By Time Measuring Patents (Class 324/535)
  • Patent number: 7292044
    Abstract: In a first embodiment of the invention there is provided an electronic chip for use with an automatic testing equipment device testing a device under test. The device under test has a plurality of pins and the electronic chip is placed in a channel of a test card that is associated with one of the pins. An input signal is provided to a pin of the device under test and the resulting output is provided to the pin electronics for the channel of the test card. In most embodiments, the output signal is a voltage signal. One purpose for the electronic chip is to measure jitter based upon timing measurements performed by the electronic chip. Jitter measurements are particularly important for high-speed serial devices. The electronic chip includes an integrating time measurement circuit for receiving the input signal and producing an output signal including a timing measurement of at least a portion of the input signal.
    Type: Grant
    Filed: November 18, 2005
    Date of Patent: November 6, 2007
    Assignee: Analog Devices, inc.
    Inventor: James Frame
  • Patent number: 7212008
    Abstract: An apparatus for detecting concealed surveillance devices coupled to a transmission line uses either a time domain or frequency domain reflectometry operation to locate any impedance anomalies on the transmission line and a non-linear junction detection operation to classify the located impedance anomalies as semiconductor or non-semiconductor based anomalies. The reflectometry operation utilizes the reflection of a test signal to determine the distance to any reflecting impedance anomalies on the transmission line that may be indicative of an electronic device being coupled to the transmission line. The non-linear junction detection operation then compares the amplitudes of re-radiated second and third harmonics of a transmitted fundamental frequency signal to determine if the reflecting impedance anomalies are the result of a semiconductor based non-linear junction. A DC bias voltage and a balanced load may be added to the transmission line to enhance the line's response to the test signals.
    Type: Grant
    Filed: November 3, 2005
    Date of Patent: May 1, 2007
    Inventors: Bruce R. Barsumian, Thomas H. Jones, Charles A. Liter
  • Patent number: 7157710
    Abstract: An apparatus and process are provided for detecting whether a corona discharge has occurred external or internal to equipment in which a broadband optical spectra sensor is placed. The broadband optical spectra sensor senses both the ultraviolet energy of the corona discharge and the infrared energy of afterglow of the discharge when the discharge occurs internal to the equipment. The sensed broadband optical spectra signal is processed and a determination is made as to whether the corona discharge occurred external or internal to the equipment from the pulse width of the sensed energy pulse.
    Type: Grant
    Filed: November 12, 2004
    Date of Patent: January 2, 2007
    Assignee: Kaiser Systems, Inc.
    Inventor: Robert A. Shannon
  • Patent number: 7096443
    Abstract: A method of determining the critical path of a circuit includes first determining the paths, their mean path transit times and their path transit time fluctuations. Paths having similar statistical parameters are combined to form one path group. For each path group, a statistical group figure is, then, calculated and, for the totality of paths considered, a statistical total figure is calculated. Finally, the critical paths of the circuit are determined by taking into consideration the total figure, comparing the group figures at or above a critical path transit time Tc.
    Type: Grant
    Filed: July 15, 2003
    Date of Patent: August 22, 2006
    Assignee: Infineon Technologies AG
    Inventors: Jörg Berthold, Henning Lorch, Martin Eisele
  • Patent number: 7075309
    Abstract: A system (20) and method to locate an anomaly (22) of a conductor (24) is provided. The system (20) uses a test set (28) to inject a test signal (36) into the conductor (24) at a location (PT) and a probe (30) to detect the test signal (36) at a second location (PP). A communication link (42) between the probe (30) and the test set (28) has a predetermined propagation delay (DS), from which the system (20) can calculate a propagation delay (DTP) of the conductor (24) between the test set (28) and the probe (30), and a propagation delay (DPA) between the probe (30) and the anomaly (22). By varying the location (PP) of the probe (30) until the propagation delay (DPA) between the probe (30) and the anomaly (22) is substantially zero, the precise location (PA) of the anomaly (22) may be determined. The propagation velocity (VC) of the conductor (24) may also be determined.
    Type: Grant
    Filed: March 7, 2005
    Date of Patent: July 11, 2006
    Assignee: Livewire Test Labs, Inc.
    Inventor: Paul Samuel Smith
  • Patent number: 7043398
    Abstract: A system for determining a signal running time between a position measuring system and an evaluation unit. The system includes a position measuring system that has a graduation connected to a moving element, a scanning unit that scans the graduation, wherein scanning of the graduation generates signals representative of a position of the moving element and a transceiver means for generating serial data that is transmitted along a data line connected to the transceiver. The system further includes an evaluation unit connected to the data line, the evaluation unit having means for determining a signal running time between the position measuring system and the evaluation unit.
