Abstract: An a.c. field measurement testing system for detecting and sizing defects in a conductor includes a probe head having field coils located on a yoke so as to induce an a.c. field in the conductor and sensor coils arranged such that central longitudinal axes of the sensor coils are orthogonal one to another. The coils are wound on a former at the same location on the former and one of the sensor coils is oriented so that a longitudinal axis thereof is parallel to the induced a.c. field.

Abstract: A plurality of fatigue life test strips (16, 18, 20, 22) has each of the strips anchored to a base (12) which is subject to thermal cycling and consequent dimensional change which causes fatigue. The base is, at best, semiconductive, and the strips are conductive. The conductivity of each of the strips is measured by test circuit (52) so that, when one fails due to fatiguing, the failure is signaled.

Abstract: This invention deals with a multipurpose hearing aid maintenance device. Its brush is used to clean a hearing aid, especially the receiver tube opening. The magnetized electrical terminal or an optional magnetic tip serves to hold small (size 13 or smaller) batteries to place them in a heating aid battery compartment or remove them from the compartment. Also, the magnetized electrical terminal holds the cell and serves as one of the two electrical terminals to test (GO/NO GO) electrical charge of the cells. Finally, the device can store one or two spare batteries.

Abstract: An apparatus and method to measure the unburnt carbon content of fly ash. A microwave signal is transmitted through or reflected from a fly ash sample and the attenuation or phase shift of the signal received by a detector/detectors is determined with respect to the incident signal and is used to provide a measure of unburnt carbon content. The detectors may be antennae means which also launch the incident signal or may be a completely separate means. A preferred embodiment comprises a microwave oscillator for launching the microwave signal into a fly ash sample in a microwave resonant cavity. Detectors determine the attenuation of phase shift of the received signal with respect to a signal from a reference microwave resonant cavity by the fly ash sample, and a measurement of the unburnt carbon content is obtained.

Abstract: A highly sensitive, direct-contact, in situ sensor for nondestructively measuring or monitoring the complex dielectric and conductive properties of solids, liquids, or gasses at microwave frequencies. A metal microstrip dipole resonator (11) is etched on the surface of a dielectric substrate (12) which is bonded to a copper ground plane (14). The dipole resonator is electromagnetically driven by mutual inductive coupling to a short nonresonant feed slot (13) formed in the ground plane (14). The slot (13) is driven by a coaxial feed line (7) or a microstrip feed line (16) extending from a swept microwave frequency source (2) which excites the incident wave (17). Alternatively, the metal resonator is omitted and the length of the slot (15) is increased so that it becomes the resonator. In use, the sensor is placed in close physical contact with the test material (9) having complex dielectric constant .epsilon.* (=.epsilon.'-j.epsilon.") or conductivity .sigma..

Abstract: In an electric apparatus such as an electric power cable system, a high frequency pulse is induced on a conductive member such as a metal sheath, where partial discharge occurs in an insulation. The high frequency pulse is detected by means of a bypass lead wire, a metal foil electrode, a detecting coil, and the like provided on the electric apparatus without interrupting a live operation of the electric apparatus.

Abstract: An electrical generator inspection system comprises an electro-magnetic core imperfection detector that provides an analog signal representative of fault currents detected between adjacent laminations of a stator core; an analog-to-digital converter coupled to the detector for converting the analog signal to a digital signal; a digital filter coupled to the output of the converter for digitally filtering the digital signal to remove noise therefrom; and means for storing predetermined signal criteria and for comparing the filtered digital signal to the predetermined criteria to determine the location of the insulation defects along the stator core. In one embodiment, the system further comprises means for storing the filtered digital signal in a memory.

Abstract: A plurality of sensor circuits each including an oscillator circuit, a detection electrode, and a ceramic resonator for changing a resonance frequency in accordance with a change in small electrostatic capacitance detected by the detector electrode and outputting a detection signal corresponding to a change in resonance frequency are formed on a circuit board. Detector electrode surfaces A.sub.1 to A.sub.4, B.sub.1 to B.sub.4, and C.sub.1 to C.sub.4 of the first to third sensor circuits are formed on the upper surface of the circuit board in a divisional manner. The detection surfaces of the respective sensor circuits are arranged to have codes in the scanning direction of an object to be detected. The fixed capacitances of the detection surfaces are decreased, and a change of state of the object can thus be detected at a high resolution.

Abstract: Two or more rising pulse waves having different rates of voltage increase are applied to a measuring end of a cable and reflected waves from a fault point on the cable are detected to measure a turnaround propagation time between the measuring end and the fault point. Additionally, ratios of the rates of voltage increase of one pulse wave and the other pulse waves are calculated. A discharge delay time at the fault point is calculated from time differences of the measured turnaround propagation time and the ratios of the voltage increasing speeds and the discharge delay time is subtracted from the measured turnaround propagation time to calculate a real turnaround propagation time.

