Bobbin

Abstract

The present article is a bobbin used in transformers, reactors, choke coils, etc., on which a winding is wound. The bobbin has a first cylindrical portion on which a primary winding is wound, and a second cylindrical portion on which a secondary winding is wound, as well as a primary side flange portion through which the primary winding is inserted, and a secondary side flange portion through which the secondary winding is inserted. The first cylindrical portion and the second cylindrical portion are partitioned by a separator portion. The wall surface of the separator portion, which is the circumferential surface of the second cylindrical portion, is provided with an annular step portion that protrudes outward from the separator portion, and the secondary winding is wound so as to ride on the step portion that protrudes outward. In addition, a circumferential groove is provided in the step portion, and a lateral groove is provided on the circumferential surface of the first cylindrical portion and the second cylindrical portion. The circumferential groove and the lateral groove are permeable with a heat dissipation resin when the primary winding and the secondary winding are wound around the bobbin. Furthermore, a core hole is provided in the axial direction of the bobbin, and a core is inserted into the core hole. The bobbin has a bottom portion on which a gap is formed between the core and the inner peripheral surface of the core hole, and the bottom portion of the bobbin has a bottom portion on which a gap is formed between the core and the inner peripheral surface of the core hole.

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