Device for displaying remaining electric energy of battery

摘要

A display device has a time-constant circuit and a switching element such as a transistor for supplying the voltage of a battery to the time-constant circuit when a battery check key is pressed. A microcomputer measures a time interval from a time when the voltage of the battery starts being supplied to the time-constant circuit to a time when a voltage of the time-constant circuit reaches a predetermined value, and determines the remaining electric energy of the battery from the measured time interval. The microcomputer supplies data to a display unit which then displays a progressively variable display mark combination representative of the determined remaining electric energy of the battery.