Abstract: An optical header for coupling an edge emitter light source to an optical fiber is disclosed. The header preferably includes a ceramic or silicon substrate that has a recess for an edge emitting laser. An optical fiber is preferably attached to a substrate and terminates at a light source. The optical fiber is oriented such that the elliptical beam of light produced is situated such that the longer axis of the elliptical beam is orthogonal to the optical fiber. The header is particularly useful when used in conjunction with an optical receiver to form a bidirectional optical transceiver.

Abstract: A control system detects an electrical resistance change in a connector coupling a remote mounted temperature sensor to a control system. A control system determines the resistance of the sensor or the connector by selectively charging or discharging a capacitor through a unidirectional circuit element or the sensor. The control system is disclosed as controlling a water heater system, although such control systems may be used to control other systems using remote mounted sensors. A calibrating circuit is used to measure a transient response of an RC circuit, from which resistance can be derived.

Abstract: A flexible hermetic sealing and method for making the same. Electronic components are coated with an adhesive such as an epoxy, and then a metallic layer consisting of gold, silver, nickel, or another metal is deposited thereon. The metal may be deposited by, for example, any well-known evaporating, sputtering or plating technique. The resultant seal is truly hermetic, and is suitable for use on individual electronic or optical components on a chip.

Abstract: A geartooth sensor utilizes an algorithm for establishing an adaptive threshold for the switch point of the sensor to minimize drift in the point at which the sensor output changes in relation to the target features it is tracking. The algorithm utilizes measured waveform peak and average outputs and applies a separate empirically derived constant to each value to quickly obtain the major portion of the adaptive threshold value from the product of the first constant and the peak output, and to refine the threshold value further with the product of the second constant and the average output.

Abstract: A thermal fluid flow or property sensor having no exposed contact wires or contact pads in the fluid flow path to obstruct measurements, flat fully passivated sensor surfaces and high corrosion resistance is implemented over a honeycombed thermal isolation chamber.

Abstract: A controller, having a microprocessor, a control potentiometer and a monitor interface circuit connected between the microprocessor and the potentiometer, operates to monitor the control potentiometer and monitor interface circuit for failures. The potentiometer along with its wiring terminals and its wiper are monitored for faults. In addition the monitor interface circuit itself is tested so that either a fault in the potentiometer or a fault in the monitor interface circuit will be detected. The monitoring includes three tests performed from time to time. First, voltages across the full potentiometer are measured and compared to a voltage determined at initial installation or commissioning. The measured voltage is compared against limits to detect whether the measured voltage is inside or outside the limits. Second, the voltage across the wiper selected portion of the control potentiometer is measured and compared against a threshold to detect a fault.

Abstract: A multi-purpose device that can serve as either a resistor, MOSFET or JFET is disclosed. The resistor is formed by selecting a first metal interconnect configuration, the MOSFET is formed by selecting a second metal interconnect configuration, and the JFET is formed by selecting a third metal interconnect configuration. Because of the dual transistor/resistor nature of this device, the density of a typical gate array that uses resistors may be increased. In addition, and because no special processing is typically required, the device may be desirable for use in other types of structures such as standard cells and custom logic.

Abstract: Full duplex CMOS communication is accomplished over a single electrical interconnect by transmitting a signal in one direction using standard voltages indicative of CMOS logic levels, and by measuring the current needed to maintain these voltages to determine the signal transmitted in the opposite direction.

Abstract: Disclosed are apparatus and methods for efficiently writing states to one or more magneto-resistive elements. In one embodiment, current switches are provided for directing a write current through a number of write lines to control the write state of the magneto-resistive elements. In another embodiment, a sense current is selectively controlled to control which magneto-resistive elements are written to a particular state. In both embodiments, a latching element may be used to sense the state of the magneto-resistive elements, and may assume a corresponding logic state.

Abstract: A remotely operated rail car status monitor and control system including a plurality of handbrake status and release monitors (HSRMs), each of which is mounted to an individual rail car of a train, and a handheld data terminal (HDT). The HSRMs are self-contained electronic sensing and control devices capable of short range radio frequency (RF) communication with the HDT, and are mounted to rail car handbrakes configured for remote release. Each HSRM is programmed with a unique ID code which corresponds to the rail car's identifier. The HSRMs monitor and record the operational state of systems on the rail car such as the handbrake, load weight and refrigerator car temperature. Operating characteristics of the train such slid wheel events and handling impacts can be monitored and stored. Systems of the rail car such as the handbrake can also be released or otherwise controlled.

