Abstract: An occupancy sensor having a primary infrared radiation sensor and a secondary infrared radiation sensor in an integrated vacuum package having a window that provides separate fields of view to the sensors, respectively. The primary sensor is for monitoring occupancy of a selected space. The secondary sensor is for monitoring the background radiation of the space. Signals from the primary and secondary sensors are electronically processed and compared, and the occupancy level of the selected space is determined. Temperature and visible light sensors may also be incorporated. Sensor information is used to control temperature, ventilation, lighting and other parameters of the selected space.

Abstract: A temperature sensor is made with a rigid substrate disposed within a metallic tube for the purpose of supporting a resistive temperature detector and conductive strips disposed on the substrate. The conductive strips of palladium silver are deposited on the substrate and in electrical communication with gold pads that are used to permit the RTD to be connected to the gold pads by wire bonding techniques. A sleeve is provided at an opposite end of the sensor to support a first end region of the rigid substrate at a preselected position within the tube. The second end region of the substrate extends away from the sleeve and toward an opposite end of the tube, which is crimped to seal it. Conductive wires are avoided within the main portion of the outer metallic tube, thus eliminating the need for fiber glass sleeved wires extending through the tube.

Abstract: A sensor bridge circuit (20) sensitive to a proximate target (12). The bridge circuit (20) has two inductor (24, 28) and two resistors (32, 34). One inductor (24) has a reactance that varies with respect to the distance (26) of the target (12) from the inductor (24), which affects a balance of the bridge parameters of which is an indication of the distance (26). Another resistor (86) is connected in parallel to one bridge resistor (34) via an input (82) in the event where the target (12) is removed so that the displacement (26) of the sensor transfer characteristic is affected by an amount which results in a change of a diagnostic status indication (62). When the input (82) is not present, the status indication (62) should not appear in the event where the target (12) is far removed. Other resistors (42, 44) connected in parallel to bridge resistors (32, 34), via several inputs (46, 48), respectively, debalance or detune the bridge (20) so as to provide certain diagnostic information.

Abstract: A multi-domain halftone gray scale active matrix liquid crystal display utilizing a mono-gap configuration for achieving a very wide viewing angle at a low-cost. The substrate of the display has areas having a rub or an alignment of different directions from the direction of the rub or alignment in other adjacent areas. Each pixel of the gray scale matrix has a plurality of subpixels such that each subpixel turns on at a different voltage than that of the other subpixels. The areas involving different rubs or alignments on the substrates may be areas of pixels or subpixels. At least one compensating retardation layer is formed on the display. The technique of enabling the combining of multiple domains and compensation with halftone grayscale pixels results in a display having significantly wider viewing angles than either a multi-domain display or a halftone grayscale display, whether compensated for or not.

Abstract: The pH of a material containing lignin is determined by directing an ultraviolet light at the material. One of the characteristics of lignin is giving off a fluorescence in response to an ultraviolet light. A monochrometer is used to observe the fluorescence and produces a signal of the intensity of the fluorescent light at varying wavelengths. This signal is displayed on a display means such as a computer screen. Calibration occurs before the pH measurement of the material occurs. The calibration data along with information from the signal is used to calculate the pH of the material. No contact with the material is required in determining the pH of the material.

Abstract: An electrostatically controlled, micromachined micromechanical capacitor having an adjustable, extensive tuning range. A configuration consists of a set of various sized beams or plates adjacent to a common plate or plates. The pairs of plates are linearly moved relative to each other to provide an adjustable capacitance. The movement of the plates is caused electrostatically by an application of a DC or low frequency voltage to the respective plates. The signals that are processed by these micromechanical capacitors are typically in the megahertz range and higher. The process for micromachining the micromechanical capacitor is similar to the process utilized in integrated circuit fabrication.

Abstract: A magnetic sensor circuit provides current sources that create a feedback loop for an amplifier of one magnetically sensitive component in order to maintain the sensor output and the corresponding amplifier input at a first preselected magnitude which can be generally equal to zero. The other current source maintains a generally identical current as a reference against which the output of another magnetically sensitive component is compared. The magnetically sensitive components can be Hall effect elements, indium antimonide sensors or magnetoresistive elements. The output of the circuit is representative of the difference between the magnetic field intensities imposed on the first and second magnetically sensitive components.

Abstract: A rotational position sensor, or angular position sensor, that having two pole pieces. Each of the pole pieces has a first end portion and a second end portion. The two second end portions are arranged in overlapping parallel association to provide a gap between them. Two magnetically sensitive components are disposed in the gap between the second end portions of the two pole pieces. The two magnetically sensitive components are used to provide redundancy in the event that one of the magnetically sensitive components experiences a failure.

Abstract: A proximity sensing circuit is provided with various attributes, including the connection of a proximity sensor coil in a feedback loop of an amplifier, the frequency hopping technique that periodically changes the two frequencies used by its proximity sensor circuit to avoid deleterious interference by constant frequency EMI sources and the provision of a self diagnosis technique. The connection of the proximity sensor coil in the feedback loop of an amplifier results in several advantages including the connection of the coil to a virtually infinite impedance, the reduction of the number of components needed in the proximity sensing circuit and decreased temperature sensitivity of the overall circuit. The frequency hopping technique that periodically changes the two frequencies used by the proximity sensor significantly decreases the likelihood that a constant frequency EMI source in the vicinity of the circuit will have a continually adverse affect on its accuracy and reliability.

Abstract: A bit serial decoder is disclosed decoding an encoded non-return to zero (NRZ) signal without the use of external clock. Transitions within the encoded NRZ signal cause a differential voltage signal to be output. This differential voltage increases at a constant rate between two transitions. At the second transition the magnitude of the differential voltage is compared to a preset value to determine a number of consecutive like bits. These consecutive bits can then be transmitted in one step to a storage means.

