Abstract: As a component belonging to a class of components having hysteresis cycles of similar characteristics, the component of the invention subjects group of probes, in the absence of field-disturbing members situated in relationship with the probes, to a determined induction field so that a "bias" induction difference (B.sub.O) appears between the two groups, which difference is not less than the value of the high switchover threshold (B.sub.H), or not greater than the value of the low switchover threshold (B.sub.B), or else lies between the switchover thresholds (B.sub.H and B.sub.B), thereby obtaining a signal in a determined logic state at the output from the hysteresis level comparator in spite of induction difference dispersions lying between the minimum value of the low threshold (B.sub.Bmin) and the maximum value of the high threshold (B.sub.Hmax). The invention is applicable to differential detection Hall effect sensors.

Abstract: A Hall generator includes a substrate body of single crystalline semi-insulating gallium arsenide having a surface. A thin layer, no greater than about 5 micrometers in thickness, of single crystalline indium arsenide is on the surface of the body and is in the form of four arms joined at a common point to form a cross. A separate metal contact is on each of the arms at the free end thereof. An accumulation layer is adjacent the outer surface of the indium arsenide layer and extends along the entire surface of the indium arsenide layer between the contacts. The accumulation layer is effective to provide a magnetic sensitivity and range of operating temperatures as if the indium arsenide layer was much thinner and had a much higher electron density and electron mobility. Electrical devices, such as field effect transistors, may be formed in the body and the surface and electrically connected to the contacts of the Hall generator in a desired circuit.

Abstract: A magnetic sensor system includes stacked substrates each including a respective Hall element for detecting mutually orthogonal magnetic fields. Each Hall device includes a semiconductor material formed as a rectangular solid in a central portion of an opposite conductivity type substrate. The semiconductor material is sandwiched in a first direction between a pair of current electrodes and sandwiched in a second direction orthogonal to the first direction between a pair of Hall voltage detecting electrodes. Multiple substrates are stacked to detect magnetic fields in three dimensions. An analog-to-digital converter is formed in an additional stacked substrate.

Abstract: An integrally molded Hall sensor device for detecting the crankshaft angle of an automotive engine. The injection mold includes a projection 1a extending into a cavity and having a width equal to that of a gap through which a magnetic shutter passes. Before the molding, the parts are assembled utilizing a skeletal frame having first and second opposing pairs of vertically extending guide members, and the inserted electrical conductor for the Hall IC is embedded in the frame. The Hall IC and associated parts are accommodated in a holder, which is thereafter fitted between the first pair of guide members, to be translatable toward the gap; a magnetic circuit member including a permanent magnet is fitted between the second pair of the guide members to be translatable toward the gap. The assembled parts are then put into the mold such that the surfaces flanking the gap are positioned at respective sides of the projection.

Abstract: A Hall effect type sensing device comprises a magnetic circuit, a Hall transducing element arranged in the magnetic circuit to output a signal depending on a change in magnetic flux, a magnetic flux changing member which is able to change the magnetic flux in the magnetic circuit, a gap part which allows the magnetic flux changing member to move therein, and a frame member having its one side provided with a recessed portion forming the gap portion, and having its other side provided with an accommodation portion at a position adjacent to the recessed portion, the accommodation portion housing the Hall transducing element and a member forming the magnetic circuit.

Abstract: An encapsulatable sensor assembly includes an external housing with internal support components for retaining an active sensor element and associated electrical circuitry in a predetermined relationship while providing a plurality of internal sequentially interconnected cavities for facilitating a flow of an encapsulating material from an encapsulating material injection port to a vented overflow to assure a complete fill of the internal cavities to restrain the internal components. The sensor assembly provides a structure for a void free encapsulation and internal leadwire stress relief concurrently with location control of the internal components while also providing a combination which is easily adaptable to automatic assembly and encapsulation techniques.

