Abstract: A force transducer having a semiconductor substrate including a surface defining a recess, such that the recess has a peripheral boundary and a flexible diaphragm connected to the surface along the peripheral boundary to enclose the recess so that the diaphragm moves in response to changes in a force applied thereto. The force transducer also includes a resonant beam connected to the surface adjacent the peripheral boundary. The resonant beam has a frequency of resonation. Movement of the diaphragm in response to changes in the force applied to the diaphragm changes the frequency of resonation of the resonant beam.

Abstract: A pressure sensor package is claimed. The pressure sensor package includes a pressure sensor base having a cavity, a pressure sensor diaphragm positioned over the cavity, and a pressure sensor cap positioned over and secured to the pressure sensor base. The pressure sensor cap further includes a deformed portion securing the cap to the base, an engaging portion adapted to allow engagement of the cap when the deformed portion is being deformed around the base, an upper portion between the engaging portion and the diaphragm, and a lower portion between the engaging portion and the deformed portion, wherein the upper portion is longer than the lower portion. The engaging portion may extend radially outwardly from the cap, such as in the form of an annular ledge.

Abstract: A power steering fluid system is filled through port (56) in the direction of normal circulation of the fluid (24).

Abstract: A method and apparatus for remotely measuring the pressure and temperature of the gas in a vehicle wheel The vehicle includes a frame member, a vehicle wheel mounted for rotation relative to the frame member about a rotation axis, and a modulator mounted on the vehicle wheel for movement therewith The modulator generates a carrier signal including a first component encoding a plurality of consecutive data signals corresponding to a physical characteristic of the vehicle wheel, and the carrier signal including a second component identifying a portion of the respective one of the data signals

Abstract: A pressure sensor package and method for producing the same. The package includes a pressure sensor base, a pressure sensor diaphragm positioned over the pressure sensor base, and a pressure sensor cap positioned over the pressure sensor diaphragm and secured relative to the pressure sensor base such that a portion of the pressure sensor diaphragm is deformed between the pressure sensor cap and the pressure sensor base. The deformation can occur along a line of deformation, preferably to form a closed path adjacent a periphery of the pressure sensor diaphragm. In one embodiment, the pressure sensor diaphragm is deformed between an inner surface of the pressure sensor cap and an outer surface of the pressure sensor base along the line of deformation, and the inner surface and the outer surface diverge from each other when moving away from the line of deformation.

Abstract: A vehicle including a frame member and a vehicle wheel mounted for rotation relative to the frame member about a rotation axis. The vehicle also includes a transmitting circuit mounted on a one of the frame member and the vehicle wheel. The transmitting circuit includes an antenna coil having a diameter. A ferrite core is mounted adjacent the transmitting circuit on the one of the frame member and the vehicle wheel. A non-planar, curved antenna coil is mounted on the other of the frame member and the vehicle wheel. The non-planar, curved antenna coil has a radius of curvature that is approximately equivalent to the rotational pathway of the transmitting circuit.

Abstract: A method of forming apparatus including a force transducer on a silicon substrate having an upper surface, the silicon substrate including a dopant of one of the n-type or the p-type, the force transducer including a cavity having spaced end walls and a beam supported in the cavity, the beam extending between the end walls of the cavity, the method including the steps of: (a) implanting in the substrate a layer of a dopant of said one of the n-type or the p-type; (b) depositing an epitaxial layer on the upper surface of the substrate, the epitaxial layer including a dopant of the other of the n-type or the p-type; (c) implanting a pair of spaced sinkers through the epitaxial layer and into electrical connection with said layer, each of the sinkers including a dopant of the one of the n-type or the p-type; (d) anodizing the substrate to form porous silicon of the sinkers and the layer; (e) oxidizing the porous silicon to form silicon dioxide; and (f) etching the silicon dioxide to form the cavity and beam.

Abstract: A pressure sensor package and a method of producing the same. The package includes a pressure sensor base, a pressure sensor diaphragm positioned over the base, and a sealing ring positioned over the pressure sensor diaphragm and creating an interference fit with the pressure sensor base. The sealing ring forms a mechanical interference with the pressure sensor base by either positioning the ring within an under cut in a sidewall of the base or deforming a portion of the base over the top of the ring. The pressure sensor base includes a recess having a bottom surface and a groove in the bottom surface, and the sealing ring and/or the pressure sensor diaphragm is positioned within the groove. The package further includes external threads for securing the package to a threaded orifice, the external threads being positioned on the output side of the package, as defined by the diaphragm.

Abstract: A method and apparatus for remotely measuring the pressure and temperature of gas in a vehicle wheel. The vehicle includes a frame member and a vehicle wheel mounted for rotation relative to the frame member about a rotation axis. A transmitting circuit is mounted on the frame member. The transmitting circuit includes a transmitting coil and generates electrical energy in the transmitting coil. A receiving circuit is mounted on the vehicle wheel for movement therewith such that, as the vehicle wheel rotates relative to the frame member, the receiving circuit is inductively coupled to the transmitting circuit. The receiving circuit includes a sensor for generating a data signal corresponding to a physical characteristic of the vehicle wheel and a wireless communication circuit for receiving the electrical energy from the transmitting coil to remotely power the receiving circuit and for transferring the data signal from the receiving circuit to the transmitting circuit.

Abstract: An apparatus including an inner member mounted for rotation about an axis, an outer member mounted for concentric rotation about the inner member relative to the axis, the outer member having an inner surface adjacent the inner member and an outer surface, and a sensor mounted adjacent the outer surface of the outer member so as to measure the rotational speed of the inner member.

