Can I use a vacuum cleaner motor in a wind generator?

Question

Can I use a vacuum cleaner motor in a wind generator?

Answer 1

No, it's a series-wound motor.  The stationary magnetic field is generated by an electromagnet; and since this is in series with the armature, reversing the supply current will not affect the rotation because both fields will reverse together.  Hence why series-wound motors are "universal" and work on both AC and DC.  (To reverse a series-wound motor, as in a drill for example, you require a switch to reverse the current in only the armature with respect to the stator.)

This type of motor cannot be used as a generator unless you rearrange the wiring, and even then you will have to apply a field  (excitation)  current to get anything out of it -- though if the generator is any good, then it will produce more power than the stator is consuming.  (A car alternator works this way.  The battery provides the initial excitation current; but once the alternator is running, its output is enough to charge the battery and so maintin excitation.)

The best type of generator for a wind turbine is a permanent magnet spinning in a fixed coil, with rectification provided by a bridge of Schottky diodes  (i.e., fast recovery and low voltage drop).  This is self-exciting and avoids the need for any brushes at all.