| 摘要 |
PURPOSE:To prevent malfunction by specifying the constitution of shift registers and the period of clocks. CONSTITUTION:Shift registers 6A, 7A of a switching means which generates time setting signal, just time signal, etc. are formed in 3-bit constitution and the periods of the clocks of the shift registers 6A, 7A are made larger than the width of bouncing which occurs at the ON and OFF of the switching means. Thereby, the chattering and bouncing which occur at the ON and OFF of the switching means when a speaker 15 is sounded as the data are inputted to a frequency dividing circuit 1 and striking sound period pulse signals are generated by changing over a rotary switch RS and turning ON of a switch SW2 of a time matching circuit 7 after the counter C1 of a time striking number setting circuit 11 has been reset via flip-flop FF1 by the pulse signals from a power source ON detecting part 5, whereby malfunction in logic operation is prevented. |
