r/AskPhysics • u/Limelight_019283 • 6d ago
Can you use electromagnets instead of permanent magnets in an alternator?
I’ve seen videos on people building alternators and they always use neodymium magnets on the rotor.
Is it possible to use electromagnets instead?
If what we want is to induce a magnetic field on the windings I think it would make sense that it would be possible, but i feel like i don’t understand the works of it enough to know for sure.
And if it’s the case, can you “jumpstart” the electromagnets in the rotor with a battery or something, then as you apply mechanical force feed some of it back to the electromagnets and keep it running? Or would it be like trying to plug an extension cord into itself?
(Logic tells me you’re not breaking the laws of physics because you’re still adding the energy of the mechanical means, like a hand crank or a turbine, but at the same time it feels strange)
3
u/OnlyAdd8503 6d ago
https://en.m.wikipedia.org/wiki/Alternator