Abstract: An electrical sensing apparatus includes a conductor having longitudinally extending sections with parallel central axes and a connector section which extends between the longitudinally extending sections. The connector section has a central axis which extends parallel to the central axes of the longitudinally extending sections. A magnetic flux sensor is disposed adjacent to the connector section to detect variations in current conducted through the conductor. The magnetic flux sensor may be at least partially disposed in a slot in the connector section and have a flux sensitive side surface which extends perpendicular to a central axis of the connector section. The magnetic flux sensor may include an electrically insulating material which is at least partially enclosed by the connector section and a Hall effect device which is supported by the electrically insulating material. The electrically insulating material may be disposed in engagement with the connector section.

Abstract: A contactless switch (20) for actuating a system between an open circuit position and a closed circuit position is disclosed. The switch includes a housing (22) and a linear actuator (34) disposed within the housing. The switch also includes a linear-to-rotary motion assembly (30) disposed within the housing. The linear-to-rotary motion assembly is coupled to the linear actuator for producing a rotary motion of the linear-to-rotary motion assembly in response to a linear displacement of the linear-to-rotary motion assembly by the linear actuator. The switch also includes a plurality of Hall effect sensors (106) and magnets (80). The sensors are disposed within the housing and the magnets are disposed on the linear-to-rotary motion assembly.

Abstract: A microelectric position sensor wherein an assembly of magnetic field sensitive elements assume first and second states when subjected to a magnetic field having an intensity below or above first or second predetermined values respectively. A magnet is selectively movable relative to the assembly, so that the elements are selectively subjected to the magnetic field. The magnet has focusing tongues for focusing the magnetic field at a region including substantially only one of the elements, so that the magnetic field within the region has an intensity above the second value, and the magnetic field outside the region has an intensity below the first value.

Abstract: A multi-current technique for offset reduction in Hall elements is extended in order to separate a piezoresistive voltage, from a Hall voltage, in similar Hall and piezoresistive devices based on a semiconductor such as, for example, Silicon. In a special embodiment, this offset compensation method exploilts directional averaging using biaxial, quadruple current injection from four electrically separate current sources, in order to obtain in-situ cancellation of the off-diagonal piezoresistive voltage that is generated across Hall voltage contacts upon the application of simple shear stress. The technique indicates the possibility of Si-based Hall elements with field-equivalent offsets well below 1milliTesla, even in devices based on (001) Silicon with current injection in the [110] type directions. Simple methods for realizing multiple sources are also discussed, some of which are based on photovoltaic effects.

Abstract: A magnetic sensor has a first sensing element and a second sensing element surrounding the first sensing element so that the sensor is directionally independent in a plane perpendicular to a sensing axis. The sensor can be mounted in a housing that has an end with a threaded rod or a pin for connection to a support member.

Abstract: A micro-sized encoder which can be used to track the rotational position, angular velocity and acceleration of micro-sized rotating devices. The encoder includes an extrusion molded, micro-sized ceramic housing adapted to receive the radically micro-polarized, mullet-pole micro-magnet with an axially shaft. End plates with integral bearings are formed which mount to the housing and support the axially shaft. A thin film Hall sensor mounted on the surface of the housing in proximity to the ratable micro-magnet is used for sensing the radial field component of the micromagnet. The sensor is in communication with sensor electronics whereby, as the micromagnet rotates, the radially alternating north and south magnetic fields are sensed to the thin film Hall sensor and counted by the sensor electronics.

Abstract: A magnetic field sensor is described that has a 0.25-0.6 micrometer thick magnetically active layer of very high electron mobility that consists essentially of epitaxial indium antimonide. The indium antimonide layer is disposed on a 0.03-1.0 micrometer thick buffer layer of In.sub.1-x Al.sub.x Sb, where "x" is about 0.01-0.2, that is substantially lattice-matched to the indium antimonide active layer.

Abstract: A flux concentrator made of a high permeability material is enclosed in a semiconductor package with a magnetic sensing integrated circuit to improve the uniformity and magnitude of the magnetic field sensed by the sensor.

