I love this. Theory and experiment in the same clip. That is how to teach electronics.

So why are we not capturing that back EMF and using it to recharge the battery to prolong is lifespan? (such as when using the coil in a motor, etc). Of course it would still have loses, but if you're recouping even a little bit each time, that would add up quite a bit over the span of the batteries total discharge; extending the usable time for each charge. Basically increasing efficiency

I need to know how to get minimum 100v or higher from 12v battery, switch and 1.75 Millihenry wire coil as about .66 ohms wire?? The inductor circuit must have a parallel outside diode, so that the balance of coil energy released fast, >100v, goes ALSO forward to the resistor load. (Coil Polarity + and - changes around so as - and +) Does the circuit require capacitor to store energy and release through load in same direction? Current flow I assumed was only positive to negative through anode. Or is that negative reverse current through cathode diode?

Hi, how to figure out Rds ON of an IGBT with the datasheet?

@biricha how does the back emf goes to -300v bcz the battery is only 9v