Abstract: Apparatus for measuring the surface resistance and electrical resistivity of a homogeneous, resistive material sample includes a measuring cell having a sample location able to receive the sample and several electrodes in the form of knives placed on the same side of the sample and guided in an insulating block whose ends are positioned on the sample, the pressure necessary for establishing good electrical contacts between the electrodes and the sample being ensured by a shim which urges the electrodes toward the sample. A first pair of the electrodes make it possible to inject a current into a sample to be tested and a second pair of the electrodes make it possible to collect a voltage from the sample.

Abstract: For measuring the charge transported in an ion or electron beam, collecting grids are provided in a cascaded manner and the galvanic currents occurring there are measured. The same surface range is measured on the collecting cascade with respect to the particle current in the vacuum. The process and apparatus have particular applicability in partial-pressure and total-pressure measuring apparatuses, e.g. mass spectrometers and Bayard-d'Alpert tubes.

Abstract: A circuit for testing the leakage resistance of a circuit point. Particularly in the case of circuits where safety is important, a circuit point, particularly an output terminal of an integrated circuit, should be tested for a leakage resistance relative to ground and/or a voltage to provide an early detection of an imminent failure condition. To this end, at least one test current is fed into the circuit point and the voltage at the circuit point is monitored by means of a comparator. When the leakage resistance decreases below a permissible value the voltage at the circuit point decreases, which can be detected by the comparator. For monitoring a leakage resistance relative to both poles two opposite test currents are applied and the comparator is constructed as a window comparator.

Abstract: An apparatus for sensing the proximity of a moving target is provided which includes a sensor for sensing a range of distances between a reference point and a moving target. The sensor preferably has a detector for detecting a distance signal representative of a range of distances between a reference point and a moving target and a maximum and minimum generator responsive to the detector for generating a maximum distance range DC voltage signal representative of a maximum distance range value between a reference point and a moving target and for generating a minimum distance range DC voltage signal representative of a minimum distance range value between a reference point and a moving target.

Abstract: An apparatus for determining the remaining life of hydraulic fluid in a hydraulic system having a hydraulic container includes a capacitor formed by a pair of electrodes. A charging circuit produces a charging current of constant magnitude. The charging current is used to charge the capacitor to a predetermined voltage. A timing circuit measures the elapsed time between the time at which the charging circuit begins to produce the charging current and the time at which the capacitor has been charged to the predetermined voltage. The timing circuit also produces a pulse width modulated signal. The magnitude of the pulse width modulated signal is indicative of the time difference. A controller receives the pulse width modulated signal and determines the life of the hydraulic fluid.

Abstract: A radio speaker short circuit detection system for a vehicle visually indicates a speaker short circuit failure. A microprocessor receives a short circuit failure signal from a short circuit detection circuit. Short circuit failure data can be stored for future diagnostic retrieval.

Abstract: A power monitoring instrument evaluates and displays the source impedance, load impedance, and distribution system impedance of an alternating current power system using voltage and current measurements taken at a source and load of the power system. The power monitoring instrument and associated voltage and current pods for coupling to voltage probes and current clamps incorporate unique safety features to minimize operator exposure to high-voltage. The measurements are performed noninvasively without disconnecting elements of the power system. Evaluation of impedances takes advantage of incidental variations in the load characteristics.

Abstract: An instrument and method for the troubleshooting and verification of copper-wire local area network (LAN) cable systems provides a series of resistance and capacitance measurements between all possible wire pairs using a pair of switch matrices and a software method for evaluating the measurements which are stored in a two-dimensional matrix. The stored measurements are evaluated against predetermined figures of merit and the decision pattern in matrix form is compared to that of a known good LAN cable system. Error messages responsive to mismatches are generated and presented to the operator via a user interface. Near-end cross talk (NEXT) isolation is evaluated using a mathematically calculated differential capacitance technique. Error messages are generated responsive to difference capacitance values larger than a figure of merit correlated to an acceptable level of NEXT isolation.

Abstract: The invention comprises a device provided with a position-setting surface and relatively movable stopping member which together hold the housing 31 of a waterproof electrical connector in a predetermined inspecting position. Pressing pieces are integrally provided on the position-setting surface or the stopping member to push in any waterproof plug associated with a terminal in the direction in which the terminal is inserted into the terminal accommodation chamber.This arrangement ensures that a semi-fitted terminal is pushed into the correct position during an inspection process.

Abstract: An impedance probe circuit and method presents a balanced load to a DC or RF voltage source and to two voltage measurement nodes. The impedance probe circuit is accurate for measurement of an impedance device X which has a range always less than the value of a characteristic impedance C. A source terminal is coupled to a voltage source having a series impedance C. A test resistor T is connected between the source terminal and one terminal X1 the unknown impedance. A reference resistor R is connected between the source terminal and the other terminal X2 of the unknown impedance. The parallel combination of the test resistor T and the reference resistor R has an impedance substantially equal to C/3. A third impedance of value C/3 is connected to the node X1 and to a first voltage measurement terminal. A fourth impedance of value C/3 is connected to the node X2 and to a second voltage measurement terminal.