Abstract: A support structure is connected with a base and supports a carrier for movement along a linear path relative to the base. The base includes inner and outer panels. A pair of Hall effect devices are mounted on the inner panel. A magnet is mounted on the carrier. An actuator member is mounted on the outer panel and extends through the inner and outer panels into engagement with the carrier. The actuator member is movable relative to the inner and outer panels to move the carrier and magnet relative to the Hall effect devices. The support structure includes a generally U-shaped support member having a pair of legs which are connected with the inner panel. The carrier is disposed between the legs of the U-shaped support member. The carrier is supported for movement relative to the Hall effect devices by tracks which are disposed on the legs of the U-shaped support member and extend parallel to the inner panel.

Abstract: The sensor apparatus includes a sensor device having a control current (I.sub.H) flowing through it, a sensitivity and a temperature dependence of the control current characterized by a temperature coefficient, and a temperature compensating circuit for compensating temperature changes adversely effecting the sensitivity of the sensor device. The temperature compensating circuit includes a circuit portion which sets or adjusts the temperature coefficient of the control current(I.sub.H) according to changes in the temperature dependent internal resistance of the sensor device so that changes in negative temperature coefficients of other physical quantities determining the sensor sensitivity are compensated.

Abstract: A process for adjusting a magneto-resistive sensor having a pair of current contacts and a pair of voltage contacts to compensate an offset error, without additional components. The magneto-resistive sensor (10) is charged with a homogeneous, definitely oriented magnetic field, a defined control current (I) is applied between its current contacts (22, 24) and at least one of the voltage contacts (30, 32) is trimmed, for example, by a laser beam (38), during the measurement of a pseudo-Hall voltage across the voltage contacts.

Abstract: A semiconductor structure is disclosed in which two regions of semiconductor material positioned adjacent to each other have different electron mobilities. By application of a magnetic field to the device, a Hall voltage is created across the boundary region between the regions of semiconductor material to modify their resistance. By detecting the change in resistance, the device can function as a memory cell, a programmable logic device, a head for hard disk drives, a measurement tool for measuring magnetic fields, or other apparatus.

Abstract: Electrical switch gear which comprises a housing formed to be substantially rotationally symmetrical and consisting of an upper housing part and a lower housing part. Inside the housing is disposed an actuating member formed as a push rod, provided in a housing chamber and provided with a permanently magnetized component, and a switching component which can be influenced by the permanently magnetized component and is provided in one housing chamber hermetically separated from the other housing chamber. To create switching gear able to make possible a larger number of switching functions, at least one permanently magnetized component is provided which is disposed on one longitudinal side of the actuating member and extends with its region of action close to one of the separating wall sides extending in the displacement direction of the actuating member.

Abstract: A tunneling ferrimagnetic magnetoresistive sensor that has a .DELTA.R/R greater than that of known magnetoresistive sensors, and that, with appropriate electrode materials, can undergo a substantial change in resistance in response to a magnetic field in the intensity range of 10s of Oe, which is typical of the intensity of the magnetic fields encountered in magnetic recording media such as discs and tapes. The tunneling ferrimagnetic magnetoresistive sensor is composed of a stack of thin-film layers that include a layer of a ferrimagnetic material, a layer of a magnetic material, and a layer of an insulator interposed between the layer of the ferrimagnetic material and the layer of the magnetic material. The ferrimagnetic material is conductive. The magnetic material is also conductive and has a coercivity substantially different from that of the ferrimagnetic material.

Abstract: A multi-function switch includes a casing, a key top member, two magnets, two magnetic detectors and a micro-computer. The key top member is mounted on the casing to permit both liner movement and rotational movement in a plane parallel with a bottom face of the casing. The two magnets are arranged on the key top member to be apart from each other at a predetermined distance. The two magnetic detectors are arranged on the casing to face the magnets' respectively, at respective neutral positions in the liner movement and rotational movement. The micro-computer detects a ratio of respective voltages generated from the magnetic detectors and further processes the obtained ratio as a desired operational signal.

