초록 ▼

A switching power supply is provided in which the efficiency is improved and the regulation and cross-regulation of an output voltage is also improved. Terminals (A) and (B) of a primary winding N1 and secondary winding N2 at which the same polarity is set are interconnected via a first capacitor C4

A switching power supply is provided in which the efficiency is improved and the regulation and cross-regulation of an output voltage is also improved. Terminals (A) and (B) of a primary winding N1 and secondary winding N2 at which the same polarity is set are interconnected via a first capacitor C4. A tap provided at a given winding position (C) of the primary winding N1 and the other terminal (D) of the secondary winding N2 are interconnected via a second capacitor. Herein, assuming that areas of the primary winding N1 divided by the tap are N.sub.11 and N.sub.12, the number of turns in the area N.sub.11 between the terminal (A) and winding position (C) is nearly the same with the number of turns existing between the one terminal (B) of the secondary winding N2 and the other terminal (C) thereof. Owing to the configuration, an equivalent coupling coefficient observed between the primary winding N1 and secondary winding N2 approaches 1.0. Consequently, the efficiency of a power supply can be improved, and regulation and cross-regulation can be improved.

대표청구항 ▼

[ I claim:] [1.] A switching power supply comprising a switching device, a control circuit, and an inductance part having at least first and second windings, for providing a plurality of output voltages from voltages induced in the at least first and second windings by operating the switching device

[ I claim:] [1.] A switching power supply comprising a switching device, a control circuit, and an inductance part having at least first and second windings, for providing a plurality of output voltages from voltages induced in the at least first and second windings by operating the switching device,the first winding having at least first and second terminals, the first winding including at least one of first and third spaced winding positions, the first winding position being defined by either the first terminal or a tap, and the third winding position being defined by either the second terminal or a tap, the second winding having at least third and fourth terminals, the second winding including at least one of second and fourth spaced winding positions, the second winding position being defined by either the third terminal or a tap, and the fourth winding position being defined by either the fourth terminal or a tap, the first and second winding positions being interconnected via a first capacitor, the third and fourth winding positions being interconnected via a second capacitorswherein a number of turns between the first and third winding positions is approximately equal to a number of turns between the second and fourth winding positions, andwherein voltages at the first and second winding positions have the same polarity, and voltages at the third and fourth winding positions have the same polarity.