Abstract: A Hall device a semiconductor region embedded in a substrate, the embedded region having opposite main and back surfaces and a pair of side surfaces parallel to and spaced apart from respective ones of the main, back and side surfaces of the substrate. A pair of current electrodes are formed of first highly doped regions embedded in the substrate respectively (i) between the main surfaces of the substrate and the semiconductor region and (ii) between the back surfaces of the substrate and semiconductor region so as to sandwich the semiconductor region between the main and back surfaces of the substrate. A pair of Hall voltage detecting electrodes are formed of second highly doped regions embedded in the substrate, respectively between side surfaces of the substrate and semiconductor region. The substrate can be made of SiO.sub.2 to increase electrical isolation between the electrodes.

Abstract: A current conductor is provided with opposing notches to produce a restricted section and with magnetic flux sensors on opposite sides of the restricted current section. The flux sensors are connected to differential amplification circuitry. The restricted section increases the concentration of magnetic flux sensed, and the differential amplification circuitry eliminates the sensing of currents in external conductive paths. An electrostatic shield is provided between the shaped conductor and the magnetic flux sensors to elminate electrostatic effects on the output signal. The flux sensors and differential amplification circuitry is fabricated in an integrated circuit chip. For small currents, the shaped conductor may be deposited on the chip; otherwise a shaped conductor is formed and a mounting substrate of insulating material, such as ceramic, is used to support the integrated circuit chip on the shaped conductor with each of the two sensors centered respectively within the two opposite notches.

Abstract: All of the resistors in a magnetic field sensitive circuit, both magnetoresistors (MRs) and fixed resistors (FRs), are formed simultaneously in a common fabrication process from a common magentoresistive material. An additional structure in the form of Hall shorting strips is applied to selected resistors to rendered them MRs, while the resistors without the additional structure function as FRs. In one circuit the resistors are arranged in pairs in two voltage divider circuits. The high voltage resistor for one circuit and the low voltage resistor from the other circuit are MRs while the remaining resistors are FRs, producing an increased magnetic sensitivity. In another circuit all resistors are MRs and are positioned so that the magentic field at one pair swings in a direction opposite to that of the other pair, further increasing the magnetic sensitivity. Discrepancies stemming from temperature coefficient mismatch and manufacturing variations are substantially reduced.

Abstract: A magnetoresistor includes a thin film of a degenerately doped semiconductor material extending between conductive contacts at opposite edges of the film. The film has a plurality of openings therethrough which are arranged in spaced parallel rows with the openings in each row being between two openings in the adjacent rows. This forms the film into two set of paths which extend around the openings. The openings are selected to be of a size such that when a magnetic field is applied perpendicular to the film, the resistance of the magnetoresistor increases because electron flow through the film between the contacts must be in a substantially circular path around the openings.

Abstract: An integrated circuit is encased in non-magnetic material and electrically connected to a Hall sensor. A permanent magnet is mounted for movement with respect to the Hall sensor to cause the Hall sensor to produce an output signal for setting a reference value.

Abstract: A rotary speed sensor system uses a permanent magnet and a Hall cell sensitive to the changing tangential component of magnetic field caused by the interrupted surface profile of a rotary element. In order to avoid anomalies caused by the variation of the base value of the tangential component of magnetic field, the output of a differential amplifier fed by the Hall cell is connected to a voltage averaging circuit which stores the average voltage of the output on a single capacitor. The output of the differential amplifier and the voltage across the capacitor are respectively coupled to the differential inputs of a Schmitt trigger exhibiting hysteresis. The Schmitt trigger thereby establishes operate and release points relative to the average voltage signal. The voltage averaging circuit is a non-linear circuit in which the voltage across the capacitor is fed back to the negative input of an operational amplifier.

Abstract: The present invention provides a current detection device comprising a core skirt for accommodating therein a core, a core stopper for fixing the core and a magnetic-sensitive element mounted on a substrate, the substrate and the core skirt having engaging portions for locating the magnetic-sensitive element, respectively, provided thereon, and further provides a core for detection of a magnetic flux.

