Hi VVV,
My switching frequency is 40Khz, which means during each 25µs period, the swiching on the primary side will be turned off, the maximum duty ratio I design is 0.6.
At each ON period, the primary side of the transformer will be charged up linearly by a 12V battery, and the peak current will reach 30A. However the switch on the secondary side won't let the current flow through in the secondary winding, so the energy will be stored in the transformer, when the switch on the primary side is switched off, the current will be draged down rapidly, and the change of the polarity on the secondary side will enable the current flow in the secondary side
I used the PWM switching fashion, so the average current in the primary side will be 6.4A. However the maximum power which is delivered to the secondary side at the maximum duty ratio is calculated as 108W. However the average power delivery is designed to be 50W.
The primary and secondary turn are both 2.5 turns(6µH) which is not alot. I choose the 20 AWG wire which will enable the 11A (continuous).
In my design, I used the ferrite toroidal core, 1.14 inch.
How do U think?
Thanks
HaliSimon