Systems and methods for reducing current imbalance between parallel bridge circuits used in a power converter of a doubly fed induction generator (DFIG) system are provided. A control system can monitor the bridge current of each of the bridge circuits coupled in parallel and generate a feedback signal indicative of the difference in bridge current between the parallel bridge circuits. Command signals for controlling the bridge circuits can then be developed based on the feedback signal to reduce current imbalance between the bridge circuits. For instance, the pulse width modulation of switching devices (e.g. IGBTs) used in the bridge circuits can be modified to reduce current imbalance between the parallel bridge circuits.

A double fed induction generator (DFIG) converter method are presented in which rotor side current spikes are attenuated using series-connected damping resistance in response to grid fault occurrences or grid fault clearances.

An arrangement for operating a rail vehicle includes a DC voltage intermediate circuit which is connected to an energy supply network, at least one traction inverter which is connected at its DC voltage side to the DC voltage intermediate circuit and at its AC voltage side which is connected one or more traction motors of the rail vehicle. An auxiliary system inverter is connected at its DC voltage side to the DC voltage intermediate circuit and is connected at its AC voltage side to a primary side of an auxiliary system transformer. Auxiliary systems are connected to a secondary side of the auxiliary system transformer via an auxiliary line. Electrical energy generated by an electrical energy supply unit is transferred via the auxiliary line, the auxiliary system transformer and the auxiliary system inverter into the DC voltage intermediate circuit for operation of the at least one traction motor.

A steam generator includes a substantially horizontal gas conduit (1) to guide a heating gas flow (2) and an evaporator unit positioned at least partially in the horizontal gas conduit for transferring heat from the heating gas to a flow medium which flows through the evaporator unit. The heat transfer section of the evaporator unit of the steam generator is bottom fed, which means that the inlet conduit is arranged at a lower region of the heat transfer section. The outlet conduit is arranged at an upper region. The inlet conduit allows an once through operation of the evaporator section which is necessary to enable operation under supercritical circumstances. The evaporator unit includes at least two evaporator stages (3, 4) which are arranged in a cascade. Each evaporator stage includes a heat transfer section (12, 21) and a separator (14, 23). The presence of the separators (14, 23) subdivides the evaporator unit into evaporator stages (3, 4).

There are provided a generator internal pipe section that extends in the horizontal direction inside a steam generator; and a communication pipe section that is connected to the generator internal pipe section and is provided with a communication path, wherein one end of the communication path is connected to the pipe path at an upper end of a cross-section perpendicular to the flow direction of the cooling water in the pipe path and the other end of the communication path is positioned at the downside in the vertical direction in relation to one end of the communication path, and wherein one end side and the other end side of the communication path are connected at a position existing at the upside in the vertical direction in relation to one end.

A waste heat steam generator for a gas and steam turbine power plant is provided. The generator has economizer, evaporator and superheater heating surfaces which form a flow path and through which a flow medium flows. An overflow line branches off from the flow path and leads to injection valves arranged downstream at a flow side of a superheater heating surface in the flow path. The overflow line permits a brief power increase of a downstream steam turbine without resulting in an excessive loss in efficiency of the steam process. The brief power increase is permitted independently of the type of waste heat steam generator. The branch location of the overflow line is arranged upstream of an evaporator heating surface at the flow medium side and downstream of an economizer heating surface.

A control method for boiler outlet temperatures includes predictive control of SH and RH desuperheater systems. The control method also includes control and optimization of steam generation conditions, for a boiler system, such as burner tilt and intensity, flue-gas recirculation, boiler fouling, and other conditions for the boiler. The control method assures a proportional-valve control action in the desuperheater system, that affects the boiler system.

An evaporator surface structure of a circulating fluidized bed boiler having a furnace that is enclosed by sidewalls and has a bottom and a ceiling. The evaporator surface structure includes at least one vertical and separate evaporator surface unit that is spaced apart from the sidewalls of the furnace. The at least one evaporator surface unit (i) is formed of planar water tube panels that extend from the bottom of the furnace to the ceiling of the furnace, and (ii) consists of two cross-wise joined vertical water tube panels.

A livestock guide and manipulator panel prod is disclosed by this invention wherein electronic shocking circuitry is provided in combination with a hand-held livestock guiding and directing panel having electronic prods of said circuitry arranged on the surface of the panel.