Abstract: A chip including a Hall element for detecting a magnetic force is p repared. On the chip is formed an unhardened magnetic resin layer, which is formed of a mixture of soft magnetic powder an dsilicone rubber. The unhardened magnetic resin layer is applied with a magnetic field and is stretched in a direction perpendicular to one face of the chip, so that its top portion is formed in a substantially conical shape and its bottom portion is formed in a substantially rectangular block, the ratio of the length Wa of its base to its height Wb, Wb/Wa, being equal to or greater than 1. The magnetic resin layer is then hardened. As a result, a magnetic force detecting semiconductor device is provided, which has a magnetic resin layer with a high magnetic force convergence that has its top portion formed in a conical shape and its bottom portion formed in a rectangular block, the ratio of the length of its base to its height being equal to and greater than 1.

Abstract: A pair of permanent magnets adjoining each other and magnetized with opposite polarities are coupled with a movable object through a connecting shaft so that the pair of permanent magnets are aligned in a direction of displacement of the movable object. A first and a second Hall element is disposed stationary at a position opposing to the pair of permanent magnets and aligned also in the direction of displacement of the movable object with a predetermined space interval between the first and second Hall elements. When the movable object is displaced in one direction, and hence the pair of magnets are moved from a neutral position at which the boundary of the pair of magnets corresponds to the center of the interval of the first and second Hall elements, output voltages of different phases are respectively generated by the first and second Hall elements.

Abstract: A wheel speed sensor comprises a Hall device disposed in a pocket in a cavity of a plastic housing. The cavity is filled with potting compound to capture and enclose the Hall device. Flux issued from a magnet that rotates with the wheel acts upon the Hall device and is concentrated on the Hall device by ferromagnetic fragments interspersed throughout the potting compound.

Abstract: A magnetic field sensor comprises a stack of ferromagnetic layers advantageously separated by an intermediate layer of proper material and so arranged that the ferromagnetic layers are with one component in an antiparallel magnetization direction. The sensor is provided with terminals for passing an electric current through the stack and for detecting a voltage drop across the stack. The magnetic resistance change with such a stack is substantially greater than in systems which do not provide an antiparallel magnetization or do not have the intermediate layer.

Abstract: Relatively minute changes in magnetic field intensity are sensed by a circuit including a wire coil connected to a Hall effect element to provide the bias current to the element. The Hall effect element is disposed in the magnetic field with the coil and the output signal of the element is proportional to the square of the intensity of the magnetic field. The circuit is included in a device for measuring magnetic anomalies such as stress or corrosion cracks in structures of magnetic material including fluid transmission pipelines.

Abstract: A position sensor for measuring the separation, in a givne direction (Oy), between a first part such as a datum element of a railway vehicle axle and a fixed second part such as a rail on which said axles runs, includes magnets (11, 12) for producing a magnetic field above the second part (10) and Hall effect probes (15) for measuring the value of the component of the field in said given direction (Oy) with variation in that value being proportional to the separation.

Abstract: A magnetic pole detecting Hall element includes a Hall element chip which is buried in a package made of resin. Leg portions having a mounting plane perpendicular to the magnetic field sensitive surface of the Hall element are formed on the package.

Abstract: A Hall effect pressure transducer incorporates a pressure-deflection diaphragm which has patterned depressions therein to enhance linearity of response; an O-ring diaphragm seal which seals the diaphragm against pressure leaks without affecting the linearity of response; a pair of magnets, preferably rectangular, oriented with their North-South axes oppositely parallel, and oriented transverse to the deflection axis of the diaphragm to provide a uniform magnetic field gradient and sensitive, accurate, linear response of the transducer to either positive or negative pressure-induced deflections of the diaphragm.

Abstract: A Hall elements and magnet assembly for use as a proximity detector includes a magnet, a pole piece mounted to one pole end of the magnet and an integrated circuit having two side-by-side Hall elements, an amplifier, interconnecting wiring providing the difference voltage between the two Hall output voltages at the input of the amplifier, and a Schmitt trigger circuit. The integrated circuit is mounted to the pole piece at the pole end of the magnet. The pole piece is a ferromagnetic member which is thinner in the center than at the periphery for achieving a highly uniform field strength across the surface of the magnet pole end toward reducing the criticality of the position of mounting of the integrated circuit in manufacturing and for extending the range of gap dimensions between a passing ferromagnetic article and the assembly for which proper detection of the passing article can be made to occur.

