Abstract: The method includes applying to the coil (3) of the motor (2) driving pulses having alternately a first and a second polarity, supplying the coil (3) with a determined quantity of electric energy during each driving pulse, detecting, after each driving pulse, the rotation or non rotation of the rotor of the motor (2) in response to said driving pulse, and adjusting said determined quantity of electric energy as a function of said detection.In order to further reduce the quantity of electric energy consumed by the motor, the method is characterised in that the adjustment of the quantity of electric energy supplied to the coil (3) is effected separately for the driving pulses having the first polarity and for the driving pulses having the second polarity.

Abstract: Transducer, in particular clockwork driving motor, comprising a stator (2) formed of two stator parts (16 and 26) and three cores (18, 19, 20) connecting respectively three magnetic poles (28, 29, 30), defined by the first stator part (16), to the second stator part (26) used to close the magnetic paths of the transducer. The coils (22 and 24) are used to supply the transducer to drive in rotation respectively the two rotors (4 and 6). The coil (23) is connected to detection means (72) used for detecting the rotation of one or other of the two rotors (4 and 6), and in particular, for detecting zero crossing of the induced voltage (or similarly of the induced current) in the coil (23). Detection of zero crossing of the induced voltage is used to provide input signals to the supply means (70) to control driving of the rotors (4 and 6) in an efficient and reliable manner, in particular in a rapid or continuous operating mode, whether in a forward or backward rotational direction.

Abstract: An electromechanical transducer (1), in particular a motor used in timepieces, having a stator (2) and two rotors (14 and 15). The two rotors (14 and 15) are situated respectively in two stator holes (4 and 6) each defined by three stator poles (8a, 10a, 12a; 8b, 10b, 12b). The transducer (1) is capable of functioning as a stepping motor, each of the two rotors being capable of rotating in the two possible rotational directions independently of the other rotor.

Abstract: The control device is intended to supply a stepping motor with driving pulses during which the mean value of the voltage applied to the coil of this motor is independent from the voltage of the power supply source of the device.For that purpose, the control device comprises a driving circuit which connects or disconnects the coil of the motor to or from the power supply source when a control signal has a first state or a second state respectively, and a control circuit which produces this control signal with its first state or its second state in dependency on the difference between a reference voltage and the voltage across the coil.

Abstract: The machine of the invention comprises a sealed enclosure (10) in which a microscope objective lens (34) is fixed and receives a laser beam (36) via a thick transparent window (38), the enclosure also containing a reaction chamber (20) constituted by a sealed box having a lid which constitutes a thin transparent window (56) beneath which the thin film object (32) to be treated is placed. Means (72, 80, 74) serve to evacuate the enclosure (10) and the reaction chamber (20) and to convey reactive gas into the reaction chamber. The invention is particularly applicable to treating electronic circuits, hybrid circuits, etc.

Abstract: Theater stage according to the invention consisting of three bodies which, in a deployed position, confer a pavilion or shell shape. The central body, built on the chassis, consists of a central floor, raised platforms, side walls and a roof. The rear body, in the form of a box is built on a high floor which slides over the central floor and the platforms. The front body consists of a lifting canopy and of several floors: a sliding low floor which may comprise a higher level and two side floors in the form of pivoting quarters which hold up the low floor and which fold back between the said low floor and the chassis.

Abstract: The purpose of the invention is the realization of a motor assembly formed from a stepping motor and its control circuit capable of operating at a maximum speed substantially greater than that obtainable with comparable existing assemblies.This is effected by substituting for the single coil or for each coil of a known motor two or more windings and adopting a control circuit which connects the windings in series or parallel according to whether motor drive pulses of low or high frequency are applied thereto. The total number of winding turns and the sum of the resistances of the windings are preferably chosen to be equal respectively to the number of turns and the resistance of the coil which they replace in order to avoid basic modification of the characteristics and performances of the motor when operating at low speed.When the windings are connected in parallel their resistance and equivalent self-inductance are less than that of a single coil.

