Ricoh Company, Ltd.

Tsuyoshi Mano

Junpei Hosoya

A power conversion device includes a power conversion circuit, a memory, a voltage detection circuit, a current detection circuit, and a control circuit. The power conversion circuit controls a switching device based on a switching pulse signal to convert direct current power into alternating current power and output the alternating current power to a power supply target. The memory stores an alternating current phase difference. The voltage detection circuit detects an alternating current voltage effective value. The current detection circuit detects an alternating current effective value. Based on the alternating current phase difference, the alternating current voltage effective value, and the alternating current effective value, the control circuit stops output of the switching pulse signal at a time when an alternating current has a value of 0.

Power conversion device, image forming apparatus, and power conversion control method

A power supply apparatus includes a clock signal generating unit that generates a clock signal with a clock frequency, a calculating unit that calculates a frequency at which a first frequency, a second frequency, and a third frequency are synchronized based on the clock frequency, an AC voltage output unit that outputs an AC voltage of the second frequency based on a signal of the first frequency, a DC voltage output unit outputting a DC voltage based on a signal of the third frequency, and an output unit that outputs based on the AC voltage and the DC voltage.

Power supply apparatus, image forming apparatus, and voltage control method

There is provided a voltage generation device for generating a voltage in which an alternating-current voltage is superimposed on a direct-current voltage, to apply the voltage to a rotary body. The voltage generation device includes a direct-current power supply, an alternating-current power supply, a variation phase determiner, and a voltage controller. The alternating-current power supply is connected to the direct-current power supply. The variation phase determiner is configured to determine whether variation of an output voltage of the alternating-current power supply and variation of an output current of the alternating-current power supply are in opposite phases. The voltage controller is configured to perform gain correction for the output voltage in a case where the variation of the output voltage and the variation of the output current are in opposite phases.

Voltage generation device, power control device, image forming apparatus, and control method

A PWM controller includes a sine wave calculator to generate a sine wave signal according to a frequency command value, a first counter to generate a first triangular wave carrier signal, and a comparator to compare the sine wave signal with the first triangular wave carrier signal, generate a PWM signal, and supply the PWM signal to a power converter. The PWM controller further includes a second counter to generate a second triangular wave carrier signal that is &#x3c0; rad behind the first triangular wave carrier signal, a carrier number calculator to calculate a carrier number based on a multiplication number, and a carrier control unit to switch the first triangular wave carrier signal and the second triangular wave carrier signal based on the carrier number, to supply the triangular wave carrier signal to the comparator.

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Tokyo, Japan

Tsuyoshi Mano