I am a student in the faculty of engineering , and in my project i need to use buck boost transformer , and i can't find it in my country so i have no way except manufacture it manually with my group , and i haven't more information about it . so if u don't mind to help me in this , plz provide me with the information i need to make this , i hope not to annoyed u but am very sorry as indeed i need it very much . thnx at all .