Abstract: What is proposed is an apparatus for a shielded terminal connector that eliminates EMI leakage from coaxial cables in which a resilient bushing of a conductive material is inserted between exposed shield portions of the coaxial cable and the interior surface of a backshell housing, the latter being compressed onto a connector housing for the cable and the resilient bushing itself so that the bushing is gripped tightly by the backshell housing and thus completely fills the space between the exposed shield portions of the cable and the surrounding interior surface of the backshell housing.

Abstract: The radial dimension of selected teeth in toothed wheels used for measuring the transmitted shaft torque are changed in a predetermined spatial pattern corresponding to desired information. Such embedded data structures within the torque measurement apparatus may be used for encoding data uniquely related to the shaft twist modulus of a particular torque meter. In this manner, the toothed torque and/or reference wheels may be used to "self-compensate" or "program" appropriate electronic signal processing apparatus so as to automatically take the particular shaft twist modulus fully into account before producing output torque measurement data. At the same time, the use of such different radial tooth dimensions provides a differential amplitude modulation component in the sensor output signal which may be used to sense the relative gap dimensions (i.e.

Abstract: An apparatus and method for measuring the torque of a rotating shaft wherein two gears are placed adjacent to each other on the shaft but are fixed to the shaft at a predetermined distance apart such that the twist in the shaft causes an angular displacement of one of the gears with respect to the other. Each gear is provided with a number of teeth equally spaced thereon, one such gear having a different number of teeth than the other gear and a unique tooth to act as a reference point thus establishing a vernier relationship between the two gears. A single sensing means is positioned at the interface between the adjacent gears and detects the amount of overlap for each pair of gear teeth (one from each gear) as they rotate thereby. Each pair of teeth will be in a different degree of alignment with one such pair being in nearest alignment. As the torque twists the shaft, the location of the pair of teeth in nearest alignment will move circumferentially around the interface between the gears.

Abstract: An AC signal source having constant frequency-amplitude product is also easily realizable in hybrid microcircuit form. A square wave oscillator output is rectified and clamped to a feedback control voltage. The resulting controlled amplitude square wave is low-pass filtered to produce a sinusoidal output signal which is typically amplified and applied to a variable-impedance load. The sinusoidal signal is also applied to a similar but simulated load of fixed impedance value and the current flowing through the simulated load is summed with a temperature-compensated reference current producing an error current which is then integrated to produce the feedback control voltage which controls the amplitude of the sinusoidal signal so as to maintain a constant frequency amplitude product.

Abstract: A liquid level sensor includes a pair of sonic waveguides separated from and parallel to one another. The waveguide pair together define axially separated pairs of lens surfaces so that sonic pulses are coupled therebetween in a time phase relationship when liquid covers those lens pairs below the liquid level, cross coupling of those lens pairs above the liquid level thereby being prevented. Since the axial separation dimension of the lens pairs is known as well as the vessel geometry and location of the waveguide pair in the vessel, counting the pulses returned by virtue of such cross coupling of those lens pairs below the liquid level will establish accurate level detection by standard algorithmic techniques.

Abstract: A method and apparatus is proposed for sampling at a low rate a broad band sparse spectrum without aliasing to a specified band in which a lowest sampling frequency is found by selecting that signal level from the spectrum which is considered negligible and finding the bandwidths at which the information bands about the carrier frequency multiple reaches this level, then arranging forbidden or unaccepted values of the remainder r of the quotient of the carrier frequency divided by the sampling frequency into a series in order of magnitude, further selecting those sampling frequencies at which adjacent forbidden ranges of the remainder become contiguous, selecting the least value thereof in order to ascertain the corresponding permissible value of the remainder r, and finally determining the corresponding least sampling frequency and the maximum integer value multiple of a clock count, thus establishing the maximum sampling interval.

Abstract: An apparatus adapted for the mounting and wiring of printed circuit boards includes front and rear supports which together define paired slots into which the circuit boards are receivable and thus transversely mountable relative thereto so as to maintain the boards in a substantially parallel, spaced apart relationship to one another. The boards can be securely locked in the mounted positions by a resilient ring or like structures which seats in a circumferential slot defined in the front and rear supports. An end bell housing is also disclosed whereby various electrical components can be assembled with the circuit boards by virtue of the locking engagement established with the rear support when the bell housing is rotated (e.g. as in a 1/4 turn) relative the rear support.

Abstract: A method and apparatus for pre-calibrating capacitive-type fuel quantity probes is proposed in which a voltage divider excitation source is connected to the low impedence electrode of the probe and is used to trim the apparent capacitance down to within a small tolerance of .+-.0.1% of the precise design value for the probe.

Abstract: A torque measurement system for measuring shaft torque has two toothed wheels mounted in spaced apart relationship. Each of the wheels has a plurality of axially extending spaced teeth along its periphery extending into spaces between the teeth of the other, forming an interlaced array of teeth having tooth spacing interstices therebetween. A discontinuity is provided in the tooth pattern at at least one location around the periphery of the two wheels to serve as an index marker. A single detector such as a variable relunctance sensor is mounted proximate the wheels to provide output signals representative of circumferential widths of tooth spacing interstices and also representative of the index marker. The widths of the interstices change upon shaft torque deflection, and signals from the sensor are processed to produce a DC signal proportional to torque.

