Anomalous voltage

[aether22]

Ok, I'm pretty sure this isn't free energy, but I can't explain the results I'm getting either.


It is a simple circuit, there is a MOSFET (http://www.vishay.com/docs/91123/sihbg20.pdf) turned on and off by a signal generator (10-14v p-p) square wave at 8-12mhz.


An Autotransformer into bridge rectifier and a cap or 2 feeds energy into a hoop coil of 'roughly' 20 turns  I'd estimate (need to change and count) wound over my thumb.   Another coil of the same diameter but fewer turns shows a reading on a scope.


I turned the Autotransformer down to 5v, but the voltage on the caps reads 40v!?


Oh, there is one other detail, A neodymium magnet placed over the air core coil, since it is a Neodymium I suspect it is saturated.
But the Neodymium grows the signal a lot, and pressure, metal or ferrite all decrease the signal, so it seems to be the magnetic field that is doing it.


So where is the voltage coming from that I read on the caps?
Can the signal generator connected gate to source provide a higher voltage than it supplies and deliver that to the drain circuit?

Any thoughts welcome.

[aether22]

Here is a schematic.

BTW the full voltage across the caps is 43v.


The voltage from the function generator make little difference between 10 and 20v, but as those are peak to peak voltages, so it's really only 10v.  I am not quite sure how much is needed for it to be fully on.


Secondly it is currently made in a breadboard, so maybe at this freq. the capacitance is causing some odd effects.

[TinselKoala]

Well, in the first place voltage is not energy, so don't get all excited if you see a voltage rise in a capacitor connected to a switched coil.

In the second place, generating a true clean square wave at 8-12 MHz is not a trivial matter. I'd like to see a scope trace of the signal you are feeding to the Gate of the mosfet.

In the third place, if you _are_ successfully turning the mosfet on and off cleanly at 8-12 MHz, then you should be getting a substantial inductive spike from the coil, which will of course charge up the capacitor to a higher voltage than you are feeding to the coil from your FWB. I'm surprised you are only getting 43 volts-- this probably indicates that the mosfet isn't really switching that cleanly. Similar arrangements using mosfets or transistors that are switching off with rapid fall times will pump the capacitor up to hundreds of volts, easily.