Abstract: A transducer for indicating position in space with reference to a coordinate system includes a magnetic field source (13), a movable button element (11) composed of a magnetically susceptible material having a central pole face (16) and a surrounding annular co-planer pole face (19) for providing uniform magnetic flux paths in the annular region between and extending from the plane of the respective pole faces, and a probe element having a plurality of sensor units (41a-d) for electronically measuring magnetic flux through a plurality of separate, geometrically congruent areas arranged around an axis of symmetry (24) in a sensing plane which is spaced from, and parallel to that of the pole faces of the movable button element.

Abstract: An apparatus is provided for sensing an angular position of a shaft or other rotatable body. The apparatus preferably includes a first and second housing portion. A circuit connected to a circuit board is housed in the housing and includes a plurality of proximity sensors. A rotatable member is rotatably attached to the circuit board and includes a position indicator. The circuit produces a signal as a function of the position of the rotatable member.

Abstract: A semiconductor magnetic to electric converter includes a Hall device, a differential amplifier for differentially amplifying an output voltage of the Hall device, a constant-current circuit forming a constant current source to the differential amplifier and an amplifier for amplifying an output of the differential amplifier. A current to voltage conversion resistor of the constant-current circuit is set to have a temperature characteristic capable of canceling a temperature characteristic of an intrinsic input resistance of the Hall device. Furthermore, the temperature characteristics of a set resistor for setting a current value of the constant current circuit, load resistors included in the differential amplifier and a load resistor of the amplifier are set to cancel out each other.

Abstract: A Hall effect device has a thin Hall element (10) having at least one hole or window and is bounded accordingly by at least one inner edge (10a, 10b) and, where required, also by an outer edge. One preferred embodiment having no current-induced misalignment voltages has a first pair of current connections (A,B) at two opposed locations on the outer edge (10a); a second pair of current connections (1,2) at two opposed locations on the inner edge (10b); at least one first pair of Hall voltage connections (C,E) at two opposed locations on the outer edge (10a) between the current connections (A,B) of the first pair; and/or at least one second pair of Hall voltage connections (3,5) at two opposed locations on the inner edge (10b) between the current connections (1,2) of the second pair. The currents (I.sub.A,B, I.sub.1,2) applied to the current connections may be dimensioned so that no misalignment voltages caused by internal voltage drops result at the Hall voltage connections.

Abstract: The invention relates to a magnetic-field sensor with a Hall effect device, a power supply, and an evaluating facility, which can be supplied with a Hall signal from the Hall-effect device and comprises an input amplifier, a storage element, and a signal superposition unit. To improve the accuracy of the magnetic-field sensor, in a first phase, a balancing signal for balancing the measurement-signal path with respect to an interface can be produced with the evaluating facility, the balancing signal being storable in the storage element, and in a second phase, the balancing signal stored in the storage element can be applied through the signal superposition unit to the interface, where it is superimposed on a Hall signal.

Abstract: A compact Hall element having a high magnetic sensitivity, a wide measuring range and which is resistant to application conditions such as high temperatures or radiations, includes a rectangular recess formed in a surface layer of an insulator layer, a negative electrode for emitting electrons and a positive electrode for collecting the electrons provided on the surface of the insulator layer surrounding the recess, a gate electrode located on the bottom of the recess so that it faces the negative electrode, Hall electrodes that are provided on the surface of both sidewalls of the recess and which are parallel with the line connecting the centers of width of the negative and positive electrodes. All of these electrodes are disposed in a vacuum containment structure.

Abstract: A vertical Hall element is formed within the epitaxial layer of a semiconductor and isolated from other components by a P type isolation diffusion. A position defining diffusion is used to accurately locate a plurality of openings within the position defining diffusion where contact diffusions are made. The position defining diffusion is made simultaneously with the base diffusion for transistors within the integrated circuit and the contact diffusions are made simultaneously with the emitter diffusion of transistors within the integrated circuit. Five contact diffusions are provided on the upper surface of the epitaxial layer and generally aligned within the region defined as the Hall element by the isolation diffusions. The center contact is used to provide electrical current flowing through the Hall effect element. Electrical current is split and flows to the two end contact diffusions.