Abstract: A method of securing a pressure sensor diaphragm to a pressure sensor base, including the steps of positioning the pressure sensor diaphragm over the pressure sensor base, placing a pressure sensor cap over the pressure sensor diaphragm, applying a tensile force to at least a portion of the cap, and deforming a portion of the cap around a portion of the base. The applying step can occur before the deforming step by engaging a portion of the cap and advancing the base toward the cap to create tension in a portion of the cap. This creates a tensile preload in the cap. The applying step can instead be performed during the deforming step by engaging a first portion of the cap and advancing a second portion of the cap toward the first portion of the cap and around a portion of the base. This can create tension in a portion of the cap when the deformation operation is being performed.

Abstract: An electronic gain circuit adapted to receive an input signal, an amplifier having a gain for amplifying the input signal to produce an output signal, and biasing resistors connected to the amplifier to automatically adjust the gain of the amplifier in response to fluctuations in ambient temperature such that the output signal of the amplifier responds to ambient temperature fluctuations.

Abstract: A temperature sensor using doped polysilicon resistors in a bridge configuration, an amplifier, and a doped polysilicon feedback resistor between the input and the output of the amplifier. The polysilicon resistors are doped with selected concentrations of impurities such as boron, phosphorus, arsenic or antimony. The resistors are doped to establish predetermined temperature coefficients so that the resistors exhibit a predetermined temperature dependence. This temperature dependence is utilized to create a temperature sensor that is stable, accurate, and rugged and that has a generally linear output to temperature response.

Abstract: A pressure sensor including a housing having an interior surface forming a cavity, and a fill passageway communicating with the cavity. The fill passageway has opposite ends defining an axis extending between the ends, and one of ends defines a fill port spaced from the cavity. A pressure transducer is mounted on said interior surface. The pressure sensor also includes a sealing member moveable across the fill port in a direction transverse to the axis between a first position allowing fluid flow through the fill passageway and a second position closing the fill passageway such that the fluid is sheared off at the fill port to seal said cavity. Preferably, the fluid pressure within the cavity before sealing is substantially equal to the fluid pressure within the cavity after sealing.

Abstract: A sensor for determining the rotational speed of a rotating element. The sensor includes a giant magnetoresistive ratio sensing device which is magnetically coupled to the rotating element and includes an output terminal. The sensing device generates an output signal at the output terminal having a frequency corresponding to the rotational speed of the rotating element. A wave-shaping circuit is connected to the output terminal for receiving the output signal and for generating a digital switching signal having a frequency equal to the frequency of the output signal. A frequency divider has an input connected to the wave shaping circuit for receiving the digital switching signal. The frequency divider generates, in response to the digital switching signal, a square wave output having a 50% duty cycle and a frequency equal to the frequency of the digital switching signal divided by a predetermined divisor.

Abstract: A sensor for detecting the angular velocity of a rotating member. The sensor includes a bobbin having an exterior defining an annular recess and a coil within the recess. The bobbin also has a generally cylindrical aperture and supports a probe and a permanent magnet in the aperture. The housing is secured to the bobbin and the housing and bobbin include tapered inner and outer surfaces, respectively, that are made to form a wedge fit seal between the bobbin and the housing to prevent the introduction of molding material during the overmolding process. The bobbin also includes supports for supporting the lead wires extending between the coil and the terminals.

Abstract: A sensor for detecting the angular velocity of a rotating member. The sensor includes a bobbin having an exterior defining an annular recess and a coil within the recess. The bobbin also has a generally cylindrical aperture and supports a probe and a permanent magnet in the aperture. The housing is secured to the bobbin and the housing and bobbin include tapered inner and outer surfaces, respectively, that are made to form a wedge fit seal between the bobbin and the housing to prevent the introduction of molding material during the overmolding process. The bobbin also includes supports for supporting the lead wires extending between the coil and the terminals.

Abstract: A method of forming apparatus including a force transducer on a silicon substrate having an upper surface, the silicon substrate including a dopant of one of the n-type or the p-type, the force transducer including a cavity having spaced side walls and a diaphragm supported in the cavity, the diaphragm extending between the side walls of the cavity, comprising the steps of: a. implant in the substrate a layer of a dopant of the one of the n-type or the p-type; b. deposit an epitaxial layer on the upper surface of the substrate, the epitaxial layer including a dopant of the other of the n-type or the p-type; c. implant spaced sinkers through the epitaxial layer and into electrical connection with the layer of a dopant of the one of the n-type or the p-type, each of the sinkers including a dopant of the one of the n-type or the p-type; d. anodize the substrate to form porous silicon of the sinkers and the layer; e. oxidize the porous silicon to form silicon dioxide; and f.

Abstract: A gas concentration sensor for use in a closed container having a constant volume and gas within the container, wherein the gas has a known pressure at a given temperature. The sensor includes a pressure sensing device disposed within the container, wherein the pressure sensing device generates a first electrical signal functionally related to the gas pressure within the container. The sensor also includes an electronic circuit connected to the pressure sensing device which amplifies the first electrical signal and produces a second electrical signal functionally related to the gas concentration within the volume at any temperature.

Abstract: A temperature sensor assembly for measuring ambient temperature and including a housing defining an enclosure. A temperature sensor is mounted within the enclosure. The housing includes a brass cap and a liner for conducting heat from the brass cap to the temperature sensor. The temperature sensor is mounted on the brass liner and is electrically insulated from the brass liner by a thermally conductive material.