| 摘要 |
PROBLEM TO BE SOLVED: To provide a charger which can charge a secondary battery with a relatively large charging current in the initial period, after the start of charging and prevent the secondary battery from being overcharged after instantaneous power supply interruption, etc. SOLUTION: A charge control circuit 3 and a discharge control circuit 4 turn on/off switching devices Q1 and Q2 respectively according to the output of an interruption detecting circuit 2. A current control means which can vary a charging current from a step-down circuit 1 to a secondary battery EB comprises resistors R1 and R2, the switching device Q1 and the charge control circuit 3. The respective resistance values of the resistors R1 and R2 are set so as to have the charging current to the secondary battery EB 1/20 CmA-1/10 CmA and approximately 1/50 CmA in the on-state of and off-state of the switching device Q1, respectively. A discharging means which discharges the secondary battery EB consists of the switching device Q2 and the discharge control circuit 4. |
