Quartz alarm clock with analogue time display - has multivibrator circuit controlling periodic switching of alarm source

摘要

The alarm clock has a quartz-oscillator, supplying pulses to a frequency divider chain, connected to an electromechanical drive for the clock mechanism, to operate an analogue time display. The clock also has a mechanical alarm switch (46, 48) and a multivibrator circuit, for periodically switching the alarm source ON and OFF. The multivibrator circuit is brought into operation upon operation of the alarm switch, so that the alarm source is initially operated on half period after operation of the alarm switch. A second bistable multi-vibrator circuit for switching the alarm source ON and OFF is controlled by the alarm switch and the manual switch for turning OFF the alarm.