Abstract: A main rectifying/smoothing circuit is connected to one end of a secondary winding of a transformer and a plurality of rectifying/smoothing circuits are connected to a plurality of central taps of the secondary winding. The rectifying/smoothing circuits are each equipped with a switch. In a preliminary driving period, a DSP, which controls the switches, reads forward drop voltages of first to third diode loads and sets feedback gains corresponding to the forward drop voltages. The DSP controls the switches based on the set feedback gains and begins rated driving.

Abstract: In a switching power supply apparatus, a main switching control circuit performs switching control of a low-side switch device and a high-side switch device based on a feedback signal corresponding to a main output voltage output from a secondary winding of a transformer, and applies and stops applying a voltage to a primary winding of the transformer. A digital signal processor, in accordance with the load status of the main load, changes set target values, performs switching control of switch devices of the sub-rectifying and smoothing circuits, and drives sub-loads.

Abstract: A main rectifying/smoothing circuit is connected to one end of a secondary winding of a transformer and a plurality of rectifying/smoothing circuits are connected to a plurality of central taps of the secondary winding. The rectifying/smoothing circuits are each equipped with a switch. In a preliminary driving period, a DSP, which controls the switches, reads forward drop voltages of first to third diode loads and sets feedback gains corresponding to the forward drop voltages. The DSP controls the switches based on the set feedback gains and begins rated driving.

Abstract: In a switching power supply apparatus, a main switching control circuit performs switching control of a low-side switch device and a high-side switch device based on a feedback signal corresponding to a main output voltage output from a secondary winding of a transformer, and applies and stops applying a voltage to a primary winding of the transformer. A digital signal processor, in accordance with the load status of the main load, changes set target values, performs switching control of switch devices of the sub-rectifying and smoothing circuits, and drives sub-loads.