Anybody can help how to determine the DC bias in a switching power supply power transformet design? Thanks!

 

Can you post the schematic of the switching power supply circuit?

hgmjr

 

Just a typical single ended switch forward or flyback.

 

I'm sorry to say that your original question makes no sense and your reply to hgmjr is not helpful either. If you post a schematic then at least we have some further basis for discussion.