Abstract: A magnetic linear position sensor includes an array of N number of magnets. The array of magnets is distributed along a line to form a magnetic field relay along the line. The sizes and positions of the magnets in the array of magnets are symmetric along the line, and the size of the magnets decreases from the sides of the array of magnets towards the center of the array of magnets. The magnetic linear position sensor further includes a magnetic field sensor spaced apart and positioned above the array of magnets. The magnetic field sensor moves back and forth over the array of magnets to sense the magnetic field of the array of magnets.

Abstract: An electrical device includes a magnetic sensor circuitry (101) for detecting magnetic field and for generating a detection signal in response to the detected magnetic field, and a control circuitry (102) for controlling operation of the electrical device in accordance with the detection signal. The magnetic sensor circuitry is configured to detect a direction related to a deviation of the magnetic field from the magnetic field of the earth, and the control circuitry is configured to control the operation of the electrical device in accordance with the detected direction. The electrical device can be controlled by using e.g. a permanent magnet (105) for directing, to the magnetic sensor circuitry, magnetic field deviating from the magnetic field of the earth and having a desired orientation. Thus, the electrical device can be controlled without an electrical connector or a radio interface.

Abstract: A method and an arrangement is provided for determining the location and/or speed of an object configured to move along a controlled trajectory, in connection with which object is fitted a measuring device measuring at least the magnetic field acting on the object in its different locations, which measuring device comprises a device configured to measure the magnetic field, from the measuring data received from which device a magnetic footprint describing the magnetic field acting on the object in its different locations is formed, which magnetic footprint is recorded in connection with a teaching run, or with self-learning, for later use.

Abstract: Several systems and methods for monitoring the proximity of a device to a power line are disclosed. Electric field monitoring systems are mounted to the device and include a plurality of electric field sensors and a monitoring system base unit. Each electric field monitoring sensor senses the strength of a magnetic field in which the sensor is positioned and transmits a corresponding magnitude output signal to the base unit when polled by the base unit. If a sensor reports a magnetic field exceeding a threshold, the frequency of polling for that sensor may be increased. If a sensor reports a magnetic field exceeding another (possibly identical) threshold, an alarm may be activated, movement of the device may be limited or stopped or another action or a combination of actions may be taken.

Abstract: A gradient sensor of a component of a magnetic field comprising at least one elementary sensor comprising a deformable mass (31) equipped with a permanent magnet (32) having a magnetization direction substantially colinear to the direction of the gradient of the component of the magnetic field to be acquired by the sensor. The deformable mass (31) is able to deform under the effect of a force exerted on the magnet by the gradient, the effect of this force being to shift it, by dragging the deformable mass (31), in a direction substantially colinear to the component of the magnetic field for which the sensor has to acquire the gradient. The deformable mass (31) is anchored to a fixed support device (33) in at least two anchoring points (36) substantially opposite relative to the mass (31). The elementary sensor also comprises measuring means (35, 35.1, 35.2, 35.3) of at least one electric variable translating deformation or stress of the deformable mass (31) engendered by the gradient.

Abstract: An operation input apparatus includes an operating unit that is displaced by the action of an operation input; an actuator output shaft that is displaced in the same direction as the operating unit by the action of the operation input; an actuator that moves the operating unit via the actuator output shaft; and a detecting element that outputs a signal corresponding to an amount of displacement of the operating unit.

Abstract: An apparatus and method of a tamperproof magnetic proximity sensor based on a magnetically shielded magnetic sensor. The proximity sensor is substantially impervious to external magnetic field and is protected by external magnetic sensors for preemptive detection of external magnetic field tamper attempts.

Abstract: The invention relates to a method for detecting changes of position of a shaftless spinning rotor (1) of an open-end spinning machine in a cavity of an active magnetic bearing, in which the position of the spinning rotor (1) is detected by a system of sensors (A, B) and on basis of the detected changes in the position of the spinning rotor (1) is adjusted controlling of the active magnetic bearing in order to eliminate undesirable changes in the position of the spinning rotor (1) in the cavity of the active magnetic bearing. Continuously is detected radial shifting of the spinning rotor (1) and simultaneously is continuously detected inclination of the spinning rotor (1), whereupon according to the detected changes in the position of the spinning rotor (1) is determined shifting and/or inclination of the spinning rotor (1) which is used for subsequent adjustment of the controlling of position of the spinning rotor (1) in the active magnetic bearing.

