Dear meysaminter
Hi
it is pretty simple . what are the specifications of your SMPS ? out put voltage and current and frequency of operation .
Thus i can help you as well .
Best Wishes
Goldsmith
Hi again
I think the transformer design , in SMPS , is a bit hard for you , isn't it ? if , yes , see below , please , it will help you to design all kind of magnetic elements of each SMPS with a general way : https://www.edaboard.com/threads/229615/
Good luck
Goldsmith