Abstract: In the present invention, the DEC output voltage is limited by comparing the DEC output and the Collective input to a predetermined maximum acceleration and generating an error signal when the maximum acceleration is exceeded. The error signal is fed back to the DEC and acts to limit its output. More particularly, the present invention is directed to a method of limiting the output of a DEC by generating a first signal representative of the acceleration demanded by the DEC, generating a second signal representative of the acceleration demanded by the collective, adding the first and second signals to form a third signal representative of the total demanded acceleration, generating a fourth signal representative of the maximum allowable demanded acceleration, subtracting the third signal from the fourth signal to obtain an error signal, and limiting the DEC output signal according to the error signal.

Abstract: A method for fault detection in a closed loop feedback control system for an actuator includes modeling the actuator for providing a model output simulating the actuator output in response to a model input which is also the actuator input, and comparing the actuator output and the model output for providing a fault indication upon exceeding a threshold. An apparatus includes a feedback control system having means for providing a feedback signal indicative of an output of the actuator, means for comparing an output demand with the feedback signal for providing an actuator output error, and means for providing to the actuator an input proportional to the error.

Abstract: The invention relates to leak isolating apparatus for multiple liquid cooled units in a coolant circulation system. The leak sensing portion of the apparatus comprises a supply flow meter and a return flow meter associated with each unit. The flow meters produce two variable electrical outputs proportional to the flow rates, and which are coupled to control logic for operating the isolating valves for the unit. The control logic compares the difference between the electrical outputs of the flow meters, and if the differences exceed a threshold, indicating a leak, operates the isolating valves. In the event of a sensed leak in a system having serially connected units, two serial valves are operated to prevent coolant flow to and from the leaking unit and a bypass valve is generated to allow coolant to flow around the leaking unit thus preserving the flow of coolant to the other units.

Abstract: An improved synchrophasing system for synchrophasing fan spools and engine core spools of one or more "slave" turbofan engines to a "master" engine is disclosed. A fuel control means is provided for modulating the flow of fuel to the slave engines to first synchrophase the operation of the engine fan spools. A variable stator vane control means is provided for then modulating the position of variable stator vanes within the slave engines to synchrophase the operation of the engine core spools.

Abstract: A novel double diffused complementary MOS (DCMOS) logic family is disclosed which allows greater tolerance to total dose gamma radiation. The logic family may be fabricated in conventional power BiCMOS IC technology in which complementary power DMOS output devices and Bi-polar transistors are integrated with high performance complementary MOS devices to perform both digital and analog functions. The incorporation is achieved without the additional masks or process modifications normally required for improving radiation tolerance.

Abstract: Control of a gas turbine engine, suitable for powering an aircraft, is accomplished by varying outlet nozzle cross section and/or a mixing of bypass air with exhaust gas at an inlet to the nozzle. The engine includes a core engine having a combustion chamber and high and low pressure turbines followed by an exhaust plenum. High and low pressure compressors driven by the turbine assembly direct air into the combustion chamber and into a bypass duct. The bypass duct extends from an outlet of the low pressure compressor. Pressure of fluid (air or exhaust) is measured at an inlet to the high pressure compressor, in the bypass duct, and in the exhaust plenum. Ratios of the pressure of the duct pressure or of the pressure at the inlet of the high-pressure compressor, to the plenum pressure are employed in a feedback loop for control of nozzle size, and also of mixing valve position in an alternate embodiment of the invention.

Abstract: A repairable cable termination comprising a cable transition adapted to receive an electrical cable. The cable transition including a first tubular region adapted to receive an outer shield of the cable, an antirotation sprocket and a second tubular region adapted to receive the inner shields of the wires in the cable. The cable termination further comprising top and bottom shells adapted to fit over the cable transition piece and including teeth adapted to engage the antirotation sprocket and prevent the cable transition from rotating relative to the top and bottom shells. The top and bottom shells being further adapted to fit over one end of the electrical connector and engage an antirotation sprocket attached thereto. The bottom shell including slots adapted to receive the ends of a C-clip which may be snapped over the top shell to hold the top and bottom shells together.