    Type: Grant
    Filed: May 7, 2002
    Date of Patent: May 9, 2006
    Assignee: Dr. Johannes Heidenhain GmbH
    Inventors: Hermann Hofbauer, Helmut Huber, Erich Strasser, Steffen Bielski
  • Patent number: 7005862
    Abstract: A propagation delay time of a cable assembly is measured by calculating a half of a time difference between a branch point of time-dependent variations of amplitude of reflection coefficient obtained by connecting a first connector with both terminals open-circuited and a second connector with one terminal short-circuited to a conversion adaptor in turn and a branch point of the time-dependent variations of the amplitude of reflection coefficient obtained by connecting one terminal of the cable assembly with other terminal connected to the first connector and one terminal of the cable assembly with other terminal connected to the second connector to the conversion adaptor in turn.
    Type: Grant
    Filed: March 31, 2005
    Date of Patent: February 28, 2006
    Assignee: Fujitsu Limited
    Inventor: Yasushi Onodera
  • Patent number: 6977507
    Abstract: A system comprises a physical layer device that is adapted to communicate with a cable medium and that includes a first input/output terminal. A first transceiver communicates with the first input/output terminal and the cable medium. A cable tester tests the cable medium and determines a cable status. An indicator communciates with the physical layer device and identifies at least one of link presence, link abscence, link activity, link duplex and or link speed of the first input/output terminal during normal operation. The cable tester also uses the indicator to indicate at least one of cable testing status during the test and/or the cable status after the test.
    Type: Grant
    Filed: December 30, 2002
    Date of Patent: December 20, 2005
    Assignee: Marvell International Ltd.
    Inventors: Donald Pannell, William Lo, Yiqing Guo
  • Patent number: 6927579
    Abstract: A system for locating parallel arcing faults in a set of wires is described. The system includes three devices that can be used in combination or alone. A first device applies a current to a wire while grounding the remaining wires of the set of wires so as to cause the parallel arc, the first device being adapted to locate the parallel arcing fault using one or more leading edges of one or more electromagnetic waveforms being conducted on the wire under test. A second device comprises a controller and two or more receivers, each receiver being electrically coupled to the controller for receiving one or more leading edges of one or more electromagnetic waveforms being radiated by the parallel arcing fault. A third device senses one or more leading edges of one or more electromagnetic waveforms as well as the ultrasonic emissions emitted from the parallel arcing fault.
    Type: Grant
    Filed: May 16, 2003
    Date of Patent: August 9, 2005
    Assignee: Astronics Advanced Electronic Systems, Corp.
    Inventor: Frederick K. Blades
  • Patent number: 6923065
    Abstract: An apparatus and method for inspecting and calculating the residual strength of an aramid fiber rope driving an elevator to determine when such rope is in need of replacement. The apparatus comprises a transmitter for introducing an acoustic wave that will travel along the aramid fiber rope and a plurality of receivers for receiving the acoustic wave after its has traversed a designated section of the rope. The transmitter and receiver provide signals indicating the times the wave was sent by the transmitter and thereafter received by the receiver. From these signals, a program calculates the wave velocity, and the modulus and residual strength of the aramid rope.
    Type: Grant
    Filed: September 12, 2003
    Date of Patent: August 2, 2005
    Assignee: Thyssen Elevator Capital Corp.
    Inventors: Rory Smith, Robert H. Sweet, James Nickerson, Michael A. Palazzola, Randall Parrish
  • Patent number: 6919727
    Abstract: Disclosed is a method of measuring the time signal of an electronic device including steps for measuring a true signal and an inverted signal. The measured true path signal and inverted path signal are combined to reduce measurement error and provide an accurate measurement of the time signal of the device under test. Also disclosed is an interface for use between a device-under-test and test equipment. The interface includes means for alternately switching a time signal from the device-under-test to provide a true signal path and an inverted signal path for measurement. A system embodiment of the invention is also disclosed in which an interface and measuring means are used to alternately measure and combine a true signal and an inverted signal to provide an accurate time measurement result.
    Type: Grant
    Filed: September 26, 2002
    Date of Patent: July 19, 2005
    Assignee: Texas Instruments Incorporated
    Inventors: Gunvant T. Patel, Nicholas Flores
  • Patent number: 6882161
    Abstract: Disclosed herein is a method of measuring a dielectric constant of a Printed Circuit Board (PCB) for a Rambus Inline Memory Module (RIMM), which includes the steps of measuring a length of a Rambus product of a PCB, applying an input waveform to the Rambus product at a certain probing position and obtaining a cross point of rising times of the input waveform and an output waveform generated by reflection of the input waveform, obtaining time corresponding to the cross point, and calculating a dielectric constant by substituting the measured length of the Rambus product and the obtained time for corresponding variables of a dielectric constant calculating equation.
