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: An intrusive fluid sensor mounting arrangement for a fluid container includes first and second tubes, the first tube being attachable to a wall of the container such that a first end of the first tube is open to the container exterior through the container wall and a second end of the first tube extends into the container; the second tube being sized to slide axially within the first tube between first and second positions; the second tube having a first end accessible from outside the container such that a sensor can be installed in and removed from the second tube; the second tube providing fluid communication between the sensor and fluid in the container when the second tube is in the first position, and substantially preventing fluid loss from the container when the second tube is in the second position.

Abstract: A circuit that electronically simulates a capacitor includes a differentiator and a current source. In the preferred embodiment, the differentiator includes a differentiating gain amplifier that produces an output signal in response to an applied input signal, with the output signal being proportional to the time rate of change of the input signal. The differentiator further includes a variable inverting gain stage that produces a reference signal that has a desired phase relationship with respect to the input signal, such as a ninety degree leading phase for sinusoidal input signals. The variable gain stage is also used to provide for different simulated capacitance values, and to compensate for variations in the differentiator fixed value component. The current source is preferably a high output impedance current source such as a Howland current pump.

Abstract: An optical wavelength detector includes a photoelectric device that produces a signal in response to incident light thereon corresponding to a characteristic of the incident light such as wavelength. A light source is provided that can selectively expose light to the photoelectric device. A memory device stores device characterization data that corresponds wavelength information to current ratio signals from the photoelectric device. The current ratio signals are digitized and form part of the address for the memory. In a temperature compensated embodiment, the optical wavelength detector includes means to determine a temperature dependent electrical characteristic of the photoelectric device. In the preferred embodiment this electrical characteristic is the forward bias voltage detected when a predetermined forward bias current is applied to the photoelectric device in the dark.

Abstract: Method and apparatus for determining jet fuel density. A microprocessor monitors the temperature, velocity of sound and dielectric constant of a jet fuel. The microprocessor determines the type of jet fuel and the density of the fuel using data from jet fuel samples of a known density and a least-squares-fit of the test data.

Abstract: A dual snubber circuit for a switching circuit including first snubber means for performing a first snubbering function in a switching operation of the switching circuit, and second snubber means for performing a second snubbering function in the switching operation of the switching circuit, the first and second snubber means performing the first and second snubbering functions substantially independently.

Abstract: An electrical connector segment, for use in industrial and transportation application, which provides engagement to another complementary coupler segment with fine incremental adjustment and prevents disengagement from vibration, jarring and shock and by those unfamiliar with its function, including a backshell assembly for joining an electrical cable to the connector segment, with the same features plus means by which ready access is provided to the juncture, of the wire leads of the cable, with the connector elements within the connector segment for maintenance, repair and modification.

Abstract: A composite torque transmitting power shaft is provided with built-in discrete sensible ferromagnetic elements. The composite shaft is formed of a non-ferromagnetic material so that the sensible elements, disposed interiorly of the shaft, can be sensed by a sensor element positioned outside of the shaft. Two groups of sensible elements are movable with respect to each other as the shaft twists under the application of torque. The elements can be sensed to provide an indication of the speed, torque or horsepower transmitted by the shaft. Further, the frequency and amplitude of torsional oscillations caused by pulsating power source or load characteristics can also be measured.

Abstract: A debris monitor apparatus and method and optical sensor apparatus and method that use the Faraday Effect to detect accumulation of debris on a magnetic probe. The probe contains a magnet and the optical sensor and is immersible in the fluid. As debris accumulates on the probe, the magnetic field changes. The optical sensor includes a magneto-optic material located within a portion of the changeable magnetic field, preferably near a node of the magnet. Means are provided to bi-directionally address the sensor magneto-optic material with linearly polarized light. Means are also provided to convert rotation of the light polarization angle into a modulation of the light's intensity. An electro-optic transducer converts the light intensity into electrical signals that indicate the quantity of debris accumulation on the probe, with a differentiated value of these signals with respect to time yielding rate of debris accumulation on the probe.

Abstract: A fiber optic harness assembly having reduced weight and bulk comprises a plurality of optical fibers and loose tube protective buffers therefor. At least two of the optical fibers and corresponding buffers are routed commonly along a first branch of the harness and respectively along the second and third branches of the harness. Similarly, strength elements extending parallel to corresponding optical fibers are routed commonly along the first branch to the intersection whereat the strength elements are divided into separate portions for extension respectively along the second and third branches. The strength elements and buffered optical fibers coextending along the harness branches are surrounded and held bundled together in contiguous relationship by respective branch portions of an outer jacket or sheath.