A trough is cut in the ground surface by a rotating member. The rotating member displaces soil upward with respect to the ground surface and rearwardly with respect to a direction of travel of the rotating member. While the soil is in the air, slurry is deposited into the trough. The soil is then redirected downward to the trough to cover the slurry with the soil.

A seed singulator for use with a vacuum disk having a seed face and a shoulder. The seed singulator has a first member and a second member supported by biasing members. The first member has upper lobes disposed at a radius of curvature slightly less than the outside radius of a row of apertures on a seed plane of the vacuum disk. The seed member has lower lobes disposed at a radius of curvature slightly greater than the inside radius than the row of apradius. The biasing members permit the lobes to move with the seed plane and the shoulder as the vacuum disk rotates thereby maintaining their position with respect to the apertures.

A seed singulator system for a seed planter may comprise a seed container including a housing defining an interior to hold seed. A seed pickup assembly may be configured to pick up seeds individually from the interior, and the pickup assembly defines a plurality of seed-retaining holes configured to hold seed when a vacuum is applied to the holes. A seed discharging assembly may be configured to discharge seed in a singular manner from the seed container. The seed discharge assembly may comprise a seed receiver structure configured to receive seeds from the seed pickup assembly, and may define a seed-receiving passage having an entry opening for a seed to pass through, with the seed-retaining holes being alignable with the entry opening. A seed ejecting structure may be configured to eject seeds one at a time from the seed pickup assembly into the entry opening of the seed receiver structure.

A method of forming a 3-phenylimino-3H-phenothiazine or a 3-phenylimino-3H-phenoxazine mediator includes providing a first reactant including phenothiazine or phenoxazine, providing a first solvent, providing a second reactant and providing a second solvent. The first reactant, first solvent, second reactant and second solvent are combined to form a reactants solution. Sodium persulfate is added to the reactants solution to couple the first and second reactants resulting in a reaction solution including the 3-phenylimino-3H-phenothiazine or the 3-phenylimino-3H-phenoxazine mediator.

The aerator rollers project below the frame for rolling engagement with the ground and are located in tandem relation relative to the direction of travel. Each aerator roller has teeth that penetrate the ground surface. The formations on each aerator roller are spaced apart from one another circumferentially around and longitudinally along the roller. Formations on one aerator roller are offset from those on the other roller permitting overlap of same. The aerator rollers are interconnected in drive and driven relation to rotate in a predetermined ratio. A hopper mounted on the frame dispenses seeds, fertilizer or the like. A rear depth control roller assembly using one or more rollers or wheels is pivotally mounted on the frame and can be brought into rolling engagement with the ground to control the depth of penetration of the formations of the aerator rollers into the ground.

A ripping mechanism for a vehicle has a support frame. A ripping member has an engagement head that is configured for plowing a groove in the ground. The ripping member is preferably positionable in a selected working position and working orientation by adjustment of the support frame. The ripping member is preferably movable relative to the support frame to cause reciprocating movement of the engagement head at least partially longitudinally. A tilt adjustment cylinder is preferably operable to orient the ripping member in the selected orientation. A vibrator mechanism is preferably operatively connected to the ripping member and activatable to cause reciprocating movement of the engagement head at least partially longitudinally.

In one embodiment, a turf aerator includes a frame having wheels, a variable displacement pump, an engine for driving at least one of the wheels and driving the pump, a tine assembly supported by the frame and being movable between lowered and raised configurations, and a swash-plate-adjustment linkage extending from the tine assembly to the pump. The tine assembly includes: a base; a hydraulic motor in hydraulic communication with the pump; rotatable cranks powered by the hydraulic motor; a downwardly-extending arm rotatably coupled to each crank; a tine extending downwardly from each downwardly-extending arm; springs operatively anchored to the base; and a guide arm extending between each downwardly-extending arm and a respective spring. The swash-plate-adjustment linkage automatically adjusts the pump with movement of the tine assembly relative to the frame to provide output to the hydraulic motor substantially only when the tine assembly is at the lowered configuration.

A cultivator may include at least one rechargeable battery for an electrical power tool as a power source. The at least one rechargeable battery may include a plurality of rechargeable batteries. Further, the plurality of rechargeable batteries may be switched in sequence, so as to be used as the power source.

