Abstract: A method of testing series passive components in electronic assemblies. Only one test pin per passive component is required, thereby reducing the cost and complexity of test fixtures and the electronic assemblies. A passive component is connected between the output of a driving circuit and (optionally) an input of a receiving circuit. The output of the driving circuit is placed in a low impedance state. The receiving end of the passive component is stimulated and the response is measured. For reactive components, the stimulus and response are AC. For resistors, multiple DC measurements may be made. A optional DC bias may be provided to limit DC current and to further reduce the small signal output impedance of the driving circuit.

Abstract: A test socket is provided as part of a high temperature electromigration test system to allow the prediction of median time to failure to temperatures in excess of 450.degree. C. of VSLI interconnects.

Abstract: A method of and an apparatus for determining an electric wiring state, having the steps of: feeding at least one pulse voltage signal into one of two lines short-circuited at their two source portions; detecting the pulse voltage signal at two end portions corresponding to the two source portions; and discriminating wiring state between the two source portions and the corresponding two end portions upon a comparison of polarities between the fed pulse voltage signal and the detected signal.

Abstract: A testing apparatus for determining the integrity of an electrical cable. ccessive portions of electrical cable pass through an aqueous electrolyte with a distance measurement unit providing an indication of the position of a portion of the cable located in the electrolyte. A capacitance measurement unit connects to a selected conductor in the cable and to an electrode in the electrolyte to continuously generate a measured capacitance signal. An X-Y plotter produces an output that displays the measured capacitance as a function of the length of the cable passing through the electrolyte.

Abstract: A system for monitoring debris in a fluid by detecting electrostatic charges associated with the fluid. Both the electrostatic characteristic of the fluid and of the debris are sensed and then separated by a processor that compares their mobility. The monitoring system may be used to detect debris in any fluid capable of being electrostatically charged, such as oil and superheated steam.

Abstract: The capacitive level limit switch used for monitoring the level of a material in a container has a capacitive probe fitted at the height of the level to be monitored so that it is covered by the material when the level has attained this height. The capacitance of the probe is compared to a threshold value determining the switching point, for establishing whether the probe is covered by material or not. For setting the switching point, the capacitance of the probe measured in one condition of the probe is stored as a first reference value and a provisional second reference value is calculated from the first reference value by addition or subtraction of a predetermined amount and is also stored. From the stored reference values the threshold value is calculated according to a prescribed function so that it lies between the two reference values.

Abstract: An apparatus and method is disclosed for the location of faults occurring within transmission systems. The disclosed apparatus and method allows a user to adjust the center frequency of a pulse output by a standard narrow bandwidth time domain reflectometer, without altering the bandwidth of the output pulse. As a result, the detection of faults occurring at a wide range of frequencies is enabled--while the cost associated with widening the bandwidth of the transmitted pulse is not incurred. Moreover, due to the narrower bandwidth, efficient fault detection is achieved as well for high frequency systems as for low frequency systems.

Abstract: A method for detecting an electrical connection between an antenna system and a receiver for a motor vehicle, the receiver having an automatic gain control with a variable impedance and a PIN diode connected therebetween, includes the steps of increasing the variable impedance of the automatic gain control, measuring signal strength of a signal received from the antenna system, decreasing the variable impedance of the automatic gain control, measuring the signal strength of the signal receiving from the antenna system, correlating the signal strength to the variable impedance to generate a correlation, and determining whether the antenna system is electrically connected to the receiver based on the correlation of the signal strength to the variable impedance.

Abstract: An error correction method reduces transmission measurement errors and improves measurement accuracy of vector network analyzers. A reflection measurement made using a thruline standard connected between a source port and load port of a transmission/reflection (T/R) test set characterizes the impedance match of the load port while a reflection calibration characterizes the source port. The source port characterization and the load port characterization are then processed to correct a transmission tracking error in subsequent transmission measurements made on a device under test (DUT), without impacting the measurement speed of the VNA. A reflection measurement made with the DUT connected between the source and load port provides a measurement of the DUT's input reflection coefficient, including the effect of the impedance mismatch of the load port. This reflection measurement and the source port characterization are processed to correct a DUT input mismatch error.

Abstract: A method and apparatus for fast response and distortion measurement of a signal transfer device. A computer processor generates a multitone test signal of predetermined duration and stores it in a memory. The test signal is read out, converted to analog form, if necessary, and applied to the input of a device under test. The output produced by the device under test in response to the test signal is acquired and digitized, if necessary, and a Fast Fourier Transform is performed on the acquired data to determine its spectral characteristics. Frequency response, harmonic distortion, intermodulation distortion, phase distortion, wow and flutter and other signal transfer characteristics are measured by the CPU by analysis of the output signal.

Abstract: A measuring apparatus and method of a permittivity of a dielectric material employs a cavity and a variable reactance connected to the outside the cavity to measure the permittivity of the dielectric material, in which a power-feeding post is installed within the cavity, the variable reactance for forcibly resonating the cavity is attached to the upper portion of the cavity at the end of the power-feeding post, a network analyzer is connected to the power-feeding post, and the dielectric material specimen to be measured fills up the cavity, so that the length of the variable reactance is adjusted to forcibly resonate the cavity and, at this time, the length of the variable reactance is measured to determine the permittivity of the dielectric material. Thus, unknown permittivity is simply measured while enabling the broadband measurement. A small cavity at a cut-off state is employed to be suitable for measuring the permittivity in a low frequency band.

