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  1. #1
    Senior Member Ted Danson's Avatar
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    Explain to me why this won't work.

    I was thinking about how to generate electricity from magnets. This is obviously a basic drawing but why couldn't you run a setup like this to gain electricity.
    The magnets push off each other due to their polar fields and spin around on a fixed axis (purple point)
    This fixed point is a rod that is connected to a generator.
    The green arrow shows the direction the "fan" spins.

    I don't exactly know how to explain how it works because it is late at night but I drew a picture to help

    Merton Enthusiast

  2. #2
    riding once again jschen's Avatar
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    You'll generate electricity, but not as much as the energy you put into it. If you have to generate the wind from a fan, then forget it. You've got a fundamental thermodynamics problem.

    If the wind is coming from some other energy source that you otherwise wouldn't have used, then yes, you can generate electricity. However, the magnets are exerting a force on each other in both directions. You'd do just as well with non-magnetic blades.
    If you notice this notice then you will notice that this notice is not worth noticing.

  3. #3
    riding once again jschen's Avatar
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    Oops... I was reading your drawing wrong. If you start at the right point, you might get the system moving a bit. But it will just wobble back and forth, since the acceleration in one direction radially is matched by the acceleration in the opposite direction in the mirror image position. (Yes, you can tilt the non-rotating magnet, but that merely changes where the equilibrium point is. It doesn't change the existence of such a point.) So there is nothing to be gained, and only frictional losses.

    Furthermore, if you're generating electricity, then there is an additional resisting force since you're taking energy out of the system. Therefore, the system will rapidly settle at a stable position.

    Ultimately, all this analysis can be simplified by simply realizing that no matter how cleverly you set up the system, you still can't get more energy out of it than is going into it.
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  4. #4
    moving target c0urt's Avatar
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    it is an actually law, you have to put power in to get power out, it it's simplest form.

    it may or may not be bernouli's principle, I need dinner.


    what jchen is write I want to also add.
    how to tape your bars http://www.flickr.com/photos/89572419@N00/sets/72157629279270681/

  5. #5
    Senior Member Ted Danson's Avatar
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    I don't understand how you are putting any work into it though. Magnets repell?
    Merton Enthusiast

  6. #6
    Senior Member
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    Read up on magnets on wikipedia, particular this section:
    http://en.wikipedia.org/wiki/Magnet#Magnetization

    The magnetic forces would cancel each other out and you would have a net-zero force.

  7. #7
    moving target c0urt's Avatar
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    it will get stuck between two magnets with a reason and just wobble. both magnets will repel in opposite directions with out a reason to repel from the magnet between them.

    or someone to push it every so often, once again power input. If you were to put it in a power circle and make the outer magnet an electro-mag and have the power coming from the inner ring, you would still need need a way to make it pulse initially.

    too late at night for diagrams
    how to tape your bars http://www.flickr.com/photos/89572419@N00/sets/72157629279270681/

  8. #8
    moving target c0urt's Avatar
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    Quote Originally Posted by darksiderising View Post
    Read up on magnets on wikipedia, particular this section:
    http://en.wikipedia.org/wiki/Magnet#Magnetization

    The magnetic forces would cancel each other out and you would have a net-zero force.
    awesome, thanks great input
    how to tape your bars http://www.flickr.com/photos/89572419@N00/sets/72157629279270681/

  9. #9
    moving target c0urt's Avatar
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    oh, and normal magnets over time a north side ran against a south side, is going to make the south side north. Or if you are really lucky, an east side messing every thing up.
    Last edited by c0urt; 07-26-09 at 01:47 AM.
    how to tape your bars http://www.flickr.com/photos/89572419@N00/sets/72157629279270681/

  10. #10
    Senior Member Snicklefritz's Avatar
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    the real thermodynamics problem:
    (1) you can't win
    (2) you can't break even
    (3) you can't get out of the game

  11. #11
    K2ProFlex baby! ilikebikes's Avatar
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    I have a working perpetual enegy engine, but I'm not telling you about it!....Oops!
    You see, their morals, their code...it's a bad joke, dropped at the first sign of trouble. They're only as good as the world allows them to be. I'll show you. When the chips are down, these...These "civilized" people...they'll eat each other. See, I'm not a monster. I'm just ahead of the curve

  12. #12
    Senior Member DannoXYZ's Avatar
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    Quote Originally Posted by Ted Danson View Post
    I don't understand how you are putting any work into it though. Magnets repell?
    Yes, but the moving magnet has to get into position to be repelled by the stationary magnet. The problem is that BEFORE it gets into that position, it will be in an ATTRACTION position. Imagine rotating your propeller anti-clockwise about 10-15 degrees. Before it can get into the repelling position, it will be pulled back by the stationary magnet and all rotation will stop.