An agricultural machine (101; 201; 301) comprising two mainly parallel, in the direction of travel, cross-running disc implement rows (102a, 102c; 202a, 202b; 304a, 304b), wherein the orientation of the disc implements (102b, 102d; 203a, 203b; 302a, 302b) contained in the mentioned disc implement rows is arranged so that the fore row (102a; 202a; 304a) has disc implements that are mounted on a frame beam (110; 211; 303) and that are angled outwards and backwards towards the sides of the machine and in a dividing line mainly parallel to the direction of travel of the machine form a first point of change (208a, 304c), and the rear row (102c, 202b; 304b) has disc implements (102d; 203b; 302b) that are mounted on a frame beam (110; 211; 303) and that are angled inwards and backwards from the sides of the machine and in the dividing line form a second point of change (208b, 304a), wherein the fore row is adapted to throw soil from the first point of change outwards towards the sides of the machine and the other row is adapted to throw soil from the sides of the machine inwards towards the second point of change. The dividing line with the first point of change (208a, 304c), and with the second point of change (208b, 304) is arranged at a predetermined distance from the centre line of the machine (101; 201; 301) across the direction of travel.

Described herein is a wear indicator (100) for use in a drill bit or a core head. The wear indicator (100) comprises an elongate element that forms part of the drill bit. The elongate element has a plurality of numbers (110, 120, 130, 140, 150, 160, 170, 180) formed along its length, each number (110, 120, 130, 140, 150, 160, 170, 180) being formed as a void and corresponds to a level of wear in accordance with the IADC dull grading system. As the drill becomes worn, the wear indicator (100) wears at the same rate to reveal one of the numbers (110, 120, 130, 140, 150, 160, 170, 180). The numbers range from “1” to “8” where the number “1” illustrates the least wear and the number “8” indicates the most wear. When unworn, none of the numbers are visible.

An arrangement having a piston configured to move along an axial pathway a rotating seal configured to seal an inside environment from an outside environment, the rotating seal configured to be acted upon by a pressure exerted from the piston, a differential pressure sensor measuring a pressure difference between a first fluid from the outside environment and a second fluid on the inside environment, a motor connected to the piston, the motor configured to actuate the piston to a position along an axial pathway and an electronic feedback control system connected to the motor, the electronic feedback system configured to interface with the differential pressure sensor and maintain a pressure generated by the piston onto the rotating seal to a desired pressure.

Disclosed is a scintillator panel provided with on a support a phosphor layer comprising columnar crystals and a protective layer sequentially in this order, wherein degraded areas on lateral surfaces of columnar crystals at an end of the phosphor layer and produced by a cutting treatment account for not less than 0% and not more than 40% of an area of all of the side surfaces of the columnar crystals. A production method of the scintillator panel is also disclosed.

A grate bar for an incinerator having a grate bar base body and a high temperature resistant cover plate covering the grate bar base body at least on a surface portion which in operation points to a combustion chamber. The cover plate is separated from the grate bar base body by a thermal insulating material. In the grate bar base body a cavity is inserted in a side pointing to the cover plate and/or in the cover plate in the side pointing to the grate bar base body, which cavity is at least partially filled with a ceramic fiber insulating material. The invention further relates to a method for producing such a grate bar.

A phase-locked loop double-point modulator may include a frequency divider having a ratio which can be changed by a first modulation signal, and an oscillator, a frequency of which can be changed by a second modulation signal correlated to the first modulation signal. A calibration circuit may be configured, in a calibration mode, to match the gains of the first and second modulation signals based on frequency measurements of the oscillator for two different calibration values of the second modulation signal. The phase-locked double-point modulator may also include an attenuator having a constant ratio greater than 1 and placed in the path of the second modulation signal, and a selector switch configured to be controlled by the calibration circuit to reduce the ratio of the attenuator in the calibration mode.

A modulator generates a baseband digital signal from an information-bearing digital signal. The baseband signal has time-varying phase and amplitude defined by a sequence of complex data words, each having an in-phase (I) component and a quadrature (Q) component. A noise-shaping modulator generates a noise-shaped digital signal from the baseband digital signal such that quantization noise in the noise-shaping modulator is attenuated by a spectral null of its noise transfer function. The spectral null is selected by a noise-shaping parameter corresponding to a selected one of a plurality of output frequencies. A signal converter generates an analog signal conveying the information of the information-bearing digital signal on an analog carrier signal having the selected output frequency.

