| 摘要 |
PROBLEM TO BE SOLVED: To charge a lithium ion battery without malfunction by judging whether a secondary battery is built in or not by program control. SOLUTION: To judge whether a lithium ion battery 3 is mounted or not, a charging circuit 2 is turned on by the direction of the output port D of CPU1. The 1 lithium ion battery 3 is charged until passage of the ON time T1 of the charging circuit 2. Then, the charge circuit 2 is turned off to stop the charging, and then it is judged whether the voltage of the battery terminal of the lithium ion battery 3 inputted into an input port C is under such level that it can be judged to be fully charged or not. Next, it is judged whether the voltage of the battery terminal is over such level that it can be judged that the battery is mounted or not, and if it is under that, the procedure returns to the start, judging that the lithium ion battery 3 is not mounted. In the case where it is mounted, the charge time T2 is set to the timer. |
