Induction motor/generator question

[rustkolector]

I build early 1900's era scale model engines and I like to drive small alternators to load the engines and to make them more interesting. The last one I built used a center rotor ceiling fan stator and worked quite well. Now I need a small 3.3" diameter motor stator for my current project. I have found a 230vac, 0.4A, 1550 RPM 3.3" dia. fan motor that I would like to convert to a PM alternator. I would like to use the alternator at 375 RPM hoping to get 24-36v ac output that will be converted to regulated 12vdc at about 15-25 watt load. The only issue is that I am pretty sure this motor is a shaded pole design. My question is, will the shaded pole stator be a problem when used as a PM alternator? Any help greatly appreciated.

[joestue]

375 rpm is rather slow, its going to be hard to meet 30 watts at that speed.
keep in mind at a more reasonable 3600 rpm, you would get 300 watts with the same torque. if you figure 50% efficiency at 30 watts and 370 rpm, you would have a 1 hp generator at 3600 rpm and 90% efficiency and that's just copper loss, ignoring windage and iron losses which escalate real quick.

A 1/4th hp 1800rpm 90v dc motor would be more suitable for what you need. at 375 rpm you'd get about 18-22 volts.

[rustkolector]

Yes, 375 RPM is slow, but the model alternator design and application requires that slow speed as it must be direct connected. I have found a small shaded pole 600 RPM, 230v motor that I am hoping will come close to my output needs. I can live with a regulated 12vdc output and hopefully this motor with get close enough to be useful. If I can get 25 watts, I will be happy.