Ferrite core

Abstract

The new structure of a ferrite core for the use of a power transformer and/or a choke coil has been found. The core is assembled by a pair of identical core halves, and each core half comprises (a) a circular center boss (6), (b) a pair of outer walls (7, 8) positioned at both the sides of said boss for mounting a coil, (c) a pair of base plates (9, 10) coupling said center boss and said outer walls, (d) each of the outer walls being substantially rectangular with an external linear wall and an inner curved wall, (e) the core half being symmetrical with regard to the first plane including a center axis of said boss and being parallel with the external linear walls of said outer walls, (f) a concaved opening (R) being provided between said base plates in the first side of the core half with regard to the reference plane which includes a center axis of said boss and is perpendicular to said first plane, (g) the length (B.sub.1) between said reference plane to the end of the first side which includes said concaved opening (R) being longer than the length (B.sub.2) between said reference plane to the end of the second side which does not have said opening (R), and (h) said length (B.sub.2) being the same as the radius (a.sub.1) of the center boss.