Eta Sa Manufacture Horlogere Suisse

Joerg Berthoud

Pascal Lagorgette

Francois Klopfenstein

Yves Godat

Nicolas Jeannet

Thierry Bonnet

François Klopfenstein

Uwe Schoenherr

Uwe Schönherr

A control circuit of a timepiece motor (), including a bipolar permanent magnet (), a stator () defining two isthmi (&) and two rest positions for the rotor, and a coil () mounted on the stator. The control circuit can determine the position of the rotor at rest. An electric pulse generator () for detecting an external magnetic field formed by a circuits for: measuring the electrical current in the coil after an electrical pulse has been triggered, comparing the measured electrical current with a reference current, measuring the time allowing measuring a rise time between triggering of the electrical pulse and the next time the electrical current flowing in the coil reaches the reference current, and processing the rise time to be able to determine whether the measured rise time indicates the presence of a given external magnetic field passing through the two isthmi.

Control circuit of a stepper motor capable of detecting an external magnetic field

The present invention concerns an electronic device comprising a calculation unit capable of generating a signal representative of a physical magnitude, for a motor driving a display device, said motor comprising a rotor in a magnetic circuit, two terminals, one positive and one negative, via which the calculation unit controls the motor, the electronic device further comprising at least one shock detector circuit connected between the calculation unit and a motor terminal for the detection of an external shock applied to the motor,

Shock detector circuit and method for operation thereof

A mechanism drives the hands of an electromechanical watch. It includes an electric motor, a set of gear wheels connected to the electric motor to move the hands forward or backward on each actuation of the electric motor, and a locking device. The locking device includes a piezoelectric actuator for locking, in a rest mode, directly or via a bolt, one wheel of the set between each actuation of the electric motor. The piezoelectric actuator releases the wheel of the set of gear wheels, when it is actuated by an electrical signal at the moment of each actuation of the electric motor to move the hands forward or backward.

Mechanism for driving the hands of an electromechanical watch, provided with a locking device

The electromechanical transducer () includes a rotor () and two coil (), the rotor being formed of first, second and third parts () made of magnetic material with respectively first, second and third superposed central zones (), a first, axially polarized, bipolar magnet () being arranged between the first and second central zones and a second bipolar magnet () axially polarized in an opposite direction to that of the first magnet being arranged between the second and third central zones. The first and third parts each include N tongues, where N is a number greater than one (N&#x3e;1), which extend radially from the central zone and the second part including 2N tongues, of which N first tongues are folded such that their respective end zones are arranged in a first geometrical plane () in which the tongues of said first part are located, and of which N second tongues are folded such that their respective end zones are arranged approximately in a second geometrical plane () in which the tongues of said third part are located. The N first tongues of the second part are located respectively opposite the N tongues of the third part whereas the N second tongues of said second part are located opposite the N tongues of the first part. The two coils are located between the first and second geometrical planes of the rotor such that, when the rotor is rotating, the end zones of the rotor tongues pass opposite said at least one coil.

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Villeret, Switzerland

Joerg Berthoud