spinning power supply

[Dino G]

I need to find or design a dc generator of sorts that will generate energy when spun in a circle. It will be fixed to a rotating object. I need to have power at the center of the rotating object but cannot have a cord or wire as the piece needs to stay mobile. A switch with a battery is not an option as the continuous replacement of the batteries would be very impractical. Does anyone have any suggestions.

Thanks,
Dino

[ante]

Dino,
Welcome to this forum.
Can you mount a permanent magnet close to the rotating object?
What kind of power do you need, Volts, Ampere, Watt?

[Lou]

Hi

You could use a rotating transformer salvaged from the head assembly of an old VCR. You could feed the primary with a 250Kc power square-wave and rectify the secondary output with Schottky diodes. I guess you'd be able to transfer a fair amount of watts in this way.

[Dino G]

Thanks for the welcome. I could mount a permanent magnet close, but it would be off center. How close would it need to be? How many cycles per second are we looking for? I will be looking for a max of 5v, about 300 mA, and bout 1-1.5 W.

[audioguru]

Hi Dino,
That's a lot of power to get out of thin air.
Good luck.

[ante]

Dino,

I was thinking something like what I have seen on bicycles where they put two coils on the inside of the front wheel fork near the rim. Then there are small magnets on the rim with even intervals. This supplies the front and rear lights with power. It should be possible to produce power with the coils in the rotating part and have some magnets fixed close to the path of the coils. Since I don