Abstract: A system for testing the conditions of at least one pair of contacts to determine if the contacts are opened or closed comprising a transmit circuit and a receive circuit. The transmit circuit generates and outputs a test signal having a known frequency and the test signal is optically coupled to the contacts. The receiving circuit receives the test signal from the contacts and outputs one output indication indicating the contacts are closed in response to receiving the test signal and outputs one other indication indicating the contacts are opened in resposne to not receiving the test signal. The receiving circuit also optically couples the test signal from the contacts to the indicating means.

Abstract: A system for detecting and locating a ground fault (34) in the field winding (2) of a machine, in which a DC potential is present across the winding (2) during machine operation and the winding (2) is normally insulated from ground, the system including: a voltage divider (4) connectable in parallel with the winding (2) and having a plurality of tap points spaced apart along the divider (4); a plurality of current paths (6, 8, 14) each connected between a respective tap and a ground connection point (16); a current detector (12) connected in the current paths (6, 8, 14) for providing an indication of the magnitude of current flowing through each path (6, 8, 14); and signal processing circuitry (20, 22, 24) connected to the current detector (12) for providing an indication of the occurrence of a current flow magnitude associated with a ground fault (34) in the field winding (2) and an indication of at least the approximate location of the ground fault (34 ) along the winding (2).

Abstract: A capacitance sensing system for sensing the rotary position of a rotating shaft, particularly one having limited rotary motion. The system uses at least four capacitances comprising fixed capacitance plate members, one of which is preferably made of four arcuate segments enclosing the shaft and the other of which is a ring member enclosing the shaft and displaced therefrom along the shaft. A dielectric member is attached to the shaft between the fixed plate members. The capacitance value of the four capacitances change as the shaft rotates in such a manner that the capacitance changes produce an output voltage which represents the rotary position of the shaft, which output voltage is insensitive to radial motions of the shaft.

Abstract: An end sensor for detecting the end of a thin film stuck to a base plate such as may be used in a printed circuit board manufacturing apparatus. The sensor includes an electoconductive contact member, preferably shaped as a rod or plate, having a tip oriented in a direction at an acute angle to a direction of conveyance of said base plate so as to contact a surface of said base plate and a surface of the thin film. The sensor may be either of the electrostatic capacity type or of the electrical resistance type.

Abstract: A circuit arrangement is disclosed for monitoring the connecting lines of a switch or sensor open in the normal condition, with a first ohmic resistance connected in series with the switch or sensor. That together with the switch or sensor and a second ohmic resistance connected in parallel to both forms a parallel circuit, whose first connecting line is connected to ground and whose second connecting line is connected, on the one hand, to a voltage supply by way of a third ohmic resistance and, on the other, with a voltage discriminator unit. The second ohmic resistance is adapted to be disconnected.

Abstract: A parallel plate dielectric analyzer is disclosed including: a distance sensor for accurately measuring the varying distance between the electrodes, such as a linear voltage differential transformer (LVDT), and a motor responsive to the distance sensor for positioning the electrodes; a force transducer for measuring the applied force on the sample and where the motor responsive to the distance sensor is also responsive to the force transducer to give a desired force by varying the electrode spacing; disposable electrodes made using thick film technology composed of a ceramic substrate with a conductor adhered to its surface; and a temperature sensor built into one of the electrodes such as a platinum ring adhered to the surface of one of the electrodes and means to measure the resistance across the platinum ring.

Abstract: A method and apparatus for measuring the moisture content of a material wherein the measuring apparatus is positioned within a falling stream of the material to thereby continuously sample the material. The mounting angle and sideboard geometry of the apparatus are selected to give equivalent of in-bin mounting in terms of density and void to solid ratio variation so that accurate measurements may be obtained. The position of the apparatus is such that sample integrity may be visually verified and measurement error by improper sampling avoided. The method and apparatus are particularly advantageous in the manufacture of concrete wherein moisture content of sand or other granular material incorporated into the concrete must be accurately determined. The present invention allows the moisture measurement to be carried out as an in-line proceedure in the manufacturing process.

Abstract: A method for detecting water saturation of thermal insulation located between a flowline and metal sheathing at a location where the flowline is positioned in a metal casing. Electrical resistance measurements are made between the metal sheathing and flowline, between the casing and the sheathing, and between the casing and the flowline. The resistance values and/or direct voltage and current measurements are used to determine actual resistance through the insulation as an indication of water saturation.

Abstract: A method for detecting water saturation of thermal insulation located between a flowline and metal sheathing at a location where the flowline is positioned in a metal casing. Electrical resistance measurements are made between the metal sheathing and flowline, between the casing and the sheathing, and between the casing and the flowline. The resistance values and/or direct voltage and current measurements are used to determine actual resistance through the insulation as an indication of water saturation.

Abstract: The invention relates to a method and apparatus to detect the superconductive state by measuring the change in the resistance of a sample. A dc magnetic field is imposed on the sample while the temperature is swept. The strength of the magnetic field is held below the critical value and is frequency modulated by the application of an ac field in such a way that total magnetic field is always positive. The resistance of the sample is measured incrementally as the temperature is swept and is phase detected at the modulation frequency. According to this embodiment, only magnetic field dependent changes demonstrating a precipitous drop in resistance identify a composition as superconductive.

