# Electromagnetic induction

1. Nov 11, 2009

### elmarsur

Assume I can maintain the oscillation of a pendulum. Can I generate a practical amount of electric current by letting the pendulum oscillate in a magnetic field?
(practical amount in this case means enough electricity to do useful work).

1)Do I need a series of pendula in their respective fields?
2)Very fine and many coils?
3) Are there any mathematical relationship possible to determine the size before experimenting?

Thank you .

2. Nov 11, 2009

### Bob S

There are two ways you can generate an electrical current (very little) with a pendulum.

1) You will need a non conducting pendulum weight. You will need a non uniform magnetic field (two neodymium magnets) with a gap between them that the pendulum swings between (so you will want a thin weight). Wrap many turns of thin copper wire around the pendulum weight (in the plane of the pendulum oscillation). If you attach the two ends of the wire together, the current generated in the wire coil will damp the pendulum swing (proof that you are generating electricity). The pendulum swing will not be damped if the two ends of the wire are not connected. ou will not be able to generate dnough voltage to charge a magnet (you will need a diode to prevent shorting the battery).

2) (not part of your initial condition). Use a magnet for your pendulum weight, and use a stationary coil.

Bob S

Last edited: Nov 11, 2009
3. Nov 11, 2009

### elmarsur

Thank you very much, Bob!
Can point 3) be addressed generally?

Also, if I found a way to maintain the oscillations without use of fossil or bio- fuels, would you be interested in participating in the project? The aim is to make it an alternate source of energy.
But number 3) might be necessary in order to give some idea of the worth of the project - in order to warrant investments.

Thank you.