Look at this DC-DC converter from another point of view: if you build 12V-28V dc-dc switchmode step-up converter you don't need a 50kHz transformer but just an inductor (rated for some amps).
What should be the current (power) at the 38V end?
Regards,
IanP
I know I,m need different, powers, votage, current, freq at 25khz etc., for some design, but the most important in the PS is the power transformer !!!!! and i need your's knowledge in what is the best soft for this application.