| 摘要 |
PROBLEM TO BE SOLVED: To provide a switching power-supply device that stably supplies a current and a voltage to a plurality of loads and avoids damage of the loads by preventing the occurrence of surge.SOLUTION: A main SW control circuit 20 switching-controls a low-side switch element Q1 and a high-side switch element Q2 on the basis of a feedback signal fb according to a main output voltage Vofrom a secondary winding of a transformer, supplies a voltage to a primary winding np of the transformer T, and stops the supply. A DSP 30 changes a set target value according to the lightness and heaviness of a main load 10, switching-controls switch elements Q21, Q22, and Q23 of a sub-rectifier smoothing circuit on the basis of the target value, and drives sub-loads 11, 12, and 13. |
