I've been looking into the feasibility of using various types of motors = as=20 wind-powered generators, so I thought I'd see what some motors I have = will=20 do. I connected the motors with diodes from each pole to 10uF 400V=20 capacitors with a common connection, and placed the load on the (+) and = (-)=20 legs.
Here are the results:
Superior Slo-Syn HSL063T1Y, 120 VAC, 0.4A, 50/60 Hz, 60/72 RPM
21K 269V 3.45W 300 RPM 11K 250V 5.68W 300 RPM 1K 92V 8.4W 300 RPMSuperior Slo-Syn SS50G20, 120 VAC, 0.3A, 50/60 Hz, 3.6 RPM (*20 gearhead = =3D=20
72 RPM)21K 141V 0.95W 300 RPM
11K 112V 1.14W 300 RPM 1K 23V 0.53W 300 RPMShinano STH-56D218, 2.1V, 1.65A, 1.8 deg/step, 1.8 ohm/phase
21K 4.24V 0.001W 300 RPM 1K 3.63V 0.013W 300 RPM 1K 14.4V 0.207W 1300 RPM 180 15.5V 1.33W 1300 RPMI was surprised at the low power output, especially the second = synchronous=20 motor, which is similar in size and specs to the first. I used a=20 battery-powered drill for the drive and speeds are approximate, but=20 generally the values are the maximum, as the output did not go up after = a=20 certain lower speed was reached. The last motor actually has eight = leads,=20 but one set is 1.8 ohms and the other set is 18 ohms, and I think they = may=20 have been used as a speed monitor. It came out of some unknown = equipment.
The first motor, which seemed most reasonable, was an almost new unit, = but I=20 expected closer to its input rating of 48 watts. The second unit came = out of=20 some old equipment and had a gearhead, probably 20:1, which I removed.
Do stepper motors go bad? Is there something about the circuit I used = that=20 limits the power obtainable? I like the fact that the power of the 72 = RPM=20 synchronous motors peak at 200-300 RPM which is reasonable for a=20 direct-drive windmill. 1300 RPM, not so much.
I also have some 1/4 HP DC brush motors I thought I might use, but I = think=20 they are rated at about 8000 RPM at 12 VDC and I will definitely need a=20 speed multiplier with belts or gears, which will reduce efficiency.
There are also lots of DC motors on eBay such as 1-2 HP treadmill motors =
which are supposed to be good for wind power. I used to have one but I = may=20 have given it away. I'm also going to look into using a three phase=20 induction motor as a generator, but it needs to be driven with a three = phase=20 source at just under the speed that is supplied on the shaft, and then = using=20 what would be the dynamic brake as the generator load.
Thanks,
Paul=20