Ceiling fan motors as induction generator


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Megawatt Man

Senior Member

Joined: 03/05/2006
Location: Australia
Posts: 119
Posted: 09:03am 11 Oct 2006      

I have written a post ot two on this subject before. The action of the capacitor is to act in part to complete a circuit and part as an energy store for the magnetic field needed to cause induction in the coils. The problem with it is that very high voltages develop, significantly higher than say 240V.
It is an interesting thing. With the cap in circuit, when you start the machine spinning, residual magnetism cause a small current to flow and that causes a bit more magnetism and that cause a larger voltage and so on.
The cap must be matched very carefully to the motor/generator, so the the capacitive VAR flow equals the inductive VAR flow. In fact the cap provides the magnetising current for the rotary machine. There's probably a bit of resonance happening here and very high voltages develop. As I have observed before, there are very many adventurous souls active on this site some of whom are game for almost anything. For those blokes, I say don't try this at home.

Megawatt Man