Abstract: The present invention relates generally to a pressure sensor and, more specifically, to a pressure equalization structure that balances the forces on the pressure sensitive component in order to reduce the stress that could otherwise be imposed on its piezoresistors. The pressure sensor provides a housing in which a cavity is formed. Within the cavity, a pressure sensitive component is disposed between a first seal and a second seal in order to expose a first surface of the pressure sensitive component to a first conduit and a second surface of the pressure sensitive component to a second conduit. The pressure surrounding the pressure sensitive structure is generally equalized to one of the first and second conduits by providing a bypass conduit connected therebetween.

Abstract: A pumped rare-earth fiber source wavelength control device, having source wavelength control effected by pump source wavelength and power control. The maintaining of pump wavelength and power control can be attained several ways such as by use of a wavelength sensitive coupler, a short length of fiber having an embedded grating, and a modulated grating embedded fiber.

Abstract: A HIGFET having a gate with a pad which is isolated from the FET heterostructure wafer by a dielectric layer to minimize leakage current between the gate and the wafer. The method of production of this device involves application of the gate metal only over the active area of the FET and a photo resist covering on the gate metal. The wafer, including the area covered by the photo resist, is covered with the dielectric layer. The photo resist layer is removed along with the dielectric layer from over the gate metal. Another layer of gate metal is formed on the preexisting gate metal including a gate pad on part of the remaining dielectric layer.

Abstract: A low-cost portable handheld still-frame thermal camera for capture of calibrated digital thermographic infrared images having a lens assembly, a slideable linear array of uncooled 8-12 um thermal IR sensors, a slider actuation mechanism, and associated digital processing capability for calibrating, displaying, and storing images captured by the camera. The sensors are preferably thermoelectric sensors. The lens passes infrared radiation, the array is contained in an evacuated chamber, and operates at room temperature. The thermographic images may be displayed immediately or remotely or may be printed by conventional techniques.

Abstract: A switch actuation mechanism is provided with a support structure that is shaped to hold two switches. Each switch is associated with a pivotable member that is rotatably attached to the support structure. The pivotable member can be moved into either a rest position or an actuating position. When in the rest position, an actuating surface of the pivotable member is placed in contact with a plunger of the associated switch. A resilient member, such as a spring, is used to urge the pivotable members into their rest positions. If an actuator, such as a plunger or latch, is move into contact with a protrusion extending from the pivotable member, the pivotable member is rotated clockwise and the actuating surface is moved out of contact with the plunger. This deactuates the switch. The two switches are arranged to provide a sequential deactuation as two actuators are moved into contact with their respective protrusions extending from the pivotable members.

Abstract: An angular position sensor is provided with a rotatable magnet and first and second ferromagnetic pole pieces. The first ends of the ferromagnetic pole pieces are disposed on opposite sides of the rotatable permanent magnet and the second ends of the ferromagnetic pole pieces are arranged in overlapping association with a magnetically sensitive component disposed therebetween. First and second ferromagnetic inserts are provided which are movable with respect gaps between the permanent magnet and the first ends of the first and second pole pieces. By changing the relative positions between the first and second inserts and their respective gaps, the gain and offset of an output signal from the magnetically sensitive component can be altered to achieve predetermined characteristics.

Abstract: A switch is provided with the ability to diagnose its own operation and provide signals that represent the actuation of the switch and various diagnostic outputs that indicate fault conditions or potential fault conditions with regard to either the switch or related machinery. A magnetically sensitive component, such as a Hall element, is used to provide an analog output signal that is representative of the position of an actuator to which a magnet structure is rigidly attached. As the actuator moves in response to an external force, the magnet structure moves with respect to a stationary magnetically sensitive component. The analog output from the magnetically sensitive component can be used to determine the position of the switch. Based on this information, a microprocessor provides a binary output signal indicating whether the switch is actuated or deactuated.

Abstract: A cable switch actuating mechanism is provided with a shaft and a cam structure that slides on the shaft. When the associated cable is pulled to exert an axial force on the shaft, the cam actuator is pushed by the shaft into a deactuating position that moves a switch operator plunger against a plunger of an associated electrical switch. If the cable breaks, the reduction enforced on the shaft causes an internal spring to move the shaft against the cam structure and, as a result, move the switch operator into its deactuating position. Appropriate gaps between the opposite ends of the cam structure and associated surfaces of the shaft allow for thermal expansion and contraction of the cable without adverse affects on the mechanism.

Abstract: A self adjusting switch mechanism is provided which permits the specific location of a switch to be determined during an initial operation that moves a mounting plate relative to a bracket portion of the mechanism. This initial movement sets the switch in its proper position and prevents further movement. Subsequent operations of the device depress a plunger of the switch but do not change the relative position of the switch housing relative to a stationary structure, such as the housing of an appliance. Certain embodiments of the mechanism further incorporate a locking mechanism that can be manually set to prevent any further movement of the mounting plate relative to the bracket portion in response to jarring forces, such as when the door of an appliance is slammed shut.

Abstract: A back-etch silicon-on-insulator SOI process that has a silicon handle wafer with an oxide layer bonded at room temperature to a silicon device wafer with an etch stop and silicon device layer. The surfaces that are bonded at room temperature are first conditioned to be hydrophilic. After bonding, the edges of the layers are sealed. The silicon device wafer, the etch-stop layer and the device layer are boron doped. Most of the silicon device wafer is ground away. Then, the remaining portion of the silicon device wafer and the etch stop layer are chemically etched away, thereby leaving a uniform layer of silicon device layer on the oxide layer of the silicon handle wafer.