Patent ID: 6046663
Filing Date: 2000-04-04
Classification: H01F

Abstract:
A transformer comprising:a coil comprising:a pair of core winding portions; anda pair of coupling portions for coupling the core winding portions so as to space the core winding portions a predetermined distance from each other, said coil bobbin being formed, on its whole outer periphery, with a groove;wherein a cross-sectional shape of said groove comprises:an open hexagon; anda pair of opposed parallel straight side portions which extend from said open hexagon;a winding which is obtained by winding a conductor directly around the groove of the coil bobbin a predetermined number of times by alignment winding; anda pair of wound cores each of which is obtained by winding an electromagnetic steel plate directly around each of the core winding portions of the coil bobbin a predetermined number of times;wherein an outer peripheral surface of each of opposite side walls of the groove at the core winding portions has an arcuate cross-sectional shape; andwherein the opposed parallel straight side portions of the groove intersect with each arcuate outer peripheral surface of the opposite side walls of the groove at the core winding portions such that the coil bobbin has a cross-sectional shape similar to a shape of distal ends of a pair of scissors.