I built the circuit that I posted earlier. The load and my switching board are both powered by a 12V 7AH LiFePO 4 battery. The switching board is powered by a 15W AC/DC adapter, which is an inefficient DC-AC-DC conversion. I could probably go DC all the way from battery to board, but going through an AC inverter allows me to measure the power usage a little easier.  I'm switching the coil on the left of the ferrite rod using my MOSFET switching board.  Power usage of the switching board when idle is 4.7W. The fans consume 0.5W each.  Switching at 100kHz takes power usage up to 7W, so 2.3W for switching at 100kHz doesn't sound too bad.  I got this interesting waveform on the scope.  The yellow trace is the left coil and the pink trace is the right coil. The left coil is connected to the power supply whereas the right coil isn't connected to a power source directly and is instead induced by the left coil. The negative spike on the yellow trace is clearly visible. I'm not sure what to make of the waveforms yet. I'm going to reflect on them and post some thoughts later. I also need to test DC power consumption with and without the right coil to see if Melnichenko was right in saying that the diode should prevent the right coil from consuming from the source. If he's correct then I'd expect power consumption to remain the same. If power consumption changes then either I've made a mistake somewhere he's wrong.
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