Abstract: A polarizerless optic sensor is provided that uses a random domain magneto-optic film and a modulated normal magnetic field to vary or modulate the energy distribution in a diffraction pattern. Light is transmitted through the film and is diffracted according to a domain duty cycle so that the center beam intensity is a function of the Faraday rotation angle of the material and the intensity of the applied normal magnetic field. The polarizerless sensor can be used to realize a speed and torque sensor, an optical switch, a magnetic field sensor and many other types of devices. The invention can be used with polarized and unpolarized input light. The sensor can be implemented using a random domain film or a stripe domain film to create a phase grating diffraction pattern.

Abstract: An apparatus and method for measuring the torque of a rotating shaft is provided, utilizing a single sensor which provides a signal which is processed to yield a temperature compensated value of the torque applied to a rotating shaft. A magneto-optic material such as a Faraday film is positioned adjacent to the rotating shaft and is subjected to a saturating magnetic field. Ferrous elements are provided about the periphery of the rotating shaft and cause the modulation of the magnetic field applied to the magneto-optic material. The rotation of the linear polarization vector of light passing through the magneto-optic material when the material is magnetized to the saturation level changes in accordance with temperature. Thus, the amplitude of the output optical signal varies in accordance with the temperature of the shaft.

Abstract: A liquid presence detector and method of using the same for a gas fluid pipe includes a helically wound insulated wire positioned inside the pipe such that an outer periphery of the wire contacts an inner surface of the pipe along an axial portion thereof. The pipe and wire form two plates of a capacitor with the pipe being connected to electrical ground for electromagnetic shielding and shock protection. The wire plate of the capacitor contacts liquid particles that travel along the pipe wall. A circuit is provided to measure capacitance between the wire and the pipe to detect liquid contacting the wire and pipe.

Abstract: A liquid presence detector and method of using the same for a gas fluid conduit is provided by a capacitor that is placed inside the conduit and that is formed of two interwoven wire grids with one of the grids being insulated and the other grid being uninsulated. In one embodiment, the capacitor is generally planar and is oriented generally transverse a longitudinal axis of the conduit with a peripheral portion lying in a generally axial orientation along an inner surface of the conduit. A circuit is provided that measures capacitance between the two wire grids. The conduit is electrically grounded. Liquid particles entrained in the gas fluid or traveling along the conduit wall contact the capacitor and changes the capacitance thereof. In another embodiment, the capacitor is formed as a generally open cylinder positioned coaxially within the conduit.

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 method and apparatus determines a quantity of liquid in a tank when at least one liquid sensor is inoperative. In a first embodiment, a plurality of tables are stored in memory which are grouped by identities of the possible inoperative sensor or sensors. One group of tables is selected based on the identified inoperative sensor or sensors. Then, that one group of tables is accessed, and the quantity of liquid in the tank is calculated based on the readings of the operative sensors. In a second embodiment, a first plurality of tables stores quantity readings for each sensor as if all sensors are operable. A second plurality of tables includes one table for each possible configuration of inoperative sensor or sensors. When the inoperative sensor or sensors are identified, one particular table in the second plurality is accessed and a quantity amount is then added to the liquid quantities determined from the first plurality of tables to provide a total liquid quantity in the tank.

Abstract: An alternator assembly for use with munitions fired from rifled bores in which both the rotor and stator are juxtaposed along the axis of the munition member and do not exceed the bore-size diameter of the member. Electrical energy is thus generated as the member or round traverses the bore, which energy is used for powering a munition tracking system and/or arming a fuse contained therein.

Abstract: A transducer system and method of use thereof by sequentially operating a comparator to produce a series of pulses in which the time distribution of the pulses is representative of the transducer value, and is used to normalize the sensed value in the event that the total transducer value varies due to environmental influences. The transducer is adapted to monitor the substantially linear movement of the level (fuel-air interface) of fuel in a tank and the angular positon of an input shaft.

Abstract: System and method of error reduction in which a comparator is sequentially operated to produce series of pulses in which the time distribution of the pulses is related to the displacement being monitored by the transducer. In particular, the comparator is sequentially operated to provide two sets of pulses using a positive ramp voltage, and then using a negative ramp voltage having a magnitude equal to the positive ramp voltage. Averaged time periods between the pulses are used to eliminate offset errors in the determination of the value that the transducer is monitoring. The transducer is adapted to monitor the substantially linear movement of the level (fuel-air interface) of fuel in a tank and the angular position of an input shaft.

Abstract: System and method of error reduction in which a comparator is sequentially operated to produce series of pulses in which the time distribution of the pulses is related to the displacement being monitored by the transducer. In particular, the comparator is sequentially operated to provide two sets of pulses using a positive ramp voltage, and then using a negative ramp voltage having a magnitude equal to the positive ramp voltage. Averaged time periods between the pulses are used to eliminate offset errors in the determination of the value that the transducer is monitoring. The transducer is adapted to monitor the substantially linear movement of the level (fuel-air interface) of fuel in a tank and the angular position of an input shaft.