Electromagnet Project

Discussion in 'Architecture & Engineering' started by Onetimetwotimes, Apr 18, 2016.

  1. Onetimetwotimes Registered Member

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    I am working on a project which is in relation to electromagnets, however I have a very mediocre understanding of electromagnetism. Below is a poorly constructed sketch of my design:

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    I would like to know if anyone could explain, or diagram how the magnetic field of this design would function. As a side note: Is there a way to control the field, as to make it dynamic throughout the different parts of the core? This of course would take more than is shown in the sketch.
     
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  3. ajanta Registered Senior Member

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  5. ajanta Registered Senior Member

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  7. ajanta Registered Senior Member

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  8. exchemist Valued Senior Member

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    I think you should ask to have this moved to Physics. Although it looks like Engineering, I think it needs physics input. It looks like a transformer core. This, so far as I understand, has no stray flux outside the core, so all the flux will stay inside the core. As least, it would if you close the ends. Is that what you intend?

    I am not sure what you mean by making it dynamic - can you elaborate with an example?

    P.S. Here is the physics of this device, I think: http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/indtor.html

    And here is a description of an inductor coil, using this principle, with some pictures: https://en.wikipedia.org/wiki/Inductor
     
    Last edited: Apr 18, 2016
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  9. billvon Valued Senior Member

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    It's a very straightforward solenoidal field bent in a circle. It is a common configuration for wound toroidal inductors.
    Sure. Increase and decrease the current. That will make the field dynamic.
     
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  10. Onetimetwotimes Registered Member

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    After searching the site for a while I came across this:

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    I believe that this is the kind of thing that I am looking to create.
    When I said "dynamic" I meant that I could control the magnetic power of different parts of the electromagnet.

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    Perhaps (if you can make sense of my poorly drawn diagram) a system in which each of the different inputs are hooked up to their respective plugs on a central chip. Allowing the power going to each of these sections to be different. Would this work to create a sort of 'warped' magnetic field?
     
  11. exchemist Valued Senior Member

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    OK. You have drawn two different things here. The first is a wire loop forming a basic solenoid with a single turn, creating an external field in space, as shown by the blue field lines. The second is like your original, i.e. a toroidal coil, in which the magnetic field forms a closed loop within the core.

    Perhaps what you mean is that the second case can be regarded as composed of lots of loops like the first, all working on creating a field inside the common toroidal core. Is that right? And do we take it that the black circle in your second diagram is indeed a magnetically conductive core?

    If so then the first observation is that this now looks like a series of transformer windings. Any change in the current flowing through one circuit will induce a current in the others. So they will affect one another. I do not think you can get different flux in different parts of the core. The flux in the core will be a sum of the effects from all the coils.

    But I'm open to correction as I'm not an electrical expert.
     
  12. billvon Valued Senior Member

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    No. You have just drawn a transformer; a common electrical component that couples several windings to the same magnetic field.
     
  13. ajanta Registered Senior Member

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    Yes, I think if the current is AC then the induce affect one another is so important but if it is DC so the affect is not important... Is it ?
     
  14. exchemist Valued Senior Member

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    Yes, but that is why I said any change in current.

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    AC is continually changing, whereas DC doesn't, apart from when you switch it on or off.
     
  15. billvon Valued Senior Member

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    Yes, it's still important. (And you did say "As a side note: Is there a way to control the field, as to make it dynamic throughout the different parts of the core?" - which means you are talking about AC.)
     
  16. Onetimetwotimes Registered Member

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    Sorry for the lack of activity, I've been busy.

    I see where the problem is, and I had a thought on what I could do about it:
    Instead of working with a ring, I could potentially work with multiple rods placed into a ring shape; like so:

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    This would allow me to control the magnetic power of each of the individual rods, correct?
     
  17. billvon Valued Senior Member

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    Not unless the air gaps between them were very significant. If they were, then although the fields created by each segment would influence the others, it would not solely determine what the field would be. In transformer terms, your K would go down.
     
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  18. Onetimetwotimes Registered Member

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    Thank you to everyone who has replied. I believe that I have enough information to continue with my project. Again thank you for your help.
     

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