    What you've got drawn is very similar to a rotary piston airplane engine. Imagine each magnet as a piston pushing up and down in each cylinder. In order to keep the system going, you have to ADD energy to the system, such as an exploding air-fuel mixture.

    In your system, you have to ADD more energy to break the rotating magnet away from the attraction position as each magnet spins past the stationary one. Where is this energy coming from?

    Also you want to draw actual magnetic-field lines on the bar magnets. They aren't linear, but wrap around the ends.

    Last edited by DannoXYZ; 07-26-09 at 03:57 PM.

  13. #13
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    When I started college, I had the same exact idea for an invention, expecting the repelling force of the magnets to keep this setup spinning indefinitely.

    However, the same answers as posted above is what would happen. End result will be the contraption will spin a bit, vibrate for a bit, then stop because the repulsive force of one magnet cancels out the attractive force of another as it spins.

  14. #14
    on by skijor's Avatar
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  15. #15
    Senior Member gman26's Avatar
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    I always wondered if there was a way to perpetually provide power to a battery running an electric car. It seems if you had a generator on each wheel and alternating battery supplies you could charge one battery while the other powers the car. Too good to be true?

  16. #16
    riding once again jschen's Avatar
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    Quote Originally Posted by gman26 View Post
    I always wondered if there was a way to perpetually provide power to a battery running an electric car. It seems if you had a generator on each wheel and alternating battery supplies you could charge one battery while the other powers the car. Too good to be true?
    Not a chance. Using one battery to charge another one is not going to gain you more usable energy than you started with. If it did, the world's energy problem would be trivial to solve.
    If you notice this notice then you will notice that this notice is not worth noticing.

  17. #17
    What is a jsharr?
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    I nominate you for the 'Coolest Poster on Foo' Ted. Keep up the good work. Now, if you engineer a couch that does the laundry and cooks, you'll have a friend for life! Start working on that now.

    Couch
    This thread needs more Chipcom!

  18. #18
    Senior Member late's Avatar
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    Take your gadget and weld onto a trianagular frame. Put your bike on the frame and pedal. Hook some wires up to your toaster.

    Pedal real fast.
    We are as gods, we might as well get good at it.
    Stewart Brand

  19. #19
    Crushing souls Hickeydog's Avatar
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    Quote Originally Posted by gman26 View Post
    I always wondered if there was a way to perpetually provide power to a battery running an electric car. It seems if you had a generator on each wheel and alternating battery supplies you could charge one battery while the other powers the car. Too good to be true?
    But what is providing the energy to turn the wheel that is charging?
    Quote Originally Posted by Wordbiker View Post

    What's frightening is how coherent Hickey was in posting that.

  20. #20
    long time visiter Alfster's Avatar
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    Quote Originally Posted by couch_incident View Post
    I nominate you for the 'Coolest Poster on Foo' Ted. Keep up the good work. Now, if you engineer a couch that does the laundry and cooks, you'll have a friend for life! Start working on that now.

    Couch
    Your priorities are all screwed up. You want to start with the basic essentials:

    http://adventuresandbox.com/2008/08/...-couch-fridge/

  21. #21
    Senior Member gman26's Avatar
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    Quote Originally Posted by jschen View Post
    Not a chance. Using one battery to charge another one is not going to gain you more usable energy than you started with. If it did, the world's energy problem would be trivial to solve.
    Not using another battery to charge a battery, using the spinning wheel to charge a battery. Then when the battery is charged, switching over to it to run the car. Meanwhile, the other battery is running the car.

  22. #22
    riding once again jschen's Avatar
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    Quote Originally Posted by gman26 View Post
    Not using another battery to charge a battery, using the spinning wheel to charge a battery. Then when the battery is charged, switching over to it to run the car. Meanwhile, the other battery ios running the car.
    The battery is what ran the motor to spin the wheel. You're still ultimately charging one battery by taking energy from another battery.
    If you notice this notice then you will notice that this notice is not worth noticing.

  23. #23
    Senior Member gman26's Avatar
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    Quote Originally Posted by jschen View Post
    The battery is what ran the motor to spin the wheel. You're still ultimately charging one battery by taking energy from another battery.
    hmmm... why is this so difficult?

  24. #24
    riding once again jschen's Avatar
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    It simply can't be done.
    If you notice this notice then you will notice that this notice is not worth noticing.

  25. #25
    Senior Member gman26's Avatar
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    Quote Originally Posted by jschen View Post
    It simply can't be done.
    "can't be done" ??

    That's not the spirit that got us where we are today. Maybe in another life.

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