Abstract: Supply circuit SC for a Hall sensor multiplication circuit HSC makes it possible to produce both circuits in monolithic technology on a common substrate and yet accomplish the polarity reversal of the output voltage U.sub.H of the multiplication circuit HSC with such accuracy that at said reversal the absolute value of the voltage U.sub.H is preserved with an accuracy of 0.01%.

Abstract: An apparatus is provided for measuring the test current in magnetoelectric fault detection, for instance by the magnetic particle method. A sensor comprising a Hall generator or a magnetoresistor is movably mounted on a diamagnetic support which clamps the sensor at a variable distance from a conductor carrying the test current. Alternatively, a plurality of sensors can be fixed to the support and the appropriate sensor selected for use.

Abstract: An electrical apparatus is provided for use with a potentiometer or variable resistance element which does not require a mechanical connection between a contact member and an activating mechanism. This is accomplished by using a magnet in at least a portion of either the contact member or the activating mechanism while constructing at least a portion of the other of such contact member and the activating mechanism of a ferromagnetic material.

Abstract: A transducer in the form of an integrated circuit comprising a Hall cell, first and second differential amplifiers, an output driver stage, a threshold voltage-generating circuit between said amplifiers, and a control circuit for selectively enabling and disabling the threshold voltage-generating circuit. The second amplifier provides an output signal representative of the enabled-disabled condition of the threshold voltage-generating circuit. A permanent magnet having a temperature coefficient is movable with respect to the transducer between given field-applying and field-removing positions. The transducer operates to change switching states between "operate" and "release" in response to the two different levels of applied magnetic fields, respectively, resulting from the two given operating positions of the magnet.

Abstract: The pressure sensor has a mechanical pressure receiving member and a mechanical-electrical transducer connected to it. The transducer comprises a permanent magnet attached with a moving portion of the pressure receiving member which cooperates with a locally fixed Hall-effect sensor mounted on the housing. To linearize the characteristic response curve of the transducer the inner surface of the housing wall is shaped like a funnel in a region between the permenent magnet and the Hall-effect sensor and in the vicinity of the permanent magnet. Because of this geometry the field strength lines are bunched increasingly on increasing separation of the permanent magnet from the Hall-effect sensor so that the field strength at the Hall-effect sensor increases and/or decreases approximately linearly with displacement path of the magnet.

Abstract: A highly magnetic Hall element comprising a substrate, a Hall element chip mounted on the substrate, and a magnetic member interposed between the substrate and the chip. The magnetic member increases the coercive force of the element, and is formed by laminating resin layers mixed with powder having a high magnetic permeability, one upon another, by stencil printing on that side of a semiconductor wafer in which a Hall element is mounted. The wafer and the magnetic member are diced together, to provide a Hall element chip. The magnetic member formed on the Hall element chip is adhered to substrate, with half-cured surface put in contact with the substrate.

Abstract: There is disclosed a circuit arrangement including a load (7) and a current source (1) for supplying current to the load via a current path with a winding (3). A core of magnetizable material (2) is coupled inductively with the winding and a Hall effect transducer (4) detects magnetic flux in the core for use in producing an output indication dependant on the magnitude of the load current. For testing the correct functioning of circuit(s), the circuit arrangement is further provided with an additional winding (6) on the magnetizable core, through which a further current source supply a further current, in which the core is also inductively coupled so that the transducer also detects flux in the core due to the further current.

Abstract: Magnetosensitive semiconductor devices are produced by forming a magnetosensitive part on one surface of a semiconductor substrate, pasting the semiconductor substrate thus formed on a jig, wrapping or etching the opposite surface of the semiconductor substrate, pasting a magnetic substrate on it with the jig pasted thereon, dividing the pasted substrates into individual unistructural elements each with a semiconductor chip and a magnetic piece, and die bonding, wire bonding and resin molding these individual elements.

