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A small wind power project


New Member
First off I'm new to this forum and I would like to say hello to all.

I have been very interested in building a wind generator for some time now, I have done some research into it and have come up with some ideas. I thought I would post here to see what you experieneced guys thought.

My goal is to power one light, enough to illuminate a room 3.5 Meters x 6 Meters X 3 Meters high. I am relatively new to electronics and have only made myself crossovers for speakers, but saying that I feel confident that with a lot of reading and guidance from more experienced people like yourselves, I could achieve this project.

I have done some extensive research and have come up with two ideas that I think maybe suitable for the generator.

One of the problems I have is, I must keep the blades rather small and I also can't go to high off the roof. I live in a top floor apartment and have access to the flat roof above me. There are chimney stacks which I can brace too, I have already braced a satellite dish to one side with no problems from neighbours, so a small windmill should be ok.

I was thinking of using a Sturmey Archer GH6 Dynohub or equivalent, the Dynohub is actually a multi pole alternator that would produce alternating current. I found this site with more info about this, there is a small video showing the guy powering a 12 Volt 11w Compact Fluorescent lamp.


My question with regards to the set up in the video, could I connect a 12Volt 11w Compact Fluorescent lamp directly to the multi pole alternator with just a manual on/off switch on the + side. Or would there be a problem with the generator still producing electricity while the switch is turned to off? Am I right in think there is no need for a blocking diode for a multi pole alternator roducing AC?

I also found the Windbelt interesting and wondered how hard it would be to make and would it produce enough energy to power a 12 Volt 11w Compact Fluorescent lamp?


Your views and opinions would be most valued, thank you.



Well-Known Member
Most Helpful Member
A windmill generator or alternator always needs a load. Without a lod (when you turn off the light) will cause its RPMs to be so fast that it falls apart. The same thing will happen in a high wind when the electronics in the bulb burn out and leave the alternator without a load.

Some wind generator controllers have a dummy load that is automatically switched to the output if the RPMs get to be too high.

Very good wind generators have variable pitch on the propeller blades. They can even 'feather" the pitch so that the prop doesn't turn in extremely high winds.

Fan-jet airplanes have variable-pitch props. When they are slowing for a landing and make a big noise do they use negative pitch for reverse thrust to slow down??


New Member
I also found the Windbelt interesting and wondered how hard it would be to make and would it produce enough energy to power a 12 Volt 11w Compact Fluorescent lamp?
He's demonstrated 40 milliwatt output in a 10 MPH wind.

To drive a Fluorescent lamp, you would wind the coils differently (more turns, thinner wire) and skip the rectification and oscillator stages. That is, after making the jump from 40mW to 11W.


New Member
Well you would want to use some kind of battery, for a dummy load, and if its not windy when you need the light.


New Member
well florescent lamps have a high voltage converter to run them..you would have to measure the input to get the amount of current you REALLY need..the driving electronics for the high voltage supply use some electricity and the transformer uses alot(quite a bit) more energy than it puts out.hope that helps you


That depends on the quality and size of the transformer, a crappy little 1VA wall wart might only 50% efficient whilst a 1GVA might be 99.99% efficient.

A 22W fluroscent tube ballast is probably about 80% efficient but that's before you take in to account the poor power factor but most modern fittings have a capacitor built in so it isn't normally a problem,

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