DC motor as generator.

[7yler]

I am attempting to build a wind turbine, as many have successfully. I have read that a permanent magnet dc motor out of a treadmill will serve well as the generator for the turbine. I'm not very electrically savvy, but I'm attempting to learn. I have posted pictures of the motor, and the multimeter that I'm using. I hooked up the red wire on the motor to the red wire on my meter, and the black wire on the motor to the black wire on my meter. I then chucked the spindle of the motor and spun it in my drill to see if I could get a reading on the meter. I had no reading on any of the "DC V" settings, and no reading on any of the "AC V" settings. BUT, I did have a reading of around 10 on the "12A" setting. I tested all settings turning the motor clockwise, and well as ccw. What does this mean? Am I able to use this as a generator for a wind turbine? Thanks for any help.

[gateman]

an automotive alternator with rectifier removed produces ac voltage, people rig them up on farm trucks to have portable power

[Geof]

Wind turbines only generate when the wind is blowing (of course ), so if you want steady power it is necessary to connect them to a bank of batteries to carry through calm spells; even to carry through fluctuations in the wind speed when it is blowing. This means you want a DC output controlled so that it is at the correct voltage for battery charging; running a permanent magnet motor as you are considering, will not give you a controlled output for charging or will either not charge or will over charge.

The easiest approach is to use a vehicle alternator with built in voltage and current control connected to a battery bank and then have an inverter off this for your AC power. To reduce wire size a 24 volt truck alternator may be the best approach.

[Andre' B]

Shrink them pics down to a reasonable size.

[gmfoster]

1. You shouldn't have much of a reading on the AC range it will be a dc generator.
2. If you are reading 10 amps with the leads basically shorted ( which is what you have with an ammeter directly across the output) then the motor is obviously working as a generator.
And you are lucky you didn't blow your meter, you should "Never" hook an ammeter directly across a source as all you have limiting the current is the internal resistance of the meter. Bad for all things involved including you if the source has enough capacity.

3. I guess you know you have to move your leads in the meter to change from voltage to current readings? The meter with the leads as shown in the picture will read current(amps) but not voltage. And you read current and no voltage when the motor was obviously working as a generator so I suspect you don't know how to use the meter.

4. If you are serious about trying to do this you should spend a few days learning at least a little about electricity. It will come in very handy.

Garry

[Al_The_Man]

I am not sure what method these motor use to make them operate uni-directional, but if it is an internal power diode for example, then obviously you will not get a generated effect in one direction, in the other direction you may not get a voltage reading, or a misleading one due to the current feeding a volt meter is not enough to forward bias the diode, you would have to put a load on the leads in order to produce a reading on the meter, if this is the case, a 60w lamp will do the trick.
BTW, one popular method now, although costly is to use an AC generator and supply you residence direct, when you are not using any power, the generator feed back in to the power grid and reverses any previous reading obtained off the grid by your residential load.
Al.