> A better way to think about what is happening is that passing a current from a power supply through an inductor transfers energy into the magnetic field. When

> A better way to think about what is happening is that passing a current from a power supply through an inductor transfers energy into the magnetic field. When you stop doing that, the magnetic field diminishes, transferring energy back into current. But this time, you direct the current into the circuit. That's not my understanding of how down-converters work. Rather, there's a big fat output capacitor that the load is connected to, and you keep topping off its charge with a MOSFET gated by a feedback loop that monitors the capacitor's voltage and actively adjusts the PWM duty cycle to keep the capacitor charged at the desired voltage regardless of what the load does. If you your input is 100V and your desired output is 10V, you just keep charging a capacitor to 10V, disconnect when it gets to 10V, and keep repeating that at hundreds of kHz, faster than the load can appreciably drain the capacitor. Inductors and diodes are "optional", but added to absorb current spikes. Their main principle doesn't rely on induction though. Boost converters, on the other hand, rely on inductors to achieve higher output voltages than the input.