| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power-supply circuit capable of controlling a rush-current prevention circuit according to a state of, for example, a power-factor improvement circuit or a load circuit and a state of an AC power-supply and capable of satisfying both of sure prevention of a rush current and reduction in power consumption. <P>SOLUTION: A power-supply circuit 1 includes a rectifier circuit 12, a smoothing capacitor C1 that smooths a DC voltage from the rectifier circuit 12 and outputs the smoothed DC voltage, and a rush-current control circuit 11 that is disposed on a path connecting an input terminal 2a and the rectifier circuit 12. The rush-current prevention circuit 11 has a rush-current prevention element 17 and an open/close element 18 connected in parallel to the rush-current prevention element 17. Moreover, the power-supply circuit 1 includes an AC-voltage detection part 14 that outputs an AC detection voltage according to an AC voltage inputted to the rectifier circuit 12, a DC-voltage detection part 15 that outputs a DC detection voltage according to charges charged in the smoothing capacitor C1, and a control circuit 16 that causes the open/close element 18 to open and close according to the AC detection voltage and the DC detection voltage. <P>COPYRIGHT: (C)2013,JPO&INPIT |
