Question about Transformers

Discussion in 'General Electronics Chat' started by worldHello, Oct 18, 2014.

  1. worldHello

    Thread Starter New Member

    Oct 15, 2014
    Hello, all:

    So I have to deal with transformers for my project. From my understanding, a typical transformer one sees in a textbook has two parameters N1 and N2. The relation between Vin and Vout is then Vout = (N1/N2 ) Vin. In other words, N1:N2 is the ratio. If N1 < N2, then it is a step down transformer.

    However, most transformers one can buy have rating of Vin and Vout with specific numbers. For example, Vin = 12 V and Vout = 6 V. I do not understand how this works. If I input a 9-volt voltage to this transformer, what would happen? Does it have to take 12 V as its input?

    Thank you.
  2. MrChips


    Oct 2, 2009
    12V:6V means that the turns ratio is 2:1.

    Hence 9V in would give you 4.5V out.
  3. crutschow


    Mar 14, 2008
    But you can't generally put more voltage at the input then its rated voltage at the rated frequency or the transformer core can saturate with subsequent high input current.
  4. t_n_k

    AAC Fanatic!

    Mar 6, 2009
    N1 presumably states the primary winding turns and N2 the secondary winding turns.
    Surely if N1 < N2 (or N2 > N1) then one has a step up transformer .....