Abstract: A magnetically-based position sensor. The sensor includes a magnet, a first collector, a second collector, and a magnetic sensing element. The magnet has at least two poles, and moves along a path. The first collector has a first end and a second end and is configured to collect a magnetic flux. In addition, the first collector is positioned at an angle relative to an axis running parallel to the path and perpendicular to the magnet. The second collector is configured to collect a magnetic flux, and is positioned at an angle relative to the axis running parallel to the path and perpendicular to the magnet, and parallel to the first collector. The magnetic sensing element is coupled to the first and second collectors. A magnetic flux is collected by the first and second collectors, and varies as the magnet moves along the path such that the magnetic flux collected by the first and second collectors indicates a position of the magnet along the path.

Abstract: Methods for determining performance information for an object located within an area include obtaining magnetic field information for the area, measuring first magnetic field data when the object is located at a first position within the area, and determining performance information for the object within the area based on the magnetic field information for the area and the first magnetic field data.

Abstract: A slue position sensing system and method of modifying a machine to include such a slue position sensing system are disclosed. The slue position sensing system may include a swing sensor housing disposed between a swing motor and a swing drive. The swing sensor housing may be coupled to a rotary position sensor that indirectly detects rotation of the target gear or a speed sensor that directly detects rotation of the target gear. For embodiments with no target gear, but with upper and lower frames rotatably coupled together by a ring gear and a swing gear, the sensor may be a rotary position sensor mounted to a slip ring assembly and magnet that are connected to a hydraulic swivel between the upper and lower frames or the sensor may be a speed sensor that detects rotation of the swing gear. The sensors generate a signal that is communicated to a controller or an ECM that accurately reflects the angular movement imparted to the work implement by the swing drive.

Abstract: Disclosed is an arrangement for high-resolution determination of positions on linear or circular ferromagnetic measuring rods (3) that have a teeth structure, said arrangement providing reliable results in an environment affected by magnetic interference. For this purpose, a magnetic field sensor (1) is placed at the point where the field of a permanent magnet (4) is at a maximum and is mounted across from the measuring rod (3) in such a way that the soft magnetic material of the measuring rod causes the field to strengthen further. The obtained field strength is sufficient to be able to use multilayer GMR sensors in which the resistance changes by more than 40 percent, thus allowing a high signal amplitude to be used for greater position resolution.

Abstract: A stroke amount detecting device includes a magnetism detecting unit, a first magnetic field generating unit and a second magnetic field generating unit. A magnetic pole of the first generating unit and a magnetic pole of the second generating unit, which are opposed to each other, have different polarities. A distance between a gap end of the first generating unit and a gap end of the second generating unit, which are located on a farther side of a rectilinear axis, is smaller than a distance between an open end of the first generating unit and an open end of the second generating unit, which are located on a closer side of the rectilinear axis. The magnetism detecting unit detects a stroke amount of an object based on a magnetic flux generated between the open end of the first generating unit and the open end of the second generating unit.

Abstract: The disclosed invention provides apparatus, systems, and methods for orientating an object in an enclosed area using a magnetic dipole deployed in the enclosed area and thereafter applying an external rotating magnetic field for applying a rotational force to the dipole along one or more selected axis. The external magnetic field is moved to manipulate object in the desired direction(s) of movement.

Abstract: In a rotation angle detection apparatus, a signal detected by a magnetoresistive element is digitalized before being subjected to subtraction of the optimum correction parameter therefrom in a subtractor, the optimum correction parameter being stored in advance in a memory. Note that during the initial transmission at the time of activation, the data size “n” of a detection target obtained by a CPU from a control device is transferred to the memory, so that the optimum correction parameter for the data size of the detection target is selected. With the above, the detection unit can relatively readily cope with a request for enlargement or the like of a through hole size made by a machine side, and detection accuracy is not deteriorated and an error in absolute position processing is reduced when the curvature of the detection target is changed.

Abstract: The position sensor includes a shift lever used to select one of five ranges P, R, N, D, and B, fixed contacts corresponding to the ranges P, R, N, D, and B, and movable contacts configured to be electrically connected to the fixed contacts. The fixed contacts include regular fixed contacts, first backup fixed contacts, and second backup fixed contacts. The first and second backup fixed contacts have their lengths in the moving direction of the movable contacts configured to be longer than the length of the regular fixed contact that corresponds to the first and second backup fixed contacts.

