Abstract: A circuit takes advantage of the voltage square times capacitance function of a capacitor to sustain output power during input power interruption with a smaller energy storage capacitor. The circuit comprises an N channel power MOSFET switch, a voltage blocking diode, an energy storage capacitor, a voltage sensing circuit and a capacitor/diode network to provide a constant MOSFET drive.

Abstract: A communication method and apparatus incorporating fault-tolerance and increased transmission reliability in a content-induced transaction overlap (CITO) system is disclosed. The system is driven by an error-detecting and correcting CITO-based protocol whereby transient failures are transparent to the user. A parity check is built into the protocol for detecting failures due to hard faults. A redundancy configuration is also disclosed which permits circumvention of fabrication defects, thereby allowing an increased manufacturing yield.

Abstract: A weather radar system is operable in an automatic mode for positioning the radar system antenna beam to scan an elevation axis between upper and lower scan limits in incremental steps as selected by a user while continuously scanning an azimuth axis for enhancing the analysis of weather conditions.

Abstract: A power converter that can be used either as a start converter or as a variabe speed constant frequency converter is utilized within a stepped waveform VSCF system having engine start capability. Interfacing with the converter are a load bus, a contactor, a field excitation controller and a starter/generator having a main generator, an exciter generator and a permanent magnet generator. Magnetic components and semiconductor components perform multi-functions and minimal degradation of input power quality occurs.

Abstract: A ring laser angular rate sensor getter mounting clip is configured so that the susceptibility of the mounting clip to radio frequency (RF) energy used to activate the getter is minimized. The clip is configured so that opposing RF current flow is induced which prevents heating of the clip beyond force relieving temperatures for the clip material, whereby the clip maintains its retaining force within a getter well via three contact surfaces to more stably retain the getter in its proper position within the well.

Abstract: A combined transducer that measures force or displacement and temperature utilizes a pair of vibrating tines to provide a simultaneous output representative of temperature and force or displacement whereby the sum or average of the vibrating frequencies of the two tines is representative of temperature and the difference is representative of force or displacement.

Abstract: An inertial measurement and navigation system using a multisensor which provides analog acceleration and rate information to an analog to digital converter whose digital output is processed by a digital demodulator and fed to an AHRS systems processor whose output is fed to a digital to analog converter. Output information from the digital to analog converter can be stored or used to provide information to the pilot oil cockpit displays. The digital demodulator includes a phase locked loop comprising a Hilbert transform phase detector, a first order IIR loop filter and a digital controlled oscillator which provides in-phase and quadrature reference signals used in demodulation.

Abstract: A wind shear detector provides an alert to the pilot of an aircraft upon the occurrence of a sustained low-level increasing performance shear if the shear occurs for a sufficiently long period of time, even if the shear is of a relatively low magnitude. An integrator is provided to integrate signals representative of low-level increasing performance shears and to provide the alert if the accumulated energy caused by the shear exceeds a predetermined level. The integrated low-level shear signal may be combined with currently occurring shear signals and the alert generated if the combination of current increasing performance shear signals and the integrated shear signal exceeds a predetermined level.

Abstract: A servo accelerometer uses a tunnel current sensor having a first sensing electrode coupled in fixed alignment with a frame and a second sensing electrode coupled to a proof mass. A position sensing circuit develops a sensing signal indicative of displacement of the proof mass. A feedback circuit provides an output signal and provides a feedback signal to electrostatic drive electrodes for applying an electrostatic repositioning force to the proof mass. The proof mass and frame are connected by a highly compliant suspension structure.

Abstract: A computer communication bus system having a communication bus (10) having a plurality of data transmission lines (26, 28, 30) and a plurality of transmission nodes (12, 14, 16, 18) connected to the communication bus (10). Each transmission node (12, 14, 16, 18) has a data source providing multi-bit data to be transmitted on the communication bus (10), a plurality of data transformers (42, 44, 46) for encoding or transforming the multi-bit data into different multi-bit encoded data formats, and a plurality of CITO transmitters for transmitting the transformed data on different data transmission lines (26, 28, 30) using a content induced transaction overlap (CITO) protocol. Using the CITO protocol, the CITO transmitters (20, 22, 24) transmit the same data on each of the transmission lines (26, 28, 30) in a different order.

Abstract: A force sensing element is formed with four vibrating beams having substantially the same width and length. The four beams are spaced apart and disposed parallel to one another and are connected at opposite ends by end portions. With such a configuration, the outer beams move in phase with each other but 180.degree. out of phase with the inner beams. As such, the linear and angular reaction forces at the end portions are effectively cancelled. One advantage of such a configuration is its relative insensitivity to manufacturing process variations. By utilizing four beams which are nearly identical in width, variation in fabrication tolerance has virtually an equal effect on beam mass such that the dynamic balance of the force sensing element is maintained to a high degree of accuracy. Various drive methodologies for the force sensing element are disclosed as well as force sensing elements with integrally-formed isolator systems.

