Abstract: A cable length indicating arrangement which utilizes the capacitance of a two wire cable (10) to determine its length. The arrangement includes an oscillator stage (14) having a frequency setting capacitor (16) across which the cable is connected. The frequency of oscillation is converted into a voltage which is provided as the input to a comparator network (70, 72, 74, 76, 78, 80) which compares this voltage against voltages derived from a voltage divider network (96, 98, 100, 102, 104, 106, 108). The comparator network includes a "ladder" of comparators each having their non-inverting inputs coupled to receive the frequency dependent voltage and their inverting inputs each connected to a respective point in a resistive divider string. The outputs of the comparators are connected to respective light emitting diodes (82, 84, 86, 88, 90, 92).

Abstract: The present invention provides a method for determining the granular nature of superconductive materials and devices which includes the steps of: conducting a substantially rectangular current pulse through the superconductive material, maintaining the temperature of the superconductive material at a substantially constant temperature which does not exceed the critical temperature of the superconductive material; determining the amplitude of the current pulse; determining the electrical resistance, R, of the superconductive material resulting from conducting current pulse through the superconductive material; increasing the current until the electrical resistance of the superconductive material becomes saturated; determining the electrical resistance difference, .delta., between the electrical resistance, R, of the saturated superconductive material and a total normal state electrical resistance of the superconductive material; generating a first output signal if .vertline..delta..vertline..ltoreq..epsilon.

Abstract: An in-situ thickness monitoring/endpoint detection method and apparatus for chemical-mechanical polishing (CMP) of a dielectric layer on a top surface of a semiconductor wafer is disclosed. The apparatus comprises center and guard electrodes and associated electronic circuitry, including a high frequency, low voltage signal generating means, for converting a current which is inversely proportional to the dielectric layer thickness into a corresponding analog voltage. A position detection device triggers an analog-to-digital converter to convert the analog voltage into a digital signal while the wafer is located within a detection region as the wafer is being polished. A control means gathers the digital signals corresponding to the thickness data for processing and CMP device control.

Abstract: Electrically conductive patterns such as antenna patterns on window glass are inspected for a wire break or a short circuit. The impedances between an electrically conductive pattern and an electrically conductive layer on an inspective table are measured at predetermined frequencies, or the levels of signals reflected from the electrically conductive pattern are measured at predetermined frequencies. A decision unit determines whether the electrically conductive pattern is acceptable or not based on the frequency characteristics of the electrically conductive pattern and the reference frequency characteristics of a reference electrically conductive pattern.

Abstract: A misfire-detecting system for an internal combustion engine detects a value of the sparking voltage generated by the igniting device after generation of the ignition command signal, determines the duration of a discharge of a spark plug, based upon the detected sparking voltage, and determines whether or not a misfire has occurred in the engine, based upon the determined duration of the discharge. For example, the misfire-detecting system measures the duration of the discharge from the time of generation of the ignition command signal, based upon the detected sparking voltage, compares the measured duration of the discharge with a predetermined time period. When the measured duration is shorter than the predetermined time period, it is determined that a misfire has occurred in the engine.

Abstract: A detection circuit for sensing small capacitive changes has been provided. The detection circuit includes a dummy integrator stage that compensates for a voltage step that results from charge injection due to an existing switch in a first integrator stage. As a result, the detection circuit is insensitive to switch injection and amplifier offset voltages.

Abstract: A circuit for measuring capacitor properties under high DC bias voltage. A apacitor is subject to a high DC bias by a high voltage supply having low AC impedance. A triangle wave voltage is applied to the capacitor at the terminal opposite the high bias voltage. A current is thereby induced due to the voltage difference across the capacitor generated by the triangle wave. The induced current is measured and properties of the capacitor calculated therefrom. The measuring circuitry is isolated from the high DC bias voltage applied to the capacitor. Therefore, the biasing voltage applied to the capacitor is limited only by the breakdown voltage of the capacitor under test.

Abstract: A two-terminal circuit element measuring apparatus of the present invention is capable of distinguishing a loose connection between a DUT and the measuring apparatus from a high impedance in the DUT. The measuring apparatus is also capable of measuring the impedance of the DUT without altering the connections between the DUT and the measuring apparatus. The measuring apparatus applies both DC and AC current signals to the DUT so as to compensate any leakage current occurring within the three-wire cable connecting the DUT and the measuring apparatus. Because of the compensation, when both DC and AC current ammeters indicate substantially zero values, it is assured that a loose connection exists.

Abstract: The invention relates to a current measuring transducer operating on the compensation principle, comprising two magnetic cores (C1, C2) with windows; windings wound thereon for both a current (Ip) to be measured and for a compensation current (Is); and means (Um, Nm, R1, D, IA) for generating the compensation current and adjusting the magnitude thereof. To compensate for induced interference voltages, a further winding (Nc1, Nc2) is arranged about both magnetic cores of the current transducer. To widen the frequency band, the windings (Nc1, Nc2) are series-connected in a closed loop through a frequency-dependent impedance (Z).

Abstract: A tester is provided for a control yoke of an oil-filled electrical power switch. The tester can be easily and safely used by a line crew member. The tester is connected to the yoke which carries electrical signals to control the position of the switch. Control signals are then furnished to the yoke in the usual manner. Indicators on the tester identify whether the yoke or the switch is the source of the problem.

Abstract: An isolation monitor is electrically connected between the earth and an isolated neutral of a transformer which supplies AC electrical power to the main distribution network. In order to measure and to locate an isolation fault occurring somewhere on the feeders, each feeder is equipped with a toroid current measuring transformer, and comprises further a secondary winding connected to a processing locator performing synchronous demodulation. Two first and second transmission lines are provided between the isolation monitor and the locator. The first synchronous line transmits synchronization pluses from the monitor to the locator, and the second line transmits to the locator the demodulated values of the input voltage furnished by the monitor.

Abstract: A test tube holding a liquid specimen therein is arranged between a pair of electrodes arranged in an opposed relation. A conductive nozzle is inserted into a test tube. An oscillator is connected to one of these electrodes and a receiver is connected to the other electrode. A nozzle is connected to a zero potential level common to the oscillator and receiver. When the tip end of the nozzle is brought down into the level of the liquid specimen, there occurs a change in electrostatic capacity between the electrodes and hence a change in the level of a signal transmitted from the oscillator to the receiver. A determining device determines, based on the change in the level of the signal, whether or not the tip end of the nozzle is in contact with the liquid level.