A signal generator for a transmitter or a receiver for transmitting or receiving RF-signals according to a given communication protocol includes an oscillator and a mismatch compensator. The oscillator is configured to provide a signal generator output signal having a signal generator output frequency and comprises a fine tuning circuit for providing a fine adjustment of the signal generator output frequency based on a fine tuning signal and a coarse tuning circuit for providing a course adjustment of the signal generator output frequency based on a coarse tuning signal. The mismatch compensator is configured to receive the signal generator output signal and compensate a frequency mismatch between a desired signal generator output frequency and the signal generator output frequency generated by the oscillator by providing the fine tuning signal for changing the state of the fine tuning circuit of the oscillator and by providing the coarse tuning signal for changing a state of the coarse tuning circuit of the oscillator. The mismatch compensator provides the coarse tuning signal during a guard period defined in the given communication protocol, during which no RF-signals are transmitted by the transmitter or no RF-signals are to be received by the receiver, such that the state of the coarse tuning circuit is changed within the guard period.

A circuit includes a switched modulator stage combining an information signal with a square wave carrier to produce a first modulated signal; and a second modulation stage forming additional steps in the first modulated signal to produce a second modulated signal.

A rail-to-rail comparator including a first comparison unit connected to a first terminal and configured to compare differential input signals to differential reference voltages; a second comparison unit connected to a second terminal and configured to compare the differential input signals to the differential reference voltages; and an output unit configured to be driven in response to a clock signal and to generate a complementary output signal according to comparison results of the first and second comparison units.

An example PWM includes a driver and a two-way oscillator. The oscillator includes, a first frequency adjust current source, a second frequency adjust current source, a capacitor, a switching reference and a comparator. The capacitor integrates a frequency adjust current by charging with the first frequency adjust current source. The capacitor subsequently integrates a second frequency adjust current by discharging with the second frequency adjust current source. The switching reference outputs a first reference voltage and a second reference voltage responsive to an oscillator signal. The comparator compares the output of the switching reference with a voltage on the capacitor. The first and second frequency adjust current sources vary the first and second frequency adjust currents to vary the frequency of the PWM signal to spread energy of switching harmonics over a frequency band and to reduce EMI.

Methods and apparatus for translating duty cycle information in duty-cycle-modulated signals to higher frequencies or higher data rates. An exemplary duty cycle translator includes a duty cycle evaluator, a high-speed digital counter, and a comparator. The duty cycle evaluator generates a first digital number representing a duty cycle of a low-frequency input duty-cycle-modulated (DCM) signal. The comparator compares the first digital number to a second digital number generated by the high-speed digital counter, and generates, based on the comparison, an output DCM signal having a higher frequency or data rate than the frequency or data rate of the low-frequency input DCM signal but a duty cycle that is substantially the same as the duty cycle of the low-frequency input DCM signal.

A communications transmitter includes a baseband processor configured to generate amplitude, angle, in-phase and quadrature baseband signals and a combination modulator that is configurable to modulate in the polar domain and, alternatively, in the quadrature domain. The combination modulator includes a quadrature modulator and a separate and distinct angle modulator that is configured to serve as a local oscillator for the quadrature modulator. In one embodiment of the invention the combination modulator is configured to modulate in the quadrature domain when the transmitter is operating according to a first communications condition (e.g., first transmit power level or first modulation scheme) and is configured to modulate in the polar domain when the transmitter is operating according to a second communications condition (e.g., second transmit power level or second modulation scheme).

A frequency modulator includes a digitally-controlled oscillator (DCO) arranged for producing a frequency deviation in response to a modulation tuning word and a phase-locked loop (PLL) tuning word. In addition, another frequency modulator includes a DCO and a DCO interface circuit. The DCO is arranged for producing a frequency deviation in response to an integer tuning word and a fractional tuning word. The DCO interface circuit is arranged for generating the integer tuning word and the fractional tuning word to the DCO, wherein the fractional tuning word is obtained through asynchronous sampling of a fixed-point tuning word.

Embodiments of digital high-speed bi-phase modulator and method for bi-phase modulation are generally described herein. In some embodiments, the digital high-speed bi-phase modulator comprises a high-speed digital divider, a high-speed digital multiplexer, and matched signal paths provided between the divider and the multiplexer. The high-speed digital divider is configured to receive a carrier signal and generate complementary output signals. The high-speed digital multiplexer is configured to switch between the complementary output signals and generate a bi-phase modulated output at a carrier frequency (fc) modulated with a bi-phase code. The bi-phase code may be provided to control inputs of the multiplexer.

