Ricoh Company, Ltd.

Ricoh Electronic Devices Co., Ltd.

Keiichi Ashida

Takahiro Tsuji

A charging circuit that simultaneously charges a battery with an electrical current supplied from an external power source and supplies the electrical current supplied from the external power source to a load includes a power supply circuit to supply an electrical current from the battery to the load when a load current required by the load is greater than a maximum supply current of the external power source, a detector to detect a voltage of the battery, and a controller to control power supply to the load as well as charging the battery. When the detected voltage of the battery is lower than the predetermined threshold, the controller stops supplying the electrical current from the battery to the load and charges the battery with the electrical current supplied from the external power source.

Charging circuit and charging method

A reference voltage generating circuit includes a first power supply, a second power supply, a first variable resistance circuit having one end connected to the first power supply and configured to be capable of adjusting a resistance value of the first variable resistance circuit, a series resistance circuit having at least one resistance and one end connected to the first variable resistance circuit, a second variable resistance circuit having one end connected to the series resistance circuit and the other end connected to the second power supply, and configured to be capable of adjusting a resistance value of the second variable resistance circuit, a first terminal arranged between the first variable resistance circuit and the series resistance circuit, a second terminal arranged between the series resistance circuit and the second variable resistance circuit, and a voltage selecting circuit configured to select one of a voltage of the first terminal and a voltage of the second terminal, and output the selected voltage as a reference voltage.

Reference voltage generating circuit and analog circuit using the same

A charge controller includes a power supply circuit and a battery charge circuit. The power supply circuit converts the input voltage into an output voltage for supply to the load at the output terminal. The power supply circuit includes an output current detection circuit and an output current limiting circuit. The output current detection circuit detects an output current supplied through the power supply circuit. The output current limiting circuit limits the output current below a maximum output current limit. The battery charge circuit derives power from the power supply circuit to charge a secondary battery. The battery charge circuit includes a charge current detection circuit and a charge current setting circuit. The charge current detection circuit detects a charge current supplied to the secondary battery. The charge current setting circuit regulates the charge current to a set current value.

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Amagasaki, Japan

Keiichi Ashida