Patent ID: 7612640

Claim:
A magnetic element comprising: a first coil; a second coil; wherein said first and second coils independently generate magnetic fluxes and each of said magnetic flux passes through two different main magnetic paths respectively; a core unit having a first and second center core which are directly wound by said first and second coils respectively; first and second planar cores disposed on top and on bottom of said first center core and said second center core respectively, and a side core located alone a first side of said first and second center cores and disposed between said first and second center cores, wherein said side core is shaped such that it has a recessed portion and an extended portion that partially extends along a second and third sides of each center core; said recessed portion and extended portion being shaped to concentric arcs of said coil; wherein a cross-sectional area of said side core is from 1 to 5 times the size of the total cross-sectional areas of said first and second center core and an open portion is formed between said planar cores on said second and third sides of each said first and second center cores that is not facing said side core.