Instructables

AC Motor to Wind turbine?

Ok Yes I know that It has to be DC for it to work as a generator. But I found a fan from Dads greenhouse and its rather larged, used for air circulation. Is there any AC to DC fix? Any rewiring or turning the coil around? Any help or suggestions would be of great help.

Actually, in a limited wind range, it is perfectly possible to extract power FROM a fan motor. What comes out needs to be rectified to put it into batteries. The kicker is that the fan MUST be spinning at close to the orginal specification speed to be effective. You will find plenty of resources to doing this with a Google search. AC machines are more efficient than DC ones, so real wind turbines do the same thing, but their construction is different from a fan.
Without complicated self-exciting coils, spinning an AC motor will generate zero power.

DC motors work by energizing a coil in a magnetic field - provided by a magnet - the coil gets its own magnetic field and these fields go UFC on each other, causing the motor to spin.
Generators work by moving a coil through a magnetic field (what you are referring to steve), and output AC current.
AC motors work somewhat like dc motors, but they generate THEIR OWN magnetic field using another coil. No power in the coil means no magnetic field, means no power is generated in the moving coil.

Unless you provide power to the ac motor's coils, there will be no output.
That's not entirely true, a DC motor can use "magnets" or coils - most traditional traction drives are/were separately excited, so there is a "field winding" and an armature winding. Depending on whether you wire them in series or parallel, you can get different benefits. Modern materials means that PM motors can usually beat them I think, except at very high loads.
http://www.qsl.net/ns8o/Induction_Generator.html

more info - it *can* be done by energizing the coils temporarily, and having large capacitors hooked up to feedback some of the current being generated into making a new magnetic field for the next section on the motor.
This what I was alluding to. The residual magnetism in the motor is often enough to self excite the machine. The kicker is as I said, you have to be near that motor's synchronous speed.
this is true :) hardly a wind-turbine-friendly project :(
Cybermurf2 years ago
there is an episode of a program called "stuck with Hackett" called "magic TV" where he removes an AC motor from a table saw and attaches it to a Volkswagen air cooled engine to power a house he took off of the grid. However, (and this is my question as well) he removed the capacitor/s from a microwave/s oven and somehow hooked them up to the output of the motor to create the electricity he needed to power the house.
here is the video:
http://science.discovery.com/videos/stuck-with-hackett-magic-tv.html

i cant figure out how he wired the capacitors or find any wiring diagram to show me how. it can be done and this proves it, can anyone give me or find a simple wiring diagram?