| 摘要 |
PURPOSE:To indicate an alarm relative to the reduction of the residual life time of a battery when the voltage of the battery is lower than a reference voltage, by comparing the voltage of the battery with the reference voltage through a comparator every closing of an input switch. CONSTITUTION:When an AC power supply is connected by closing an input switch 3, an input sensor 21 is operated to convert the sensed signal into an electrical signal by a sensed-signal converter 22. The converted signal is inputted into a timer 23 to operate the timer 23, and its time-up signal is inputted to a comparator 24. In the comparator 24, the voltage of a battery 11 is sensed, and this sensed signal is compared with a reference voltage integrated into the comparator 24. When the voltage of the battery 11 is lower than the reference voltage, an alarm is indicated by an indicator 25. Thereby, the reduction of the residual life time of the battery 11 is sensed automatically to indicate the alarm, and based on the indication, the battery 11 can be replaced with another one surely. |