Abstract: A Hall-effect device for detecting a magnetic flux intensity has a pair of input terminals connected respectively to a constant-voltage regulated power supply and an FET. The FET has a gate connected to the output terminal of an operational amplifier. One of the input terminals of the operational amplifier is connected to the junction between a variable resistor and a temperature-dependent variable resistor which jointly serve as a voltage divider. The temperature-dependent variable resistor has a temperature characteristic of resistance which is opposite to the temperature characteristic of sensitivity of the Hall-effect device. When the ambient temperature varies, the sensitivity of the Hall-effect device also varies, and so does the resistance of the temperature-dependent variable resistor. The divided voltage applied from the voltage divider to the operational amplifier drops, lowering the voltage applied to the gate of the FET.

Abstract: A magnetic sensor, memory, and magnetic imager has been described for sensing a magnetic field in two directions concurrently incorporating a bar of semiconductor material having a rectangular cross-section, electrodes for introducing current along the length of the semiconductor material, and electrodes positioned on respective corners of the rectangular cross-section at a common distance along the current path whereby the Hall voltage may be detected concurrently in two directions. The memory includes the above magnetic sensor plus a disk having a magnetic layer thereon for storing information, a positioner for moving the disk, a memory control circuit and a signal processor circuit. The magnetic imager includes a plurality of magnetic field sensors positioned in a one or two-dimensional array. The invention overcomes the problem of mapping magnetic fields with high spatial resolution with high magnetic sensitivity in two directions concurrently.

Abstract: For detecting the position of a magnetic element having a field component zeroing in at least one point in space, typically in a plane, a plurality of elementary Hall-effect sensors are integrated side by side and aligned in a direction perpendicular to the zeroing field component and to the current flowing through the elementary sensors. The elementary sensor generating a zero output voltage therefore indicates the zero position of the field component and consequently the position of the magnetic element with respect to the position sensor, so that The outputs of the elementary sensors provide a quantized numeric code indicating the position of the magnetic element.

Abstract: A magnetic field sensor having a planar element made of a material formed by crystalline magnetoresistive thin layers with an anisotropy of resistivity in the planar element also having, in the planar element, two magnetization axes of different values. This sensor also has two electrical connections enabling, in the presence of an external magnetic field, the flow of a current in the element in a first direction that is not collinear with each of the axes of magnetization and two electrical connections enabling a measurement of voltage in a second direction transversal to the first direction. This sensor thus works by planar Hall effect.

Abstract: A Hall effect device and a method of obtaining a magnetic field map of a magnetic body with the Hall effect device. The device comprises: (1) a substrate, (2) a first layer having a first Hall coefficient deposited over the substrate and (3) a second layer having a second Hall coefficient deposited over the first layer, the first and second layers cooperating to create, in the Hall effect device, a third Hall coefficient different from the first and second Hall coefficients. Creation of the third Hall coefficient by cooperation of the first and second layers allows use of materials for the first and second layers that were previously unavailable for Hall effect devices due to their relatively weak Hall coefficient.

Abstract: A magnetic position detector including a magnetic field generating element and a magnetic field detector that are arranged together so that a field generating element can be longitudinally positioned relative to the detector. The magnetic field generating element includes first, second and third longitudinally axially lined magnets. The second and third magnets are located adjacent the opposed ends of the first magnet and are spaced apart from the first magnet. The magnets are arranged so that the first magnet has a first polarity and the second and third magnets have an opposed polarity. The magnets are spaced apart to define inter-magnet gaps. The magnetic field detector includes a Hall element sensitive to the magnetic flux generated by the magnets. A power supply supplies a small bias voltage to produce an offset Hall effect output signal. The bias voltage is adjusted so that the Hall element output signal switches polarity as the Hall element passes over the inter-magnet gaps.

