Method for controlling the vibration frequency of a mechanical vibration system of an electromechanical clockwork, and circuit arrangement for carrying out the method

摘要

In a method for controlling the vibration frequency of a mechanical vibration system of an electromechanical clockwork, and in a circuit arrangement for carrying out the method, the aim is to improve the mean accuracy in conjunction with a reduced power requirement for the drive by means of a controller which can be set in a manner which is functionally uncritical. For this purpose, the temporal occurrence of a measurement pulse (22) which is obtained inductively in the mechanical vibration zero crossing is compared with an assigned reference pulse (25) obtained in a quartz-stabilised way, and given a prematurely started measurement pulse (22) in the three-step operation a drive pulse (18) of excessive energy content is coupled electromagnetically into the mechanical vibration system (pendulum 7). If the measurement pulse (22) thereafter starts too late with respect to the assigned reference pulse (25), the coupling in of vibratory energy is blanked out completely and in the case when the measurement pulse (22) and reference pulse (25) coincide a standard drive pulse (18) is triggered which just compensates friction losses in the mechanical vibration system (pendulum 7) in the electromechanical clockwork (1), or preferably slightly over-compensates. Synchronism between the reference pulses (25) and the assigned measurement pulses (22) is produced by arranging that after starting of the mechanical vibration system (pendulum 7) the first reference pulse (25) is triggered by a measurement pulse (22) after a few settling vibration periods. Used preferably to lengthen the transit time of battery-operated suspension-pendulum or ring (torsion)-pendulum clocks, in which the mechanical vibration system serves chiefly not the keeping of time but only the mechanical drive of the motion gear (4). IMAGE