Does an Electric Generator Need Permanent Magnets?

[metacogitans]

If I have a source of mechanical energy (say, a windmill) to rotate a coil in a generator, could I use copper coil electromagnets hooked up to the same battery the commutator is connected to instead of permanent magnets?

 

[John Cuthber]

You can have a generator without permanent magnets.

https://en.wikipedia.org/wiki/Excitation_(magnetic)

[metacogitans]

Thanks, "self-excitation" was the term I was looking for. I wasted way too much time trying to find that on google.

 

The electromagnets can be hooked up to the same battery that's being charged, right?

Edited January 31, 2016 by metacogitans

[studiot]

If I have a source of mechanical energy (say, a windmill) to rotate a coil in a generator, could I use copper coil electromagnets hooked up to the same battery the commutator is connected to instead of permanent magnets?

 

 

No.

 

In fact if you had asked the question does an electric generator need magnets at all the answer would still be no.

 

A simple example is piezoelectric generators.

 

There was even a proposal and some experiments to recover energy from vehicles braking by the use of 'hit plates', using this method.

[fiveworlds]

If I have a source of mechanical energy (say, a windmill) to rotate a coil in a generator, could I use copper coil electromagnets hooked up to the same battery the commutator is connected to instead of permanent magnets?

 

Why would this be necessary though? We can make permanent magnets now there was a time we were worried about running out but not anymore.