Controls for motors used as generators

[deb]

I am going to use used motors as generators for a small wind system. What I need is control systems to avoid too high and too low rpm's. I had a look on the internet, but everything I found was really expensive. Does somebody know a chep supplier or an easier way to disconnect my generator when its rpm is dangerous?

[Norm]

  A blocking diode for low rpm....a good furling system for too high rpm, a search on this board has any number of tips for furling systems......and blocking diodes.

               Have Fun

                ( :>) Norm

[TomW]

deb;

Does somebody know a chep supplier or an easier way to disconnect my generator when its rpm is dangerous?

This is the LAST thing you want to do to a wind machine in high winds. If you were to do this the blade would freewheel and could quite possibly destroy your machine if the speed gets too high.

What you probably want is to have the machine turn itself out of the wind and or connect a dump load to it to consume the power and keep a load on the blades.

Just my opinion and may not be held by others.

T

[DanB]

agreeing with Tom here...

the wind turbine must always be hooked to a load, usually the batteries.  RPM should never become "dangerous" unless it has no furling system - or it becomes disconnected, if the alternator and the blades are reasonably well matched.

[domwild]

Hugh Piggott in his scoraigwind web site has a circuit diagram for a load shedder. He takes down AC, converts it to low voltage AC, drives a LM2917 tacho chip which then converts the frequency (=RPM) to voltage. The voltage drives an opamp which switches via optocoupler - triacs the AC load from the phases to a dump load at high RPM. Hopefully furling will obviate such a complicated piece of electronics.