# Limiting angular velocity

1. Jun 3, 2010

### Magma828

I'm thinking of making an electricity generator which is rotated by hand, or possibly something like wind, or gerbils on a treadmill etc etc..

Anyway, the current and emf produced would vary depending on the velocity at which the generator is turned, correct?

I therefore need a way of keeping the angular velocity constant. My idea was to somehow set a maximum velocity for the rotation of the generator, but not affect the velocity of the turning handle. I could rotate the handle at a velocity higher than the required velocity, and any extra energy could be dissipated as heat or something.

Does anyone have any ideas on how to accomplish this?

Or any other method which would keep the emf+current at a set value.

2. Jun 8, 2010

### skumar26

this would have been thought first by the electricity invnetor and that is why we are dependent on resources to produce electricity. In other word almost impossible

3. Jun 8, 2010

### Magma828

What exactly do you mean by 'dependant on resources'?

4. Jun 18, 2010

### agurvinder

see the system you are talking to BUILD/DESIGN will need a brain to analyze that the input speed is reducing/increasing and send the data to the output speed controller to keep the output speed constant.

this is very difficult (if not impossible) as you will need an electronically controlled variable torque gearbox to link your generator to the source of input

5. Jun 18, 2010

### Magma828

How on earth do wind farms work then? Do they just have a complex gearbox that has to be continuously adjusted?

6. Jun 18, 2010

### agurvinder

no but dont forget that wind farms DO NOT produce a constant voltage output. the gear box inside is mechanical with a very high transmission ratio i.e. small movement of blade results in significant rpm of the generator.
and it is a variable generator and that is the only reason wind turbines are not considered primary sources of power.