Just a thought:
If the motor is of the syncrones type then consider removing about three
of the shunted turns of copper from the stator and winding an alternator
in the three gaps that are left drill a hole down the centre of the
shaft to just above the stator and a hole across the shaft to bring the
cables through at the rotating end use a six pulse diode bridge and you
should get voltage out. What you are effectively making is a motor
alternator the transformer is made for you as part of the motor.

Regards Steve...

-----Original Message-----
From: pic microcontroller discussion list
[mailto:PICLIST@MITVMA.MIT.EDU] On Behalf Of D. Jay Newman
Sent: 29 November 2003 22:17
To: PICLIST@MITVMA.MIT.EDU
Subject: Re: [EE:] Transferring power to a rotating circuit

> >BUT it may be easier to simply use a fixed magnet and rotate a coil
past it
> >to generate voltage.
>
> In this case, where does the power come from?  I know it'll work, but
I'm
> having trouble working out the source of the energy.  Does it come
from
> the fan, indirectly?  If we increase the load on the coil, does the
current
> draw of the fan increase?  This may require some experimentation...

The power comes from the movement between the coil and the magnet. The
moving
part will experience a "resistance" because of this. So yes, the fan
motor
will need to be stronger than otherwise to do this.
--
D. Jay Newman           !
jay@sprucegrove.com     ! Xander: Giles, don't make cave-slayer unhappy.
http://enerd.ws/robots/ !

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