Abstract: A magnetism detection elements are arranged in an arrangement direction substantially perpendicular to a tooth trace of a gear when viewed from a magnetism generation unit and send a signal according to a magnetic flux flowing between the gear and the magnetism generation unit. A detection unit detects rotation of the gear according to the signal. A case accommodates the magnetism detection elements. A movement restriction unit is equipped to the case and located on the side of the gear at a place between the magnetism detection elements to restrict a magnetic foreign matter, which adheres to the case, from moving in the arrangement direction of the magnetism detection elements.

Abstract: A magnetic position detecting device includes a magnet; first to fourth magnetoelectric conversion elements formed on a virtual plane; and a flux guide made of a magnetic material. The flux guide includes first and second protrusions provided at a distance from each other in a direction parallel to the virtual plane. A specific portion recessed in a concave shape is provided in the flux guide in a mid-portion between the first and second protrusions. The first and fourth magnetoelectric conversion elements are provided approximately in the mid-portion between the first and second protrusions. The second magnetoelectric conversion element is provided between the first protrusion and the mid-portion.

Abstract: A gear position sensor employs a sliding electrical connection between arcuate conductors and flexible wiper arms held on opposite surfaces that rotate relative to each other with the movement of a gear selector shaft. The traces may have multiple segments joined by resistors to provide flexible change in resistance value and resistance range for different applications.

Abstract: A system for positioning based on magnetic field characteristics includes a system apparatus and a client device. The system apparatus includes a characteristic magnetic field generation device, a magnetic field characteristic database and a processing device. The characteristic magnetic field generation device is used for generating a plurality of characteristic magnetic fields in a predetermined space. The characteristic magnetic fields have at least two magnetic field characteristics. The magnetic field, characteristic database has a plurality of characteristic values and a plurality of positioning values. Each of the characteristic values corresponds to each of the magnetic field characteristics. The characteristic values correspond to the magnetic field characteristics. The client device includes a magnet detecting component and a processor. The magnet detecting component is used for detecting the magnetic field characteristics and for outputting a magnetic field signal.

Abstract: A metal plate (14) is buried in a gasket (12) of a case (10) for accommodating an electric device such as an inverter. The metal plate (14) is connected to a control board (400) in the case (10), and the voltage of the metal plate (14) is determined. A reference voltage is applied to the metal plate (14), and the case (10) is grounded. When the metal plate (14) is brought into contact with the case (10) or disconnected due to a crash, the voltage of the metal plate (14) is thereby changed, and the control board (400) detects a crash, based on the change in the voltage.

Abstract: Cyclic motion of a ferromagnetic part in an environment made noisy by at least one electric source with an A.C. component is measured using at least one first magnetometer sensitive to the moving part and a sensor of an image of current in the electric source. An estimate is calculated of noise linked to the electric source on a signal measured by the first magnetometer and then subtracted from the measured signal.

Abstract: The invention provides methods and systems for determining the position of a remote object such as an in vivo medical device such as capsule or probe within a medical patient. Integrated computer and computer executable remote permanent magnetic dipole position and orientation detection system monitors remote object movement. User interface displays remote permanent magnetic dipole location and orientation in a 3-dimensional view. Database stores object position movement in association with time. Magnetic sensor planes detect remote objects with permanent magnetic dipole and generate magnetic field information signal. Computer stores and searches location and posture information use a file.

Abstract: In a method of identifying a direction of stacking in a stacked ceramic capacitor, while density of magnetic flux generated from a magnetism generation apparatus is measured with a magnetic flux density measurement instrument, a stacked ceramic capacitor is caused to pass between a magnetism generation apparatus and the magnetic flux density measurement instrument and variation in magnetic flux density at least at the time of passage of the stacked ceramic capacitor is measured. Based on a result of measurement of magnetic flux density, a direction in which a plurality of internal electrodes are stacked in the stacked ceramic capacitor is identified.

Abstract: A scale is used in a displacement detection apparatus (100) which detects a position of an object, the scale includes a pattern periodically formed in a measurement direction (an X direction), and the pattern is configured so as to change a physical property in a direction (a Y direction) perpendicular to the measurement direction without changing phase information in the measurement direction when a detector reading the pattern moves relative to the pattern in the direction perpendicular to the measurement direction.

