| 摘要 |
PURPOSE:To provide a battery driven device which can more efficiently use a chargeable battery only for memory backup especially with respect to the power source. CONSTITUTION:This device is provided with a power supply circuit 14, to which the power output is supplied from a battery 10 of a main power source and a chargeable battery 12 only for data backup and which supplies, the power output of the battery 10 to each part and supplies the power output of the battery 12 to a circuit part where data to be backed up is stored in the case of reduction of the output voltage of the battery 10 to a value lower than the output voltage of the second battery 12, and a charging circuit 16 which charges the battery 12 with the power output of the battery 10 in the case of the output voltage of the battery higher than that of the battery 12. |
