A continuously rotating electric motor includes a rotor provided with permanent magnets and a stator formed by two coils in which, when the rotor is rotating, two induced voltage signals (U.sub.B1 and U.sub.B2) are respectively generated, which signals have an electric phase shift where 590, preferably 30<<65. The control device includes a circuit for detecting intersection times (T.sub.C) at which values of the two induced voltage signals are substantially equal. The control device is arranged to generate electric driving pulses to rotate the rotor, which are respectively initiated at initiation times determined by respective intersection times, and such that the electric driving pulses can be applied to the two coils arranged in series. Preferably, the control device is arranged such that the initiation times of the electric driving pulses occur directly after detections of corresponding intersection times.

A motor drive unit for driving a direct current electric motor including a moving part equipped with permanent magnets. The motor drive unit, which is powered by a voltage supply source, includes a switch circuit, an inductor circuit and a capacitor circuit including a set of capacitors. By selectively opening and closing the switches of the switch circuit, a series of consecutive low energy pulses can be generated such that the power consumption of the motor drive circuit is minimized.

A motor drive unit for driving a direct current electric motor including a moving part equipped with permanent magnets. The motor drive unit, which is powered by a voltage supply source, includes a switch circuit, an inductor circuit and a capacitor circuit including a set of capacitors. By selectively opening and closing the switches of the switch circuit, a series of consecutive low energy pulses can be generated such that the power consumption of the motor drive circuit is minimized.

A method for measuring the medium frequency of a digital signal derived from a reference periodic signal generated by an electronic oscillator (quartz oscillator) forming a timepiece (2) which includes an analogue time display device and a continuous rotation electromechanical transducer (generator or continuous rotation motor) which is kinematically linked to this display device and wherein the medium rotational speed is regulated by a regulation device. The medium frequency of the digital signal is determined by a measurement device (70) without galvanic contact with the movement of the timepiece. The measurement method makes it possible to determine the rate of the timepiece and the precision of the electronic oscillator based on regulation impulses detected by a magnetic sensor (72) and over a measurement period limited to the duration of an inhibition cycle of periods of the reference periodic signal.

A method for measuring the medium frequency of a digital signal derived from a reference periodic signal generated by an electronic oscillator (quartz oscillator) forming a timepiece (2) which includes an analogue time display device and a continuous rotation electromechanical transducer (generator or continuous rotation motor) which is kinematically linked to this display device and wherein the medium rotational speed is regulated by a regulation device. The medium frequency of the digital signal is determined by a measurement device (70) without galvanic contact with the movement of the timepiece. The measurement method makes it possible to determine the rate of the timepiece and the precision of the electronic oscillator based on regulation impulses detected by a magnetic sensor (72) and over a measurement period limited to the duration of an inhibition cycle of periods of the reference periodic signal.

An electronic watch includes a power generating mechanism; a battery that is charged with power generated by the power generating mechanism; hands that include a second hand; a driving source that rotates the hands; a driving circuit that drives the driving source with power supplied by the battery; and a control circuit that controls the driving circuit. The control circuit executes a first stopping operation for stopping the driving circuit and the control circuit in a power saving mode for suppressing power consumption and when a first determination time elapses without any power being generated by the power generating mechanism. The control circuit executes a second stopping operation for stopping the driving circuit and the control circuit in the power saving mode and when a second determination time elapses while a voltage of the battery is at a level equal to or lower than a predetermined level.

An electronic watch includes a power generating mechanism; a battery that is charged with power generated by the power generating mechanism; hands that include a second hand; a driving source that rotates the hands; a driving circuit that drives the driving source with power supplied by the battery; and a control circuit that controls the driving circuit. The control circuit executes a first stopping operation for stopping the driving circuit and the control circuit in a power saving mode for suppressing power consumption and when a first determination time elapses without any power being generated by the power generating mechanism. The control circuit executes a second stopping operation for stopping the driving circuit and the control circuit in the power saving mode and when a second determination time elapses while a voltage of the battery is at a level equal to or lower than a predetermined level.

A hand position identification device includes a rotation detection unit that detects a rotation state of a rotor by using an induced voltage generated in a motor for rotating a hand, a storage unit that stores a timing information piece relating to a timing at which the induced voltage exceeds a predetermined threshold, and a control unit that compares a first timing information piece stored in the storage unit and obtained in a case where the hand is located at a first position, with a second timing information piece obtained in a case where the hand is located at a second position, and that identifies the second position as an identified position in a case where a difference between the first timing information piece and the second timing information piece is equal to or more than a predetermined amount.

A hand position control device includes a mode switching unit that is capable of switching between a normal hand movement mode and a manual hand position setting mode and a control unit that sets a pulse width of a driving pulse to be output to a coil of a motor that rotates a hand and sets a manual pulse width of the driving pulse in the manual hand position setting mode to be larger than a normal pulse width of the driving pulse in the normal hand movement mode.

Timepiece movement fitted with an electromagnetic transducer comprising at least one coil and a rotor formed of a central shaft, of two magnetic plates that are mounted on the central shaft and of a plurality of bipolar magnets which are axially polarized and mounted on at least one of the two magnetic plates, said at least one coil penetrating at least partially into a circular space which is defined by the rotor between its two magnetic plates and left free by this rotor. The central shaft comprises a pinion which engages with a wheel of the timepiece movement, this pinion being arranged between the two magnetic plates and said wheel being partially arranged between the two magnetic plates, in an angular sector of the circular space that is left free by the electromagnetic transducer, so as to engage with the pinion. Advantageously, said wheel has a roller that is almost or entirely non-conductive and a non-magnetic staff.