I am designing a flyback converter. Now, necessary parameters are as stated -
Vin(voltage to primary) = 17-32V, Vout(voltage to secondary) = 12V, Iout = 3Amps.
Now, based on the above requirements, I calculated the following parameters for the flyback transformer -
Pout = 36W,
Assuming 80% efficiency, Pin = 45W.
Iaverage = Pin/Vin = 45/17 = 2.647Amps.
Iavg 0 Ipk*(Duty cycle)*0.5. Where D - 50% duty cycle. Hence-forth , Ipk(peak current) = 2.647/(0.5*0.5) = 10Amps.
So, V = LdI/dT => L = 17(ton)/dI = 8.02uH. The inductance o0f the primary coil.
Nr(ratios) = Nsec/Npri = 0.70588 => Nsec = (Npri)*(0.705). Now, with the above values, I tried selecting a flyback transformer.
I am looking at the transformer PA3856.006NL.
Now, is my approach correct ? If so, in the transformer I have show, where is the turns ratio specified ?
Also, what is the actual advantage of have a dual output in the secondary ? Does it have to do with the current on the output and its effects on the transformer saturation current.