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Re: 2 questions on resonance
"HDN,
there are two resonant systems; the 60Hz power supply and cap, and the
RF primary and cap which is tuned to the secondary.
>> I the case of no high frequency effects and just simply resonating a
> large inductor at 60 hz, where X(L)=X(C) in series,a resonant rise of
> voltage can also be measured ( about 15/1 in my model) Does this voltage
> buildup instantly in 1/4 cycle or does it take several cycles as in the TC
> high frequency model. I was wondering about this in light of the fact that
> since no frequency conversion takes place in the simple LC circuit does the
> voltage instantly built up? HDN
>>
It would take multiple cycles to build up much voltage. But since the
resonant
charging condition reduces the impedance of the system, the cap will
charge to a higher voltage than it would otherwise (if the system wasn't
resonant, there wouldn't be enough time to charge the large cap in one
half cycle, because the impedance would limit the current, and slow
down the cap charging). There is however some small voltage build up
even in 1/2 cycle, maybe 15% or so it seems. I have some info on this,
I'll have to look it up again.
John Freau"
In the "good old days of spark transmitters" it was quite common to use
the 60 Hz resonance of the primary circuit to control the discharge
rate. Thordarson (and probably others) made special transformers with
an adjustable shunt between primary and secondary to permit adjustment
of the leakage reactance in order to get resonance. I have such a
transformer (1 kW) which I intend to work with some day. I have never
read a good description on how the variable shunt was used, but suspect
that it was adjusted for "maximum good" with either fixed or, much more
commonly, rotary gaps. Sounds as if Reinhardt (sp???) has descibed
German NST's with a very similar arrangement.
Ed