| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a switching power supply and a control method thereof, equipped with a current resonance converter part, capable of performing protection operation without requirement for duplicating a control circuit for normal operation. <P>SOLUTION: A switching power supply 1 includes a current resonance converter part 3 which converts PFC voltage and outputs it to a load circuit, a switching control part 12 which controls switching operation of switch elements Q3 and Q4, and an output voltage detection part 11 which detects an output voltage and then outputs an output signal that corresponds to the detection value to the switching control part 12. The switching control part 12 derives a switching frequency for making an output voltage a predetermined value on the basis of the output signal from the output voltage detection part 11, and on the basis of the derived switching frequency, determines occurrence of abnormality of the switching power supply 1. In a case where an abnormality is determined to have occurred, switching operation of the switch elements Q3 and Q4 are stopped, to assure safety of a device at the time of occurrence of abnormality. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
