A hybrid pulse transformer with permanent magnets

This paper compares the operating range of a conventional pulse transformer (PT) and a hybrid pulse transformer (HPT) which is designed for miniaturization and increased output power of flyback converters. The HPT expands the operating range of the primary magnetomotive force by impressing the dc bias in cores with permanent magnets. The operating ranges of the conventional PT and the HPT are, respectively, 32 and 54 A, the operating range of the HPT is 1.7 times that of the conventional PT. The maximum output powers P/sub 2 m/of the conventional PT and the HPT are proportional to the square of their respective operating ranges. The P/sub 2 m/values of the conventional PT and the HPT are, respectively, 8.6 and 23.2 W, the P/sub 2 m/of the HPT is 2.7 times that of the conventional PT.