I just found a 12 volt DC permanent magnet motor and I want to make a wind generator from it.

I just found a 12 volt DC permanent magnet motor and I want to make a wind generator from it. It is a small motor about 5 inches diameter and 5 inches in length that was part of a big rig air horn compressor.. I did try spinning it with my drill and it produced a lot of DC voltage at low RPM . The voltage range from a few volts DC to upwards of (if I was reading my DVM right) over 1000 volts. Don't  laugh if I am wrong, this is all new to me even though I am a born tinkerer and have a somewhat working knowledge of DC electricity and experience in building circuit boards as well as being good at fabrication. Where can I find information regarding wiring this thing up to charge a car battery or maybe several car batteries? My main goal is to build a small 12 volt emergency lighting system for my house plus maybe powering a 400 watt power inverter as well.  I think I can figure out how to fabricate the propellers, mounts and such but I just don't know how to wire this thing up and I am hoping that some of you can tell me where to find the information and or schematics for such a project. Thanks!?

frollard6 years ago
It's exactly as it seems.

Attach blades, hook up to a battery through a CHARGE CONTROLLER (Vital if you want your battery to survive -- best purchased).

A safety feature is hook everything up through a high power switch that can short out the 2 leads from the motor. This will provide a short circuit, which can draw extreme load, which will brake the turbine in case of excess wind.

Double check your readings. I doubt the motor was putting out upwards of 1000 volts. 1000 DC is hard to come by, particularly in an automotive application. I'm guessing probably 10 or 100 if you're REALLY pushing it. Open circuit, it may show much higher voltage than it would under load. Salvage the heater element out of a toaster and put the connection across that. Measure the resistance of the heater wire and THEN test voltage while running. From that you can gather the amps and the watts.
seandogue frollard6 years ago
"Open circuit, it may show much higher voltage than it would under load. "


A few points first. I think you may have read your DVM wrong, a 12 Volt DC Motor will likely only produce give/take 5 Volts excess, which means you most likely won't be able to power your house, especially on DC current. House fixtures take AC. Only hook appliances unless you use a rectifier. But here is a good site that explains everything. I want to build one bad, so good luck!:
just search this site and google. you will find your answer there