coil design

Discussion in 'General Electronics Chat' started by elre, Jun 23, 2007.

  1. elre

    Thread Starter New Member

    Jun 23, 2007
    Hello Guys,

    i want to buils a 120v DC bobine using PVC of a transformer(the rectangular plastic), for an AWG 24 wire how many turns should i be doing?

    is there a formula for that?

  2. beenthere

    Retired Moderator

    Apr 20, 2004
    It's hard to answer your question, as it is hard to tell if you want to wind a transformer secondary of if you just want an inductor. The formula for winding an inductance is here -

    If it's a transformer, the ratio of primary turns to the secondary turns gives the output voltage. If you can't get at the primary, you may have to wind the secondary experimentally - put on some turns, apply power, and use a meter to check the secondary voltage. Add or subtract turns until the voltage is correct.
  3. elre

    Thread Starter New Member

    Jun 23, 2007
    thanks man
    but i need it to be used as electro magnet but i need to have it on the a PVC with air core nothing in the middle just empty. will that formula works?
    still i don't see how to relate voltage and number of turns with the dimentions of the pvc.

    i hope some one can help.
  4. kender

    AAC Fanatic!

    Jan 17, 2007
    Yes, the first two formulae will work for air core. Just substitute mu_r = 1 .
    Be aware that the rest of the formulae assume that the inductor is circular, but your inductor is rectangular.