Abstract: An electronic clock emitting half-hourly time signals corresponding to sh' bells comprises an electromagnetic striker driven by a crystal-controlled oscillator via a multistage binary frequency divider whose last several stages, with the exception of the penultimate stage, have outputs interconnected by a logical coincidence gate to generate a succession of output pulses occurring in pairs during the first half of every cycle of a square wave emitted by the final stage. This square wave steps a motor which drives an associated clockwork entraining a multibank rotary switch and alternately closing, for short periods on the full hour and on the half hour, respective contacts which transmit the square wave to a control circuit including an electronic pulse counter.

Abstract: An electronic clock emitting half-hourly time signals corresponding to the strokes of ships' bells comprises an electromagnetic striker driven by a normally blocked astable multivibrator whenever the closure of contacts operated by an associated clockwork, stepped by a crystal-controlled square-wave generator, coincides with a half-circle of predetermined polarity of the generated square wave. The multivibrator has a period of approximately 3/4 the duration of a half-circle of the square wave whereby not more than two pulses energizing the striker mechanism can be emitted by it during an unblocking half-circle so that strokes occurring at the ends of a second, third and fourth hour of a four-hour watch will appear in distinct pairs while those on the preceding half-hours will form one or more pairs followed by a single stroke after a larger time interval.