Simple Experiment: Extraction of Energy from Permanent Magnets

[dieter]

Thanks Forest. Actually the german wikipedia entry on magnetism even says "Every magnetic Field contains Energy." Although wikipedia often isn't really helpful ^^.


See it this way: if you put two magnets into a glass pipe in repelling order, the top one will float above the bottom one at a certain distance. If you replace the bottom one by a much stronger then this distance becomes larger, simply because the repulsion forces add up.


Now, it is certainly possible to limit the current draw as desired, and finally ending up just like in the pipe example with two repelling forces, that are added together.

[Zephir]

Now replace the permanent magnet by a much bigger, stronger permanent magnet. Repeat the exact same test, with the same DC pulse to the coil. This time the coil is pushed much further away than before

The stronger magnet also induces stronger back electromotive force within the coil. That is, you would need to use higher voltage at the input for to achieve the same increase of current, like at the case of weak or no magnet (plain ferromagnetic core). You can imagine it in reversed way, by utilizing the coil as a dynamo. The moving of coil inside stronger magnetic field would induce higher voltage at the coil. This is just the voltage, which you should overcome once you arrange the experiment in the opposite way: by utilizing the force exerted by coil loaded with voltage pulse.

In my theory you cannot draw energy from coils and magnets until their response will be perfectly symmetric and reversible in time like the ideal spring - only under situation, when the magnetization of coil of magnet exhibits some delay, jumps of steps.

[pomodoro]

By using a stronger magnet you are obviously making the device more efficient.  Considering the fact that this is how good old dc motors with permanent magnets fixed to the case work, you should be getting more shaft output power than dc input if you were extracting any power at all out of the magnet. I think something in the mid  90% is about the best you can get back, but i'm not much into motors.

Here is a system that probably really works, but practically could be a problem.
You could use a system for example that changes the capacitance of an already charged capacitor. A solvent between plates acts as a dielectric . Charge this cap and allow the acetone or whateversolvent  to evaporate.  The decrease in capacitance has given the cap many joules indeed, huge amounts more.  Check it out by simple calcs  using dielectric constants, and its not hocus pocus.

[gotoluc]

Hi Dieter,

I have experimented with this some years back.
It's true you can demonstrate these differences but how practical is it in real world application?
What's not being considered here is the difference in work force achieved between an air core vs a cored coil and the reason no practical motor has no cores.

Now, lets say you stay with coreless coils and you keep increasing the size of your magnet and even make larger coil if you wish.
In time there will be a point where the coil will produce as great of current (generator effect) then the coils input, which is caused by the coil moving through the larger magnet.

This is "counter EMF" and happens to all coils when moved in a magnetic field while the input power is switched on.
At this point you will realize the breaking effect caused by any coil moving in a magnetic field "while powered".
There are other braking effects at play as well.
At the same time the coils copper mass is subject to Eddy Currents which is another braking effect which increases proportionally with a stronger magnet or magnetic field.

Consider that at this time your test device is too small to visually detect these braking forces. However, in time as you increase the size of your magnet and decrease your coils dc resistance it will become more apparent.

I have taken builds and tests to those levels.
This may save you time and money if you read the remainder of the topic below which has video demos and results.
Even though my tests are done with cores the results eventually come to the same. No Gain

http://overunity.com/8429/mostly-permanent-magnet-motor-with-minimal-input-power/msg420188/#msg420188

You cannot escape the above facts.
However, there may be a motor coil topology that once you power the coil the outside magnet flux field may not penetrate the coil which in return may beat the above laws.

That's what I'm interested in and working on.

Regards

Luc

[synchro1]

Some interesting results:


https://www.youtube.com/watch?v=asCp-wLQ0UU