# Finding Transformer turns??

Discussion in 'General Electronics Chat' started by bsk, Sep 15, 2009.

1. ### bsk Thread Starter New Member

Sep 15, 2009
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I know the formulas Ep/Es = Np/Ns = Is/Ip to find information dealing with a transformer...but these only work if you know three of the four needed information. For example if you need to know the number of secondary turns, you need to know Primary and Secondary Voltage or Amps, also you need the number of primary turns. My question is what if you now the Primary and Secondary Voltage, the Primary and Secondary Amps, but you don't have either of the turns...is there anyway to find the turns in primary and secondary????

2. ### bountyhunter Well-Known Member

Sep 7, 2009
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You determine the primary turns by establishing the right flux density in the core (and primary inductance) and use the right wire gauge for primary current. Then calculate the secondary turns to get the correct output voltage.

3. ### t_n_k AAC Fanatic!

Mar 6, 2009
5,448
783
No - you can only determine the primary-to-secondary turns ratio. If you were designing a transformer from scratch you would need to know a lot more information about the parameters for the transformer core itself.