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Inductor/coil/choke design confusion

  1. Jun 26, 2012 #1
    Hello all,
    i have an equation for flux density taking the inductor chrecteristics into account as

    Bmax= (Vrms * 10^8)/(4.44*A*N*f)

    but the company i work for has given it at

    Bmax=(Vl * 10^4)/(4.44*A*N*Vss)

    where Vl = voltage across inductor.

    i am finding alot of variation for equations for the paratmeters of inductor/choke design.

    i was wonderign if someone could shed light light on this confusion??

  2. jcsd
  3. Jun 26, 2012 #2


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    You would need to define the symbols in those formulae first. Is the second formula just for a particular circuit? (Vss seems to be a supply voltage?)
    What's the background to this?
  4. Jun 26, 2012 #3
    Vrms = rms of supply (what i understood this to be)
    A = cross section of core
    N= number of turns of coil
    f= frequency of supply
    Vss = supply voltage

    the equations given to me for choke design work but are not accurate so i started to search around for an answer. there are lot of variations in the equations and also for Inductance i found the same thing.
  5. Jun 26, 2012 #4


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    The formula you have been given must be making assumptions about the frequency being used and, I guess, is supposed to make life easier for you to get an answer. It looks totally wrong and it is not 'dimensionally correct' because there is a V, top and bottom. But it may work in the particular context that they want you to work.
    I should ask your boss what to do, if that's acceptable in your organisation. He is paid to sort that sort of thing out (?).
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