| 摘要 |
PURPOSE:To generate a sound signal at every 30min at night automatically by dividing one day into two time bands and inhibiting the sound signal after 15min and 45min from a just o'clock in one time band. CONSTITUTION:In the time band from 6 a.m. to 10:45 p.m., the output of a discrimination circuit 9 is turned to ''0'' and gates 19, 20 are opened. Pulses are outputted from pulse generators 15, 16, 17 at 15min, 30min and 45min respectively. Slightly before the just o'clock a switch 21 is turned on and a pulse is outputted from a pulse generator 14 at the just o'clock. When respective pulses are inputted to a control circuit, the sound is signalled. At the time band from 11 p.m. to 5:45 a.m., the output of the discrimination circuit 9 is turned to ''1'' and the gates 19, 20 are closed. Since pulses at 15min and 45min are not inputted to the control circuit, sound signal is generated every 30min. At that time, sound volume can be automatically controlled. |