Abstract: A security circuit includes a Hall-effect sensor for generating an output signal in response to a sensed variation in magnetic field strength. A supply voltage source is connected to the Hall-effect sensor. A latch circuit receives the Hall-effect sensor output signal and generates a latched output signal. The latch circuit operates between a set and a reset state. Circuitry is provided for monitoring the supply voltage source and for generating an output signal applied to the latch circuit. The latch circuit generates the latched output signal in response to the Hall-effect sensor output signal and the output signal generated by the monitoring circuit when the supply voltage is at a predetermined level. The latch circuit is reset when the supply voltage is below the predetermined level.

Abstract: A magnetic field sensor apparatus that comprises an active layer of indium antimonide or indium arsenide supported on an elemental semiconductor substrate. Magnetoresistor sensors of indium antimonide and indium arsenide active layers on silicon and germanium substrate wafers are described. Means are described for providing reduced electric fields and parasitic conduction in the elemental semiconductor substrate. The means includes unique device geometries and buffer layers between the active layers and the substrate wafers.

Abstract: A semiconductor structure is disclosed in which two regions of semiconductor material positioned adjacent to each other have different electron mobilities. By application of a magnetic field to the device, a Hall voltage is created across the boundary region between the regions of semiconductor material to modify their resistance. By detecting the change in resistance, the device can function as a memory cell, a programmable logic device, a head for hard disk drives, a measurement tool for measuring magnetic fields, or other apparatus.

Abstract: A magnetoresistor is monolithically integrated with an active circuit by growing a thin film magnetoresistor on a semiconductor substrate after the substrate has been doped and annealed for the active devices. The magnetoresistor is grown through a window in a mask, with the mask and magnetoresistor materials selected such that the magnetoresistor is substantially non-adherent to the mask. InSb is preferred for the magnetoresistor, Si.sub.3 N.sub.4 for the mask and GaAs for the substrate. The non-adherence allows the mask to be substantially thinner than the magnetoresistor without impairing the removal of the mask after the magnetoresistor has been established.

Abstract: An operator presence sensor for an operator's seat on equipment, such as skid steer loaders and the like, provides a signal to indicate when the seat is occupied. The operator presence is sensed by permitting seat rails to pivot about their forward end against leaf springs designed to support the seat weight plus a known fraction of an operator's weight so that the rear of the seat is raised when the seat is unoccupied and when an operator occupies the seat the springs deflect and the rear of the seat moves down, resting on a seat support pan. An electronic sensor detects seat position to provide a position signal.

Abstract: A Hall-effect sensor having a distributed array of current sources connected to an active region formed in a substrate of an integrated circuit. A corresponding array of current sinks is connected to the active region of the substrate opposite the current sources. When current flows in a path parallel to a first dimension of the active region from the current sources to the current sinks, a measurable Hall voltage develops across the active region if a magnetic field is passed through the sensor. This Hall voltage is measured by two terminals connected across a second dimension of the active region of the substrate. The measured Hall voltage sensitivity is very high according to this configuration.

Abstract: There is provided a magnetoresistance effect element comprising a substrate and at least two magnetic thin layers which are laminated with interposing a non-magnetic thin layer therebetween on said substrate, wherein adjacent magnetic thin layers through the non-magnetic thin layer have different coercive forces, characterized in that a metal thin film is provided in an interface between at least one of the magnetic layers and the non-magnetic layer which is adjacent thereto, and the metal thin film is made of a substance which is different from that of the adjacent non-magnetic layer.

Abstract: A programmable hand-actuatable controller and method of producing control signals using same are disclosed. The programmable controller has a compact housing from which a rotatable shift lever extends. A twist grip type handle is rotatably mounted to the end portion of the shift lever. A flexible electronic circuit carrying Hall-effect sensor is affixed to the lever and is electrically interfaced with a signal processing module contained within the housing. Directional control signals are produced when shift lever is shifted to any of three detented positions about a first rotational axis for selections of forward, neutral, and reverse directions. Gear ratio control signals are produced for selection of various gear ratios when the handle is rotated to any of a plurality of detented positions about a second rotational axis disposed along the longitudinal extent of the lever.

