Inductance ratio

Discussion in 'Feedback and Suggestions' started by debjit625, Aug 26, 2010.

  1. debjit625

    Thread Starter Well-Known Member

    Apr 17, 2010
    790
    186
    Isnt it a error at http://www.allaboutcircuits.com/vol_2/chpt_9/7.html

    Here the Inductance ratio is given as (N secondary/N primary)^2 which should be (Number of primary turns / Number of secondary turns)^2

    Now in example, for a step up transformer 125V to 250V is given

    And how this ratio could be 2:1 it should be 1:2 as per Primary:Secondary .

    EDIT :: here is another thing
    Should both be same?
     
    Last edited: Aug 26, 2010
  2. Wendy

    Moderator

    Mar 24, 2008
    20,765
    2,536
    Seems OK to me...

    [​IMG]

    That last sentence covers it, "N = number of turns in winding".
     
  3. debjit625

    Thread Starter Well-Known Member

    Apr 17, 2010
    790
    186
    How a step up transformer which step up 125V to 250V have 2:1 ratio rather 1:2, as it should have low primary turns w.r.t secondary turns.
     
  4. studiot

    AAC Fanatic!

    Nov 9, 2007
    5,005
    513
    Remember

    Turns ratio = voltage ratio = 1/current ratio = N2/N1

    Where N2 is the secondary turns N1 is the primary turns.

    Thus there are twice as many secondary turns as primary to step up 125 volts primary to 250 volts secondary.
    Thus the turns ratio = 2/1 = 2:1

    Of course the current ratio is the reciprocal ie 1/2 = 1:2 and the secondary current is half the primary.
     
Loading...