A step motor particularly suited for use in electronic timepieces wherein the induced current generated by the stepping of the rotor is utilized to minimize the power consumption thereof. The step motor includes a permanent magnet rotor adapted to be stepped through a specific angle, at least two stator poles surrounding same, and an electromagnetic core coupled to the stator poles for providing at least first and second magnetic orientation to said stator poles in order to step said rotor through the specific angle. Coupled to the electromagnetic core is a circuit for applying driving pulses to the stator pole to effect said orientations thereof, and a second circuit coupled to said first mentioned circuit for terminating each drive pulse applied to said electromagnetic core at a time coincident with completion of the stepping of the rotor through the specific angle.
A battery operated watch includes an actuator mechanism adapted to actuating indicator hands of the watch. The actuating mechanism includes a gear train adapted to drive indicator hands, a motor for driving the gear train, and an electronic block unit. The electronic block unit includes an oscillator and electronic circuit for operating the motor. A mechanism plate and bridge are provided. A carrier plate of insulative material is disposed between the mechanism plate and bridge. The carrier plate has pockets, including indentations, bores and openings, for receiving and retaining in position at least some components of the actuating mechanism. Means is provided for securing the mechanism plate, bridge, and carrier plate together, including a plurality of pillars extending between the mechanism plate and the bridge.
The invention relates to a step motor particularly for an electronic timepiece, comprising a stator whose two free ends constitute two pole pieces 4, 5, delimiting therebetween an air-gap 6 in which is accommodated the rotor 2. Each pole piece is provided with a recess 8 of cylindrical shape so that the axis of each cylinder is parallel with the axis of rotation Ar of the rotor 2. The two axes of the said cylinders are shifted from one another by a value comprised between 80.mu. and 200.mu. in a direction perpendicular to the plane P defined by the axis of rotation Ar of the rotor 2 and the main direction of the flux 13 generated by an exciting coil associated with the stator. The radii of the rotor 2 and the stator 3 are in the order of about 800.mu. and 1500.mu. respectively.
The invention relates to a step motor particularly for an electronic timepiece, comprising a stator whose two free ends constitute two pole pieces delimiting therebetween an air-gap in which is accommodated the rotor. Each pole piece is provided with a recess of cylindrical shape so that the axis of each cylinder is parallel with the axis of rotation Ar of the rotor. The two axes of the said cylinders are shifted from one another by a value comprised between 80.mu. and 200.mu. in a direction perpendicular to the plane defined by the axis of rotation Ar of the rotor and the main direction of the flux generated by an exciting coil associated with the stator. The radii of the rotor and the stator are in the order of about 800.mu. and 1500.mu. respectively.
A stepping motor unit includes an annular motor mount having a center opening, a rotor which is rotatably supported on the annular motor mount, and a pair of stators which are supported on the annular motor mount to cause the rotor to rotate due to magnetic force. The stators have linear coil holders for holding the coils, which are arranged substantially along the inner and outer peripheries of the annular motor mount.
The method and circuit are particularly suitable for use in timepieces and are adapted to supply the motor with chopped-voltage pulses of variable durations as a function of the load conditions of the motor. A chopped pulse of variable duration T.sub.7 is composed of a partial pulse T.sub.4 of fixed duration and of a constant number of partial pulses T.sub.6i of variable duration, spaced by intervals T.sub.5i which are themselves determined by the duration of current drop between the preceding peak and a reference value. The durations T.sub.6i are proportional to the intervals T.sub.5i.