Abstract: A Hall effect sensor of two-dimensional electron gas type comprising, on an insulating substrate, a quantum well structure, a carrier injection layer adjacent to the quantum well structure, of thickness less than 250 .ANG. and having an density per unit area of donors integrated over the whole thickness of the carrier injection layer less than 5.times.10.sup.12 cm.sup.-2, an insulating burial layer deposited on the carrier injection layer, having a conduction band with an energy level greater than the Fermi energy of the sensor and a thickness greater than 200 .ANG.. Applicable to the field of electricity meters and current sensors.

Abstract: A signal generator for generating an electrical signal which varies in accordance with movement of an actuating member includes a plunger slidable mounted within a housing which carries a pair of permanent magnets for generating a magnetic field to be applied to a hall effect generator. As the plunger is moved relative to the hall effect generator, the magnets are also moved relative to the hall effect generator, thereby varying the magnetic field applied thereto. Accordingly, a variable output signal is generated as a function of the position of the input member.

Abstract: A linear Hall circuit that utilizes a single-ended output Hall current to sense a magnetic field so as to measure the magnetic field strength. A first operational amplifier configured as a transresistance amplifier converts the output Hall current of a Hall device to an output voltage. To avoid inducing a bias-based nonlinearity in the output Hall current, a second operational amplifier, having two resistors connected to both bias electrodes of the Hall device, respectively, is used to inject feedback Hall currents in them. The average value of the bias currents is then kept from varying with the output Hall current of the Hall device.

Abstract: A motion transducer for measuring the displacement of, for example, shafts in gas control modules. The shaft 14 carries two magnets 10, 12 each of hollow cylindrical form, the magnet 10 presenting a south pole everywhere over its external cylindrical face and the magnet 12 presenting a north pole everywhere over its external cylindrical face. The shaft 14 moves vertically past an array of Hall-effect sensors 18-24 to produce sinusoidal voltage outputs at the sensors. The outputs are combined in a summing amplifier (FIG. 3). The combined output is not affected by rotation of the shaft and magnets nor by tilting or sideways displacement of the axis 16 of the shaft. That is because no matter what the rotational position is the sensors are always subjected to the same magnetic field and, if the shaft tilts or is displaced sideways an increased field at some sensors is compensated by a decreased field at others.(FIG. 1 is suggested as the accompanying drawing).

Abstract: A sensor for automatically triggering safety devices in motor vehicles, the sensor has a housing having a housing recess with a base and a tilting body located in the housing recess, the tilting body serving as a seismic mass and triggering a control signal when a predetermined threshold value is exceeded, the tilting body having an edge and a base. The base of the housing recess is provided with knobs at least in the region of the edge of the tilting body. The base of the tilting body is flat at least in the region of the knobs.

Abstract: A signal generator for generating an electrical signal which varies in accordance with movement of an actuating member includes a plunger slidable mounted within a housing which carries a pair of permanent magnets for generating a magnetic field to be applied to a hall effect generator. As the plunger is moved relative to the hall effect generator, the magnets are also moved relative to the hall effect generator, thereby varying the magnetic field applied thereto. Accordingly, a variable output signal is generated as a function of the position of the input member.

Abstract: A semiconductor film is provided characterized by having high carrier mobility and carrier density. The semiconductor film is doped with the rare-earth element erbium so as to improve its temperature stability. The semiconductor film is thereby particularly suited for use as a magnetic field sensing device, such as a Hall effect sensor or magnetoresistor. The semiconductor film is formed from a narrow-gap Group III-V compound, preferably indium antimonide, which is n-doped with the erbium to provide an electron density sufficient to increase temperature stability. In particular, the semiconductor film is characterized by a nini-structure which is generated using a slab-doping technique. The slab-doping process encompasses the growing of alternating layers of doped and undoped layers of the Group III-V compound, with the doped layers being substantially thinner than the undoped layers, and preferably as thin as one atomic plane.

