POWER SUPPLY AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To prevent electric shock, breakage and malfunction of a load to enhance the safety of a power supply.

SOLUTION: The power supply includes: a rectifying circuit part 22 for rectifying a voltage input from an external power supply; a smoothing capacitor 23 for smoothing the output voltage of the rectifying circuit part; a DC/DC conversion unit 24 for converting the voltage smoothed with the smoothing capacitor into a predetermined voltage and supplies it to a load; an AC detecting unit 21 for detecting the presence/absence of the input of voltage to the rectifying circuit part and outputting the AC detection signal; an output control switch 25 interposed between the DC/DC conversion unit and the load; and an output control unit 26 into which a power saving signal indicating that the load is in a power saving mode or not is input from outside and the AC detection signal is input from the AC detecting unit, and when the power saving signal indicates that the power supply is in the power saving mode and the AC detecting signal indicates the absence of voltage input to the rectifying circuit part, closes the output control switch to supply voltage from the DC/DC conversion unit to the load.

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