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Re: 20 joules at 100 bps vs 4 joules at 500 bps - any difference?

Original poster: FutureT@xxxxxxx

In a message dated 7/16/05 4:02:06 PM Eastern Daylight Time, tesla@xxxxxxxxxx writes:


Hi John,

I'm thinking of two types of experiments:  One with a SRSG where one is
limited to multiples of 120 bps (sounds like you have this one covered) and
the other using a ARSG where you have more choices of BPS (but should
probably avoid 60 and 120 bps so you dont alias with the line frequency).
With SRSG, seems like one advantage of 240 bps is a smaller Cp (STR).  Did
you change Cp in your comparisons between 120 and 240 bps to keep the same
power and still fully charge Cp.  Seems like going to half the Cp at 240
bps would necessitate a smaller toroid (with smaller reach)

Gerry R.



Gerry,

I did the tests in various ways which I can't all remember right now.
In some cases I just adjusted the input variac so the input wattage
was the same for both break-rates, then I compared the voltage
on the caps to see if that was as it would be expected to be.
I think in some tests I did use the smaller Cp, but in others
I just let the cap charge up less at the 240 bps.  In many cases
I used a breakout point so the spark was able to break out
no matter what.  I tried various toroids sizes, etc.  But all the
tests gave similar results pretty much.  I think I found that
the suitable toroid size was tied somewhat to the input power,
and somewhat to the bang size at least if a breakout point was
used.  It seems that at high bps, a spark can travel further from
a given size toroid.  For example at 120 bps a spark may travel
only 3 times the toroid's diameter.  But at 400 bps, the spark
may be able to travel 4 times the toroid's diameter.  This may
have something to do with the way the spark tends to coalesce
into a sort of tendril at times, more so than at 120 bps.  There
were so many things happening it was hard to pin it all down.
I think many folks use toroids that are considerably smaller
than the maximum size that could be used.  For example
my TT-42 coil can break out of a 6" x 24" toroid (barely), but
I normally use a 4" x 13" toroid on the coil, so I lose 2" of
spark length.

Cheers,
John