Abstract: A magnetic resonance gyroscope wherein the pump lamp includes an isotopic mixture of Hg, which controls the optical spectra of the pump beam to eliminate .sup.201 Hg alignment moments and to reduce light-induced frequency shifts. The inclusion of quarter-wavelength plates, reflection polarizers, and adjustable magnetic fields acting on the pump and readout lamps permit fine tuning control over the respective spectra to further enhance the rate bias stability of the gyroscope.

Abstract: A gyro includes a rotatable hub with a flexing member centrally supporting a rotor. The rotor is further supported by a pair of piezoelectric force transducers angularly separated by 90 degrees. The rotor turns with the hub. Oscillators drive the transducers and, as the gyro undergoes angular displacement, the oscillators "follow" the instant natural frequency of the transducers. FM signals are generated which may be resolved into two digital signals indicative of angular rate about the gyro case X and Y axes.

Abstract: A stand-alone digital processor based system includes a five-output state digital filter provided with magnitude and time data relative to a received TACAN signal. Threshold detection is provided for validating the received signal magnitude. The filter outputs produce phase signals which are combined in the digital processor, in accordance with an algorithm, to generate bearing data. The bearing data is stored and scaled prior to updating a display.

Abstract: A commutator brush holder mounts a pair of tension band springs in quadrature relation. Both springs contact the brush end remote from the commutator and urge the brush into contact with the commutator, with constant force. The quadrature springs promote full and intimate contact between the brush and commutator, thereby minimizing brush bounce and tilt and resultant transient signal generation.

Abstract: A transimpedance amplifier is connected in a positive regenerative loop with a crystal resonator. The transimpedance amplifier includes a high gain amplifier with a parallel resistor and capacitor thereacross. A virtual ground is created at the node between the resonator and the amplifier input thereby eliminating circuit sensitivity to inherent capacitive changes between the resonator and true ground. Components are chosen to maintain oscillations at series resonance and achieve insensitivity to changes in the motional resistance of the resonator.

Abstract: The complexity of a memory driver system is decreased by minimizing the number of half-select current driver circuits and corresponding terminals and wires connected between the driver lines and the core stack. This is effected by maximizing the number of current paths between memory drivers.

Abstract: An electro-static capacitive accelerometer is a square law device and includes two fixed plates and an intermediary movable plate. A control circuit detects unbalances in the accelerometer, due to acceleration, and generates a signal which induces a corresponding electro-static corrective torque on the accelerometer thus forcing it toward a null condition. The signal is proportional to the acceleration. The invention eliminates prior art summing amplifiers in the control circuit for linearizing the torque of the accelerometer.

Abstract: Gyro drift is reduced by measuring the positional relation between the rotating field of a driving synchronous gyro motor and a reference point on the gyro rotor at start-up. After the measurement is made, it is adjusted to a pre-established fixed value. Adjustments to the pre-established value occur each time the gyro is started.

Abstract: A ring laser gyro is electromechanically oscillated so that oppositely moving light beams in the gyro do not exhibit an undesirable lock-in effect. A piezoelectric transducer mounted in the gyro measures the dither. Analog/digital circuitry converts the measurement to digital dither signals. A non-compensated beam combiner and photodetector assembly are integrally mounted to the gyro for producing beam frequency outputs from the light beams, indicative of inertial rotation of the gyro. The beat frequency outputs and dither signal are input to logic circuitry which eliminates the effect of the dither signal on the beam frequency output signals.

Abstract: An impedance is connected by a switching circuit, to sense/inhibit windings of a core memory at the end of each memory cycle. The result is an effectively decreased time constant for the core windings which permits faster memory operation. The circuit further reverse biases diodes connected to the input terminals of a sense amplifier during a read cycle thereby increasing the isolation of this amplifier from the effects of inhibit current pulses occurring during a memory read cycle.

