# motor working as generator after switch off

Which motor continues to rotate after switch off and functions as generator in the circuit?

## Replies

• lion911
well.. generally.. we need something to power on the motor to rotate, then we turn this energy to electrically energy.. it is a law for conservation of energy.

if you need a self rotate motor on a circuit, this could be tough. However you could try to create a feed back circuit using the motor. Eg. put a small power supply to start up a motor then join the motor with one or a few dynamo, power will be generate by dynamo.

then join power generated by dynamo to your motor.

now you can shut your initial power supply of motor down. then you can get the motor moving by itself.. however power would lose in the process due to alot of factor therefore it just a matter of time motor will eventually stop.

well.. should build up this circuit and try whether it works or not cause i personally never try it before XD, but theoretically i think it can work ^_^
• sauravgoswami
hey tat is too much power consuming!!!!
• lion911
our supply is use to start of a small motor.. which wouldnt consume too much. 3V should be sufficient for a motor to roll on and generate DC power from dynamo.

check #-Link-Snipped-# for a 6V dynamo and a small example,where they checking power output of a dynamo

and btw, to start a motor after switch off, maybe you can just create a circuit full of capacitors. then connect to a power supply and motor so what you need to do is turn on power supply, then wait a few sec or minute to charge up all capacitors then switch off, motor will still continue to rotate and you could turn mechanical power of the motor to any form of generator.

example i given above is to turn electrical --> mechanical --> magnetic --> electrical

just did a circulation since you wan the power supply to switch off ^_^
• sauravgoswami
why not take a feedback fro the generator itself,say if a generator is giving out 6V we can take 3v to power the motor!!!
• kashish0711
Induction generator
It takes the current and when the rotor of it after starting is rotated at more that synchronous speed using any prime mover, you will see that it will start supplying current to the mains instead of drawing it. 😀
😀 yeah that's the answer I was looking for.

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