In a simple circuit consisting of nothing more than a voltage source and inductor (with flyback diode in parallel) and a normally closed switch...i understand that when the switch opens the magnetic field collapses and the inductor starts to build up voltage in opposition to the change in current, driving current through the flyback diode. however, does the current traveling through the diode flow through to the power supply or loop back through the inductor? I'm guessing tries to go through the power supply to ground. but doesn't this damage your power supply? this seems like such a common practice for protecting against your inductive switching device from back-emf (in this case a switch), but nobody ever seems to talk about where that current goes?