Abstract: A tire pressure sensing system for on-board use in an automotive vehicle comprises a transmitter mounted to rotate with each tire and a receiver that is disposed in sensing relationship to each transmitter. Each receiver is a Hall Effect sensor. Each transmitter comprises three magnetic poles that are effective to cause the Hall Effect sensor to develop a bi-directional pulse waveform during passage of the transmitter past the receiver. Electronic circuitry processes the signal waveform that is created by the Hall Effect sensor in response to passage of the magnetic poles. The circuitry develops one rectangular pulse waveform from one magnetic polarity and another rectangular pulse waveform from the other magnetic polarity.

Abstract: A temperature compensated position sensor which may be used with hydraulic and pneumatic actuators having a magnetic piston and a non-magnetic cylinder is disclosed. The position sensor comprises a pair of Hall effect sensors mounted adjacent a permanent magnet on the outside of a hydraulic cylinder. One Hall effect sensor is oriented upside down with respect to the second Hall effect sensor such that the two Hall effects sensors perceive equal and opposite magnetic fields. The voltage outputs of both Hall effect sensors are amplified, and one is inverted. The resultant voltage signals are added together. Because changes in temperature produce equal changes in the output voltage of each sensor, the summing process cancels out temperature induced variations in the voltage signals. The resultant sum is dependent only on the magnitude of the magnetic field perceived by the Hall effect sensors, regardless of the variation in temperature.

Abstract: A medical infusion pump includes a housing (10), a pump assembly (30), a bubble sensor assembly (120), a pressure sensor assembly (140) and a flow control assembly (180). The pump assembly includes a ring (26) with teeth (44) and a wheel (46) mounted for eccentric rotation within the ring. The pumping action is developed by the rotation of the wheel which continuously closes a portion of tubing (36) against one or two teeth as it goes through the pumping cycle. The bubble sensor includes a pair of sensor blocks (124) defining a generally V-shaped trough for cradling a portion of the tubing. The pressure sensor assembly detects pressure variations by movement of a diaphragm (168) coupled to a magnet (162) which is operatively coupled to a Hall effect circuit (160). The flow control assembly includes a thumb wheel (196) having a cam groove (197) interacting with a valve stem (199) for controlling the fluid flow through an orifice and associated valve seat (194).

Abstract: A Hall-Effect position sensing system is provided that is particularly advantageous for use in vehicular applications such as for sensing position of a transmission gear change shift rail by requiring only a single power conductor (34) between a Hall-Effect switch device (90) and a remote power source (20) such as a battery by connecting a signal output terminal (16) of device (90) to conductor (34) in close proximity to device (90) and including a drop resistor (r.sub.1) such that a micro-processor (24) is able to provide an output control signal (32) indicative of position by monitoring the effect of the output signal of device (R) on conductor (34).

Abstract: The pressure measuring device has a housing in which a pressure chamber is located in a pin extending freely in the interior of the housing from a base. The pressure chamber wall is deformable elastically under an applied pressure. In the free end portion of the pin a magnetoresistive sensor is mounted which is moved with the chamber wall in a displacement occurring because of pressure changes in the chamber and thus is displaced relative to a permanent magnet. The magnet is mounted slightly transversely in the end portion of a compensating sleeve which surrounds the pin with wall contact. The change of the magnetic field at the sensor on displacement causes a proportional resistance change of the sensor so that an electrical signal proportional to the pressure change is generated which is a measure of the pressure. An amplifier for the signal from the magnetoresistive sensor can be mounted inside the housing adjacent the permanent magnet or the magnetoresistive sensor.

Abstract: A temperature compensated Hall-effect sensor apparatus is disclosed which senses the position of a moving body and provides an output signal indicative of the position of the moving body. The apparatus includes a Hall device which senses the application and subsequent removal of a magnetic field and provides an output signal to a constant gain amplifier. Circuitry is provided in the constant gain amplifier for adjusting the gain of the amplifier and also for nulling-out any offset voltage received from the Hall device. The output of the constant gain amplifier is input to a sensitivity compensation and hysteresis circuit for setting a positive-going threshold trip level and a negative-going threshold trip level into a comparator.