Abstract: In a semiconductor device, a first resistor is connected between the base and collector of a dummy bipolar transisitor, a second resistor is connected between the base and emitter of the dummy bipolar transistor, and a third resistor is connected to the collector of the dummy bipolar transistor. A first pad and a second pad are connected to the base and emitter, respectively, of the dummy bipolar transistor. A third pad is connected to the third resistor. A fourth pad is connected to the collector of the dummy bipolar transistor.

Abstract: A device for testing for disconnection of bus lines of a semiconductor device includes switches having current ratios formed in a geometric series connected to ends of a group of n of the bus lines. At least one testing electrode is connected to the switches and at least one power electrode is connected to the group of n of the bus lines. A disconnection of one or more of the bus lines can be determined according to a current flowing through the testing electrode.

Abstract: Apparatus and method are disclosed for performing testing and fault isolation of high density passive boards and substrates. Using a small number of moving probes, simultaneous network resistance and network capacitance measurements may be performed. Thus, test time is minimized by eliminating the need for electrical switching and/or excessive probe movement during the test of a normal circuit board network. Simultaneous network capacitance and network leakage measurement are also achieved using phase-sensitive detection. Dual-frequency measurement techniques allow the measurement of both the capacitance value and resistance value of a leakage path between a network being measured and an unknown network. Any leakage resistance between a network under test and ground or power planes within the circuit board may also be determined from the measurements.

Abstract: Methods for rapidly adjusting the impedance of a variable impedance apparatus to match the impedance of a source to the impedance of a load, where the load impedance is a nonlinear function of the power delivered to the load, are described. In addition, an automatic impedance matching apparatus for matching the impedance of a source to the impedance of a load and for maintaining a stable plasma are described. The apparatus includes a variable impedance apparatus, a plurality of electric field sensors, a photosensitive detector, a data processor, and a memory.

Abstract: Disclosed herein is a transformer assembly, comprising a toroidal transformer element including a ring and a secondary winding wound around the ring; the ring being arranged to receive a main therethrough to form a primary winding; and a recording medium containing a set of successive incremental factors, each of the factors relating a measurement of a power component for one increment of power flowing through the secondary winding with an expected value of the power component for the increment of power flowing through the secondary winding, both the measurement and the expected value corresponding to a flow of power through the primary winding, wherein the transformer element, together with the set of factors, is capable of generating measurements of power with improved accuracy when corrected by the factors.

Abstract: Apparatus for monitoring the health and response of critical electromechanical control valves to detect the likelihood of future valve malfunction includes the use of Fourier transform decomposition and time-domain wavelets to selectively enhance portions of the valve response signal for comparison with a normal valve response signal.

Abstract: An in-circuit ohmmeter is provided, including a pair of input terminals connectable to a resistance of an unknown value. A pair of current generators are connected electrically in series for generating an electrical current to be passed through the unknown resistance to develop a differential voltage across the input terminals, and a circuit is provided for determining the amount of the electrical current passed through the unknown resistance. A semiconductor switch switches the pair of current generators on and off. A current generator protection circuit comprising a plurality of diodes is connected across the input terminals. A differential amplifier circuit receives and amplifies the differential voltage so that a value of the unknown resistance may be calculated based on the differential voltage and the determined amount of electrical current passed through the resistance. An inverter circuit is disposed intermediate the input terminals and the differential amplifier circuit.

Abstract: A device for gauging the level of a fluid in a container includes a floating roof, a transmitter for feeding a first microwave signal downwards in the direction of a fluid surface of the fluid, and a receiver for receiving a reflected microwave signal. The device includes a collector located above and in the vicinity of the floating roof, collecting the first microwave signal producing a collected microwave signal. The device also includes a vertical wave guide passing through the floating roof. The vertical wave guide guides the collected microwave signal to the fluid surface, and receives a reflected microwave signal reflected from the fluid surface. The vertical wave guide then guides the reflected microwave signal back to the collector and further to the receiver. It is a special feature to permit accurate measurement of the level of the fluid surface without having direct access to the surface.

Abstract: A monitor current to a squib as an air bag actuating element conducts in one and the opposite directions alternately. Each produced voltage value is differentially amplified with a positive reference voltage and a difference between the amplified voltages are calculated. Thus, an offset voltage of an operational amplifier used for the differential amplification is cancelled, and the difference between the two detected voltages becomes a voltage value which will be produced by a monitor current twice as large in current level. Thus, the squib is diagnosed accurately.

Abstract: An apparatus for testing the insulation of an insulated electrical conductor has an alternating current high voltage power source which provides a high test voltage between the electrical conductor and an electrode to reveal defects in the insulation. A high Q antiresonant circuit, tuned to a predetermined frequency, is connected in series with the electrode and power source for shunting most frequency components of the corona and noise currents to ground and for non-shunting an insulation fault voltage of the predetermined frequency resulting from an arc current due to a defect in the insulation. The fault voltage signal non-shunted by the antiresonant circuit is provided through a coupling impedance to a transmission cable having a pair of twisted wires for transmission to a remote location. Impedance matching transformers, coupled to both pairs of ends of the twisted wires, are tuned to the same frequency as the antiresonant circuit to minimize attenuation of the signal.