Abstract: Magnetic field sensor arrangements and methods provide a magnetic field sensor positioned proximate to a magnet with an axis of sensitivity aligned relative to the magnet in orientations that provide a good sensitivity and a mechanical difference from other arrangements.

Abstract: A detection system comprising a plurality of magnetic field generators and a plurality of magnetic field detectors located adjacent to a detection area, and a control system arranged to generate magnetic field using the generators, and, for each of the generators, to make measurements of the magnetic field generated using each of the detectors, and processing means arranged to process the measurements to generate a data set characterising the detection area.

Abstract: The Comprehensive Motion Detector Switch (CMDS) is a device used to sense repetitive mechanical motion in an industrial environment. The rotation of a pulley on a conveyor would be a typical application. This CMDS device is unique in that is has no internal moving parts, has a non-critical target sensing distance, and provides multiple output signals. The CMDS provides a speed-switch output which gives indication that the target device is in motion. The speed-switch signal is switch selectable between a pulsed output or as a constant stop-switch output. Additionally there is a field programmable under-speed signal available. This signal will indicate when the target device slows by a fixed percentage of the programmed speed. Another feature is that the CMDS device is available in both hard-wired and wireless versions.

Abstract: A magnetic field measuring device includes a support base, a measuring mechanism, and a displacement sensor. The measuring mechanism is positioned on the support base, and includes a mounting plate, a swing arm, a connecting member, an elastic member, and a measuring magnet. The mounting plate is connected to the support base. The swing arm is rotatably positioned on the mounting plate. The elastic member is positioned between the connecting member and the swing arm. The measuring magnet is connected to the swing arm, opposite to the support base. The displacement sensor is positioned on the support base, opposite to the swing arm.

Abstract: A circuit to detect a movement of an object includes a magnetic field sensing element for generating a magnetic field signal proportional to a magnetic field associated with the object and a motion detector to generate a motion signal indicative of the movement of the object. The motion detector includes a peak identifying circuit to provide a peak signal and a peak sample selection module that selects a sample associated with one or more prior cycles of a magnetic field signal to generate a selected peak signal. The motion detector further includes a threshold generator to generate a threshold signal as a function of the selected peak signal and a comparator to compare the threshold signal with the magnetic field signal to generate the motion signal. Peak samples from prior magnetic field signal cycles may be averaged for use to establish the threshold signal. A method associated with the circuit is also described.

Abstract: A sensor arrangement for determining the position and/or change in position of a measurement object relative to a sensor, wherein a magnet is assigned to the measurement object, is configured, with respect to the design of an operationally reliable sensor with low production costs, such that the sensor has a first conductor and a second conductor which is arranged alongside the first conductor and such that a magnetically soft film is arranged in the area of influence of the first and second conductors, the permeability of which film changes under the influence of a magnetic field and which film influences the electromagnetic coupling between the first and second conductors. A corresponding method is specified.

Abstract: An air spring height sensor (100) is provided which comprises a receiver (101) for receiving a height signal and an evaluation unit (200). The receiver is adapted for being mounted to an air spring so as to sense a height signal with respect to said air spring. The evaluation unit comprises an input terminal (201), a multiplexer (240), a first signal branch (210) starting from the input terminal and terminating at a first multiplexer input (241), and a second signal branch (220) starting from the input terminal and terminating at a second multiplexer input (242). The first signal branch includes a first amplitude limiter (211) being adapted to cut off the amplitude above a predetermined first threshold value. The multiplexer is adapted to select a measurement signal from one of the inputs of the multiplexer.

Abstract: A position detection device includes a detection portion and a magnetism generation portion. The detection portion includes a first magnetism detection element and a second magnetism detection element. The first magnetism detection element and the second magnetism detection element are disposed on a plane. The magnetism generation portion is disposed at a position opposite the detection portion. The magnetism generation portion includes mutually opposing magnetic fluxes with respect to the detection portion by performing bipolar magnetization on a face opposite the plane where the first magnetism detection element and the second magnetism detection element are disposed.

