Title: Electric watch having an electromechanical movement including a correction mechanism for small errors

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Abstract: An electric watch comprising a precise resonator, connected to an oscillator to which a frequency divider is connected. A control device is connected to the watch movement and to the frequency divider for controlling the watch movement to eliminate small errors in indicated time. The control device comprises a first counter synchronized in operation with the watch movement and a second reference counter connected to the divider, a comparator being connected to the counters for comparing the states thereof and coupled to the watch movement for maintaining the counters in phase while varying the speed of the watch movement. The second reference counter can be set to a predetermined state independent of the first counter from outside the watch. In one embodiment the watch movement includes a step motor supplied with impulses from the divider, the comparator being connected to the step motor to act on the frequency of the impulses supplied by the divider to vary the speed of the motor until the first and second counters are equal. In a second embodiment a motor coil serves for applying energy to the watch movement to vary its speed of operation, the motor coil being connected to the comparator to be controlled thereby to effect speed change of the watch movement until the counters are equalized.


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