I would like to build a flyback-converter that is presented in a research paper. The following information about the transformer have been provided:
Switching frequency: 50 kHz Number of primary turns: 9 Turn ratio: 10 Magnetizing inductance: 14uH Leakage inductance: 0,4uH Core: ETD 44 Input voltage: 35 V
The converter is rated for 250 W. There are 2 outputs with the center connected, so I would need 9:90:90 windings if I understand it correctly.
The transformer will be operating in DCM/BCM hybrid mode. The output will be a half-wave of a 50 Hz sine, in the low voltage regions it will operate in DCM.
From some oscilloscope measurements in the paper I can see, that the peak current through the primary winding is at about 40 A. The conduction loss of teh transformer has been calculated as 0.7 W, and Irms and Rl have been measured to calculate it (but aren't stated in the paper).
Unfortunately I don't have experience with winding transformers, so I don't know what core I need, if the core needs to have an air gap, what diameter wire I need and so on. How can I determine that, so the transformer I will build matches or at least comes super close to the values specified above?
Also is ETD 44 the "best" core for this or are there other, more efficient cores which could be used here?