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Magnetic turbine

  1. Mar 10, 2010 #1
    Hello, I'm new and know relatively nothing about physics :blushing:

    I have been quite fond of AutoCAD and designed something a while back, and I've asked countless different people if it would work, none of them can actually tell me. So I thought I'd come along here and ask you intelligent folk - the images are attached, I hope you can see them clearly.

    I'm not quite sure I'll explain this accurately, but I'll give it a bash:
    The black parts in the drawing represent rare earth magnet (as I'm told these are permanent magnets) http://en.wikipedia.org/wiki/Rare-earth_magnet which can be cut up to 1mmx1mm. These magnets are angled in such a way that the bottom magnet sends out the the same polarity to the ones on the turbine. With these forces acting on eachother, at these angles, I hope to produce spin.

    This device is approx. 20mmx20mm. What happens is, the turbine rotates around the axis of the tube. On the plane where it rotates I intend to place a magnetic ring connected to the turbine, on the plane of the tube I intend to wrap copper wire, then thread it up the tube and down the tube. Once this is achieved I would encapsulate it and stick it on a motherboard-like platform, possibly attaching as many as 50 of these devices to each board. I'm not sure on the electronics of it, but I then intend to connect each device via a bus and output it through a central bus. I envision to have maybe 20 or 30 of these boards sitting inside a cabnet sending out electricity.

    Will it work?

    Attached Files:

  2. jcsd
  3. Mar 10, 2010 #2
    I can't really understand what you are trying to do here? What is it thats going to rotate the turbines? How is it you're going to be making electricity from these things?
  4. Mar 10, 2010 #3
    No it won't work. Magnets unfortunately are not magic.

    The problem here is one of simple conservation. You can't pull motion/electricity etc out of nothing. No matter how strong your magnets are. For every 'pull' of a magnet, there is an equivilant 'push'
  5. Mar 10, 2010 #4
    I inted for the magnets to rotate the turbine. Perhaps turbine is not the appropriate word for this, but it is similar. There is a ring in the centre of the tubrine (where it sits on the tube), on the insides of this ring I want to put a circular magnet lining the inside face of this ring. On the tube at where the turbine sits, I want to strand copper wire around the circular face of the tube, each end of the copper wire is to be routed out of each end of the tube. When the circular magnet and copper wires interact there should be some form of electricity, no?
  6. Mar 10, 2010 #5
    I understand that, so I created the both magnets (the ones on the turbine and the one on the base) to be at an angle of 22.5 degrees, this way the push of the magnet works in conjunction with the pull.
  7. Mar 10, 2010 #6


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    Staff: Mentor

    The energy to sustain rotation has to come from somewhere. You cannot use a static magnetic field to generate sustained rotation. What you are describing so far is a perpetual motion machine, which is not an allowed topic here at the PF. Please tell us what external energy source is meant to provide the forces to turn the shaft.
  8. Mar 11, 2010 #7
    The shaft isn't rotating, the propellar-like turbine is rotating around the shaft. I know what I am describing, I am also aware of the old adage of energy conservation. Tell me why it wouldn't work, without using these easy retorts? Is this not a reasonable request?
  9. Mar 11, 2010 #8
    Ok imagine you are a little peice of metal, as you start to move through a magnetic field you recieve a 'push' increasing your speed. This happens until you reach half way when the magnet begins to drag you back. So although you have passed into another fields 'push' you are still being 'pulled' back by the previous magnet.

    The upshot of this is even with a perfect (no loss) system the very best you can achieve is the magnets will sustain the motion indefinately.

    When you try to then extract something, in this case electricity via the use of copper wires the 'turbine' will grind to a halt. As any current made, generates a magnetic field of its own (which acts in the opposite direction 'driving' field).

    I'm going to try an analogy:
    The way you are envisioning this is like a merry go round, with someone giving it a push every time the magnets come round does round. What you aren't realising is that trying to extract electricity from the system is like someone is standing opposite you pushing back in the opposite direction with more force than you are pushing forward with.
    Last edited: Mar 11, 2010
  10. Mar 11, 2010 #9
    Lets say the bottom magnets face has a polarity of + and the magnets on the turbines, lets their faces have a polarity of + too. The negative faces of these magnets are facing in the opposite direction, couldn't these negative faces, as well as the copper wires, be insulated to reduce the drag, so that only the positive polarities interact?
  11. Mar 11, 2010 #10
    It makes no difference what so ever. It's not a matter of trying to tweak it, the entire concept is totally unsound. sorry.

    No matter what you do, static magnetic fields will not create nor sustain motion indefinately in a real system.
  12. Mar 11, 2010 #11
    But, as you can see in the attached images, the force would be stronger where the magnets were closer together, and weaker where they are further apart. So the person trying to push on the one side is alot weaker than the one pushing on the other. Not so?
  13. Mar 11, 2010 #12
    Try and make me understand, because as far as I can see it, there is a counter for every bit of logic that you provide.
  14. Mar 11, 2010 #13
    No... not so.

    Not only is it totally impossible to get this to sustain motion indefinately as you have both magnetic hysteresis, and friction losses from bearings to contend with.

    The act of trying to remove energy is like putting a brake on a car. It acts to retard the motion.

    That really is the end of it. The concept simply will not work, not even in theory.

    Frankly I don't have the time nor the inclination to teach you the concepts of classical electomagnetism required for you to 'believe me'. Even basic theory says this can't work, you don't want to believe us then that is your perogative.

    Classical electomagnetism is the topic you need to read up on. Go forth and read up (wikipedia doesn't count).
  15. Mar 11, 2010 #14
    I see. If I take water out of a glass, and I wanted the glass to remain fill then something needs to refill the glass with water, but what if the water that was already there, refilled itself. If these magnets are permanent, then their energy never needs renewing, and so outputting energy wouldn't necessarily negatively affect the amount of energy produced. Right?
  16. Mar 11, 2010 #15


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    Staff: Mentor

    Okay, so you are talking about perpetual motion after all. Please re-read the Rules link at the top of the page. Thread closed.
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