Abstract: An apparatus for mounting a plurality of electrical circuit boards in a spaced-apart coaxial relationship while yet permitting the circuit boards to be eccentrically moved out of the coaxial relationship during manufacture and/or maintenance. A first elongated, preferably hollow, mounting member transverse to the circuit boards mounts them for pivotable movement about a transverse axis defined by the first member. A second mounting member may be employed so as to effect rigid union between the circuit boards in an engaged position and which pivots to a disengaged position to permit eccentric pivotable movement of the circuit boards about the transverse axis defined by the first mounting member.

Abstract: Apparatus and method for convoluting TEFLON tubing without use of wires, rotating a mandrel which has a diameter smaller than that of the TEFLON, threading the mandrel at the other end, rotating and assemblying over a threaded portion a means in an opposite direction thereof, and supporting at each end means allowing the mandrel to pass axially therethrough and having a series of worm gears rotatingly mounted in diametrical opposite pairs.

Abstract: A system for independently determining the capacitance and resistance of a capacitive sensor, in which the sensor and a reference capacitor are sequentially energized from two alternating voltage sources of different frequencies, and average sensor and reference capacitor current valves at the two frequencies are measured and supplied to a computer which periodically calculates the sensor capacitance and resistance.

Abstract: An electrode assembly for use in a capacitance type probe for measuring volume or height of an electrically conductive liquid. The probe includes an inner conductor which an electrical conductive wire is connected at one end. The inner conductor is surrounded by a thick-wall TEFLON tube which functions as an insulator. A thin-wall TEFLON sleeve is heat shrunk onto the thick-wall TEFLON tube and the ends of the thin-wall sleeve are heated and sealed about the thick-wall tube to prevent any leakage of fluid to the inner conductor. The assembly is also provided with a polyurethane foam to provide rigidity and to prevent moisture from forming within the assembly.

Abstract: An end connector including a threaded nipple end that cooperates with a spring and swage sleeve to secure the end connector to a convoluted plastic tube. The swage sleeve fits over the spring in the convolutions of the plastic tube in order to secure the plastic tube to the nipple by the spring forcing the tube into the threads of the nipple.

Abstract: A signal selection system, including a plurality of detection circuits having inputs receiving respective direct voltage signals and outputs connected to a scan bus. Each detector circuit includes an operational amplifier having a non-inverting input receiving one of the direct voltage signals, an inverting input connected to the scan bus, and an output connected via a diode to the scan bus, so that the scan bus is maintained at essentially the highest or lowest signal of the signals being scanned, depending on the orientation of the detector circuit diodes. The system includes a plurality of indicators, associated respectively with the detector circuit diodes, for indicating whenever the associated diode is forward-biased, and an alarm circuit connected to the scan bus for indicating whenever the scan bus voltage exceeds a maximum value if the signal being detected is the highest signal, or whenever the scan bus voltage is less than a minimum value if the signal being detected is the lowest signal.

Abstract: A capacitive probe detection system is described which incorporates a synchronous switching system to switch the current flow through a capacitive probe to a signal integrating circuit only during the whole of every positive half cycle of the current flow attributable to the capacitive component of the probe. In this way that current due to the resistive component of the probe and to spurious noise pulses is eliminated by the integrator when performing its integrating action.

Abstract: A circuit for detecting failure of a segment in a digital display which includes a comparator connected to the energizing circuit for the display segments so that when a segment fails and is addressed, the comparator output is changed to provide a blanking signal which is fed by a circuit to the blanking input of the display driver for blanking the display. The energizing circuit for the display includes lamp test means, which, after display blanking, is actuated to energize all of the segments thereby permitting identification of the failed segment. Release of the lamp test means activates a timer circuit for providing an override signal for overriding the blanking signal to return the display to normal operation for a predetermined period of time following which the display will be blanked again when the failed segment is again addressed.

Abstract: A capacitance type fuel quantity gauge for a fuel tank which includes a probe capacitor in the fuel tank having a capacitance which varies in accordance with the fuel level and connected by one conductor to the output of a Lo-Z oscillator, two oppositely polled diodes connected together and to the capacitor, the positive diodes connected by another conductor to a signal conditioner and the negative diode connected to the one conductor by an inductance, the one conductor connected to the oscillator output and to the signal conditioner by a capacitor and inductance, respectively, so that the one conductor carries both the Lo-Z signal and the DC negative signal.

Abstract: A capacitance type fuel quantity gauge for an aircraft fuel tank including a probe capacitor whose capacitance varies in accordance with the level of fuel in the tank with a Lo-Z oscillator connected to the probe capacitor together with a pair of diodes for producing a DC output signal which is fed to signal processing circuitry, the diodes being disposed in a metal enclosure for isolation from interfering signals and the interconnecting leads to the diodes passing through feedthrough capacitors to block the entry of such interfering signals into the metal enclosure.

Abstract: A device for detecting the presence of contaminating water in a fuel tank as well as for measuring the density of the fuel in the tank which includes an elongated body of optical material arranged to be mounted in a fuel tank in a vertically extending position, one side face of the body forming an interface with the fluid in the tank, and a plurality of light sensors on the opposite face of the body arranged in spaced-apart relationship, together with light-emitting means at the bottom of the body which emit a divergent group of rays of successively increasing angles of incidence upwardly so that those rays exceeding the critical angle at the interface for a fuel of a specific index of refraction are reflected to illuminate those sensors corresponding to the rays exceeding the critical angle to thereby provide a detected output representing the density of the fluid, the light-emitting means providing a second group of rays striking the lower portion of the interface which are reflected when water is present t