Abstract: A human surrogate head model (HSHM) to measure brain/skull displacement due to a physical force, such as due to an explosive, ballistic, or automotive crash type of event. A HSHM may include a plurality of magnetic field generators positioned stationary relative to a HSHM skull, each to generate a magnetic field oriented with respect to a corresponding one of multiple directions. The HSHM may include one or more electromagnetic force (EMF)-based displacement sensors, each of which may include three inductive coils oriented orthogonally with respect to one another and co-aligned about a central point. A signal processor may be implemented to separate signals generated by each coil of each EMF-based displacement sensor into a plurality of component magnitudes, each attributable to a corresponding one of the magnetic fields. A computer-implemented model may be implemented to correlate between the component magnitudes and a corresponding position and orientation of the displacement sensor.

Abstract: A method is described for manufacturing an encoder element having a base body and a magnetic layer situated on the outer circumference of the base body, including the following steps: providing the base body; providing a magnetic or magnetizable powdery material; directly applying the powdery material to the outer circumference or to an end face of the base body to generate the magnetic layer in such a way that an integral, direct joint is created between the base body and the magnetic layer; and magnetizing the applied magnetic layer.

Abstract: The invention relates to a sensor arrangement for use in a sensor bearing with a magnetic ring (14) with multiple pole pairs, the sensor arrangement including at least three magnetic sensors (16) and to a sensor bearing using such a sensor arrangement. It is proposed that the at least three magnetic sensors (16) are encapsulated in a prefabricated package (17).

Abstract: A distance sensor and a washing machine including the distance sensor are provided. The washing machine may include a main body having a laundry loading hole formed therein, a door coupled to the main body, at a position corresponding to the laundry loading hole, and a plurality of reed sensors. The door may include a magnet disposed therein. The plurality of reed sensors provided in the main body and react to the magnet provided in the door to determine an open/closed state of the door.

Abstract: A position sensor module (1) for control capsules (2), having a base carrier (3) which base carrier (3) has a first receiving space (4) in which is arranged a sensor chip (5) and a second receiving space (6) in which is arranged a plug contact strip (7) of a plug contact arrangement (8) which is connected to chip contacts (9) of the sensor chip (5), and a cover part (10) which covers the first receiving space (4) and the second receiving space (6). The cover part leaves open an access opening (11) to the plug contact strip (7), and fixes the sensor chip (5) and the plug contact arrangement (8) to the base carrier (3).

Abstract: A position sensing head combines a sensing element and a simplified electronic module to enable operation with one wire, in addition to a circuit common, for providing power and transmitting a signal, while separating the sensing head from signal conditioning circuits by over 10 meters. The simplicity of the electronic module allows the use of basic electronic components that operate at more than 225° C. The signal is a variable frequency impressed onto the one wire, which can be read by a frequency meter. Another signal, such as a position or temperature, can be impressed onto the one wire at the same time as the first signal. The second signal is of a different frequency range so that it will not interfere with the first. A demodulator circuit can separate the two signals. The sensing element construction allows for locating up to three active elements measuring the same target.

Abstract: A position sensor arrangement that can determine the two-dimensional position of a variety of different movable devices, such as an electronic joystick. According to one embodiment, the position sensor arrangement includes two pair of magnetic sensing elements that are angularly offset or skewed with respect to one another in order to provide redundancy and accuracy with a minimum number of sensing elements.

Abstract: A position detecting device is provided, which is configured to minimize leakage of magnetic flux in an electromagnetic induction system. The position detecting device includes: a sensor unit including a plurality of first loop coils arranged in a first direction and a plurality of second loop coils arranged in a second direction intersecting with the first direction; a yoke sheet provided on a side of the sensor unit that is opposite to a side that faces a position indicator; an auxiliary loop coil provided at a corner part of the sensor unit; a signal transmitter configured to transmit a signal to one of the coils in order to generate a magnetic field to induce an induced current in a coil of the position indicator; and a controller configured to select one of the coils, and to control whether to transmit a signal from the signal transmitter to the selected one of the coils or to make the selected one of the coils receive a signal from the position indicator.

Abstract: The present invention provides a single component implementing highly precise pulse detection for rotational or liner position detecting apparatuses for jog dials and mechanical products. Focusing on the fact that the phase difference between the magnetic fields in circumferential and radial directions generated by a magnetized ring is precisely 90 degrees, a position detecting apparatus of the present invention includes two Hall elements placed at a distance; a protective film provided on magnetic sensitive portions of the two Hall elements to cover the magnetic sensitive portions; a thin-film magnetic plate placed on the protective film to cover the magnetic sensitive portions of the two Hall elements; and further a processing circuit calculating the sum and difference of the signals from the two Hall elements to generate signals having an accurate phase difference of 90 degrees. The position detecting apparatus can therefore detect the rotation direction and precise rotation angle.

