Fdk Corporation

Tomoki Onaka

Norio Fukui

Yukio Ono

Miyabi Ishikawa

A charging device of the present invention includes a DC-DC converter, a charging circuit that charges a secondary battery, a power supply voltage detecting circuit that detects an input voltage Ve, an output voltage setting circuit that sets an output voltage of the DC-DC converter, and a charging control section that controls the charging circuit and the output voltage setting circuit based on the input voltage Ve, and the charging control section increases the output voltage of the DC-DC converter by a predetermined voltage in a stepwise manner while monitoring the input voltage Ve, and in a case where the input voltage Ve is decreased to a first threshold voltage Vthor less before the output voltage of the DC-DC converter increases to a rated charging voltage, the charging control section keeps the output voltage of the DC-DC converter at a voltage that is one step lower than a voltage at a time point of the case.

Charging device that can optimize charging current of a secondary battery

A switching power supply includes an input terminal and an output terminal, a voltage converter including a first switching circuit configured to serve as a trigger for inputting a voltage from the input terminal and a second switching circuit configured to serve as a trigger for outputting, after the input voltage is converted, the converted voltage from the output terminal O, a control circuit configured to output a control signal for selectively sequentially driving the first switching circuit and the second switching circuit, and a delay circuit configured to delay, based on the control signal for driving any one of the first switching circuit and the second switching circuit, a subsequent driving timing of the other switching circuit that is not driven to provide a dead time when both the first switching circuit and the second switching circuit are turned off.

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Tokyo, Japan

Tomoki Onaka