| 摘要 |
PURPOSE:To prevent time from varying even if a time setting switch is touched carelessly, by providing a resetting circuit which operates on the ending of the operation of the time setting switch and stores an unadjustable state in a display kind storage circuit a certain time later. CONSTITUTION:To adjust the time display on a display device 34 to current time, a timer setting switch 7 is operated and a display kind storage circuit 18 is placed in a timer display state temporarily. At this time, a second counter 25 is cleared to (0). Then, a minute setting switch 10 is operated to supply a clock pulse P6 to a minute counter 24, whose value is set, and an hour setting switch 9 is operated to supply a clock pulse P6 to a hour counter 23. At this time, a subtracting counter 12 is preset to, for example, (5) during the setting of minute and second data, then performs subtracting operation after the time setting; when its value reaches (0), information showing an invariably timer display state is stored in the storage circuit 18 and at the same time, AND circuts 26 and 28 are closed to prevent the time from varying even if the switches 9 and 10 are operated carelessly. |
