| 摘要 |
PURPOSE:To produce alarm sounds of changing pitches by synthesizing two or more kinds of driving signals through the ultilization of respective frequency dividing stage outputs thereby producing alarm sounds. CONSTITUTION:The frequency divided outputs from a frequency dividing circuit 4 go through an AND gate 28 which is opened by way of a coincidence memory circuit 16 and priority circuit 20 at the alarm set time to open an AND gate 27 to which the divided outputs phix from a circuit 4 are applied. On the other hand, the divided outputs phi1 are applied to an FF 40 whose input clock is the divided outputs phi2 throgh the inverter of the circuit 4. The AND gate 38 to which the divided outputs phiy of the circuit 4 are applied is opened by the outputs phi1 of a phase deviated according to the outputs phi1, phi2 outputted by the FF 40, at the timing differing from the opening timing of the gate 27. an alarm sound producing circuit is driven by the divided outputs phix, phiy differing with the first and second halves, whereby the alarm sounds of changing pitches being not monotonous may be produced. |