Abstract: A compact, lightweight wrist-worn cardiac data and event monitor having dry skin electrodes integral with the monitor's housing is disclosed. Preferably, the skin electrodes are made of titanium nitride-plated stainless steel and form inner, wrist-contacting, and outer, other hand's palm-contactable regions of the housing. Chronometric and other multiple functions are provided to increase the functional density of the monitor by partitioning and very-large-scale-integrating the circuitry, which includes signal detection; data conversion, storage, display and telecommunication; and external pushbutton controls operable by the patient's other hand. In accordance with the preferred embodiment, a telephonic transmitter is integrally included within the housing for remote diagnostic purposes without the need for external connections.

Abstract: Circuitry for monitoring the function of electric load, an output stage and a control circuit for driving the output stage and the lines that connect these elements. The circuitry includes at least one fault acquisition logic that is connected in parallel with the output stage. The fault acquisition logic has a terminal that connects to an input of the output stage and another terminal that connects to the output of the output stage. The fault acquisition logic also is connected to a reference potential. The fault acquisition logic has a comparator for comparing potentials for determining fault conditions. Detected fault conditions may be stored in a buffer memory that connects to a main memory. The buffer memory may also have a time delay associated with it. The circuitry also may include a coder for encoding signals indicative of the fault conditions that are detected by the fault acquisition logic. The circuitry may further include a safety disconnect to protect the output stage against overload.

Abstract: The invention relates to a method of inspecting and correcting a thin film transistor liquid crystal substrate and an apparatus therefor, where a plurality of scan lines and signal lines are connected electrically in common at each one terminal side respectively, and an infrared image outside the pixel domain is detected after lapse of a prescribed time from the time point of applying voltage between the scan lines and the signal lines, and an infrared image outside the pixel domain is detected after lapse of a prescribed time from the time point of stopping the voltage application, and the scan lines and the signal lines relating to variation of the heating state are detected from difference or quotient between an infrared image at the voltage applying state and an infrared image at the stopping state of voltage application, thereby a pixel address with a shortcircuit defect occurring is specified.

Abstract: A capacitive position sensor has a scale (10), having hollow or raised topographical features, and a cursor (20) having an electrode array comprising at least two transmitting electrodes (21a, 21b) and at least one receiving electrode (21c) separated by shielding electrodes (21g). The coupling capacitances (Cac, Cbc) between transmitting and receiving cursor (20) electrodes are modified as a function of the position (x) of the scale topographic feature (11) relative to the cursor, the evaluation of the variation of the signals picked up by the receiving electrode permitting a precise measurement of the relative displacement between scale and cursor.

Abstract: In an electrical supply network containing a generator, critical fluctuations in real power can occur. The load angle of the generator is representative of these fluctuations. The present invention provides a method which measures the real and reactive power flow, the current and the voltage on a line to the generator and feeds these measured values along with reactance values Y.sub.L and Y.sub.Q of the generator and line to a computing device. The computing device determines an output signal .delta. which represents the load angle of the generator and fluctuations in real power. The output signal .delta. is provided to an indicating device and/or a reactive power compensator.

Abstract: A device for generating a trigger signal from ignition pulses of an ignition system, in which each one of the ignition pulses occurring in the ignition system is represented regardless of whether the ignition process is suppressed or not. The device can be connected to an ignition system which has at least one ignition coil with a primary winding and at least one secondary winding, where the first terminal of the primary winding is connected to the first terminal of a voltage source and the second terminal of the primary winding is connected by means of a controllable switch with a second terminal of the voltage source.

Abstract: A method for determining an electrical characteristic (such as a resistance) of an antifuse of a programmable device.

Abstract: A testing method and apparatus for conductive materials using electric current which makes it possible to rapidly evaluate the electromigration resistance of conductive materials. The apparatus includes a substrate support for supporting a substrate on which an interconnector pattern is formed, a cooling vessel for cooling the substrate, a first current supply for applying a first current to the interconnector, a resistance measurer for measuring the resistance of the interconnector pattern while the first electric current is being applied to the interconnector pattern, a second current supply for applying a second electric current larger than the first electric current to the interconnector pattern, and a controller which controls the repetition of the measurement of resistance of the interconnector pattern and the application of the second current to the interconnector pattern.

Abstract: A reference AC signal having a frequency of about 4-10 Hz is injected into a line of a DC electrical network for performing insulation measuring in a processing unit. The AC signal is measured in a mixed bridge having a first resistive dividing bridge connected in parallel with a second capacitive dividing bridge between the line and the ground. The intermediate output points of the first and second bridges are joined together and connected in an input of the processing unit. The impedance and the dividing ratio of the two bridges cause the DC voltage measured at said input to be low in relation to the value of the AC voltage measured at the output of said mixed bridge.

Abstract: Impedance measurement of battery cells within a battery system comprising at least one string of battery cells is accomplished by dividing each of the strings into at least two portions. A loading current for measurement purposes is only imposed on a portion of one of the strings at any given time and battery cell voltage measurements are made only within this string portion.