Super Capacitors

Discussion in 'OnBoard Electronics & Controls' started by Doug Lord, Jan 13, 2009.

  1. robherc
    Joined: Dec 2008
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    robherc Designer/Hobbyist

    Once upon a time...in another (schoolkid) life...

    The Prototype:
    I took the magnets out of several of the "Science Fair Magnetic Wand" toys available at the time.
    3 of them, evenly spaced I put on the spokes of my improvised spindle
    5 of them I spaced evenly in the outer ring.

    The Experiment:
    I had to coax it a little (poor design...high friction & low power), but it did "spin up". It wasn't very efficient, was very poorly built, and spun a bit unevenly (prob. needed to change the spacing of the magnets, and reduce tolerances a LOT). It didn't spin for long, though, as the whole thing quickly tore itself apart...lol, what did you really expect, I was in 7th grade at the time, and had zero funds to work with. Heck, I built most of it out of Elmer's glue & popsicle sticks! :p
     
  2. Boston

    Boston Previous Member

    my theory is that in a single field it will work but if you use a number of fields to make up the cube you end up with "bumps in the road"

    ya I did a lot of that when I was a kid as well
    memories
    Im thinkin a lot of folks on this forum did
     
  3. robherc
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    robherc Designer/Hobbyist

    OK, if the poles of your spheres were aligned facing clockwise/counter-clockwise, you're right, it would NOT be a mag. bearing.

    Here's what I THINK would happen in that scenario:
    (for illustration purposes, assume the shaft is aligned vertically, and the spheres are mounted on horizontal arms, with their poles aligned with N facing clockwise)

    The N poles of your spheres would be receiving mag. repulsion equally from directly above & directly below themselves.
    The S poles would be receiving mag. attraction equally from directly above & below themselves.
    The only physical outcome I can forsee being effected in this way is the demagnetization of whichever magnet(s) is weaker, along with partial demag. of the stronger one(s).
    Also, if the spindle & arms weren't holding the spheres PERFECTLY centered between the two half-cube magnets, and/or the two half-cube magnets weren't putting off PERFECTLY identical fields, there would be a tremendous torque on the arms as the S poles of the spheres tried to align with the nearer/stronger half-cube, and the N pole of the spheres tried to align itself at the balance-point between the two half-cubes.

    Like I said, this is what I THINK would happen. I don't know for sure, and I haven't done any experimentation, so don't take it as a slam, of get too upset if you disagree.
     
  4. Boston

    Boston Previous Member

    exactly correct on every point
    except I think it will spin in the process of demagnetizing
    its like suspending a pare of misalined dipoles on a pivot within a otherwise aligned field
    yes you have torque between the spheres if there is so much as the slightest misalignment between the two dipoles
    but
    you should get spin as a result of the push pull of there fields orientation in the cube

    maybe
    Ill eventually build the thing and see what happens
     
  5. robherc
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    robherc Designer/Hobbyist

    I'm thinking the only way I could have made my motor spin smoothly would be to use at least one circular-polarized magnet with clockwise magnetization.
    Ideally, I think it would work BEST if you used two circular-polarized magnets. The big drawback there is that you'd have to have the two magnets aligned with a VERY small gap between the magnets. I'm guessing that might have to be done in a vacuum, and with lathe-polished magnets as the requisite gap may be too small for 3 air molecules abreast! The mag interference lines from circular-polarized magnets stay VERY close to the magnet.

    Good luck, & I hope you prove me wrong...I don't expect it, but surprises can be pleasant from time to time...esp. when they're useful!
     
  6. Boston

    Boston Previous Member

    and thats exactly what is drawn in the original diagram I provided
    two large apposing like poles with a slight gap between them
    although not quite as small as you suggest

    I suppose now that Im thinkin of that thing I could throw one together
    I looked up some sources and someone makes spherical magnets
    now all I need do is find some of those circular ones
    get some Popsicle sticks
    and some Elmers
     
  7. robherc
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    robherc Designer/Hobbyist

    lol, I heard that SOME brushless motors use circular-polarized magnets...but I know some use ring-shaped magnets that are NOT circular-polarized, so I'm not sure if it was true or not. Best way to tell would be to hold another magnet near it to see if one end attracts & the other repels: if yes, then it's NOT circular-polarized; if no, then it may be. I'll post a diagram of a circular-polarized mag. in a minute...lemme open up paintbrush now......

    ...and I think I've had enough experience to recommend that you at least use superglue with your popsicle sticks! :cool: lol
     
  8. robherc
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    robherc Designer/Hobbyist

    Here's the promised diagram (imagine the little black/white rectangles are the molecules making up the magnet)
     

    Attached Files:

  9. Boston

    Boston Previous Member

    nice !
     
  10. ancient kayaker
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    ancient kayaker aka Terry Haines

    If the field is entirely contained within the body of the magnet then there will be no external field, thus it will not function as a magnet. Not sure if that's what you were trying to achieve.
     
  11. Boston

    Boston Previous Member

    it sorta is
    these things work ( maybe ) on the idea that your encasing a normal polarized object in a field that is only north
    or south doesnt really mater which
    kinda an artificial monopole field
     
  12. robherc
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    robherc Designer/Hobbyist

    Supposedly, the field isn't entirely contained within the body of these magnets, but is kept very NEAR the body. I believe the main design issue in making motors with these magnets (check out brushless motor design...they SAY they use 'em) is that you must put the interfering field VERY close to the circ. polarized magnet...but that's not my field of expertise. All I know is that they do it, and Honda Insights/Toyota Prius' run...so it must work.
     
  13. ancient kayaker
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    ancient kayaker aka Terry Haines

    My understanding of brushless motor design is the field magnet has a radial field. That would require, if I understand it correctly, one pole at the center and the other on the periphery. The field has to get out to interact with rotor windings in either a motor or generator (or a sensor come to that).
     
  14. Boston

    Boston Previous Member

    well the reference was to an artificial monopole field

    on the cube it can be easily created by taking a cube that is magnetic
    cutting it in half
    flipping one half over and placing two n polarized sides against one another

    that creates the field that Im refering to as being monopole
    its evenly distributed and only n in orientation
    the armature is placed within this area
    with its orientation perpendicular to the plane of the field of the cube

    B
     

  15. CDK
    Joined: Aug 2007
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    CDK retired engineer

    Boston, let me assure you that the following is not intended to insult you in any way and that no similarities between you and my neighbor are implied, but this magnetic brainchild of yours is staying alive so long that I cannot resist the temptation any longer.
    Your drawing in post #46 reminds me of all the "drawings" I've seen and the stories I've heard from my neighbor in the next village. We are 2 miles apart and see each other maybe once a month, so we get along fine....
    A belt driven generator / electric motor combination that needs no external power once it runs, a bulb with an unbreakable filament, a power cable without loss and a wind turbine that even generates power without wind. A very nice one was an outboard motor mounted inside a boat. The prop pushes water to the stern where it is deflected back to the bow and guided back to the prop. An ideal solution for shallow waters. Years later I saw an actual patent text for the same principle, that could also be used for trucks, trains and planes.
    This guy never found the time to build prototypes for any of his inventions, but he is convinced that they will work.
    He is a retired German opera singer on a liquid diet who starts the day with a bottle of beer and ends it with stronger stuff. This forum fortunately has nothing to fear from him because of the language barrier. It would not surprise me that, when confronted with this magnetic contraption, he would pull something very similar from his bookshelf.
     
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