Abstract: A control system for operating an actuator in a mechanical system, such as an aircraft turbine engine, employs redundant electronic control channels for increased operational safety in the event of a failure of one of the control channels. In accordance with the reliability or integrity of the various components of the system, a network of triplex redundant electronic control units connects with duplex redundant input driver ports of a servo actuator, the network including a converter of triplex to duplex wherein the converter employs a duplex section of electronic circuits. The control units may include a schedule or memory addressed by a set of input parameters or variables for outputting a desired value of output parameter or variable. The converter includes a fan-in circuit by which signals of the three control units are applied to two power amplifiers for driving the two input sections of the servo actuator.

Abstract: The invention relates to the hermetic packaging of typically one or two dice for high power density applications. The package, which is intended for surface mounting to a heating sinking substrate, is particularly compact. Compactness in surface mount applications is measured as a minimum ratio of package area to die area. In accordance with the invention, compactness is achieved by using a novel vertically developed design in which the electrical connections lie within vertical extensions of the die boundaries giving a package to die ratio of less than 2 to 1.

Abstract: A control system for a gas turbine engine receives a signal representative of a first target engine operating condition and also receives a signal representative of an actual engine condition. The system produces an error signal representative of the difference between the target signal and the actual engine condition signal. A gain means adjusts the gain of the error signal to be equal to the desired change in the controlled engine parameter. The output of the gain means is then coupled to an activator of the engine which controls the parameter.

Abstract: A current regulator providing a highly accurate bidirectional output current, proportional to a control voltage (V.sub.i) and suited to monolithic integration is disclosed. The regulator uses a clocked integrator which integrates an error charge, arrived at by taking a precisely ratioed sample charge proportional to a voltage drop (V.sub.F), free of its common mode voltage, which is in turn proportional to the load current, and one proportional to the control voltage (V.sub.i), and combining them subtractively to form the error charge. The arrangement uses two small charge ratioing capacitors charged respectively to V.sub.F and V.sub.i, and a slightly larger integrating capacitor. The clocking is at a 10 KHZ rate. High impedance circuitry is utilized so that highly accurate, integrated capacitors of modest size and high relative accuracy may be used. These establish a regulator transfer function of high accuracy.

Abstract: The present invention relates to a low-pressure chemical vapor deposition (LPCVD) process for depositing silicon dioxide. In particular, the present invention describes a process involving a pre-cleaning step in which all impurities are removed from the substrate followed by a LPCVD step performed at temperatures of between 200.degree. C. and 300.degree. C. The process of the present invention is intended to replace higher temperature LPCVD and thermal processes for depositing silicon dioxide.More particularly, the present invention involves a process in which a substrate is washed using a predetermined cleaning process. The substrate is then exposed to a dilute hydrofluoric acid solution which removes native oxide and contaminants from the surface. Next, the substrate is rinsed with, for example, de-ionized water or ultra-clean water to remove any hydrofluoric acid or other residue from the previous process steps.

Abstract: An optical storage medium for storing binary data adapted to be written upon by a laser forming an array of encoded spots is composed of a substrate possibly covered with a mirror layer and including a matrix of a transparent dielectric material such as a polymer upon which a vacuum deposited discontinuous film of nucleated metallic islands is deposited having thicknesses of less than about 100 .ANG.. The particles extend up to 1000 .ANG. transversely generally parallel to the surface of said substrate. The islands are separated by a short distance for facilitating coalescence of particles together to effect writing of spots at low energy by the lateral motion and gathering of the islands during heating of the islands by a laser beam or the like. Each spot represents a data bit in a binary position code. The matrix material has low thermal conductivity and preferably a low melting point to facilitate writing at low energy.

