Abstract: A method is provided for accomplishing unified testing of a digital/RF system (10'), comprised of a digital controller (14), a base-band processor (20), an RF transmitter (24) and an RF receiver (34). The digital portion of the digital/RF system (10'), including the digital controller (14) and the base-band processor (20), is tested by a digital test technique such as Boundary-Scan testing. Test patterns for the RF elements are down-loaded from the digital controller (14) to the base-band processor via a Boundary-Scan Test Access Port (TAP). Thereafter, the RF transmitter (24) and the RF receiver (34) are tested by applying the test patterns from the base-band processor to the RF transmitter for transmission thereby. The signal produced by the RF transmitter (24) in response to the applied test pattern is converted to a first digital signal stream for processing by the base-band processor (20) to determine the operability of the transmitter.

Abstract: The present invention involves measurement of an electrical current by means of a current transformer having the current to be measured passing in an axial direction through the current transformer, and the voltage induced thereby in the windings of the current transformer are used to produce a first voltage. A Hall effect is used in series with the current transformer to produce a second voltage measurement corresponding to the current measured by the Hall effect sensor. When the two measurements agree to within a predetermined value (typically 5% of the root-mean-square current values measured by each sensor) then the current transformer reading is used as the more accurate. Otherwise, the Hall effect current sensor is used as the more accurate current measurement.

Abstract: A reusable test socket is described for testing singulated bare die to determine, before packaging, that the bare die is a "known good die". The socket contains a circuit pad pattern in the mirror image of the bond pad pattern of the bare die to be tested. Each pad of the socket contains a conductive elastomeric probe which has been "screened" onto the bond pad. The socket also contains an alignment template for orienting the bare die onto the elastomeric probes of the pad pattern of the test socket. Additionally, the socket can be a singular piece or it can be made of two main pieces; the first being a socket, and the second being a test board designed to mate with the socket. Further, the socket can be utilized in conjunction with a clamp for holding the bare die in place and with a thermoelectric cooler. The thermoelectric cooler is used to heat or cool the die at all temperatures required for military certification and other extended temperature applications.

Abstract: The inspection apparatus of the invention inspects a display device including first and second bus lines formed on an active matrix substrate. The inspection apparatus includes a first substrate unit and a second substrate unit each having a pair of substrates and connecting films therebetween. On one substrate of each substrate unit, inspection terminals and first inspection lines are formed and each of the inspection lines are connected to one of the inspection terminals. On the other substrate of each substrate unit, second inspection lines are provided. The first and second inspection lines of the substrates are selectively connected by the connecting films. During inspection, the second inspection lines of the first substrate unit are brought directly in contact with the first bus lines, so that each of the first bus lines is connected to one of the inspection terminals of the first substrate unit.

Abstract: A tester and method for testing a rectifier-regulator. A ramping voltage generator generates a ramping input voltage during each of a multiplicity of ramping cycles in response to ramping voltage control signals provided by a controller. A relay circuit relays the ramping input voltage to one of the input terminals of the rectifier-regulator during each ramping cycle in response to relay control signals provided by the controller. The rectifier-regulator provides in response a ramping output voltage at its output terminal during each of the ramping cycles. A voltage measurement circuit makes voltage measurements during each of the ramping cycles representing the ramping output voltage. A trip point determination circuit determines when the trip point of the rectifier-regulator occurs during each of the ramping cycles and generates in response a trip point signal during each of the ramping cycles indicating that the trip point has occurred.

Abstract: A high-voltage measurement device for an electrical high-voltage switchboard plant having an measurement electrode built into an encapsulating housing, as well as an electrical conductor which conducts a measurement signal provided by the measurement electrode, connected with the electrode, and passed through the wall of the encapsulating housing in insulated manner. To protect operating personnel from high voltage which occurs at the conductor, the conductor is grounded by metal springs outside the encapsulating housing. These metal springs can be lifted up from the conductor if necessary, by means of activation elements. This is done, for example, by setting a switchboard housing onto a measurement housing which surrounds the conductor. If the switchboard housing is removed, the conductor is automatically grounded again by the metal springs. This high-voltage measurement device can be used for all types of gas-insulated high-voltage switchboard plants.

