Abstract: A target acquisition system for a photoelectric control unit which helps avoid interference problems due to optical and electrical noise. The system provides for the interpulse interval between light pulses transmitted by the photoelectric control unit to be varied in accordance with pseudo-random jitter factors during the target acquisition process. Noise which may be on frequency with the normal repetition rate of the photoelectric control unit is then eliminated from the detection process pursuant to synchronous detection procedures.

Abstract: A plurality of heat sinks assembled to form a rack in a lightweight box accommodate printed circuit cards between the heat sinks and circulate cooling oil through the heat sinks to drain the test heat from the boards quickly. Each heat sink includes a porous metal foam core configured in zigzag shape to provide a tortuous path for the fluid flow which extends into lateral fins comprising the side plates of the metal foam for receiving the cards or ground plates therefore. These plates are clamped against the fins for close contact to the cooling fluid thereby shortening the heat flow path. Brazed on aluminum top and bottom cover plates make a fluid tight connection with the porous metal. The brazed on top and bottom plates are also configured in the zigzag pattern of the foam.

Abstract: The present invention describes a process for the compaction and densification of discrete powder materials utilizing a high amplitude stress wave which produces a high pressure condition at a surface of the particles thereby driving said stress wave into and through the particles.

Abstract: A system for directing the ionized gases which can exit from the vent openings of the arc chambers in high power circuit breakers away from the line terminals of the circuit breaker and isolating these terminals from infiltration by such gases. The system includes a deflection plate, interphase barriers and end plates mounted in proximity to the vent openings and around the line terminals.

Abstract: A variable pressure passive regenerative fuel cell system is provided wherein both the fuel cell and electrolyzer are designed to operate under variable pressure conditions.

Abstract: A communication system and a method for using an approximating frequency synthesizer with frequency correction by digital signal processing (DSP) means to provide a radio transmitter or receiver with rapid high resolution tuning capabilities. A user selects a frequency upon which he wishes to transmit or receive information. An approximating synthesizer is used to provide an RF injection frequency. A radio controller interprets the user selected frequency and determines the closet available approximating synthesizer frequency. The controller commands the approximating synthesizer to the determined available frequency and calculates the difference in the determined available frequency and the user selected frequency. The calculated difference or error is passed on to the DSP for correction during frequency mixing in a single or multiple step process.

Abstract: A non-invasive system for accurately determining the counter EMF or speed voltages in an electric motor during motor operation. The system includes a mechanism for determining the phase angle of the stator current within the dq frame of reference and a mechanism for transforming feedback voltages into a new frame of reference defined by this phase angle. The speed voltage values thereby detected are free from stator resistance effects and represent parameters of improved accuracy which can be used in motor control functions.

Abstract: A palm operable electrical switching apparatus which is integrally constructed with the cover plate of an electrical junction box. The switching apparatus comprises a padded button assembly which is easily operable from off-center directions, an activator assembly which converts motion transferred from the button assembly to straight line movement suitable for operating an electrical switch such as a contact block and a contact block positioned for actuation by the activator assembly. The switching apparatus enables a higher degree of operational flexibility and greater amount of conformity with human operators.

Abstract: A photoelectric control unit including an electronic system having a system architecture which is adapted for allowing the unit to readily and accurately determine its own operating margin. This architecture system includes a pair of variable gain modules which operate in conjunction with a pair of separate signal channels. The signal channels have comparators for comparing signal amplitudes on their respective channels with a common reference level. Operating margin values are determined by varying the gain of the amplification modules and tracking the output from the comparators on the signal channels. The photoelectric control unit can then use operating margin values to automatically set the system gain and thereby adjust the sensitivity of the unit for optimum performance.

Abstract: An apparatus and method of calibrating a digital to analog converter including means for establishing and storing a minimum and maximum analog endpoint value slightly in excess of the desired operating range of the DAC and then scaling each respective raw data point of the DAC within the established endpoint values.

Abstract: An advance in-flight windshear detection system which utilizes a scanning mirror to direct infrared energy located in a three dimensional space in front of the aircraft which is divided into a plurality of variable columns, onto a linear array of photoconductive infrared detectors, the detector emitting a signal representative of the radiant energy at various points in said variable located columns, and a computer for generating a displayable representation of the air temperature in front of the aircraft, the computer further capable of interpolating and extrapolating the air temperatures in the three dimensional space based upon the known and or calculated lapse rate; and a display device for graphically displaying the air temperature in front of the aircraft and above the flight path vector so as to provide a more accurate indication of windshear which is less affected by the uncertainties arising from measuring air temperature in a typically more turbulent region along the flight path vector as the aircraf

Abstract: Static electric charges are removed from the proof mass 10 and support 12 of an accelerometer by covering the proof mass 10 and support 12 with a thin metallic film 36, such as chromium oxide.

