'true" spark length was Re: Desktop Bipolar Coil

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>" <Mddeming-at-aol-dot-com>

In a message dated 6/30/03 1:41:08 PM Eastern Daylight Time, 
tesla-at-pupman-dot-com writes:


>John is quite correct on this matter.
>
>If you want to determine a "true" spark length for you coil, rectify the AC
>to DC and then insert a large value resistor (say 20 Meg) in series with the
>HV power supply to the cap.  This will "fire" the circuit once every 2-3
>seconds.
>
>You measure this output spark length and you will have a close to true value
>for the output of your system.  This prevents "spark growth" as a function
>of power input.
>
>This is a HF AC current however the spark length is very close to what a DC
>peak value would be and is accurate to determine actual output voltage.
>This also is in very close agreement with Terry Fritz's antenna pickup
>voltages.
>
>Dr. Resonance


Hi Dr. R, John, All,

        I am not at all sure that the "true" spark length is even a 
definable concept. It's like asking what is the "true" maximum height a 
given athlete can jump, or the "true" maximum speed a particular driver in 
a given car can achieve. It all depends on the day, location, environmental 
conditions and the breakfast menu.

        Since electrical discharge is a fractal phenomenon, the "True" 
length is indeterminate and may be anything greater than the straight line 
distance and less than infinity. One can talk about the greatest 
straight-line interval achieved with a given coil under such-and-such 
conditions, etc. One can determine through many multiple tests a "most 
probable" upper bound on spark interval (not length). TCs are far too 
complex to be able to speak intelligently about single-value performance.

Hopefully this may help take some of the fuzziness out of the discussion.

Matt D.