Abstract: A fiber optic gyroscope having polarization error-correcting modulation. Polarization errors originate from the interference of primary waves and secondary cross-coupled waves. Although these error signals are very difficult to remove modulation signals may be applied to the integrated optics chip that minimize the total error over a period of time. By providing distinct but inter-related modulation signals to opposing inputs of the sensing coil, the various polarization errors can be averaged to zero over the period of the modulation signals.

Abstract: A non-volatile latch having a power supply terminal and a ground terminal is disclosed. The non-volatile latch includes a pair of cross-coupled inverter elements each having a power supply terminal and a ground terminal. Magneto-resistive elements are interposed between the power supply terminals of both cross-coupled inverter elements and the power supply terminal of the non-volatile latch. In addition, magneto-resistive elements are interposed between the ground terminals of both cross-coupled inverter elements and the ground terminal of the non-volatile latch. By including magneto-resistive elements in each supply line, the effects of transistor parameter variation can be minimized.

Abstract: A digital to synchro converter converts digital values to an analog synchro signal. The values are mapped in a memory and sent to a digital to analog converter converting the digital values to analog values. Sample and hold circuitry is then used to create the analog synchro signal.

Abstract: On a railroad car handbrake system the main handbrake shaft, used to turn the chain, is utilized during its rotation to drive a target object to a magnetic sensor. The target object may be driven by cam plates, gears, screw mechanisms or the like and may be a magnetic or ferromagnetic object. The sensor system disclosed is rugged and easily adapted to existing handbrake systems.

Abstract: A pipeline distortion monitoring system equipped with an inertial system measures geometric characteristics of the pipeline, and generates signals representative of the characteristics. Additional sensor means are used to aid in correcting the signals. Corrected signals along with other characteristics yield pipeline profile characteristics used to assess pipeline distortions.

Abstract: A method and circuit to strip the composite synchronization (sync) from a composite video signal is disclosed. This invention utilizes a phase-locked loop and a switchable input operational amplifier to remove the sync portion of the video signal without bandlimiting or introducing non-linearities to the video signal. The phase-locked loop creates a high frequency clock from which a signal can be created that fully encompasses the sync portion of the composite video signal. This signal controls the switchable input operational amplifier to select blank level voltage during sync or allow the video to pass when sync is not present.

Abstract: Apparatus for mounting and making electrical connections to sensor devices for use in three axis sensing including a flexible circuit and a substrate shaped so that when a portion of the flexible tape is secured to the substrate the sensor devices can be mounted on the substrate for sensing in the desired three directions. The sensors are connected to conductors in the flexible tape by wirebonds or by other means.

Abstract: There is disclosed a system and method for maintaining data coherency between a primary process controller operable to execute process control tasks and a backup process controller operable to replace the primary process controller upon failure, wherein the primary process controller cyclically executes the process control tasks during base control cycles having a period, T. The system comprises 1) a tracking circuit operable to detect changed data in a main memory in the primary process controller; 2) a data buffer for temporarily storing the changed data; and 3) data transfer circuitry for transferring the changed data in the data buffer to a backup memory in the backup process controller at least once during each base control cycle of the primary process controller, such that the transfer of changed data does not interfere with execution of the process control tasks.

Abstract: A low energy switch contact design uses a flat spring moveable contact with contact portions made from the sides of the spring bent ninety degrees from the main spring body so as to make point contact with a stationary contact edge located either above or below the moveable contact. The spring is preferably bifurcated for redundancy of contact.

Abstract: A fiber optic hygrometer apparatus and method for sensing and measuring the dew point of an atmosphere is disclosed that includes a controller for controlling the operation of the apparatus and a first optical fiber for transmitting light energy from a source of light energy to an optical core extending into the atmosphere being monitored. The optical core includes an end that is prepared as a reflecting surface, allowing the light energy reaching the optical core to be internally reflected back toward the source. A second optical fiber captures the light energy internally reflected from the optical core and conveys the captured light energy to a light energy detector. The light energy detector is arranged to output signals to the controller representing the magnitude of the light energy captured. A cooling device and a temperature-sensing device operationally connected to the controller are attached to the optical core.