| 摘要 |
PROBLEM TO BE SOLVED: To achieve the reduction of the power consumption and the improvement of the efficiency of a switching power supply circuit. SOLUTION: A load detecting circuit 210 for detecting the heaviness of a load, and a switching stopping and controlling circuit 220 that stops the switching operation of a transistor based on the detection signals from the load detecting circuit, are provided in the switching power supply circuit. An AC once before inverting it into the AC of high frequency is rectified by switching on and off the transistor, and further rectified after transforming a voltage to supply the electric power to the load. In the case of a light load, the switching operation of the transistor is stopped to reduce the power consumption. COPYRIGHT: (C)2004,JPO
|