Abstract: Reproducability in the manufacture of rotating shaft sensing encoders and similar devices employing Hall effect switching devices to sense changes in magnetic fields is achieved in the present invention by forming a frame of the encoder as a unitary or one piece arrangement for both supporting a shaft bearing and an angular behavior sensor, such as a Hall effect switch, thus controlling tolerances, air gaps and angular orientation of the sensor. Calibration of such a device to compensate for manufacturing variability in the Hall sensing device as well as any other variabilities in the encoder is then achieved by providing a reversable calibrating magnetic field close to the Hall effect switch and moving that magnetic field until the desired switch calibration is achieved.

Abstract: An inventive Hall element formed from semiconductor material is disclosed. The inventive Hall element comprises a plurality of interconnected portions formed in a common semiconductor layer. Depending on how the portions are interconnected, the Hall element may detect the sum or difference of magnetic field values. The invention enables the realization of very large Hall elements which can be used in electrical meters to measure a magnetic field produced by an electric current.

Abstract: A force measuring device includes a rigid base plate and a first diaphragm symmetrical about a central normal axis and arranged in spaced parallel relationship to the base plate. An elastic connection between the base plate and a peripheral rim of said first diaphragm hermetically closes a cavity formed between the base plate and first diaphragm. A first projection is formed, for force introduction to the device, on an outer surface of the first diaphragm and extends along the central normal axis; a second projection extends from an inner surface along the central normal axis toward the base plate. A displacement sensor is arranged in the cavity between the base plate and second projection for sensing any displacement therebetween upon force application to the device, to generate an electrical signal indicative of the force applied.

Abstract: A Hall-effect control apparatus incorporating an actuator member having a magnetic core, and which is pivotally mounted on a base for movement in X-axis and Y-axis directions. An electrically energized coil excited with a. c. voltage produces a fluctuating magnetic field in the vicinity of the core. Four Hall-effect sensors are mounted on the base, and are arranged to sense changes in the a. c. field as the core member moves. The output of the Hall-effect sensors is both d. c. and a. c.; an electrical circuit connected therewith processes these voltages so as to cancel out any d. c. components thereof. The output of the electrical circuit in turn provides two voltages which are indicative of the X-axis and the Y-axis positions of the actuator member. The device is immune to interruption arising from d. c. fields, such as that of the earth; also significant immunity against error due to temperature fluctuations is realizeable, as is immunity to error arising from aging of the various components.

Abstract: A current sensor for use with a conductor with known cross-sectional characteristics is an electronic circuit having a monolithic Hall-effect element disposed substantially perpendicular to the conductor first major surface. A conductive loop substantially encircles the element and is oriented such that its flux is substantially orthogonal to the element surface. An amplifier sets current flow in the loop responsive to minimization of the differential Hall voltage across element. The loop current, at null, will be related to the conductor current by the ratio of the conductor flux path length to the loop flux path length.

Abstract: In order to have a large flexibility of application with simultaneously a reasonable number of different piece parts for a so called transformer keyboard the key element is subdivided. A base (1) usable for all applications includes elements for the protection against rotation (14) and for fixing (13) it on a printed circuit board (6) without screws and without soldering operations, further elements to guide (18) the stem (2) and to limit its stroke. The stem receives a ferromagnetic core (4) within its guidance (21). The shape and the size of wall portions (2', 22) change in accordance with the desired raster of the keyboard wherein the key element is used. A cap (3) carrying the marking has the same shape for all stems and is connected to the stem in a detatchable manner (27, 33). Due to their small height these key elements are especially suited in applications for data terminal keyboards with an ergonomically good design.

Abstract: Angular rotation of a member, such as the shaft of a tension arm assembly, is sensed by the combination of a circular type of magnet secured to the rotatable member and selectively polarized relative to its diameter to define a magnetic north-south pole pair, and a stationary Hall Effect transducing device secured in close and constant proximity to the ring magnet. A circuit coupled to the transducing device includes offset and amplification stages. In a preferred embodiment, the Hall Effect transducing device is located in the region of a magnetic null of the field generated by the magnetic poles, when the rotatable member is in a selected angular position. The constant gap between the transducing device and the circular magnet optimizes the generation of a linear output via the circuit, to accurately sense the member rotation.

