Coupling off the cap I think would change the system totally, I have tried that many times, it just does not work, whatever the cop is. As far as I am concerned, the ou power input has to be from within the circuit and part of it, output to input just detunes every time.
Regards
Mike
Dear Mike Your observation is correct for a basic tank circuit, however the capacitor in this case is a progressive peak charging accumulator that is not directly involved in the tank resonance, but is inserted into it. In that respect, the accumulator capacitor is not really a factor in the overall resonance of the circuit, this resonance being a function of the self resonance of the coil and the tank formed by the coil, external capacitor and diode capacitance. The only direct involvement I can think of is the charging voltage on the capacitor back biasing the diodes, thus altering their capacitance, this would be the parametric element, but I could be wrong about this, as back bias may be far less effective than forward bias in changing capacitance. If the circuit is redrawn with the stray capacitance of the dangling clip lead returned to the ground of the sig gen, we have a series resonant circuit formed by the stray capacitance of the clip lead and the coil, and the variable capacitance of the diodes, this in addition to the coil self resonance due to it's own parasitic capacitance. The peak detector is inserted in this loop and it's capacitor does not directly contribute to the resonance of the circuit, it's value is too low for the frequencies involved. What suggestions do you have for looping the circuit, as I thought the idea I suggested had some merit based on the topology. Maybe if I post a schematic what I had in mind would be clearer. regards P.S. when performing these experiments it is a good idea to elevate the coil with some porcelain standoffs, silk thread or nylon line for consistency of capacitance to the air, as lying on a bench can lead to variabilities in capacitance. I would for consistency also suggest using a tunable "gimmick capacitor" back to the gen ground instead of flying cliplead. A sturdy breadboard with fixed positions for all components should produce greater consistency in measurement.
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Topic: Dr. Stiffler returns with a new device: SFM (Read 47776 times)
