| 摘要 |
PROBLEM TO BE SOLVED: To provide a switching power supply that makes it possible to prevent dielectric breakdown of a transformer due to overload and reduce its size and cost. SOLUTION: The switching power supply includes: a transformer T1 having primary winding L1 and secondary winding L2; a switching circuit 6 that has a switching element Q1, switches the switching element Q1 between on state and off state to convert direct-current input voltage into alternating-current voltage, and supplies it to the primary winding L1 of the transformer T1; a conversion circuit 12 that converts alternating-current voltage induced in the secondary winding L2 of the transformer T1 into direct-current voltage and outputs the obtained direct-current voltage to a load; an overload detection circuit 4 that detects overload based on the alternating-current voltage induced in the secondary winding L2 of the transformer T1; and a switching frequency conversion circuit 5 that, when overload is detected by the overload detection circuit 4, destroys the switching element Q1 to stop the output of the conversion circuit 12. COPYRIGHT: (C)2007,JPO&INPIT
|
