Switching power supply

Abstract

A switching power supply device of the invention includes: a switching circuit for interrupting direct current to generate a pulse voltage; a transformer including a primary winding, a secondary winding, and a core for magnetically coupling the primary winding and the secondary winding; a multi-layer wiring board having wiring lines constituting the primary winding and the secondary winding; a rectifier circuit for rectifying an alternating current; a smoothing circuit for suppressing ripple; and a control circuit for controlling an output voltage from the smoothing circuit. The multi-layer wiring board is provided with at least the switching circuit and the rectifier circuit and is arranged on a main wiring board, and the control circuit is arranged on the main wiring board.

Description

technical field

[0001] The invention relates to a switching power supply device arranged inside electronic equipment. Background technique

[0002] Currently, a switching power supply unit is used as a power supply unit mounted in electronic equipment such as a personal computer. This switching power supply device is a kind of DC stabilized power supply, and its structure is such that the DC obtained from a commercial power supply or a battery or other power supply is converted into an audible frequency or higher (about several hundred kHz) by using the high-speed switching action of a semiconductor device such as a transistor. Control the pulse width and pulse interval of the pulse voltage, thereby outputting a constant voltage direct current. Since the switching power supply device configured in this way is characterized in that the output voltage is always kept constant regardless of the power consumption fluctuation of the load, it is small, lightweight, and high in eff...