Abstract: A gyro motor supply provides an alternating signal to a gyro hysterisis motor. A detector senses the passage of a reference point on the gyro flywheel during each revolution thereof. A logic circuit is driven by the detector output and controls the phase of the alternating signal thereby ensuring a repeatable gyro start-up condition wherein the phasing is fixed between the reference point on the flywheel and a vector of the rotating field of the motor.

Abstract: A gyro includes piezoelectric force transducers which are oscillator driven. As the gyro undergoes angular displacement, the oscillators "follow" the instant natural frequency of the transducers and FM signals are generated at the oscillator outputs which are processed by the present invention to produce digital signals proportional to gyro angular inputs and resolved about two axes.

Abstract: Separate photodetectors and preamplifiers of prior art path controllers are replaced with an electronic circuit using the outputs of gyro fringe detectors. A ring laser gyro ordinarily includes fringe detectors for producing a data signal. Thus, the same detectors are used to serve two purposes. Pathlength controller simplification and cost reduction is thus realized since it is unnecessary to mount and align separate photodetectors to a gyro and to connect these photodetectors via flexible connections to a vibrating gyro.

Abstract: A switching circuit turns on at the beginning of a first clock signal and turns off in response to a gyroscope shaft detector signal. During the time the switching circuit remains on, a counter counts the cycles of a second clock signal. This resultant count is employed as an error signal for adjusting the output frequency of a pulse generator which is connected to a gyroscope motor. A feedback loop is created between the aforementioned components for achieving a preselected constant gyroscope motor speed.

Abstract: The power switch driver circuit of a brushless DC motor control ensures synchronous operation by utilizing a ROM addressed by motor shaft position sensors. Excess current drawn by the motor windings is sensed by a detector which provides an additional bit of address input to correct the condition. The address input may also be modified by a bit signifying forward or reverse operation of the motor.

Abstract: A dredging assembly pivotally suspended by a boom from a floating vessel includes an underwater frame that is propelled by rotation of spaded wheels to exert a forward propelling force on excavating drums mounted at a forward end of the frame. The drums are rotated independently of the propelling wheels in a direction opposite thereto during forward travel. Fixed baffles within the drums confine excavated material for removal by suction pressure.

Abstract: Photoelectrochemical cell structures and methods of fabricaton are disclosed which provide for easily manufactured efficient energy conversion devices. The structures incorporate one or more chambers for the electrolyte, and utilize semiconductor photoelectrodes. In the plural chamber structure, the semiconductor may be opaque, and need not necessarily be a thin film. Specific dopants for the semiconductor provide for decreased dark current and increased open circuit voltage. Post deposition treatment is disclosed for the semiconductor to provide an increased shorting current. Increased sputtering wattage is provided to increase the short circuit current available from the cell. An electrolyte composition is described having improved performance at high light intensity.In a multi-chamber embodiment, the electrode placement causes the photoactive site to be at an end of the chamber removed from the irradiation window, thereby permitting the use of non-transparent photoelectrodes.

Abstract: A detection device comprising two spark-gap electrodes connected to a voltage pulse source having an amplitude greater than the striking voltage of the spark-gap, so that each pulse produces a spark between said electrodes. Such a detection device is characterized in that it comprises, connected to at least one of the electrodes, a detection circuit able to supply at its output a signal whose amplitude is representative of a definite condition of the atmosphere present between said electrodes, particularly of the presence or of the absence, between the electrodes, of an ionized gas such as a flame.Main uses: devices for the generation of sparks for igniting a fuel.

Abstract: In a moulding apparatus for producing a plastics material container matrix, a lower mould member defining a bore from its lower surface to its upper surface, die means slidably displaceable within said bore for deforming said plastics material, cutter means slidably displaceable within said bore defining at least one cutting edge extending obliquely to the longitudinal axis of the cutter means, and an upper mould member having a pressure member displaceably mounted thereon, the lower surface of the pressure member defining a cavity aligned with said bore in said lower mould member, which cavity receives at least a portion of said cutter member and die means when they are displaced.