relationship between core size and turns in transformer

Discussion in 'General Electronics Chat' started by adeel, Jul 19, 2008.

  1. adeel

    Thread Starter Member

    Jun 28, 2008
    hi, friends i got a problem need ur help .:)
    i have two cores of size 1.5 * 2 and 1.5 * 2.5 i am surprised how many turns i have to use for primary in 1.5*2 core and how many in 1.5 * 2.5
    iron core. detail is
    for 220 volts 50/60 hz
    for 275 volts 50/60 hz
    and for secndary 24 volts when using 220 primary winding

    i realy want to know if core size changes then how turns changes is there any easy formula to determine turns and core size . i found 400 tuns for core size 1.5*2 and 350 turns for core 1.5*2.5 is it rite for primary windings
    i will be very thankfull to u if u can solve my problem . thanks
  2. SgtWookie


    Jul 17, 2007
    Basically, the larger the core size, the more efficient it is. No, there isn't an easy formula.
    Here is a good page to get a lot of information on how transformers work, and lots of transformer theory.
  3. John Luciani

    AAC Fanatic!

    Apr 3, 2007
    To determine inductance the formula is

    N^2 = L / AL

    N is the number of turns, L is the inductance, AL is the nominal core inductance that
    is specified in the manufacturers datasheet. There is a lot of information about transformer
    design at

    Your larger core has a larger cross sectional area (and larger AL) which reduces the
    number of turns required to get the same inductance.

    (* jcl *)