transformer windings

Discussion in 'General Electronics Chat' started by mentaaal, Apr 24, 2007.

  1. mentaaal

    Thread Starter Senior Member

    Oct 17, 2005
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    Ok i hope this doesnt seem like too stupid a question but in transformer windings, is the wire used insulated? I mean as it is coiled tightly into a solenoid what stops the current/voltage from going through the the many rings as if the wire was just laid adjacent to the core? in pictures i have never seen individual strand insulation or is there insulation and i just have to take a better look?

    cheers
     
  2. Dave

    Retired Moderator

    Nov 17, 2003
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    Take an iron core and wrap an uninsulated wire around it to form a winding, what do you get? The windings will short out rendering the arrangement useless.

    The idea is to pass a current through the wound wire which induces a magnetic field which propagates into the iron core. This magnetic field induces eddy currents within the iron core, which would induce a current in a second winding positioned somewhere around the iron core. Look at Ampere's Law, Faraday's Law, and if you can brave it Maxwell's Equations for information.

    Dave
     
  3. recca02

    Senior Member

    Apr 2, 2007
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    i think you might be talking about the enameling of the wire.that does the work of insulation.
     
  4. Dave

    Retired Moderator

    Nov 17, 2003
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    Yeah, the important point being that for the transformer arrangement to work, the winding has to be insulated from the core otherwise on a fundamental level it doesn't work.

    Dave
     
  5. recca02

    Senior Member

    Apr 2, 2007
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    like mr dave said it is important to insulate the wire from core and themselves
    so that the current travels in circular path. in shell type winding as far as i know primary and sec winding are shared on the core sides such that half of the windings are on both sides hence again insulation might be req.
     
  6. Dave

    Retired Moderator

    Nov 17, 2003
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    Mentaaal,

    Can I bring your attention to our article on Transformers, particularly Voume II - Chapter 9.1 which explicitly states at the start:

    Further reading of this section of the e-book may help your understanding of the subject. Feel free to question further.

    Dave
     
  7. mentaaal

    Thread Starter Senior Member

    Oct 17, 2005
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    once again thank you guys for swiftly resolving my query. i have to say i have ready the entire dc and ac sections but it has been a while and i am sure i didnt take it all in. i guess i already new the answer i just needed confirmation particularly as the windings on a transformer dont look insulated at all, it just looks like plain wire.
    cheers!
     
  8. n9352527

    AAC Fanatic!

    Oct 14, 2005
    1,198
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    They are enamelled copper wires, like recca02 mentioned above. The plain ones do sometime look like bare copper, except they are a bit more shiny. There are also coloured ones, like green, red, blue, etc.
     
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