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How can you move with magnets?

  1. Dec 26, 2015 #1
    How can you make something move forward or backwards with magnets. I didn't got it in here :


    Minute : 5:00 forward

    It said how the train move but i don't understand why it moves. It makes no sense for me because it is the same force that keeps the train floating?
     
  2. jcsd
  3. Dec 26, 2015 #2

    jambaugh

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    Start by understanding how an object can be levitate with magnetic fields. You've seen this done with magnets repulsing each other.

    Now imagine you attach an array of magnets to a board, like a drink tray, and you levitate another magnetic object on this tray. You can make the perimeter magnets stronger so the object stays in the middle of the tray, nice and stable.

    Now imagine you, pick up the tray and carry the object levitated on this tray across some distance. No real mystery to this, right?

    Well now picture using an array of electromagnets with their currents controlled so as to reproduce the same moving magnetic field as you had with the hand carried tray of magnets. It will have the same effect of moving the object along.
     
  4. Dec 26, 2015 #3

    LURCH

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    Or you could picture it this way:
    Same tray as Jambough imaged, but put another magnet under the tray. This is not the magnets that are levitating the tray, it's separate. The tray is attracted to this magnet. You pull this magnet along the track, and the tray follows it.

    This is basically what moves a maglev. Except of course, that the magnets for a maglev are electromagnets, so you don't have to physically move them. Reversing their polarity is as simple as flipping a switch. The magnets in a maglev track switch on and off as the train approaches, passes over, and retreats.
     
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