Patent ID: 8089331

Claim:
A planar magnetic structure comprising a printed wiring board having at least one winding segment; an inner clearance through said printed wiring board within said winding segment; at least one outer clearance through said printed wiring board external to said winding segment; a core having an inner leg extending through said inner clearance and at least one outer leg extending through said outer clearance defining a gap occupied by said winding segment; an inner shield between said inner clearance and said inner core leg, said inner shield surrounding said inner leg but being less than one turn defining a shield gap; said shields reducing the voltage gradient between said core legs and said winding segment; and at least one outer electrostatic shield between said outer clearance and said at least one core outer leg, said outer shield disposed between said outer leg and inner leg; and a guard barrier proximate said shield gap and between said shield gap and said winding segments; said guard barrier reducing the voltage gradient between said inner shield end at said gap and said winding segment.