| 摘要 |
PURPOSE:To simplify the detection of the discharge service life of a battery, and also, to have a sufficient margin for replacing the battery by executing integration of the power failure time, and outputting a backup use battery discharge alarm signal to the outside, when the integrating value reaches the discharge service life time of the backup use battery, which is set in advance. CONSTITUTION:When a power source of +5V is disconnected, a power failure detecting signal 10 goes to significant. A power failure time integrating part 18 integrates the time when the power failure detecting signal 10 is significant. When the power source of +5V is turned on, the power failure detecting signal 10 goes to insignificant, therefore, the power failure time integrating part 18 suspends the integration of the power failure time, and holds the integrating value of the power failure time. When the power source of +5V is disconnected again, the integration of the power failure time is started, the power failure time is added to the integrating value which is held up to the present. When a value integrated by the power failure time integrating part 18 coincides with a value which is set in advance by a discharge time setting part 20, a primary battery discharge alarm signal 19 goes to insignificant, and informed to the outside. |
