Scoposcopy: AyeAye’s Negative Charging Effect Demo 1
Where is the charge on the capacitor coming from? Why is it “backwards” in polarity?
The confusion comes, I think, from our mental models. We tend to think of components as “ideal”. The mosfet is an ideal switch, the Gate doesn’t pass any current to the other pins, the capacitances have no effect, diodes are perfect and infinitely fast, etc etc. But these idealizations aren’t really true. When we are in the nonlinear behaviour region of component specifications the idealizations may be very misleading.
I don’t know in this case if the device is storing the EM energy from the mains pickup, onto the capacitor, or if the energy is coming from the FG through the mosfet capacitances. I am currently believing the former. “Tickling” the mosfet gate seems to enable the circuit to act as a detector (in the radio sense) for the mains oscillating field, enabling a tiny bit of that energy to make it onto the capacitor and be trapped there by the diode.
Ayeaye used a very slow diode in his circuit, and the diode I’m using is also pretty slow. I think that a faster diode will have an effect… but will it help (more voltage) or hurt? I dunno, that’s why we experiment. At the moment I think a faster diode will help, by trapping more of the available spike voltage on the capacitor. The cap should be able to charge up to the top of the spike, which seems to be limited to just over 2 volts by some other circuit action.
