| 摘要 |
<p>PROBLEM TO BE SOLVED: To suppress a surge current generated in a flyback circuit by operating a power outage detection circuit to stop the flyback circuit in the event of a power outage or a power sag and soft-starting the flyback circuit at commercial power supply recovery.SOLUTION: An emergency unit 300 includes: a rectification circuit DB; a flyback circuit 320 that converts a voltage rectified by the rectification circuit DB to a preset setting value of DC voltage to be output as an output voltage, executes a soft start of gradually increasing the output voltage toward the setting value in the case of initiating a start from a stopped state, and has a power factor improvement function; and a power outage detection section 310 that monitors a voltage value of an AC voltage input by the rectification circuit DB, and if detecting that the voltage value of the AC voltage has becomes lower than a preset setting voltage, stops the operation of the flyback circuit 320 and, when the voltage value of the AC voltage later becomes equal to or higher than the setting voltage, restarts the flyback circuit 320 by the soft start.</p> |
