Building an inductor to specs?

Discussion in 'General Electronics Chat' started by electronice123, Oct 23, 2008.

  1. electronice123

    Thread Starter AAC Fanatic!

    Oct 10, 2008
    I am trying to make an inductor that will operate in the audio range of about 10-20kHz. The size of the inductor is 50mH.

    I want to build the inductor on a iron core rod.

    How do I determine the core material, the wire size, and the number of turns required to get the inductance needed.

    Any references or help will be greatly appreciated!
    Last edited: Oct 23, 2008
  2. steveb

    Senior Member

    Jul 3, 2008
    I'm not one to rely on software tools, but iron core inductors can get a little tricky with nonlinearity, heating and aging effects. I would recommend going to and then at the bottom of the page they have a link to their software (it was free last time I used it). This helps you choose the right core composition and lets you predict the current dependence and (i think) frequency dependence of inductance. You may have to buy one of their cores and wind it yourself, but the software spits out the wire size and number of turns and tells you core and copper losses.

    I'm know there are other ways to get the answer, and you could learn a lot by diving into all the details, but this is a quick and dirty method if you are too busy.
  3. mik3

    Senior Member

    Feb 4, 2008



    L=inducatnce in henries
    N=number of turns
    k=effective length of the core in meters
    m=mo*mr , mo=permeability of vaccum and mr=relative permeability of iron (about 1000)
    A=cross sectional area of the core in m^2