Panasonic Corporation

Kazuhisa Takada

Masato Yoshida

Shigenori Arai

Ryou Watabe

There is provided a charging apparatus that, even when an AC adapter is connected and there is heavy load, makes it possible to reduce heat produced due to the power loss of a control transistor, reduce cost and area for implementation, and improve safety. Charging apparatushas: P-channel MOS transistors Mand Mthat control charging current; current detecting resistance Rs that is connected to current output terminals of P-channel MOS transistors Mand Mand detects the charging current; switchthat is arranged on a path that bypasses current detecting resistance Rs; and loadthat receives power supply from batterywithout involving current detecting resistance Rs when switchis closed. Current difference amplifieramplifies the detected voltage of current detecting resistance Rs, comparatorcompares the output voltage of current difference amplifierwith the reference voltage, and thereby, when current flowing into batteryis equal to or less than a predetermined value, switchis closed and current detecting resistance Rs is short-circuited.

Growing community of inventors

Kanagawa, Japan

Kazuhisa Takada