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TC Output Voltage
Hi everyone,
I think I have figured out a way to measure output
voltage indirectly (at least using lumped circuit values). Since
we can measure the primary directly, we can observe the amplitude
of two successive beat envelopes. The ring-down, ring-back-up of the
primary will show a drop in amplitude due to losses and if the
system is prevented from breaking out into sparks, spark losses are
excluded from these losses. Using the difference in successive peak
primary amplitudes, we can deduce system Q and compare that with
theoretical calcs. We can also make a good estimate of the losses
over one half of a beat hump and thereby quantify how much energy
went to the secondary first time round, also how much arrived back
at the primary. These are a couple of random thoughts. I would
appreciate anyone else who can contribute to this doing so with
out relegating it to pooh-pooh status. If anyone cares to, the VSWR
view of things could also be used to calculate Vsec, bearing in mind
that the helix is topped by a lumped capacitance and that secondary
current with a top hat is considerably more uniform than that you
would find in a pure helical resonator.
A friend of mine who is an RF engineer has examined some
structures and come to the conclusion that a low Zo is required in
the secondary. That is, a low L/C ratio in the helix itself. That runs
completely counter to what we actually do in these machines (Lo
Zprim, Hi Zsec) with Zsec dragged down by a lumped topload. As a
result, I have suggested that antenna theory is not really applicable
to what we are trying to do with our coils. Antennas are of course
designed to radiate prodigiously whereas we are ideally after none at
all (v. high radiation resistance).
Any thoughts on the above would be appreciated.
Malcolm