| 摘要 |
PURPOSE:To prevent a preset current time from being changed even when a time-specifying switch is depressed by mistake and to avoid the complexity of the operation of setting a reserved time. CONSTITUTION:An hour-specifying switch 14 which specifies hours with one hour as unit every depressing operation is connected to the time input port I<1> of a clock integrated circuit 27 which outputs time indication signals. A minute-specifying switch 15 which specifies minutes with one minute as unit every depressing operation is connected to the minute input port I2 of the integrated circuit 27. Both switches 14 and 15 are connected to a constant voltage power source 26 via a time set switch 16 common to those. The appointed set input port I3 of the integrated circuit 27 is connected to the power source 26 via the first on-off switch 17a of a mechanical reserved time set switch 17 having first and second on-off switches 17a and 17b interlocking each other, and the second on-off switch 17b is inserted to a circuit which is parallel with the set switch 16 and connects the minute-specifying switch 15 to the power source 26. |
