Canon Kabushiki Kaisha

Jun Kawakatsu

Yasuhiro Shimura

Junya Kobayashi

The power supply apparatus comprising a generation unit configured to generate a pulse signal, a memory unit configured to store information set in advance on the driving frequency, and a determination unit configured to determine an error of the input voltage and an error of a load, to a piece of the information stored in the memory unit, a driving frequency detected by the detection unit under a state where a load is connected to the convertor, and based on a result of comparing, to a piece of the information stored in the memory unit, a driving frequency detected by the detection unit under a state where the load is not connected to the convertor.

Power supply and image forming apparatus

The power supply apparatus, when a switching element is driven at a second frequency lower than a first frequency, determines a duty of a pulse signal according to a predetermined voltage so that a frequency of the pulse signal input to a feedback unit is equal to or more than a predetermined frequency.

Power supply apparatus and image forming apparatus

A power supply device controls a driving frequency of a transformer in which a primary side and a secondary side are insulated, thereby converting a voltage input to the primary side, and supplying a voltage output to the secondary side to a load. The power supply device includes a control unit, a switching element, and a setting unit. The control unit is configured to control operation of the switching element for driving the primary side of the transformer. The setting unit is configured to set an upper limit driving frequency of a driving frequency of the switching element. In a case where a voltage to be input to the primary side is higher than a rated input voltage, the control unit controls the operation of the switching element to perform driving by using the upper limit driving frequency as the driving frequency of the switching element.

Power supply device having switching element with driving frequency control based on input voltage and image forming apparatus having power supply device

A power supply device includes a switching unit configured to switch to a first path in which a current smoothed by a smoothing unit is supplied to a boost converter and to a second path in which the smoothed current is supplied to a load without passing through the boost converter. The switching unit includes a first switching element to be turned on and a second switching element to be turned off when the first path is formed.

Power supply device and image forming apparatus

A power source apparatus includes a transformer configured to output a voltage, a feedback unit configured to output a feedback signal based on the voltage output from the transformer, and a driving unit configured to drive the transformer according to a setting signal for setting the output voltage and the feedback signal. Whichever of a voltage of positive polarity and a voltage of negative polarity is output, the feedback unit controls the voltage output according to a value of a difference between the output voltage and a threshold value.

Power source apparatus and image forming apparatus

A power supply includes a rectification unit configured to be able to switch a rectification method between a voltage doubler rectification method and a full-wave rectification method according to an input alternating voltage, two capacitive elements serially connected between lines from the rectification unit, a monitoring unit configured to monitor a first voltage applied between the lines between which the two capacitive elements are connected and a second voltage applied across one of the capacitive elements that is connected to a lower potential side of the lines, and a switch configured to operate according to the second voltage, wherein the power supply interrupts the alternating voltage according to an operating state of the switch, the first voltage, and the second voltage.

Power supply switching rectification method according to input alternating voltage, and image forming apparatus having the same

A power supply includes a transformer, a switching unit configured to drive the transformer at a primary side of the transformer, a voltage adjustment unit configured to adjust voltage of a capacitive element at a secondary side of the transformer, at the primary side thereof, and a plurality of constant voltage members connected across the terminals of the capacitive element at the secondary side of the transformer, wherein the power supply generates voltage having a predetermined polarity during the period before the voltage of the capacitive element at the secondary side of the transformer becomes a predetermined voltage by the voltage adjustment unit, and generates voltage having a polarity opposite to the predetermined polarity after the voltage of the capacitive element at the secondary side becomes the predetermined voltage.

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Yokohama, Japan

Jun Kawakatsu