I have stayed away from transformers to drive H bridges for years , but no mo . Any ferrite with a few wraps around it works . Advantage is you can use any transistor Mosfet or BT . You can go big power also !
Same with off line switchers ( PS) . But you are just as well off with one driver xsistor ! it has the same effeciency as a bipolar drive ! And you can make it oscillate ( alias "blockin" Royer osc ) and it so easy to control . Even buck regulators can osc' ! You only lose at the extreme end where the xsistor needs to be on full .
BTW i'll be writting a free NewForth OpSys for the ARM cpu PDAs soon ..FREE
Just disassembled Gforth .... No Forth ..No innner interpreter no nothing , inside it has only C !