A radio frequency generator includes a power control module, a frequency control module and a pulse generating module. The power control module is configured to generate a power signal indicating power levels for target states of a power amplifier. The frequency control module is configured to generate a frequency signal indicating frequencies for the target states of the power amplifier. The pulse generating module is configured to (i) supply an output signal to the power amplifier, (ii) recall at least one of a latest power level or a latest frequency for one of the target states of the power amplifier, and (iii) adjust a current power level and a current frequency of the output signal from a first state to a second state based on the power signal, the frequency signal, and at least one of the latest power level and the latest frequency of the power amplifier.

Provided is a method of generating a driving signal for driving a dual mode supply modulator for a power amplifier. The method includes obtaining an envelope of a complex baseband signal to be transmitted, comparing the envelope of the complex signal with a preset threshold value, when a current envelope of the complex signal is the preset threshold value or greater or when there is a result having the preset threshold value or greater in previous N comparisons, outputting a digital board output signal configured with a first logic level through a digital-to-analog converter; and when the current envelope of the complex signal is smaller than the preset threshold value and when there is no result having the preset threshold value or greater in the previous N comparisons, outputting a digital board output signal configured with a second logic level through the digital-to-analog converter.

An ultra-wide band frequency modulator is disclosed. The frequency modulator includes a direct modulation phase lock loop that receives a small component. The frequency modulator also includes a delay module that produces a plurality of delay lines. The frequency modulator further includes an edge selector that receives a large component and the plurality of delay lines.

The present invention provides a digitally controlled, current starved, pulse width modulator (PWM). In the PWM of the present invention, the amount of current from the voltage source to the ring oscillator is controlled by the proposed header circuit. By changing the header current, the pulse width of the switching signal generated at the output of the ring oscillator is dynamically controlled, where the duty cycle can vary between 50% and 90%. A duty cycle to voltage converter is used to ensure the accuracy of the system under process, voltage, and temperature (PVT) variations. The proposed pulse width modulator is appropriate for dynamic voltage scaling systems due to the small on-chip area and high accuracy under process, voltage, and temperature variations.

Systems and methods for operating with oscillators configured to produce an oscillating signal having an arbitrary frequency are described. The frequency of the oscillating signal may be shifted to remove its arbitrary nature by application of multiple tuning signals or values to the oscillator. Alternatively, the arbitrary frequency may be accommodated by adjusting operation one or more components of a circuit receiving the oscillating signal.

A memristor-based emulator including a memristor circuit for use in digital modulation that includes a first current feedback operational amplifier (CFOA) having multiple terminals in communication with a capacitor Cd and in further communication with a resistor Ri. A second CFOA having multiple terminals is in communication with the first CFOA and is adapted to be in further communication with a voltage vM to provide an input current iM for integration by a capacitor Ci. A nonlinear resistor is in communication with the second CFOA. A third CFOA having multiple terminals is in communication with the nonlinear resistor and is in further communication with the first CFOA and a resistor Rd. The third CFOA and the resistor Rd act as an inverting amplifier associated with the nonlinear resistor to increase a current gain to increase a difference between ON and OFF values of a resistance of a realized memristor.

A modulator which has a first terminal to receive a carrier signal, a second terminal to receive a first control signal to control a frequency band of the carrier signal and a third terminal to receive a second control signal to control a modulation depth of the carrier signal.

An electromagnetic actuator comprising a core moving between a latched position and an open position, a permanent magnet, a coil designed to generate a first magnetic control flux to move the core from an open position to a latched position, and a second magnetic control flux designed to facilitate movement of the moving core from the latched position to the open position. The permanent magnet is positioned on the moving core so as to be at least partly outside the fixed magnetic circuit in which the first magnetic control flux flows in the open position, and to be at least partly inside the fixed magnetic circuit used for flow of a magnetic polarization flux of the magnet in the latched position.

A children's tray with a placement indicator includes a tray and a groove/spot formed in the tray to indicate where an eating item (including food, utensils, or dishware) is to be placed. The tray can be mounted, removably or fixedly, to a variety of child support structures, including high chairs, booster seats and bouncers and includes a wall around the periphery intended to prevent items from falling off of the tray. The groove/spot formed in the tray may be formed from of a material having a higher coefficient of friction than the material used to form the tray. The groove/spot formed in the tray may be formed from of a material having a different color than the material used to form the tray.

