| 摘要 |
PROBLEM TO BE SOLVED: To perform charging by a primary battery even if there is no charger, and to automatically switch a charging power supply. SOLUTION: There is provided a detection switch 4 that is turned on/off in accordance with the situation whether or not the primary batteries 3a to 3c are attached to a primary battery holder. In a normal state that the primary batteries 3a to 3c are not attached, terminals a and c of a charging changeover switch 18 are connected to each other by the detection signal of the detection switch 4, and a voltage fed from an external charger is inputted to a DC-DC converter 17. A secondary battery 11 is charged with the output of the prescribed value of the DC/DC converter 17. When the primary batteries 3a to 3c are attached, the detection switch 4 is turned on, the terminals b and c of the charging changeover switch 18 are connected, and output voltages of the primary batteries are inputted to the DC-DC converter 17. The secondary battery 11 is charged with the output of the prescribed value of the DC/DC converter 17. COPYRIGHT: (C)2005,JPO&NCIPI |
