The Wind is Free!

Greystoke wrote:Correct
If the field is constant then there is no change in time, and so d?/dt = emf = zero

I still don't understand you...what about this principle:
"A charged particle moving in a B-field will feel a sideways force that is proportional to the strength of the magnetic field, the component of the velocity that is perpendicular to the magnetic field and the charge of the particle. This force is known as the Lorentz force"

BTW, I created this image with Vizimag, which shows fairly accurately the field between two magnets as they are in the generators.

Lorentz force
That's the force acting on a charged particle. So what do you want to do with a force It doesn't create a voltage.
(I suspected that you are confused with this)

Leave Lorentz force alone. It has nothing to do with generating electricity. What you need to know is Faraday's law of electromagnetic induction which states that:
? = -d?/dt (see Wikipedia on Faraday's Law)


That's a powerfull program you got there. It gives a very good idea of the field distribution, and this picture supports the suggestion that the coils should never be much bigger than the magnet.

Thanks for your patience in trying to improve my understanding. I was thinking the charged particles are the electrons in the copper wire, and if they experience a force, surely that generates an emf, i.e. voltage?

Farady's law apparently "... applies whether the field itself changes in strength or the conductor is moved through it."

In a PM generator, the conductor is being moved relative to the magnetic field (the magnets are in motion).