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Use of magnets to create power?

  1. Feb 18, 2012 #1

    i have just joined and this is my first post.I was hoping to find out if anyone has(using only fixed magnets) created a propulsion or any kind of power generator.I have a few ideas that id like to try, although there probably fundamentally flawed, if no one else has achieved it. All and any advice would be greatly recieved.
  2. jcsd
  3. Feb 18, 2012 #2
    Magnets are used to transfer power from power plants to homes and business all the time. But a fixed magnet wont do much.

    To supply power you need an input of power, or energy. There isnt much usable energy in a permanent magnet at all.
  4. Feb 18, 2012 #3
    The thing to understand is that a permanent magnet is not emanating any kind of energy, nor is the field changing or in motion. It's actually as static a phenomenon as a brick.

    Magnets seem to emanate a kind of "force field" that should represent energy, but the fact is it doesn't. It won't repel another magnet, for example, unless some outside force first pushes the other magnet into range. This is no different than compressing a spring, or lifting a brick against gravity and dropping it. The outside force is the one supplying the energy.

    Regardless, people have been trying to create motors powered exclusively by permanant magnets since they were discovered (I've read claims going back to the 1200's anyway). No one has succeeded for the same reason the brick powered motor has never worked.

    Electric motors work by magnetic fields because, being electrically generated, they can be switched on and off, or from one polarity to the other quickly and conveniently, and it is that constant changing of the field that you need to create continuous motion. You can't substitute permanent magnets with their static fields for the 'changing field' coils in a motor and expect to get any motion out of it.

    On the other hand, if you think you've found a way around any principle that seems to be in the way, I'd encourage you to try to make a working embodiment. You'll either 1.) succeed, or 2.) learn something.
  5. Feb 19, 2012 #4
    thank you for your help.I realised a few mistakes id made last night.I know that magnets dont expel energy and it was my wording that was the problem.i was thinking along the lines of 2/3 permanent magnets(maybe 1 electromagnet powered by the output after the initial input). I was hoping to use their constant expulsion/retraction with a self feeding loop which after reaching a certain speed would create a constant surplus of energy.Yes i know perpetual motion isnt supposed to be workable on earth but im hoping i might of spied a way o do it.
  6. Feb 19, 2012 #5


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    Staff: Mentor

    You most assuredly have not. I advise you to simply turn away from even attempting that road, as it will do nothing but lead to failure. Many thousands of amateurs, and even a few professionals, have been down it before simply because they don't know enough about how it works to see that it won't work. Since perpetual motion machines are against the rules for discussing, I advise you to do a google search for sites explaining why perpetual motion doesn't work.
  7. Feb 19, 2012 #6
    Somewhere in all this, though, you are still making the assumption that magnets are an energy source. Otherwise, you couldn't be concluding there's a way to have a surplus.

    I'm thinking what you may not realize is that it takes more energy to push a magnet relative to a coil when you are drawing electricity from the coil than when you aren't. The harder it is to push, the more electricity you get. Generating electricity pushes back on the magnet and slows it down. The electricity isn't ever coming from the magnet, it comes from the energy it takes to push the magnet. The magnet is just a tool that reaches into the wire so you can push the electrons around.
  8. Feb 19, 2012 #7


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    Staff: Mentor

    To bounce off of what zoobyshoe said, think of the magnets as a way to apply a force without having to physically touch something. So they are glorified sticks. You can hit a rock with a stick but it isn't the stick itself that's generating any energy, it is merely transferring it from you to the rock. Without someone behind the stick to make it work, it will never hit the rock.
  9. Feb 19, 2012 #8


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    Staff: Mentor

    We won't help you with this. It is a waste of your time and ours. Thread locked.
  10. Feb 19, 2012 #9

    jim hardy

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    Gold Member

    There's a magnet factory near my home. I enjoy watching them make permanent magnets which they do by placing the megnetic material inside a big coil and applying tremendous current.

    I suppose that process does some work on the magnet, aligning all those dipoles.
    And that energy might be stored in the magnetic field of the magnet.
    The most energy you could extract from a magnet would be however much work had been done in magnetizing it, when you de-magnetize it
    which isn't a lot.
    And you won't wont recover even that much.

    There's an experiment decribed in freshman physics books
    one wraps two coils of several turns each around a bar of iron,
    connects an amplifier and speaker to one,
    and applies a very slowly increasing DC current to the other.
    The speaker will give "clicks" as magnetism increases. The magnetic realignment of atoms in the iron isn't entirely smooth but proceeds in a "grainy" manner, and the second coil detects those sudden little upward ticks of magnetic flux. .

    Give it a try
    and read up on magnetism.

    In fact I am going to recommend Jack M Janicke's "Magnetic Measurements Handbook" it is best layman's introduction i have ever seen .
    I got so interested i built his Fluxgate Magnetometer.
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