Abstract: A magnetic force microscopy method and improved magnetic tip for detecting and quantifying internal magnetic fields resulting from current of integrated circuits. Detection of the current is used for failure analysis, design verification, and model validation. The interaction of the current on the integrated chip with a magnetic field can be detected using a cantilevered magnetic tip. Enhanced sensitivity for both ac and dc current and voltage detection is achieved with voltage by an ac coupling or a heterodyne technique. The techniques can be used to extract information from analog circuits.

Abstract: A reflection type magnetooptic sensor head is disclosed. The respective structural elements are aligned following a light source in the order of a light inputting/outputting path, polarizer, Faraday rotator, and reflecting mirror. The Faraday rotator is made of a (111) bismuth-substituted iron garnet single crystal film having [111] axis at an angle of 5-60 degrees with an axis normal to the film surface. The reflecting mirror is positioned such that a light incident upon the reflecting mirror is substantially normal to the surface of the reflecting mirror.

Abstract: A process for locating common electrode shorts in an electronic array, such as an x- y- addressed imager assembly having a short circuit between an address line and an overlying common electrode layer, includes the steps of applying a test voltage to the addressed line shorted to the common electrode, measuring current at each of a plurality of common electrode contact points disposed at selected intervals along selected edges of the common electrode, and processing the respective measured currents in accordance with a selected relationship to localize a short circuit location along the length of the shorted address line. In imager assembly arrangements in which it is possible to measure currents on opposite sides of the common electrode disposed substantially perpendicular to the orientation of the shorted address line, the selected relationship is I.sub.A-N /I.sub.a-n =(L-X)/X, wherein: I.sub.A-N are the measured currents from common electrode contact points along one common electrode opposite edge; I.sub.

Abstract: An electro-optics current sensing system for sensing and avoiding thermally induced measurement errors in a current sensor includes a beam generator, such as a light emitting diode or a laser diode, thermally coupled to the current sensor for encoding into the optical beam supplied by the beam generator both temperature and sensed current information. An electro-optics (E/O) demodulator which includes a wavelength division multiplexer (WDM) demodulates the encoded optical beam to recover the temperature and sensed current information from a pair of demodulated signals which can be further processed for filtering resistivity changes from the sensed current measurement.

Abstract: The present inventors have discovered that a compact, highly sensitive current sensor can be made for any inductive component having an air gap in its magnetic path by disposing a layer of magnetoresistive material in the path of the fringing magnetic field. In the preferred embodiment, a thin magnetoresistive film of La.sub.w Ca.sub.x Mn.sub.y O.sub.z on a LaAlO.sub.3 /Al.sub.2 O.sub.3 substrate provides a high sensitivity in the range of 1-100 mV/ampere of DC current in the inductive component. The current sensor consumes a very small amount of power and provides the desirable electrical isolation between the sensor and the active device circuit.

Abstract: A test fixture operates under the control of a computer to make automatic correction in test contact spacing between the test fixture contact pins and the circuit under test. The computer detects continuity test failures and raises the test fixture to bring the test contact pins into proximity with the leads of the circuit under test. The computer controls rotation of a motor that drives a screw and moves a shaft and wedge assembly in the horizontal direction. A push rod is attached to the test fixture by way of a base plate and angle brackets. The push rod resting on the wedge slide up and down to raise and lower the test fixture.

Abstract: An apparatus and method for locating light sensitive circuit design flaws on an integrated circuit chip comprises placing the integrated circuit chip on a load board, which is coupled electrically with a tester to supply operating power to the chip device. The current used by the chip device is continuously measured. A stereoscopic microscope is used to direct a spot of light through one of the eyepieces of the microscope onto the upper surface of the chip; and the spot of light is moved along a predetermined path to scan the surface of the chip. Through the other eyepiece of the microscope, the location of the spot of light is observed. When the measured current drain undergoes changes, as the spot of light impinges on the chip, the location is noted. The quadrant or other area of the chip, in which the change of current consumption occurred as a result of the spot of light, then is scanned a second time with a smaller spot of light; and the process is repeated.

