| 摘要 |
PROBLEM TO BE SOLVED: To provide a switching circuit which can make charging possible while electricity is turned on without shifting between precharge and regular charge repeatedly. SOLUTION: A charge switching circuit 60 is provided with a first terminal 68 connected to both terminals of a battery, a second terminal 69 connected to a charging terminal of a charging circuit, a first switch 61 connected between the first terminal 68 and the second terminal 69 and opened/closed by control of a CPU 18, a second switch 62 connected between the first terminal 68 and the second terminal 69 and opened/closed by control of a precharge control circuit 64, a third switch 63 with one end connected to the first terminal 68 through a voltage division circuit 66 and the other end connected to the negative pole terminal of the battery and so controlled as to be closed when the precharge control circuit 64 is operating and opened when the precharge control circuit 64 stops, and a voltage detection circuit 65 which detects the voltage at a voltage division point 70 of the voltage division circuit 66 and outputs a control signal 67 which stops the operation of the CPU 18 when the detected voltage is a threshold voltage (3 V) or below and causes the CPU 18 to start regular charging when the detected voltage is threshold voltage or above.
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