Would this self energizing gravity device work?

Question

So I was thinking about making a small seesaw that could cradle a metal ball on each end, weighted so when one is dropped, the other lifts, and on and on it goes. To ensure the momentum does not stop, there would be a sort of ceiling above the seesaw, with an electromagnet on each end. The idea would be to have the magnets turn on as the ball ascends towards it (helping the lift), and then turning off before contact to let gravity take it down and bounce the other side up towards another magnet turning on. A circuit board would be used to program the on/off timing.

So lets say this works all fine and dandy, could the moving seesaw be used to turn a servo and distribute the energy to the electromagnets? Thereby powering itself?

Answer 1

You would need more than 2 weights to power the device. Only 2 weights falling alternately will certainly not provide enough frequency of "power strokes" and there are long "dead times".

(For example, there will be 2 long durations in each cycle where one weight would be falling and the other one still sitting in the see-saw ... Or, one weight rising towards the electromagnet and the other one sitting in the see-saw.)

The question is how do you sustain the seesaw motion or atleast make it more frequent.

Does the solution lie in placing the electromagnets closer to the seesaw, so the falling and rising times are shorter? Wrong, because as the seesaw is placed closer to the electromagnet the available gravitational potential will be smaller. This would not generate enough electricity to power the electromagnets.

Next, the question of mass of the falling "weights". You want lighter masses to make them rise higher and reduce the duty on the electromagnet. (Because, the seesaw will impart an impulse or force to the mass, so smaller the mass, the higher will be the acceleration requiring a smaller magnetic force to lift it.)

However, the light masses would not be able to handle the "load" of powering a generator. In other words, the change in momentum of the lighter masses would not provide sufficient torque for electricity generation.

You can put together some rough numbers and confirm all this. Remember to factor in the friction, air-resistance and the efficiency of electricity production in the generator. Not to mention, the energy required for the timing mechanism and the sensor/transducer combo to actuate it.

Answer 2

No.  In principle, if there were no friction and no losses of any other kind, it might keep going indefinitely.   In reality, you would lose energy at each conversion step.

Even in principle, of course, you could not use your device to do external work without reducing its energy.

Answer 3

Yes, in theory, that should work. However, until you actually know how much power it will take to turn on and off the magnets, and then find out how much power its able to generate on its own, it might not be possible. If youve got the time, I say try it.

Answer 4

Unfortunately, no. I don't have enough background in EE to derive the result analytically, but from the laws of physics, you can prove that all machines must obey the law of conservation of energy. If your servo generated enough energy to power the circuit board and electromagnets, it would violate that law.

Even if, at some future date, we discovered that the law of conservation of energy had exceptions, they wouldn't be in macroscopic electromagnetism and mechanics of materials - those have been known to obey the law for a century or more.

(P.S. You may find it useful to look up perpetual motion machines (third source) - people have been trying to make devices that power themselves for a long time.)