A storage magnetic element, which minimizes the
power loss in the planar winding due to the fringe
magnetic field associated with a discrete air gap, is presented. The invention describes a construction technique wherein the
magnetic core is formed by an E section made of high permeability magnetic material and an I section made by a material capable to store energy due to its distributed gap structure. The I section of the
magnetic core in one of the embodiments is covered by an
electrically conductive shied to force the
magnetic flux into the I section and to minimize the component of the fringe
magnetic field perpendicular on the planar winding. In another embodiment of this invention the
electrically conductive shield is replaced by a high magnetic permeability material to accomplished the same goal of reducing the
magnetic field component perpendicular on the planar winding. In a prefer embodiment of this invention the I section of the
magnetic core has a cavity which will accommodate the middle leg of the E section. This construction will force the fringe magnetic field at the edge of the gap to be parallel with the planar winding of the storage magnetic element. In another embodiment of this invention a flat I section is used with the addition of another high permeability magnetic material placed on the I section on top of the winding. This construction will force the fringe magnetic field around the edge of the gap to be parallel with the planar winding. The embodiments of this invention are aimed at reducing the fringe magnetic field perpendicular on the planar winding, lowering the
eddy current induced by this field.