Advice on making a small (trial) permanent magnet motor / alternator

[Finlay]

I'll see if I can work out how to post a diagram.   I just realised a mistake by the way.   I meant to say you need 3 coils for every two magnet pole pairs which means 3 coils for every 4 magnets - not 3 for every 2 as i said in my preious post.

[Clive_]

Hi Finlay,

Thant would be really helpful, thank you and thanks for all the info - its starting to make more sense now 

Clive.

[Finlay]

You end up with 3 wires coming out of the generator.  One end of each of the coil sets (-1 +2 & -3) are wired together in the middle and they are not used externally.  The other ends (+1, -2 & +3) are wired in what is called a full H-bridge rectifier as in the picture link I sent.  Descriptively - each phase wire is connected to the middle of a pair of diodes connected in series so that positive current flows out of one diode while negative current flows out of the other diode.   All of the ends of the 'positive flowing' diodes are connected together to make the positive terminal, and the ends of all the 'negative flowing' diodes are connected together to make the negative terminal.  This way you turn a 3-phase AC generator output into a 2 wire DC output.

[Clive_]

Hi,

I think I'm starting to get what you mean.

Clive.