| 摘要 |
PURPOSE:To signal the time when external noise is getting smaller and the passing min from the time signal by giving a selection circuit selecting sound data read out of a sound ROM and a restart circuit signaling the time when noise is getting smaller. CONSTITUTION:When external noise is larger, an AND gate 84 is opened because the output signal of a noise detecting circuit is 'H', whereas an AND gate 86 is closed. When an external switch is operated, an output 48a comes to 'H', and is inputted to the set input S of FFs 90, 68 and 80 through an AND gate 84. The output Q is considered to the 'H'. When the output Q of the FF90 comes to 'H', an AND gate 72 is opened. When the inverse of the output Q comes to 'L', a reset passing time counter 32 is released, and starts counting. The output Q of the FF68 comes to 'H', whereby a sound signal generator circuit 38 starts its action. Since a code signal in a standby code ROM28 is outputted to the sound signal generator circuit 38 at that time, a sound is emitted from a pronunciation circuit 40. |