Abstract: A circuit for combining electronic signal power from multiple input ports to a single set of output terminals or for dividing a single signal at a set of input terminals and providing it to multiple output ports. The circuit has a three-winding transformer and a balance resistor or resistors corresponding to each of the multiple ports. Each port is connected to a first winding of its corresponding transformer. The second windings of the transformers are connected together and to the single set of terminals. Third windings of the transformers are connected together through their corresponding balance resistors.

Abstract: A combined angle-faceted, superluminescent diode and readout photodetector with an optical fiber coupled at one end of the superluminescent diode and the readout photodetector coupled at the other end wherein no fiber-optic couplers are used to couple the optical fiber with the readout photodetector.

Abstract: The present invention provides a highly efficient, high speed, and low power method and apparatus for extraction of a single signal from a set of frequency division multiplexed (FDM) signals. The apparatus operates on an analytical digital FDM-type group of signals to decompose the overall signal spectrum by octaves until a single signal or channel is selected. The signal selection is accomplished by transferring received FDM signals into a bandsplitting filter where the spectrum is divided into an upper and lower half-band spectrum. The upper half-band is complex shifted into the lower haIf-band and one half-band eliminated from further consideration. The selected half-band is decimated by a factor of two and recirculated through the filter where it is repetitively half-band filtered, complex shifted, and decimated until a desired single channel remains. The signal data from one processing pass is interleaved with data from previous passes to increase processing efficiency and speed.

Abstract: A package for enclosing and mounting a multichip module to a printed wiring board including a ceramic base with an elevated peripheral ledge constructed of a material, having a coefficient of thermal expansion differing substantially from the coefficient of thermal expansion of the material of a serpentine sidewall mounted to the base, and having a lid mounted to the top of the sidewall. The package includes electrical contacts extending through the ledge for connecting the multichip module to the circuit board. The sidewall is a series of interconnected short segments having acute angles at their interconnection forming a pleated shape.

Abstract: Data from long range aids such as the global positioning system (GPS) and an inertial navigation system (INS) and short range aids such as a microwave landing system (MLS) are used to smoothly and automatically transition an aircraft from the long range aids to the short range aids. During cruise a Kalman filter combines data from the global positioning system and the inertial navigation system to provide accurate enroute information. When the aircraft arrives in the vicinity of the airport and begins to acquire valid data from the microwave landing system, the Kalman filter is calibrated with the MLS data to permit Precision landing with GPS/INS data alone in case the MLS system subsequently fails. In addition, navigation information begins to be derived from a weighted sum of the GPS/INS and MLS data, the weighting being determined by distance from the airport. In a first region farthest from the airport, the GPS/INS data is given a 1.

Abstract: In a skywave adaptable communication network, the time required to initiate communications between two transceivers can often be an important factor where the propagation characteristics of signals at various frequencies may bary drastically with time. The present invention not only improves upon known prior art by accepting the first frequency that it hears as a communication frequency when two nodes are attempting to communicate from a known list of probe frequencies to be transmitted at known times, it initially uses predictive frequencies in probe signal format during the time that would later be used for traffic information after link-up has occurred where the predictive frequencies may be based on algorithms, experience or whatever. Once link-up has occurred, the probe signals are used to allow the system to then adaptively change to better quality signals as these better quality signals are received, analyzed and compared with present working frequency signals.

Abstract: An improved air traffic control (ATC) system which utilizes traffic alert and collision avoidance systems (TCAS) as a component together with a flight control computer of an aircraft autopilot, a data radio and an interactive touch screen display device to produce a system for allowing easy trailing of another aircraft on trans-oceanic flights and to reduce landing delays at busy airports under IFR conditions.

Abstract: A system for suppressing spurious product signals and radiation resulting from the leakage of local oscillator signal energy in superheterodyne radio receivers. The system includes a 0.degree. signal splitter, a 180.degree. signal splitter, a pair of mixers and a 180.degree. signal combiner. The splitters split the communications input signal and local oscillator signal into signal components which are mixed together in the mixers to form intermediate frequency components which are combined in the combiner.