| 摘要 |
The problem addressed by the present invention is to enable quick discharge of residual charge in an X capacitor at the time of unplugging, without the addition of external elements or components. A power source control circuit (13), which generates and outputs a drive pulse for controlling turning a switching element (SW) ON and OFF, is provided with an ON/OFF control signal generation circuit which generates a control signal for controlling turning ON and OFF the switching element (SW) for intermittently passing a current to the primary winding of a voltage conversion transformer, a high-voltage input start-up terminal (HV) into which an unrectified AC voltage is inputted, a high-voltage input monitoring circuit (40) which monitors the voltage of said high-voltage input start-up terminal, and a discharge means (45) which is connected between the high-voltage input start-up terminal and a ground point, wherein the discharge means is turned ON if the high-voltage input monitoring circuit detects that during a prescribed time period, the voltage of the high-voltage input start-up terminal does not fall below a prescribed voltage value. |
