| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply capable of discharging an X-capacitor with a simple circuit configuration and of reducing power consumption.SOLUTION: A power supply includes: a zero-crossing detector section for detecting zero-crossings of AC voltage; a first capacitive element connected between a line after an AC voltage rectification and the ground; a first discharge resistor for discharging electric charge accumulated in the first capacitive element; a first switch for blocking the current flowing through the first discharge resistor; a second capacitive element connected between two lines to which the AC voltage is supplied; and an input voltage detection section for detecting cut-off of the AC voltage input. The power supply has a first state where the first switch is turned off and a second state where the first switch is turned on. When the input voltage detection section detects cut-off of the AC voltage input, the electric charge accumulated in the second capacitive element is discharged by turning the first switch on. |
