggested by Mark Barton) was that in adding topload, people
invariably compensate by adding to Lp thereby increasing raw primary 
Q.

I guess more measurements are the order of the day,

Malcolm