Abstract: A self-contained electric fuel pump includes a pair of coaxially spaced inlet and outlet end caps joined by a case to form a pump housing. A d.c. motor includes an armature journaled for rotation within the housing and coupled to a pump mechanism for feeding fuel through the housing from the inlet to the outlet, fuel within the housing surrounding the armature being at substantially outlet pressure. A pressure sensor comprises a magnetic piston slideable against adjustable spring force within a bore in the outlet end cap as a function of fuel pressure within the pump housing. A Hall sensor is responsive to varying magnetic field as a function of piston position for applying electrical power to the pump armature as a function of pump outlet pressure.

Abstract: A strain gauge comprised of a premagnetized ferromagnetic film wherein any change in length of the film is converted into a planar Hall voltage by employing the property of magnetostriction and the planar Hall effect. Alternately, a change in the length of the film can also be measured as a change in electric conductivity by employing the properties of magnetostriction and magnetoresistance. The strain gauge is deposited on a substrate by thin-film techniques and has a very high sensitivity.

Abstract: A shock absorber includes a piston slidably mounted in a fluid cylinder for decelerating the motion of an object acting on the shock absorber. A metering mechanism adjusts the rate at which fluid escapes from the cylinder upon displacement of the piston caused by impact of the object. A proximity sensor disposed in the end of the cylinder provides an indication of when the piston reaches a displacement position corresponding to a stroke length in which maximum energy is transferred from the object to the fluid. The proximity sensor includes an electrical probe extending through the end wall of the cylinder and possesses an electrical property whose magnitude varies in accordance with the distance between the piston and the probe.

Abstract: An actuator system for positioning a flight control surface on an aircraft in which a primary braking device provides a continuous braking action to the actuator screw shaft by means of a load bearing disc brake wheel and a pair of rachet wheels contiguous therewith, the torque between the disc brake wheel and the rachet wheel (which ever wheel is being racheted by the load bearing disc) is proportional to the load on the screw shaft (and hence the actuator for the flight control surface). A Hall-effect device is mounted above the pawls associated with the rachet wheels for measuring the movement of the pawls in a closed loop circuit for the purpose of determining not only a faultlessly running braking condition but also to indicate whether a faulty condition exists, as well as what kind of fault is being detected.

Abstract: A circuit which compensates for fluctuations in the transfer characteristic of a magnetic field sensor is disclosed. More particularly, an auxiliary magnetic field is generated preferably by a coil which is connected to a voltage generator by way of a voltage/current transducer. The auxiliary magnetic field along with the magnetic field to be measured is detected by the magnetic field sensor. The portion of the sensor output signal due to the auxiliary magnetic field is correlated with the voltage produced by the voltage generator by means of a correlator circuit. If the portion of the magnetic field sensor output due to the auxiliary magnetic field is not properly correlated with the signal from the voltage generator a feedback signal is sent to the magnetic field sensor to adjust the transfer characteristic.

Abstract: A pressure responsive apparatus having a Hall-effect detector is described. The apparatus preferably includes a pressure gauge having a Bourdon tube responsive to an external pressure. The Bourdon tube has mounted thereto a pair of magnets supported on, or attached to, an end thereof for generating a low power, magnetic flux field. The Hall-effect detector is mounted in proximity to the pair of magnets and generates an output voltage having values corresponding to movement of the magnets with respect to the detector. A processing circuit receives the output voltage from the Hall-effect detector, and in response thereto generates a plurality of output signals proportional to the sensed pressure variations in the Bourdon tube.

Abstract: An improved pressure sensor includes a Bourdon tube, as its sensing element, and an indicator controlled thereby. At least one tightly closed container is secured to a free end of the Bourdon tube and is partly filled with a bulk material. If the Bourdon tube is made to vibrate as a result of pressure shocks or vibration forces acting upon its fixed end frictional forces that consume vibration energy arise between the container and the amounts of bulk material contained. The indicator includes Hall elements and permanent magnets, which magnets are secured on the Bourdon tube and are moved by it relative to the Hall elements.