very strong magnet ?

Discussion in 'The Projects Forum' started by MegaMan, Mar 12, 2010.

  1. MegaMan

    Thread Starter Member

    Sep 25, 2009
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    hi , and how can someone make a very powerful electric magnet , and also with small size ?
     
  2. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    8,754
    760
    size matters when it comes to electro magnets buddy....the bigger, more power required, more powerful magnet
     
  3. rjenkins

    AAC Fanatic!

    Nov 6, 2005
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    The relative strength of an electromagnet is measured by it's Ampere-Turns rating.

    More turns and/or more current increase the strength.

    You are limited on current by how much the wire is rated for (and heat build-up within the coil), turns are only limited by size.

    The absolute strength also depends on the magnetic core and physical layout.

    Depending what you mean by 'small', you probably cannot match the strength of a small neodymium permanent magnet.

    Even for small industrial lifting on cranes, permanent magnets are used in preference to electromagnets.
     
  4. hgmjr

    Moderator

    Jan 28, 2005
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    As I understand it, the amount of power in a magnet is only a small fraction of the power it took to manufacture the magnet in the first instance.

    hgmjr
     
  5. Duane P Wetick

    Active Member

    Apr 23, 2009
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    A very strong DC electromagnet can be made by machining a cup out of a steel billet, leaving a center pole that will accept a wire-wound bobbin.
    You can experiment with various numbers of magnet-wire turns to get an idea of the strength factor, (amperes x turns).

    Cheers, DPW [ Everything has limitations...and I hate limitations.]
     
  6. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
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    You can get rare earth magnets from Radio Shack or Edmund Scientific, and a lot of other science supply houses.

    Also, you can disassemble an old hard drive and get some mighty powerful magnets.


    Eric
     
  7. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
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    Oops. Missed the Electro part. :)

    Well the info is still good, anyway.


    Eric
     
  8. MegaMan

    Thread Starter Member

    Sep 25, 2009
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    thanks people ^_^ ...
     
  9. bhvm

    Active Member

    Jul 16, 2009
    53
    2
    Ask Politely to any PC shop and get an Old, damaged Desktop HDD.

    HDDs have one of the BEST EVER Rare earth magnets!
    These are permanent magnets, not electros.

    I ripped apart one and It was so hard even to get out!
    Actually, i thought it was glued, but! Actually the magnet itself was so strongly attached to the casing.
     
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