In a manipulator needle portion defect repairing method, the existence of an abrasion or a fracture in a needle portion for holding a sample at an end of a manipulator disposed in an FIB device is confirmed using a microscope function of the FIB device. The abrasion or the fracture in the needle portion is then repaired by chemical vapor deposition using a focused ion beam of the FIB device.

A manual release valve is provided for a electro-hydraulic actuator of the type including a piston movable in a cylinder and defining a piston side chamber and a rod side chamber, the valve threadedly attached to the housing of the actuator and extending at least partially within the fluid housing conduits, the valve moveable from a closed position fully seated in the housing to an open position for fluidly connecting both the piston side chamber and the rod side chamber to the reservoir, the valve further including a pressure relief portion that is operable when the valve is in the closed position for relieving pressure from at least one of the piston side chamber or the rod side chamber.

Graphite and/or carbon surfaces are coated with a titanium nitride coating by exposing the substrate to electric arc thermal spray process wherein titanium wire as the source of titanium and nitrogen is used as the propelling (atomizing) gas.

A geared motor actuator having a simplified mechanical structure for driving a closing part, such as a vehicle window, moved as far as at least one end position by an electric motor (MO) via a gear (G), preferably a worm gear. Shortly before the end position is reached, switch-off of the electric motor (MO) is performed in accordance with a control device (ST). The gear (G) is drive-connected to an output driver of the closing part without any damping means. The worm wheel (4) of the worm gear, being a solid, integral component that is preferably injection-molded from plastic, is preferably designed to include the output driver as part of the integral component, and provided with a drive pinion (4.1).

This disclosure relates to a micro manipulator having a simple structure and having high possibility of recording a biological signal of a neuron at a desired position by improving positioning resolution of an electrode disposed adjacent to a subject's brain neuron or an electrode holder attached with the electrode. The micro manipulator according to the disclosure includes: a motor which includes a shaft and a vibration portion; a mobile which is connected to the shaft so as to be movable along the shaft; and a frame which supports the motor, wherein an electrode is connected to the mobile in a direction parallel to a longitudinal direction of the shaft, and wherein when the mobile moves linearly in accordance with a vibration of the shaft due to the vibration portion, the electrode moves linearly.

A linear actuator for a variable-geometry member of a turbocharger includes a piston/rod assembly that can axially translate and also pivot to a limited extent. A permanent magnet is mounted in a fixed position within the actuator. A non-magnetized flux carrier is mounted in the piston/rod assembly, and its movement alters the magnetic field of the magnet. A Halls effects sensor detects the magnetic field and the signals produced by the sensor are used for determining axial position of the piston/rod assembly.

A fluid actuator includes a housing having a fluid chamber providing a first friction surface. An actuating member is arranged in the fluid chamber and has a second friction surface slideably engaging the first friction surface. The actuating member is configured to slide within the chamber between first and second positions. An insert is constructed from a first thermoplastic material and provides one of the first and second friction surfaces. A body structurally supports the insert and provides one of the housing or actuating member. The body is constructed from a second thermoplastic material molded about the insert and including short reinforcing fibers.

The present invention relates to a position sensor and limit switch apparatus for an actuator. The actuator has a cylinder and a piston with at least one magnetized portion reciprocatingly disposed within the cylinder. The apparatus includes an elongate housing aligned parallel with the cylinder. A magnetostrictive linear displacement transducer is disposed within the housing for sensing the position of the at least one magnetized portion. The apparatus includes a switch means responsive to the transducer for operatively interrupting actuation of the piston upon the at least one magnetized portion reaching a limit position.

A pneumatic actuator comprises a containment jacket (2) and an activating bar (14) mounted through the containment jacket (2) and able to move between a first operating position and a second operating position. The actuator (1) also comprises a fixed part (23) integral with the jacket (2) having a main axis of extension (X), and a mobile part (26) slidably connected to the fixed part (23), and operatively connected to the activating bar (14) in such a way that it moves with the bar. The fixed part (23) also comprises at least a core (25) made of ferromagnetic material extending along the axis (X). Two magnets (29) are attached to the mobile part (26) on diametrically opposite sides relative to the main axis of extension (X). The mobile part (26) can also move relative to the fixed part (23) between a first position of maximum magnetic uncoupling between the magnets (29) and the ferromagnetic core (25), and a second position of maximum magnetic coupling between the magnets (29) and the ferromagnetic core (25). Finally, a sensor (30) for detecting the magnetic field is mounted at one end of the ferromagnetic core (25).