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Smart magnets that connect either way?

  1. Jan 8, 2013 #1
    "Smart magnets" that connect either way?

    Hi all. I was wondering about a particular kind of toy train that is sold to young children these days. I bought a few for my son for Christmas, and I am trying to figure out how they work. The train cars have magnetic connectors that can attach to the next car, but the thing is, they attach either way, even if you turn the cars around such that the polarity should be reversed. The manufacturer calls them "smart magnets."

    Does anyone know how this is being done?

    Here is a link to the product:

    https://www.amazon.com/Take-Along-Thomas-Friends-James/dp/B0006TNC0K

    Thanks!
     
  2. jcsd
  3. Jan 8, 2013 #2
    Re: "Smart magnets" that connect either way?

    Ok. here i am giving you a pdf file. May be this is useful for you or not...
     

    Attached Files:

  4. Jan 8, 2013 #3

    mfb

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    Re: "Smart magnets" that connect either way?

    As far as I understand the pdf, the electronics checks for nearby magnets, and decides which polarity the magnet needs based on the result.

    I think I saw a different, mechanical system somewhere, where the magnets could rotate to get their relative orientation correct.
     
  5. Jan 8, 2013 #4
    Re: "Smart magnets" that connect either way?

    Hmm, the electronics seem like an awfully expensive way to get things to stick together. A magnet in a metal shell, such that the magnet can flip around in the shell, could probably work.
     
  6. Jan 8, 2013 #5

    BobG

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    Re: "Smart magnets" that connect either way?

    And, having seen (and bought) those trains for my grandson, a far more likely description of the magnets on those particular trains. I seriously doubt they have electronic circuit boards inside of them, nor electromagnets.

    I have to remember to never buy my grandson an electric train. Adding on to the wooden train sets is addicting enough. I think there's only one more thing I want to buy for his - except there always seems to be only one more thing I want to add to it.
     
  7. Jan 8, 2013 #6

    Low-Q

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    Re: "Smart magnets" that connect either way?

    One option is that the magnets is magnetized perpendicular and horizontally to the connection, and opposite on front/rear of the train. No matter which way the cars are attached, the magnets will always have a N-S / S-N attraction, on each side (left, right) of the magnets. Very smart, but not excactly rocket science :-)

    However, if my suggestion is correct, if you turn one car upside down, the magnets should repel.

    Vidar
     
  8. Jan 8, 2013 #7

    mfb

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    Re: "Smart magnets" that connect either way?

    You can get this with any magnet orientation. The interesting thing is that those "smart magnets" attract in all combinations.

    With just 3 wagons, here is an alternative solution:
    NS--wagon--SN
    SN--wagon--NS
    iron--wagon--iron (not with a permanent magnetic field)

    It might be possible to add wagons with vertical and horizontal magnets to get up to 7 different wagons, all attracting all other 6.
    With magnetic axes rotated by 90°, the force is not strong, but there should be some attraction.
     
  9. Jan 8, 2013 #8

    Low-Q

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    Re: "Smart magnets" that connect either way?

    What I ment was, if you face the front or rear of the train, the magnetic orientation is always N to the left and S to the right. I assume you got that, but I just have to be sure ;-)
    This orientation will also partially prevent the cars from tipping.

    Vidar
     
  10. Jan 9, 2013 #9

    mfb

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    Re: "Smart magnets" that connect either way?

    Ah, now I understand. That is a good idea indeed.
     
  11. Jan 9, 2013 #10
    Re: "Smart magnets" that connect either way?

    Are you certain of the polarity?

    I know that flexible magnetic sheet, such as used for refrigerator magnets, have a "striped" polarity -- the poles are reversed in alternating stripes across the sheet. You can flip one around and they still attract, with only a small change in alignment.
     
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