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Confused about electromagnet?

  1. Apr 29, 2013 #1

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    Confused about electromagnet??

    How do i calculate the magnet field for an Solenoid with an ironcore with x windings and y amps..

    The same for an horseshoe magnet, where there is an air gap about 2mm..

    For some reason does my calculation not make sense..
     
    Last edited: Apr 29, 2013
  2. jcsd
  3. Apr 29, 2013 #2

    mfb

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    It would be easier to look for a mistake if you added your calculations here.
     
  4. Apr 29, 2013 #3

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    ohh sorry my bad..

    I have choosen to use 1A as constant.

    For the Horseshoe magnet

    B = [itex]\frac{i*n*µ0*µr}{lj+2vµr+2xµr}[/itex]


    lj = length of the ironcore = 0.034+0.011+0.034
    µ0 = 4pi *10^-7
    x= length of one of the airgaps
    v= length of the other airgap
    µr = Relative permability = µ0(1+XM)=5000
    I = 1
    For the solonoid

    B = µrH

    H=[itex]\frac{N*I}{l}[/itex]
    l = 0.065
    I = 1

    I know B = 0.4
    I've been trying to solve for N, windings, and for the solonoid do i get 22, and for the horseshoe do i get 1688..
     
  5. Apr 29, 2013 #4

    mfb

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    And where is the issue with those solutions?

    I don't understand the horseshoe geometry with multiple (4?) air gaps.
     
  6. Apr 29, 2013 #5
    looks like a homework problem. move to other thread??
     
  7. Apr 29, 2013 #6

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    Homework... Well, is more like a project.. I am trying to build an Electromagnet which capable off pulling a certain amount of newton..
    I done conversion from Newton to Tesla...
    Now do i have define the tesla value..

    http://snag.gy/oL7D5.jpg
     
  8. Apr 30, 2013 #7
    horseshoe magnet will have only one air gap. how come you have 4? please draw the detailed diagram of the magnet.
     
  9. Apr 30, 2013 #8

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    Here is a picture of the one I've been working with
    http://snag.gy/A7zJd.jpg

    There is an airgap between each leg, each leg has to pull a piece of metal with 3N, in the distance of 2 mm, i am quite unsure about the next one, but would the airgap between the the metal pieces have something to say?
     
    Last edited: Apr 30, 2013
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