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Re: 3MV/meter
Hi all,
I have been using single shot methodology for measuring coil
parameters and performance for several years now. In fact I used it
to get the primary Q measurements which should be posted soon. With
a cap voltage of 12kV on the coil in question I can get a single
solid channel spark 17+" long to a discharge rod (Ecp about 7.2J).
I have serious doubts about 3MV/metre though. The Ctot of the
secondary of this coil is 26pF. Ignoring gap losses, the best it can
theoretically do at this energy level is 744kV. The spark length
according to my rule of thumb of around 35kV/inch is about 600kV at
this energy. That seems reasonable considering the secondary only gets
one ringup under these conditions.
Richard wrote....
> There was an old article By DC cox in a TCBA NEWS of yesteryear. In this
> article he suggested single pulsing a Tesla coil to determine the actual
> voltage output.
>
> He recommended DC charging of the normal tank capacitor and single firing
> the system. The resultant non-ionic spark length would represent the
> actual output capabilities.
>
> I have thought this out a bit and if you were to just align you gap for
> normal presntation with air flow or whatever quench method you use, and
> apply any DC voltage which will charge the cap to its air break over
> point in the gap, it will fire as a close analog to real operation. Next
> a grounded object which is relatively flat should be moved in or out from
> the toroid (which has a moderately pointed object on it (the capacity
> will not assist in single shot storage). Room lights should be out or
> very dim. At the point where a true streamer arcs (not just a brush
> connect), this is the output of you coil based on the DC, 3 megavolt/
> meter, air breakdown rule. It is important to closely mime the real
> conditions of your coil system to make this really hold.
<snip>