Abstract: An exciter for an internal combustion engine igniter plug includes a charging circuit and a discharge circuit; the charging circuit being connectable to a power supply and the discharge circuit being connectable to the plug to produce sparks; the discharge circuit comprising a storage capacitor connected to the charging circuit, a gated solid state switching device connected between the capacitor and the plug, and a trigger means for gating the switching device on and off; the capacitor being discharged when the switching device is gated on and the capacitor being charged by the charging circuit after the switching device is gated off.

Abstract: Apparatus for associating target reply signals with target signatures, wherein each reply signal is received from a target transponder within a selectable time period, and further wherein each target signature comprises a first set of parameter values that identify a target position and movement relative to an interrogating aircraft, the apparatus including reply processor means for producing a target report for each reply signal, the target report having a second set of parameter values; and report processing means for: 1) comparing each target report with each target signature to identify which report/signature pairs are potential matches, each comparison between a target report and a target signature being based on comparisons of corresponding parameter values to produce a probability of match for each parameter comparison; and 2) identifying which report/signature matches are best based on comparison of each report/signature potential match with each other potential report/signature potential match includ

Abstract: An exciter for an internal combustion engine igniter plug, comprises a continuous AC charging circuit and a discharge circuit. The discharge circuit is connectable to the plug and the charging circuit includes a transformer having a primary winding connectable to an AC power source and a secondary winding connected to the discharge circuit. The discharge circuit includes a storage capacitor connected to the transformer secondary winding such that current induced in the secondary charges the capacitor at a generally constant rate. A switching device is connected in series between the capacitor and the plug; and a trigger circuit triggers the switching device in response to charge on the capacitor; with the charging circuit and trigger circuit operating to maintain a generally constant spark rate. A current multiplier is also provided to substantially increase the peak currents delivered to the plug.

Abstract: Calibration apparatus for an antenna/receiver system having, in combination, means for receiving one or more electromagnetic data encoded signals from a transmitter and producing in response to each data signal two signals having a phase relationship, the receiving means comprising an antenna; signal processing means for using the phase relationship to determine information related to the data signals; and means for coupling a calibration signal into the antenna to produce two calibration signals having a known phase relationship; the signal processing means using the known phase relationship to compensate for phase errors when processing the data signals.

Abstract: Apparatus for rejecting multipath reply signals received from a target transponder within a selectable time period, comprising: a top antenna and a bottom antenna to detect reply signals; means for determining an altitude code associated with each reply signal detected by the antennas respectively; means for determining a differential time of arrival (DTA) value for each reply signal detected by the antennas respectively; and processing means for: 1) producing, for each top antenna reply signal, a top antenna target report that includes the altitude code and DTA values; 2) producing for each bottom antenna reply signal, a bottom antenna target report that includes the altitude code and DTA data; and 3) comparing each top antenna report data with corresponding data from each bottom antenna report, and marking out each bottom antenna report that is a multipath reply based on such comparison.

Abstract: Apparatus and method for detecting rotation of a shaft include a first antenna for transmitting electromagnetic energy into the shaft, a second antenna disposed for rotation with the shaft for modulating electromagnetic energy passing through the shaft in relation to the shaft rotational speed, and a detector for detecting the modulated electromagnetic energy that passes through the shaft.

Abstract: Apparatus for determining static torque on a rotatable shaft includes at least two elements that when coupled to the shaft have a torque dependent relationship to each other; a sensor for detecting the torque dependent relationship when the shaft is under static load; and means for rotating the sensor about the shaft under static load and through an arc that is less than a full rotation about the shaft.

Abstract: A baffle assembly for use in an ultrasonic system for measuring the level of a contained volume of liquid by calculating the density of the liquid by determining the dielectric constant thereof. The baffle assembly is located at the lower end of a stillwell located within the volume of liquid, The assembly includes a pair of concentric sleeves formed of electrically conductive material located to surround the lower end portion of the stillwell. The sleeves are uniformly radially spaced from one another so as to function as a capacitor so that the electrical capacitance between the respective opposed surfaces of the sleeves may be determined.

Abstract: Embedded smart structures include active electronics which control and collect data from sensors and actuators and transmit data to the exterior of a body by electromagnetic antenna radiation to a conformal power and data interrogation interface. Multiple embedded smart structures are powered and interrogated by a network of conformal powering and interrogation units. Multiple embedded sensors each having an antenna with a defined narrow band resonant frequency are powered and interrogated by a single external powering and data interrogation antenna.

Abstract: Apparatus for contactless interrogation of an sensor integrally disposed with a structure including a pair of coils for coupling signals across a gap between a sensing circuit having a sense coil and an interrogation circuit having an exciter coil connectable to a variable frequency supply, the sensing circuit comprising a circuit for changing current through the sense coil in relation to the sensor output; the interrogation circuit comprising a circuit for detecting current in the exciter coil induced by the sense coil current; and control means for determining the sensor output based on the exciter coil current compensated for the gap.