Abstract: An apparatus for use in measuring the straightness of a tube includes a flat support surface made of electrically insulative material and a plurality of strips of electrically conductive material oriented parallel to one another on the support surface. The strips are substantially uniform in shape and thickness, and a layer of dielectric material covers each of the strips of conductive material. The layers of dielectric material are of uniform thickness along the length of the strips and are adapted to support a tube to be tested for straightness so that a capacitor is formed by each of the strips and the tube. An oscillators is provided for generating pulses each having a pulse width proportional to the capacitance between at least one of the strips and the tube and representative of the size of gap between the at least one strip and the tube.

Abstract: A device for detecting and indicating the position of a terminal wherein a first detector circuit indicates that the terminal is in the proper receptacle and a second circuit indicates that the terminal is locked in place.

Abstract: A device for detecting the residual capacity of a battery comprises a battery current measuring circuit for measuring battery current, a battery voltage measuring circuit for measuring battery voltage, a converting circuit for converting the measured current into a voltage value, based on the internal impedance of the battery, and a comparator circuit for comparing the conversion voltage value with the measured voltage. When the measured voltage is smaller than the conversion voltage value, the comparator circuit operates a battery residual-capacity detect signal indicating that the residual capacity of the battery is small.

Abstract: The unknown capacitor or a standard capacitor are switched, one at a time, in parallel to a frequency setting circuit which sets the frequency of operation. The parallel combination of the unknown capacitor and the frequency setting circuit form a first parallel resonant circuit and the parallel combination of the standard capacitor and the frequency setting circuit form a second resonant parallel circuit. These resonant circuits are part of the feedback network of an oscillator. The bottom ends of the resonant circuits are connected to an instrumentation amplifier for maintaining the bottom ends at vertual ground in order to make three terminal measurements. A frequency meter is provided for measuring the frequency of resonance of the first resonant circuit and the second resonant circuit.

Abstract: An ignition coil primary winding signal processing system that is suitable for use with cathode ray tube based instruments used in the troubleshooting, diagnosing, and servicing of spark ignition internal combustion engines. A primary trigger signal gnerator (4) processes the waveform obtained from the primary winding of the ignition coil of an internal combustion engine, V.sub.S, and produces a logical signal, V.sub.L, which drives a bistable circuit. The bistable circuit includes a D flip-flop FF1 that produces a square wave trigger signal, V.sub.T, whose rising edge corresponds to the point in time of the ignition points break, or the equivalent occurs in an electronic or transistorized ignition system. A dwell angle-to-voltage converter (8) also processes the complex waveform obtained from the ignition coil primary winding of an internal combustion engine, V.sub.S, and produces a nonfluctuating waveform, V.sub.C4, that is compared to a reference voltage.

Abstract: A distributorless ignition interface unit for use with an engine analyzer for analyzing an internal combustion engine includes a processing circuit which responds to analog signals representing true and wasted firings for the cylinders of the engine under test to determine the number of cylinders of the engine and the polarity of the firing of each cylinder and to then characterize the engine by determining the order of the true and wasted firing signals produced during an engine cycle and for producing a parade pattern of true or wasted secondary signals for application to the engine analyzer.

Abstract: A vane-type galvanometer employs a stator having a unibody type structure. Narrow bridge regions of the stator are magnetically saturated to produce regions of high magnetic reluctance and salient magnetic poles in the stator. A pre-wound bobbin is mounted to the stator for generating a control flux to thereby exert a torque on a vane armature.

Abstract: A capacitive sensor for measuring a displacement comprises a slide carrying groups of emitting electrodes (1 to 32) disposed facing receiving electrodes (51 and 52) carried by a scale. A periodic configuration of signals is applied to the emitting electrodes by electronic circuits (60 to 65h) which permit a separate switching of each group of electrodes. There is thus obtained a more precise definition of the signals received by the receiving electrodes situated facing the scale and thus a greater precision of the measurement of displacements.

Abstract: A steering sensor is installed in a vehicle by utilizing a clearance between a steering wheel and a turn signal switch assembly. This makes it possible to provide a steering sensor having a high degree of universality, since the sensor can be simply retrofitted on an existing vehicle not already having such a sensor. The steering sensor can be utilized widely in navigation or other systems requiring such a sensor.

Abstract: A coaxial cable testing device has a modular construction wherein the several pieces may be configured in different arrangements to fulfill the separate functions of a flashlight, a continuity checker, a cable identifier, and a bandit splitter detector. The pieces are provided with connector elements which allow each of the pieces to fit together and the pieces are small enough to conveniently fit in the shirt pocket of a cable television technician. In the flashlight configuration, a battery pack (10) and a flexible flashlight assembly (18) are interconnected. In the continuity checker or cable identifier configuration, the battery pack (10) is connected to one end of a cable (28) and the detector section (24) and shorting plug (26) are connected to the other end of the cable (28). In the bandit splitter detector configuration, the battery pack (10) is connected to the detector section (24) which is connected to the cable (28).