| 摘要 |
PROBLEM TO BE SOLVED: To provide a charging circuit of a constant current charge system which can surely charge a battery even in the case that a charger of, low charge current supply capacity is used, and a charge control method using the charging circuit. SOLUTION: The charging circuit of the constant-current constant-voltage charge system, which is equipped at least with a charger detecting circuit 6, a charge current monitoring circuit 7, a power source for a constant current reference, a voltage monitoring circuit 8, a reference power source 11 for a constant voltage, a constant current constant voltage charging circuit 9, an FET 2, and a charge control circuit 12, is provided with a charger voltage monitoring circuit 5 which monitors the supply voltage of a charger. The circuit uses a D-A converter 10 for the constant current reference where a voltage value is variable as a reference power source for a constant current. In the case that a supply voltage on the charger side reaches a threshold or under, the circuit it adjusts the voltage of the D-A converter 10 for the constant current reference into a charge current fit for the charger thereby executing constant current saving charge. By this, the circuit can charge a battery without fail even in the case that the charger of the low current supply capacity is used. COPYRIGHT: (C)2007,JPO&INPIT |
