Factory made DC - DC isolated converters are fairly cheap and very reliable. Check out any of the big on line electronics supply companies. Digikey, mouser, Allied, and countless more carry about every voltage input and output range you can think of and in power ratings from under a watt to over 100 watts.
All certification requirements are already met too!
Hi , My client needs ATEX approval and some custom voltages .
Like 5V to 5.25V(200mA) isolation. 3V to 3.3V(250mA) etc . Also the size has to be too small.
With all of todays HF transforming frequencies I doubt the FCC is monitoring the 100KHz and below bands with much interest any more.
Technically everything that move electrons and makes an alternating magnetic field is a radio transmitter.
I have a pair of broad band hash transmitters I typically call my 300 amp MIG welder and my 105 amp plasma cutter.
The FCC doest seem to mind my multi KW broad band hash transmissions!
I don't see any output filter inductors. Also, where's the feedback loop? Do you need regulated outputs? This doesn't appear to be regulated. At the power levels you're dealing with, 1.25W, a push-pull is overkill. A flyback is a good choice if you need isolation. If noise is a problem, then a forward converter is right for the job. The forward requires an inductor for each output.