Abstract: An apparatus and method of wavelength detection and parameter sensing uses a variable magnetic field applied to a Faraday effect thin magnetizable film to perform spectral analysis based on detected intensity distribution of diffracted light for known magnetic field strengths. The strength of the applied magnetic field can also be varied by change in a physical parameter relative to a fixed magnet in a magnetic circuit which generates a magnetic field about the grating to produce diffracted wavelengths which correspond to the parameter which influences the magnetic circuit.

Abstract: A transducer assembly for an ultrasonic liquid level measuring device utilizing a piezoelectric crystal for generating ultrasonic pulses to be transmitted through a volume of liquid. The assembly includes an enclosure for the piezoelectric crystal assembly, that defines an interior space and a sealed opening for a cable. The enclosure is provided with a metallic layer that shields the entire interior space from electromagnetic interference. The assembly also includes a crystal housing assembly and a terminal block all located within the sealed enclosure.

Abstract: An optic sensor system comprising N optic sensors, each of the N sensors operating with received input light and providing output light having a characteristic corresponding to a sensed parameter; a number, less than N+2, of devices wherein each of the devices operates as a light source and as a light detector such that one device can be used to transmit interrogation light to two of the sensors, with two other of the devices being used to receive output light from the interrogated sensors; and optic waveguide means for transmitting light between the sensors and the devices.

Abstract: A modular device for assembling, wiring harnesses, cables and the like includes a number of elongate elements, a number of cable guiding means, each of the cable guiding means being selectively positionable along different points along the length of one of the elongate elements, and a number of securement means for removably securing the elongate elements in a fixed relationship.

Abstract: A liquid gauging system for a liquid container, the system comprising sensor means for producing a first electromagnetic signal that corresponds to liquid quantity in the container, and remote interrogation means for receiving the first electromagnetic signal and producing a system output that corresponds to the liquid quantity; the sensor means being energized by a second electromagnetic signal transmitted by the remote interrogation means.

Abstract: A proximity detector apparatus that uses the Faraday Effect to detect position changes of a target. The proximity detector includes a permanent magnet having a magnetic field that changes as the target moves to or from a predetermined position. A self-referencing optical sensor is provided that detects the changed magnetic field. The optical sensor includes a magneto-optic material positioned near a node of the magnet. Means are provided to transmit polarized interrogation light along an optical path that includes the magneto-optic material. The optical path is bi-directionally addressed and is non-reciprocal. The optical sensor transduces the changed magnetic field into a modulation of the interrogation light's intensity. Means are provided to detect variations in the interrogation light intensity and to determine a ratio such as the difference over the sum ratio for two interrogation light samples that traveled the optic path in opposite directions.

Abstract: A programmed PWM controller for controlling an inverter is provided which includes memory means for storing a plurality of drive data words representing a pulsewidth modulation sequence, each drive data word including a driveword and a drivetime word, the drivewords being used to operate the inverter; first digital means for selectively retrieving each of the plurality of drive data words from the memory means according to the pulsewidth modulation sequence in response to a next drive data word request signal; and second digital means governed by the drivetime word for generating the next drive data word request signal.

Abstract: An optical point level sensor for fluids includes a prism exposable to a fluid such that electromagnetic energy is reflected internally the prism dependent on the fluid level; and a lens optically connectable to an electromagnetic energy source and an electromagnetic energy detector such that electromagnetic energy from the source enters the lens at a first location axisymmetric to a second location where electromagnetic energy exits the lens to the detector. In one embodiment the lens is a GRIN lens.

Abstract: Ultrasonic fuel gauging apparatus for a fuel tank having a plurality of ultrasonic fuel level sensors for sensing fuel levels at respective predetermined locations in a tank based on echo ranging; a memory means for storing sensor data; and a state device for interrogating each of the sensors by controlling the application of transmit pulses to each of the sensors and for receiving output signals corresponding to return echoes, the state device operating in response to a sequential state counter.

Abstract: Methods and apparatus for detecting and decoding transponder reply signals of the type having a plurality of associated time discrete pulses including two bracket pulses and a number of related data pulses that may have been transmitted at discrete data time intervals between the bracket pulses such that the signal content detected during the data time intervals corresponds to the reply signal data code, comprising receiver means for receiving the reply signals and producing in-phase (I), quadrature (Q) phase and video (V) signals for each received pulse; means for detecting received pulses and storing the I/Q/V signals in a first memory; means for storing in a second memory pointer values that correspond to the temporal location of pulse I/Q/V signals in the first memory; means for identifying, based on time of arrival (TOA) values, pairs of potential bracket pulses wherein each pair marks the beginning and end of a reply code; and processor means for 1) determining an angle of arrival (AOA) value for each d