Abstract: A circuit has two multiplier modules. Each multiplier module has at least one controllable potentiometer for adjusting the amplitude ratio between an output signal and an input signal of the module. The potentiometers have substantially identical characteristics and they are controlled in the same manner such that the amplitude ratios of the multiplier modules are substantially equal. One of the modules receives as its input signal the first signal to be multiplied and delivers an output signal that is proportional to the product of the two operands, while the other module receives as its input signal a reference voltage and as its output signal it delivers a feedback signal which is servo-controlled to a value that is approximately equal to the value of the second signal to be multiplied. The circuit is applicable to meters for electrical energy.

Abstract: An apparatus for testing respective electrical components in situ within a circuit having a plurality of the electrical components. A power bus is connected between a power source and switching devices operable for conducting test current to respective ones of the electrical components. A comparator circuit includes inputs connected to the power bus and to a reference potential. A processor is programmed to actuate respective switching devices for causing a test current to be conducted from the power bus through a respective component, while sensing any output signal from the comparator circuit corresponding to an increased potential on the power bus indicative of a reduced current flow caused by an open or failed component.

Abstract: A method of measuring the high-frequency C-V characteristics of a MIS (e.g. MOS) device is disclosed. The method comprises the steps of providing the MIS device in a shielding-box shielding the device from an outside electromagnetic light, illuminating the device with a light of a wavelength preventing an induction of excess carriers at the surface of the semiconductor, applying a voltage of a high frequency to a gate electrode of the device, and alternating a sweep direction of the voltage. An apparatus implementing the method is also disclosed. The method and the apparatus accurately measure the MOS capacitance in response to a voltage applied to the gate electrode.

Abstract: A device for inspecting a component, such as a dovetail slot of a gas turbine engine or the like, includes an eddy current array circuit having an active face for positioning on the surface of the component during the inspection operation and a backing disposed on a face of the eddy current array circuit opposite to the active face. The eddy current array circuit and the backing are disposed over the operating face and expandable sides of an expandable bar. The expandable bar has a slot formed therein with interior side edges which narrow toward the operating face of the bar at a predetermined slope. An expanding wedge with angled sides is positioned to cause the angled sides to respectively matingly engage the interior sides of the slot to cause the exterior sides of the expandable bar to expand outwardly a greater distance as the wedge is pushed deeper into the slot to cause the eddy current array circuit into conformance with the shape of the surface being inspected.

Abstract: A current sensor for measuring a primary electrical current inducing a magnetic flux density defined over a known region comprises: a first sensor for measuring magnetic flux due to the primary current over a first predetermined area included within the known region; and a second sensor for measuring magnetic flux due to the primary current over a second predetermined area within the known region, the magnetic flux due to the primary current measured by the second sensor being a substantially predetermined calibrated amount different from the magnetic flux due to the primary current measured by the first sensor. The current sensor may further include a current source for generating a current inducing a magnetic flux density within the known region to at least partially offset the difference between the magnetic flux due to the primary current measured by the first sensor and the magnetic flux due to the primary current measured by the second sensor.

Abstract: A test fixture for printed circuit boards having an initial seal member and a final seal member. The test fixture includes a probe plate with a pair of channels about its periphery for receiving a pair of seal members. An initial seal member is positioned in the outer channel in the probe plate to spring-bias the diaphragm board and provide an initial seal for the test fixture. A final seal member resides in the inner channel in the probe plate and provides an absolute seal for the test fixture. The final seal does not move during operation thereby reducing friction wear. The two seal members operate separately from one another and can be replaced individually without replacing the other.

Abstract: A system for unintrusively determining parameters such as current, voltage and power delivered through a service line to a customer for verifying accuracy of the customer's entrance meter. The system includes a sensor apparatus for monitoring voltage and current on the power line. A voltage clamp mechanism is disposed within a sensor housing such that an insulation piercing voltage sensor can be manually actuated to pierce the electrical insulation of the power line and contact the conductor. The sensor apparatus also includes a split-core current transformer fabricated to minimize the air gap between the split-core sections when the apparatus is closed about the power line. A pole unit is electrically connected to each sensor apparatus for monitoring the voltage and current, calculating the power consumed in kilowatt-hours and storing calculated kilowatt-hours in memory with an appropriate date/time stamp, for subsequent retrieval and comparison with the customer's entrance meter readings.