Free Stuff

So I went to the dump today and stole a few motors. I took this big double fan thing and then I ripped the stator off an old washing machine. Mary thought I was trying to steal stuff and sell the metal for profit but I told her I was making a windmill and she let me have it. I'm not sure she believed me though! Anyhow perhaps I'll get some pics up here soon. I'm not sure about the double fan, but the motor in the washing machine had an electromagnet for a rotor. I couldn't get the rotor out anyways because it was attached to something on the other side of some sheet metal. It had a few real nice bearings that were very tempting, but I had limited tools and not so much time. I have yet to crack open the fan motors, but since they are AC I'm going to bet they have electromagnet rotors.

If I didn't mention before, the rotor has to have a magnetic field provided by either permanent magnets or electromagnets. An electromagnet is a coil of wire with a charge in it... which isn't good for a windmill. It's possible to use electromagnets in windmill rotors, but it's much more complicated and the fact that the rotor has to be charged for the electromagnet to work detracts from the overall power output of the turbine. The alternative, namely permanent magnets, is great, but expensive. That is the reason why most AC motors don't have permanent magnets, it just isn't cost effective. (for instance, the magnets might cost $100 whereas the electromagnet/coil might cost $5-$10)

A new term:

Steel laminates are those layers of steel in the stator/rotor that help with overheating. The spinning creates eddy currents and the steel laminates help to dissipate those. Hopefully I'll get some picture up here soon, the stator I ripped from the washing machine is really cool.