Abstract: A sensor system for detecting gear modes of an automobile transmission is disposed about a detent lever internally within the transmission case. The system includes an encoder capable of generating a magnetic field disposed on or about a detent lever, and at least one sensor, such as a Hall-effect sensor, disposed opposite the encoder. The encoder is a magnetic strip having at least one track encoded thereon, wherein the sensor is juxtaposed with the encoded track such that it produces a digital signal representative of the position of the encoder means and the corresponding gear mode.

Abstract: An integral pressure sensor for a pressurized vessel, including a housing, a core element, a seal and a spring. This combination is disposed on the interior of the pressurized vessel. The core element is preferably a magnetic element or a steel ball which moves in the housing under the effect of the vessel pressure, and the chamber or housing pressure. The spring and seal combination together with the core element, function to trap a specified volume of the pressurized medium in the chamber when the vessel is initially pressurized. When the pressurized vessel leaks, the trapped pressure within the chamber exceeds the vessel pressure thereby causing the core element to move. The position or presence of the core element is detected using a detecting device such as a Hall-effect device or another magnetic device.

Abstract: A magnet device having a predetermined field profile has an elongated permanent magnet, having a longitudinal axis and a peripheral surface, magnetized diametrically with the direction of magnetization extending transversely to the longitudinal axis and rotating about at least a portion of the length of the longitudinal axis of the magnet. The rate of rotation is selected to provide a predetermined magnetic field profile as presented to a Hall effect device positioned a fixed distance from the peripheral surface of the magnet when relative movement between the Hall effect device and the permanent magnet occurs. The magnet is formed of a composite material which includes a magnetically isotropic permanent magnet powder adhered together by an adhesive non-magnetic binder.

Abstract: An electrical power controller includes an integrated circuit having a Hall element, a Hall voltage amplifier, a ramp signal generator, and a voltage comparator. The output of the ramp generator is connected to one input of the voltage comparator and the output of the Hall voltage amplifier is connected to the outer comparator input. During intervals when the amplified Hall voltage exceeds the ramp voltage, the output of the comparator changes from one binary state to the other such that a stream of pulses is generated at the output of the comparator. Thus as a magnetic field at the Hall element increases, the Hall voltage increases and the width of each pulse in the stream of pulses grows proportionally. Mechanical means is provided for manually moving and guiding the pole of a magnet along a path toward the integrated circuit. Constructions of such controllers adapted for use as lamp dimmers and DC motor speed controllers are described.

Abstract: A magnetic field sensing device in the form of a sensor unit which reduces the effective air gap between the sensing device and its exciter is provided by packaging the sensing device in the manner that provides protection from the environment while simultaneously minimizing the distance between the sensing device and its exterior surface adjacent its exciter. The present invention is particularly suitable for automotive applications, such as magnetic field sensing devices for detecting the wheel speed for an electronic anti-lock braking system.

Abstract: A signaling gauge may utilize a magnetically actuated variable resistor made up of a plurality of noncaptivating, magnetically actuated switch elements, each of which is mounted in an influence zone of a path of a magnet carried on an arm of a condition sensor such as a gauge movement. The arm may be an indicating pointer of the gauge. The gauge may alternatively utilize a magnetically-sensitive, variable-resistance element in a contactless arrangement with a magnet. The variable resistance element may include a plurality of noncaptivating, magnetically actuated switch elements and associated resistors mounted in an influence zone of a path of a magnet. The contactless arrangement eliminates the need for electromechanical contacts.

Abstract: In an apparatus of detecting an environmental physical quantity such as magnetism and temperature by utilizing a sensitive element having an internal, electrical physical quantity which changes as the environmental physical quantity changes, an external operator element is provided which acts, when the environmental physical quantity acting on the sensitive element changes, a physical quantity corresponding to the change on the sensitive element, an electrical quantity supplied to generate in the external operator a physical quantity corresponding to the change is detected, and the environmental physical quantity is detected from the electrical quantity to provide a detection signal devoid of hysteresis and "depression".