So I'm doing a project for school, doing wind power generation. I plan on using an alternator for my electromagnet. Problem is, I got this alternator from a junkyard. I hooked it up to my multi-meter, and can't get anything out of it! Can spinning an alternator by hand generate anything? I'm a newbie to anything electrical, so please bear with me, and break it down for me! I plan on using a fan style blade with belt to turn alternator to produce 1.5V and 150 mA
Can you explain why I can't get anything out of it? I got three wires coming from it, a red one with a cap that says Bat, and a red one and a black one (much smaller guage) coming out of a plug into the alternator. What are each of these wires, and why can't I generate any power by spinning it? Thanks in advance

 

Somewhere along the way you will learn that to generate power, you will have coils moving through a magnetic field. The problem with your alternator is you do not have a magnetic field. I don't know what year or style alternator you have, but one of the small wires may be labeled "F". This is the field wire. If you take a 1.5v flashlight battery and hook the + end to the "F" terminal, and the neg end to the case of the alternator, then when you spin it, you are going to get something on the "bat" terminal(large terminal).

Put a couple of flashlight batteries on it, and you will have 3v on the field, and you will get even more power.

So with a alternator, you have to have power to make power. This works ok, since you need to store the energy from the windmill anyway.

The only way you are going to spin a generator, and get power with no power going to it will be to get a dc motor that has permanent magnets in it. These make the motor have a field all the time, and all you have to do is spin it, and it will generate power. Those small little gold dc motors in toys are usually permanent magnet motors and they will work, and will light a small flashlight light. If you want something bigger, try a motor out of a treadmill, or any dc motor that your screwdriver will stick to the case of the motor.

 

search "generator bike light"

$15.99 on amazon.com
Amazon.com: Bell Generator Bicycle Light Set: Sports & Outdoors

 

Thanks Franklin! I figured out the hard way that in fact an alternator is not magnetized all the time, and will probably be using a PMDC motor for this. Thanks!