Abstract: An electric power supplying device includes a main power supply that supplies electric power to each component of an apparatus, an auxiliary power supply that supplies electric power to an assisted component in the apparatus, the assisted component requiring power supply during start-up time of the apparatus and having a whose start-up time being equal to or longer than a predetermined period of time, a discharging control circuit that controls the auxiliary power supply to cause the auxiliary power supply to output a voltage, the output voltage being lower than a voltage output by the main power supply and being equal to or more than a lower limit voltage of a voltage range that the assisted component is operable, and a power supply prevention circuit that prevents the auxiliary power supply from supplying power to a component other than the assisted component in the apparatus.

Abstract: An electric power supplying device includes a main power supply that supplies electric power to each component of an apparatus, an auxiliary power supply that supplies electric power to an assisted component in the apparatus, the assisted component requiring power supply during start-up time of the apparatus and having a whose start-up time being equal to or longer than a predetermined period of time, a discharging control circuit that controls the auxiliary power supply to cause the auxiliary power supply to output a voltage, the output voltage being lower than a voltage output by the main power supply and being equal to or more than a lower limit voltage of a voltage range that the assisted component is operable, and a power supply prevention circuit that prevents the auxiliary power supply from supplying power to a component other than the assisted component in the apparatus.

Abstract: A commercial AC power shutdown detecting apparatus includes a photocoupler including a light-emitting element and a light-receiving element, a lighting circuit that flows a pulsating current through the light-emitting element of the photocoupler to turn on and off light of the light-emitting element, a charging-discharging circuit including a capacitor and a resistor that charges the capacitor via the resistor when the light-emitting element is turned off, and discharges the capacitor via the light-receiving element and the a resistor when the light-emitting element is turned on, and a comparing circuit that compares a voltage value between capacitor terminals with a predetermined voltage value intermediate between a maximum voltage value between the capacitor terminals when the light-emitting element repeats turning light on and off and the consistent DC voltage value, and outputs a shutdown detection signal if the voltage value between the capacitor terminals exceeds the predetermined voltage value.

Abstract: An image forming apparatus includes a plurality of power generation units, a charge control unit, a charge switch unit, and a controller, Each of the plurality of power generation units is respectively provided to a corresponding one of a plurality of high-temperature portions in the image forming apparatus to generate power based on temperatures of the high-temperature portions. The charge control unit charges a power storage unit with electrical energy generated by the power generation units. The charge switch unit switches between the power generation units to connect one of the power generation units to the charge control unit. The controller controls the charge switch unit to selectively connect one of the power generation units capable of achieving a maximum power generation efficiency to the charge control unit.