Abstract: An angle measuring system includes a first component group and a second component group, the first component group being mounted in a manner allowing rotation about an axis relative to the second component group. The first component group includes a ring having a running surface and an angle scaling. The second component group has a further ring having a further running surface, as well as a sensor for scanning the angle scaling. Rolling elements are arranged between the running surfaces, the angle scaling being applied such that a geometric pattern of the angle scaling in a first region differs from a geometric pattern of the angle scaling in a second region as a function of radial runouts of the running surfaces and/or of the rolling elements.

Abstract: A method and a device for identifying a position of a local coil of a magnetic resonance imaging scanner relative to a position of a patient couch are provided. The device includes at least one reading unit that is configured to determine a position of at least one label at the local coil relative to the at least one reading unit. The device also includes a position determination apparatus that is configured to determine the position of the patient couch relative to the magnetic resonance imaging scanner. The device includes a position determination apparatus that is configured to determine the position of the local coil relative to the patient couch based on the determined position of the at least one label and the determined position of the patient couch.

Abstract: A CPP MR sensor interposes a tapered soft magnetic flux guide (FG) layer between a hard magnetic biasing layer (HB) and the free layer of the sensor stack. The flux guide channels the flux of the hard magnetic biasing layer to effectively bias the free layer, while eliminating instability problems associated with magnetostatic coupling between the hard bias layers and the upper and lower shields surrounding the sensor when the reader-shield-spacing (RSS) is small.

Abstract: An induction detecting type rotary encoder includes: a stator; a rotor configured to be rotated with respect to a rotary shaft; a first transmitting coil; a second transmitting coil; a first receiving coil; a second receiving coil; a first magnetic flux coupling body; and a second magnetic flux coupling body. The first transmitting coil is disposed between the first and second receiving coils. A distance between the second transmitting coil and the rotary shaft is larger than that of the second receiving coil and the rotary shaft. The first magnetic flux coupling body forms a first track for causing a periodic change for each rotation. The second magnetic flux coupling body forms a second track for causing a periodic change for each rotation. The second magnetic flux coupling body has a pattern of which an inner peripheral side is substantially continuous in a circumferential direction.

Abstract: A self-contained device intended to be carried by a wheel-tire assembly in order to locate whether the assembly is positioned on the right side or on the left side of a vehicle is described. The device includes two magnetic sensors with axes of maximum sensitivity, the sensors providing two periodic signals that are phase shifted relative to one another. Each signal is representative of variations in the magnitude of the magnetic field detected by the sensor during a revolution of the wheel-tire assembly. The device also includes a processing unit programmed to determine, from the phase shift between the two periodic signals, a direction in which the wheel-tire assembly is rotating and to deduce, from this direction of rotation and from a direction of travel of the vehicle, whether the wheel-tire assembly is located on the right side or on the left side. The two magnetic sensors are intended to be positioned on the wheel-tire assembly at distinct azimuthal locations.

Abstract: A position sensor that detects operation positions of an operation member includes an element array having three stages, each including one or more detection elements. A detected subject is detected by each detection element in two adjacent upstream and downstream stages to determine an operation position of the operation member. Whenever the operation member is shifted by one operation position, the detected subject is moved relative to the element array by one stage. Each detection element outputs a detection result of the detected subject. The element array includes at least three detection elements of which the detection results change whenever the operation member is shifted by one operation position. A detection element in the upstream side stage detects the detected subject before the operation position shifting, and a detection element in the downstream side stage detects the detected subject after the operation position shifting.

Abstract: Provided are a method and an apparatus for creating a magnetic field map that extracts magnetic field information of a building from floor plan information of the building. The magnetic field map of the building may be generated based on the floor plan information and the magnetic field information.

Abstract: A linear sensor is described with a casing (5), with a pin (7) which contains a permanent magnet (1) and which is mounted in the casing (5) in a linearly displaceable manner against the force of a spring (6), and with a magnetic field sensor (3) attached to said casing (5) for detecting of a displacement of the permanent magnet (1). The invention provides that the pin (7) is controlled by a first cylindrical guide (8) and a second cylindrical guide (8).