Patent ID: 7236077

Claim:
A transformer having adjustable leakage inductance, said transformer comprising: a primary winding coil; a secondary winding coil; a bobbin including a winding section for winding said primary winding coil and said secondary winding coil thereon, wherein said bobbin further includes a channel therein; and a magnetic core assembly partially embedded into said channel of said bobbin, wherein said primary winding coil and said secondary winding coil are partially overlapped with each other and wound around said winding section of said bobbin to be defined as an overlap region, the region where said primary winding coil and said secondary winding coil are not overlapped with each other is defined as a non-overlap region, and the leakage inductance of said transformer is adjusted according to an overlap ratio of said overlap region to the sum of said overlap region and said non-overlap region.