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Re: 2 questions on resonance
In a message dated 99-04-07 07:28:11 EDT, you write:
><< Using resonant charging,
> > in non-shunted xfrmer system, the ballast inductance can be
> > adjusted to give resonant charging.
> > >
>I am somewhat confused here, is not this cap value determined by the
> acting impedance of the secondary at open condition? If this is true than
> how can it be that the inductance of the power supply (secondary of
> transformer expressed as inductive reactance X(L)?) is matched to the
> capacitance of the TC tank cap {X(C)? as in resonance where X(L)=X(C) ?}
> Many different values of C could be used in different coil setups as
> determined by L of TC primary. How then are these matched in any way? HDN
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