| 摘要 |
PROBLEM TO BE SOLVED: To discharge electric charge carried by a smoothing capacitor in a short period of time when power supply to the smoothing capacitor is shut off while operation of a main power supply circuit is stopped by control of a sub power supply circuit.SOLUTION: A direct current obtained by rectifying an AC current from an AC power supply is smoothed by a smoothing capacitor 54b and is supplied respectively to a main power supply circuit 56 which generates a DC power of 24 V and a sub power supply circuit 57 which generates a DC power of 5 V. The main power supply circuit 56 is turned on/off by a control part 58 which operates by power generated by the sub power supply circuit 57. When an AC monitor circuit 53 detects that power supply from the AC power supply is shut off while the main power supply circuit 56 is turned off, the control part 58 starts discharging control in which power consumption promotion processing in the control part 58 is performed. |
