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Perpetual Battery with Pickup Coil and Magnents

  1. Dec 13, 2012 #1

    I recently was thinking about an idea for a perpetual battery. I have an extremely limited amount of Physics knowledge (just a Conceptual Physics [Algebraic Physics] class) as I am still in high school. Does anyone know if this would work:

    1. Have a tube
    2. Wrap the tube in copper wire (so the tube has a copper coil over it)
    3. Have a magnet on one side of the tube (-) and have another on the other end (+)
    4. Have yet another magnet (in a cylindrical like shape) inside the tube
    5. The magnet would go back and forth inside the tube

    My questions are:

    Would the magnet actually go back and forth or would it be in equilibrium?

    If the magnet was in equilibrium would there be a way to alternate the end magnets so that the magnet would actually go back and forth?

    If the magnet were to move, would a measurable amount of electricity be produced even with an extremely long tube and extremely powerful magnets?

  2. jcsd
  3. Dec 13, 2012 #2


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    Staff: Mentor

    Perpetual motion and over unity devices are not allowed for discussion per PF rules.
    And no, it wouldn't work. Both concepts are impossible.
  4. Dec 13, 2012 #3


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    Science Advisor
    Gold Member

    If you made a magnet inside move(give it some non zero initial velocity) then it'd produce some current while its kinetic energy gets dissipated. Then it'd eventually(rather quickly) stop at some equilibrium point and stay there.

    The thing to remember is that inducing a current by moving a magnet produces a force on it acting against the movement.

    Your "tube battery" is kinda built with the same principle on which bicycle dynamos work. You can't just spin it once for it to produce infinite energy, you have to keep spinning it(i.e.put some mechanical energy into it that gets converted into electricity).

    And no, there's no good way of alternating the top/bottom magnets, as doing so requires more energy than you'd get from the magnet inside.

    It's still a good idea, though. They use something very similar in those flashlights that you charge up by shaking them up and down.
  5. Dec 13, 2012 #4


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    Staff: Mentor

    Perpetual motion and free energy are banned topics here on the PF. They are listed in the Banned Topics section of the Rules link at the top of the page. This thread is closed.

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