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Secondary Research (fwd)
---------- Forwarded message ----------
Date: Thu, 27 Feb 1997 09:09:24 +1200
From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
To: tesla-at-pupman-dot-com
Subject: Secondary Research
Hi All,
I still have a long way to go in this exercise, but thought a
preliminary finding might be of interest. It seems clear that the
efficiency of a number of power supplies (or use of available power)
leaves a lot to be desired. A reality check on one of the largest
systems in the survey shows that power getting to the primary all but
matches the measured power input. You can check your system by:
(1) Measure power input (watts, not V.A.)
(2) Multiply break rate by peak capacitor energy (0.5CV^2) to get a
figure in watts and compare the two.
In a lot of cases I've checked so far these two figures are
worlds apart. To get maximum efficiency, resonant or inductive
charging of Cp is a must. Unfortunately, using neon transformers to
best effect like this can result in an early death for them. To be
fair, I have assumed that neons are being used right up to peak o/c
output voltage. This will not always be the case. You can open the
gap so wide that the transformer takes a couple of cycles to swing up
to some enormous values halving or reducing rep rate for a static gap
even further. Closing the gap to a more reasonable value gets the rep
rate to the desirable value but reduces Ec considerably.
It would be most useful to have a table of gap settings vs
breakdown voltage (which will be somewhat different from DC) but it
will no doubt vary for different gap geometries. A useful guide
though for ensuring neon survival in my opinion. I have read of
instances where gaps have been opened up to 1/2" or more. As a rough
guide, the gap on my coil here at work fires at around 8kV when set to
about 0.06" (1/2" rounded tungsten electrodes).
Other comments welcomed of course,
Malcolm