Abstract: An improved augmentor fuel supply system including a fuel source, a pump for pressurizing the fuel, a flow control means for controlling the flow and pressure of fuel to a fuel disbursement means (e.g., an augmentor) and a return path for recirculating unburned fuel. The flow control means includes a restrictor means such as a small orifice in parallel with a controllable valve. The restrictor means allows fuel to flow to the fuel disbursement means when the controllable valve is shut off. Further, according to the present invention, a second restrictor means, such as a small orifice is included in the return path. Finally, a check valve is included in the return path to ensure that fuel does not flow into the augmentor through the return path.

Abstract: The present invention is directed to an electrical cable assembly comprising a cable termination piece adapted to engage a backshell nut. The cable outer shield is terminated at the termination piece. The backshell assembly comprises an outer backshell cable shield connected between two backshell nuts such that the backshell may be disengaged from the connector and, or the cable termination piece to access the signal wires in the cable.

Abstract: The present invention relates to a method of accessing and repairing electrical opens in conducting metal lines on a semiconductor chip or other substrate using laser plating techniques. What has been described is a maskless means of repairing discontinuities in a conductor disposed on the surface of a substrate wherein the surface is locally irradiated to form a reversible carbonaceous layer thereon. This reversible carbonaceous layer acts as a base for electrodeless deposition of a metal to form a bridge across the discontinuity by laser-enhanced exchange plating or other suitable methods. Further, a means of accessing and repairing a discontinuity buried by a cover layer of an insulating or passivating material is described, wherein access to the discontinuity is provided by ablating away the cover layer using a pulsed excimer laser at a first power level.

Abstract: The invention relates to an AC to DC converter having an improved power factor achieved by combining boost converter operation at the beginning and ending of each half wave of the AC input waveform, with passive operation at the middle portion of each half wave. The timing of the operation is based on comparing the instantaneous voltage with a stored average voltage, which has the effect of making boost converter operation go off at a fixed angle after the beginning of each half wave and go on at a fixed angle before the ending of each half wave, the angles being independent of the average AC voltage. The converter increases the power factor to a value between 90 and 97% and reduces the current waveform distortion to between 15 and 29%.

Abstract: A sense circuit for detecting charge on a TFT/LCD cell capacitor, which comprises a first, integrating circuit attached to the TFT/LCD cell capacitor through a data line, wherein the data line is connected to the cell capacitance through a thin film transistor. The thin film transistor including a gate, a drain and a source, wherein the source is connected to the cell capacitor and the drain is connected to the data line. A first, gate supply voltage adapted to drive the gate of the thin film transistor. And a reset circuit adapted to reset the integrating circuit. This embodiment may further include a source for charging said cell capacitor prior to measuring the charge. Further, a method of testing a partially constructed electronic circuit, for example the cell of an LCD, prior to installation of the backplate. The partial circuit comprising an array of contact electrodes, for example cell pad electrodes and an array of address electrodes, for example gate electrodes.

Abstract: In accordance with the present invention, a fuel flow circuit comprises a source of fluid, a first means for pressurizing the combustible fluid and pumping the pressurized fluid along a first path leading to a combustion apparatus for an internal combustion engine. The first means for pressurizing further pumping the combustible fluid along a second path to a first fluid-driven actuator adaptable to control some aspect of the engine. The first means for pressurizing further pumping the combustible fluid along a third path to a second means for pressurizing the combustible fluid. The second means for pressurizing pumping the combustible fluid along a fourth path, including a first diverting means, to a second fluid-driven actuator adapted to control some aspect of the engine or exhaust nozzle.

Abstract: A speed and phase sensor counterrotates aircraft propellers. A toothed wheel is attached to each propeller, and the teeth trigger a sensor as they pass, producing a sequence of signals. From the sequence of signals, rotational speed of each propeller is computer based on time intervals between successive signals. The speed can be computed several times during one revolution, thus giving speed information which is highly up-to-date. Given that spacing between teeth may not be uniform, the signals produced may be nonuniform in time. Error coefficients are derived to correct for nonuniformities in the resulting signals, thus allowing accurate speed to be computed despite the spacing nonuniformities. Phase can be viewed as the relative rotational position of one propeller with respect to the other, but measured at a fixed time. Phase is computed from the signals.