US Patent 7489219 Power inductor with reduced DC current saturation

A power inductor includes a first magnetic core having first and second ends. The first magnetic core includes ferrite bead core material. An inner cavity arranged in the first magnetic core extends from the first end to the second end. A conductor passes through the cavity. A slotted air gap arranged in the first magnetic core material extends from the first end to the second end. A second magnetic core is one of located in and adjacent to the air gap and has a permeability that is lower than the first magnetic core.