| 摘要 |
To measure input power as accurate as possible, a power supply apparatus includes an AC/DC converter that generates a direct-current internal power supply from an alternating-current commercial power supply, an output-voltage measurement unit that measures an output voltage of the internal power supply, an output-current measurement unit that measures an output current of the internal power supply, a temperature measurement unit that measures an environmental temperature of the power supply apparatus itself, a storage device that stores therein in advance conversion efficiency data in which a correspondence between a conversion efficiencyηof the AC/DC converter and the environmental temperature is recorded, and a computation unit that determines the conversion efficiencyηbased on the environmental temperature and the conversion efficiency data and calculates the input power of the commercial power supply by using the determined conversion efficiencyη, the output voltage, and the output current. |