Abstract: A ratiometric circuit (40) includes a differential capacitive sensor (42) for sensing a change in capacitance, a differential capacitive detector (46) operatively connected to the differential capacitive sensor for detecting a change in the capacitance of the differential capacitve sensor, an error voltage generator (48) operatively connected to the differential capacitve detector for generating a corrective voltage in response to the detected change in capacitance, and a bias circuit (50) operatively connected to the differential capacitive sensor for generating a bias voltage inversely proportional to and independent of a supply voltage for maintaining the ratiometricity between an output voltage of the differential capacitive sensor and the supply voltage.

Abstract: Analog and mixed signal integrated circuits are tested using the modified Volterra series to model the integrated circuit being tested. An adaptive algorithm, for example, least mean square or Kalman, is used to determine to coefficients of the Volterra series. The coefficients are then used to calculate the THD and SNR.

Abstract: A circuit breaker tripper includes a first charging circuit for charging an RC shorting time control circuit. A relay is connected to a pair of probes that are connected to an active line which enables a charging of the RC shorting time control circuit. Activation of a switch causes a relay to apply a short circuit across the active line, thereby causing a tripping of the circuit breaker. At the same time, a discharge circuit is activated which causes the relay open the short circuit after a preset period. Since the circuit breaker tripper relies on enabling sufficient current flow through the circuit breaker to trip it, a test circuit is provided which enables operation of the tripper only if the branch circuit is within a safe operating range for the circuit breaker tripper.

Abstract: An orientation sensor especially suitable for use in an underground device is disclosed herein. This orientation sensor includes a sensor housing defining a closed internal chamber, an arrangement of electrically conductive members in a predetermined positional relationship to one another within the chamber and a flowable material contained within the housing chamber and through which electrical connections between the electrically conductive members are made such that a comparison between an electrical property, specifically voltage, of a first combination of conductive members to the corresponding electrical property of a second combination of conductive members can be used to determine a particular orientation parameter, specifically pitch or roll of the sensor.

Abstract: Time Domain Reflectometry ("TDR") methods and apparatus for measuring propagation velocities of RF pulses to determine material liquid contents, moisture profiles, material levels and dielectric constants including: i) TDR probes and/or probe adaptors, including series averaging probes and multi-segment probes, all employing remotely operable, normally open, variable impedance devices such as diodes; ii) bias insertion and switching networks for rendering selected normally open variable impedance devices conductive one at a time to establish precise unambiguous timing markers T.sub.1 . . . T.sub.

Abstract: A circuit tests a back-up battery for a power supply. A power source is coupled to a load to deliver power at a normal rated voltage during normal operation. However, during a battery test interval, the power source voltage is lowered to a test mode voltage. This lowers the load voltage, and in response, the circuit attempts to supply the load from the battery. The load voltage is monitored during the test interval to determine if the battery is able to supply rated power. However, the main power source is still instantly available at the test mode voltage to drive the load if the battery fails during the battery test interval. This ensures uninterrupted operation during the test mode. Upon failure of the battery during the test mode, the power supply is quickly ramped up to the normal rated voltage (although the test mode voltage meets output specifications).

Abstract: A capacitive type proximity sensor having improved range and sensitivity between a surface of arbitrary shape and an intruding object in the vicinity of the surface having one or more outer conductors on the surface which serve as capacitive sensing elements shaped to conform to the underlying surface of a machine. Each sensing element is backed by a reflector driven at the same voltage and in phase with the corresponding capacitive sensing element. Each reflector, in turn, serves to reflect the electric field lines of the capacitive sensing element away from the surface of the machine on which the sensor is mounted so as to enhance the component constituted by the capacitance between the sensing element and an intruding object as a fraction of the total capacitance between the sensing element and ground.

Abstract: In apparatus for measuring the output power an RF transmitter stage (34) connected to an antenna (44) via a quarter wavelength stripline (38), a manual probe (20) is applied connect the output of the transmitter stage to a power meter (24) and connect the output end of the stripline (38) to ground. Thus, RF signals which were passed to the antenna (44) are switched to the power meter (24). All the circuitry including the antenna (44) is mounted on a printed circuit board (60) disposed within a housing (14) which has an aperture (18) to enable the probe (20) to be inserted. By providing a suitable meter, parameters other than RF power can be measured.

Abstract: A method of pinpointing the location between manholes of a fault in an electrical cable typically buried underground in an urban environment, the fault being caused by an insulation defect which may be broken down by a high voltage includes the steps of applying the voltage to break down the fault insulation defect to induce a transient fault pulse on the cable on both sides of the fault traveling away from the fault. By the use of a ferrite type transformer coupler producing an output voltage, the direction of the transient fault pulse is determined by relating the polarity of the output voltage to the initial high voltage pulse which was applied.