Abstract: A method and means for evaluating transponder reply signals in a secondary radar system to differentiate valid replies from false replies. Transponder reply signals received by the interrogating radar are decoded to establish conformity with an established format. All decoded replies to a succession of N interrogation signals are stored in their order of reception in an array of N shift registers. A reply filter is associated with each of the N shift registers. The reply filters operate in parallel to scan the stages of each associated shift register. A unary adder provides the number M of replies detected by the reply filters at each scan step. Reply decision means selects a threshold value that is dependent upon operating conditions of the radar and generates a valid reply signal whenever the value M equals or exceeds the selected threshold value.

Abstract: A servo accelerometer permits compliant suspension with a pair of flexures by using a plurality of tunnel current position sensors each respectively associated with a corresponding pair of electrostatic drive electrodes. The tunnel current position sensors and the electrostatic drive electrodes are positioned to control undesired movement of the proof mass about a first axis which is normal to the input axis of the accelerometer. In another embodiment, three tunnel current sensors and three pairs of drive electrodes are used to control movement of the proof mass about the first axis and a second axis.

Abstract: A system for reducing power in electronic systems blocks current paths by electrically isolating idle, targeted devices through switching off the various device's entire sets of pins from the rest of the electronic system. Solid state switches are connected to every pin of a targeted device. In one logic state a control signal will turn the switches on and thereby connect the targeted device to the remainder of the system. In another logic state, the control signal will isolate the targeted device.

Abstract: A circuit wherein a current sensing device is incorporated in an AC input line. An AC output is taken from the output of said current sensing device, and from an other AC input line. Circuitry including a bi-directional bridge rectifier followed by a bi-directional switching regulator and an energy storage capacitor adds current to or subtracts current from the instantaneous output load current. The arrangement is such that the AC output is equal to the AC input with no regulation effect. Substantially one hundred percent efficiency results when very little power factor correction is required.

Abstract: A plan position indicator display is converted to a correctly scaled perspective display based on aircraft altitude and display parameters. Two cartesian based display memories are involved. One memory stores the plan position indicator image to be converted and the other memory stores the converted image ready for direct display on a bit-mapped display device. The arrangement is such that a plan position indicator display pixel address is provided for each pixel in the memory which stores the converted image for permitting said latter memory to be completely filled with the most appropriate pixel values at the frame rate without the need for further pixel filling or erasing.

Abstract: Attachment of optical fibers to Optical Electronic Integrated Circuits on silicon substrates is accomplished by utilizing precision grooves combined with a vertical waveguide interface formed mechanically or electrochemically. The optical fiber must be prepared with a perpendicular end face.

Abstract: A method for making all complementary BiCDMOS devices on a SOI substrate (10). Isolated n.sup.- and p.sup.- regions (20,32,34,36,40,42) are formed on the silicon layer (16) and oxidized. LOCOS oxide regions (28) are formed on selected pairs of the n.sup.- and p.sup.- regions on which gates (44) for complementary DMOS device (114,116) and field plates (46) for complementary bipolar devices (118,120) are formed. Gates (48) for complementary MOS devices (122,124) are formed directly on the oxidized silicon layer (24). N-type and p-type dopants are then implanted into the silicon layer (16) forming n body and p body areas (54,56,58,60). Selected n.sup.+ and p.sup.+ areas (66,68) are formed in the n body and p body areas (54,56,58,60) as well as selected areas of n.sup.- and p.sup.- regions (30,32,34,36,40,42). The substrate (10) is then covered with an oxide layer and windows etched therethrough to expose said n.sup.+ and p.sup.+ areas (66,68) and selected areas of the gates (44,48) and field plates (46).

Abstract: A method of detecting a target signal at a target signal level below the level of clutter in the return signals of a radar receiver. The receiver i.f. signals are correlated by multiplying delayed i.f. signals with undelayed i.f. signals. The correlated signals are filtered and then decomposed into their spectral component frequencies. The spectral components are compared, in turn, with individual thresholds. The individual thresholds are formed by summing the weighted values of selected ones of the spectral components, the selection being such that the spectral component being compared with a threshold is not used in forming that threshold. A target output signal is generated whenever any one of the spectral components exceeds the level of the threshold against which it is compared. In a second embodiment, in-phase and quadrature correlator signals are formed by the use of two correlators and two delay lines having different delay times that provide a 90 degree phase difference.

Abstract: A system for correcting errors in static pressure, airspeed or airspeed rate caused by maneuvering that causes variations in static air pressure measurements compares a barometrically derived vertical velocity or altitude signal with an inertially-derived vertical velocity or altitude signal to provide a correction signal that is representative of changes in static air pressure and is used to correct the static pressure, airspeed or airspeed rate signal.