Abstract: The device includes two driving circuit (C.sub.1, C.sub.2) each of which includes six power transistors (T.sub.11 -T.sub.16, T.sub.21 -T.sub.26) that are connected in pairs into three parallel circuit branches. A first coil (B.sub.11) of one of the motors and a first coil (B.sub.21) of the other are, on the one hand, both connected to the junctions of the transistors of one of the branches of one of the driving circuits (C.sub.1) and, on the other hand, respectively connected to the junctions of the transistors of the two other branches of this circuit. The same applies for the second coils (B.sub.12, B.sub.22) of the motors and the other driving circuit (C.sub.2). The various transistors are controlled so that the two coils of the same motor simultaneously receive the current pulses which are needed to make it turn but by preventing the simultaneous application of current pulses to a coil from one of the motors and to a coil from the other.

Abstract: The method involves supplying to the motor drive pulses generated by a control circuit, determining by means of a measurement circuit a physical magnitude representative of the motion of the rotor, interrupting the drive pulse at a given instant defined by a calculating circuit according to the time taken by the physical magnitude to reach, in a comparator, a reference level, controlling by means of a missed step detecting circuit whether or not the rotor has effected a step, retrieving if need be a non-effected step, summing the number of missed or non-effected steps in a counting circuit, and modifying in a reference circuit the reference level depending on the number of steps that have been missed in a given period of time.The device for putting this method into operation enables the motor to operate under optimal security and energy consumption conditions and can be used to advantage in timepieces.

Abstract: The invention concerns a method for controlling a bidirectional stepping motor having two windings and three pole faces.The invention comprises applying current pulses alternately to only one of the motor windings to cause it to rotate in one direction and to only the other of the motor windings to cause it to rotate in the other direction.The invention is used for controlling bidirectional motors which are employed in particular in timepieces.

Abstract: The rotor of a stepping motor may remain blocked in an intermediate position different from a rest position if its control circuit adjusts the electric energy of the driving pulses to the minimum corresponding to the actual mechanical load of the motor determined by a measuring circuit. To remove this risk, the method consists in producing with the aid of a generator and applying to the motor, pulses which allow release of the rotor when it has remained blocked in an intermediate position in response to a driving pulse. The release pulses are distinct from any correction pulses which are applied in known manner to make up a lost step. The release pulses precede the correction pulses and are preferably of such polarity as to return the rotor to its starting position to ensure correct action of the ensuing correction pulses.This method applies in particular to the control of the stepping motor of an electronic timepiece.

Abstract: The motor unit comprises a stator, two independent rotors having each a permanent magnet located in a cylindrical space defined by three pole faces of the stator, two windings and at least a positioning magnet for holding both rotors, in the absence of current in the windings, in a position in which the magnetic axes of their magnets are each coincident with a rest axis. The field produced by the flow of a current in one of the windings is always at an obtuse angle to one of the rest axes and at an acute angle to the other.The two rotors perform steps of 360.degree. independently of each other in response to pairs of current pulses, the first of which is applied to one of the windings and the second of which is applied to the other winding. The direction of the current pulses determines which of the rotors performs a step, and the order in which the current pulses are applied to the windings determines the direction of rotation of that rotor.The motor unit can be used in particular in an electronic timepiece.

Abstract: The present invention comprises measuring, upon application of a drive pulse to the actuating coil 5 of the stepping motor, the variation in the magnetic induction flux in the stator of the motor, and interrupting the drive pulse when the variation in flux reaches a predetermined value. Measurement of the variation in flux may be effected, for example, by detecting the current in the actuating coil and integrating the difference between the supply voltage of the actuating coil and the product of the current by the d.c. resistance of the coil, or by providing an auxiliary detection coil 71 and integrating the voltage induced therein in an integrator 73, 74. When the integrator outputs exceeds the magnitude of either a positive or negative reference voltage, a comparator circuit 78, 79, 81 provides the signal to a circuit 13 to terminate the drive pulse.

Abstract: A miniature electric stepping motor comprising a magnetized rotor adapted for rotation in the air gap of a stationary magnetic circuit having an electric excitation coil connected to a control device. The control device cmprises means for applying to the excitation coil control impulses of a first polarity and of an amplitude and a width such that the rotor rotates in a first direction of rotation from one stable equilibrium position to the next one and means for applying to the excitation coil, upon an outer control, starting from each stable equilibrium position, first a pre-impulse of said first polarity and subsequently a control impulse in the reverse direction, having a polarity opposite to the said first polarity, such that the rotor, after having reversed its direction of rotation, moves in the reverse direction of rotation until it reaches the stable equilibrium position following that at which the said pre-impulse has been applied.