To prevent overvoltage in advance and to charge the target in a short time, by switching an object charge voltage to switch the action from the charge by constant current to constant voltage, according to the charge current being detected by applying prescribed voltage.
A control circuit 24 switches the action from constant current drive to constant voltage drive, when the terminal voltage of a battery 8 comes a prescribed changeover voltage after start of charge, by the control the control circuit 25 arranged in a protective circuit 23. At this time, changeover high voltage VH and low voltage VL are set as objective charge voltage. Then, the control circuit 25 switches the action of the control circuit 24, based on the output signal of a switch circuit 34 and switches the operation mode from the charge by constant current to the charge by constant voltage. As a result, this charge circuit can prevent overvoltage, and charge a battery 8 in a short time by supplying it intermittently with a charge current.
IKEDA TAMON
TAKEI TOSHITAKA
