Claims
- 1. An electronic clock emitting time signals corresponding to the strokes of ships' bells, comprising:
- a clockwork including a generator of a square wave with two interleaved first and second half-cycles of different voltage levels;
- normally blocked pulse-producing means with a recurrence period equal to less than a half-cycle but not less than a quarter-cycle of said square wave;
- a striker mechanism connected to an output of said pulse-producing means for sounding a stroke in response to each pulse emitted thereby;
- normally open switch means briefly closed by said clockwork every thirty minutes for activating a switching circuit into emission of an unblocking signal to said pulse-producing means, said generator having an enabling circuit connected to said pulse-producing means for making said unblocking signal effective only during said first half-cycles whereby not more than two consecutive pulses can be emitted to said striker mechanism during any cycle of said square wave; and
- control means coupled with said clockwork and connected to said pulse-producing means for deactivating said switching circuit after the emission of a number of pulses rising from one through eight in successive half-hour intervals of a four-hour operating period.
- 2. An electronic clock as defined in claim 1 wherein said pulse-producing means comprises an astable multivibrator with complementary first and second transistors connected in cascade, said second transistor having a collector lead constituting said output and forming part of a feedback connection to a base of said first transistor, said feedback connection including a capacitor in series with a resistor.
- 3. An electronic clock as defined in claim 2 wherein said switching circuit is connected to said base via a further resistor, said enabling circuit comprising a diode inserted between said generator and said base.
- 4. An electronic clock as defined in claim 1 wherein said generator is connected to said switch means for activating said switching circuit only during one of said second half-cycles.
- 5. An electronic clock as defined in claim 4 wherein said switch means comprises a first contact pair closed by said clockwork on the full hour and a second contact pair in parallel with said first contact pair closed by said clockwork on the half hour, said switching circuit including a first flip-flop with setting and resetting inputs respectively connected to said first and second contact pairs, a second flip-flop with a setting input connected to a set output of said first flip-flop, and a third flip-flop with a setting input connected to a reset output of said first flip-flop, said second and third flip-flops having outputs connected through a logic gate to said pulse-producing means for transmitting said unblocking signal thereto in response to a switchover of said first flip-flop, said second and third flip-flops having resetting inputs connected to said control means.
- 6. An electronic clock as defined in claim 5 wherein said control means comprises a fourth flip-flop respectively settable and resettable by said pulse-producing means at the beginning and at the end of a pulse emitted thereby, counting means with a stepping input connected to a set output of said fourth flip-flop, timing means coupled with said clockwork for emitting numerical signals representing the number of strokes to be sounded on each full and half hour of said operating period, and comparison means with input connections to said counting means and to said timing means for resetting said second and third flip-flops and said counting means upon the count of the latter equaling the value of said numerical signals.
- 7. An electronic clock as defined in claim 6, further comprising a coincidence gate with inputs connected to said comparison means and to a reset output of said fourth flip-flop for resetting said counting means and said second and third flip-flops only upon termination of a pulse emitted by said pulse-producing means.
- 8. An electronic clock as defined in claim 5 or 6, further comprising a pair of capacitors respectively inserted between the setting inputs of said second and third flip-flops and the set and reset outputs of said first flip-flop.
- 9. An electronic clock as defined in claim 1, 2 or 4 wherein said half-cycle has a duration of one second, said recurrence period being substantially three-quarters of a second, said pulses having a width of less than one-tenth of a second.
- 10. An electronic clock as defined in claim 1, 2 or 4 wherein said striker mechanism comprises electromagnetic coil means and a swingable magnetic armature controlled by said coil means.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2817762 |
Apr 1978 |
DEX |
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CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of our copending application Ser. No. 29,758 filed Apr. 12, 1979 and now abandoned.
US Referenced Citations (4)
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
29758 |
Apr 1979 |
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