    Type: Grant
    Filed: May 28, 2003
    Date of Patent: April 19, 2005
    Assignee: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Young-Woo Kim, Byoung-Ho Rhee, Dek-Gin Yang, Young-Sang Cho, Dong-Hwan Lee
  • Patent number: 6853196
    Abstract: A method for electrical cable testing by Pulse-Arrested Spark Discharge (PASD) uses the cable response to a short-duration high-voltage incident pulse to determine the location of an electrical breakdown that occurs at a defect site in the cable. The apparatus for cable testing by PASD includes a pulser for generating the short-duration high-voltage incident pulse, at least one diagnostic sensor to detect the incident pulse and the breakdown-induced reflected and/or transmitted pulses propagating from the electrical breakdown at the defect site, and a transient recorder to record the cable response. The method and apparatus are particularly useful to determine the location of defect sites in critical but inaccessible electrical cabling systems in aging aircraft, ships, nuclear power plants, and industrial complexes.
    Type: Grant
    Filed: April 12, 2002
    Date of Patent: February 8, 2005
    Assignee: Sandia Corporation
    Inventors: John R. Barnum, Larry K. Warne, Roy E. Jorgenson, Larry X. Schneider
  • Publication number: 20040207406
    Abstract: A test vehicle a system and method for evaluating an interconnect module manufacturing process while dynamically testing performance with high-speed operational frequencies is disclosed. An interconnect module designed at many of the manufacturing process limits offers complete and fast failure analysis so that manufacturing defects can be quickly located and the process improved. Failure analysis, particularly on 90 nm technologies and beyond is becoming extremely difficult. At-speed testing is also becoming very important to the yield and reliability of products. This invention incorporates a self-timed speed circuit that can detect subtle resistive faults and also show the exact location in the array where the speed fault occurred based on test program datalogs from scan flip flops.
    Type: Application
    Filed: April 16, 2003
    Publication date: October 21, 2004
    Inventor: Richard Schultz
  • Patent number: 6784819
    Abstract: A technique for deskewing digitizer channels in an automatic test system includes applying a waveform of known frequency to the input of each digitizer channel. Each digitizer channel samples the waveform to produce a respective data record. A Discrete Fourier Transform (DFT), or a portion thereof, is then taken for each data record to determine, at minimum, the phase of the waveform. Phase differences across different digitizer channels are converted to time differences, which values are applied to subsequent digitizer measurements to correct for timing skew. Because a large number of samples in a digitizer's data record contribute to the computed phase of the waveform, the effects of timing jitter are substantially eliminated from skew measurements, without the need for repeating measurements and explicitly averaging results.
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: August 31, 2004
    Assignee: Teradyne, Inc.
    Inventor: Ka Ho Colin Chow
  • Patent number: 6774639
    Abstract: An apparatus for detecting partial discharge in on-line high voltage electrical equipment containing a dielectric, such as high voltage transformers. The apparatus includes an ultrasonic transducer and an annular capacitive plate for detecting, respectively, the ultrasonic pulse and the radio frequency pulse generated by the occurrence of partial discharge in the equipment.
    Type: Grant
    Filed: July 10, 2002
    Date of Patent: August 10, 2004
    Assignees: TransGrid, University of Technology, Syndey
    Inventor: Joseph Unsworth
  • Patent number: 6737877
    Abstract: Embodiments of the invention describe a method and apparatus used to determine the position of a wiper on a potentiometer without the need for an external ADC. Two capacitors are each connected to an end of a potentiometer, and then are charged or discharged simultaneously by a current source or current sink attached to the wiper of the potentiometer. The time required for each of the capacitors to charge or discharge to a threshold voltage level is measured and subsequently used to determine the position of the wiper on the potentiometer.
    Type: Grant
    Filed: August 30, 2002
    Date of Patent: May 18, 2004
    Assignee: Cypress Semiconductor Corp.
    Inventors: Barry S. Hatton, David G. Wright
  • Publication number: 20040061507
    Abstract: Disclosed is a method of measuring the time signal of an electronic device including steps for measuring a true signal and an inverted signal. The measured true path signal and inverted path signal are combined to reduce measurement error and provide an accurate measurement of the time signal of the device under test. Also disclosed is an interface for use between a device-under-test and test equipment. The interface includes means for alternately switching a time signal from the device-under-test to provide a true signal path and an inverted signal path for measurement. A system embodiment of the invention is also disclosed in which an interface and measuring means are used to alternately measure and combine a true signal and an inverted signal to provide an accurate time measurement result.
    Type: Application
    Filed: September 26, 2002
    Publication date: April 1, 2004
    Inventors: Gunvant T. Patel, Nicholas Flores
  • Patent number: 6703840
    Abstract: Methods automatic process control of biasing and testing a heated-electrode refrigerant sensor for use in a refrigerant detector. An unbiased sensor may be mounted in a manufacturing station, and while mounted may be biased by applying current to electrically heat the sensor and by applying a voltage potential between the sensor's anode and cathode, thereby generating a bias current at the cathode, and after the sensor is at least partially biased, the bias current is used to electrically test the sensor's construction. If the temperature of the sensor is held constant at a bias temperature, the acceptability of the sensor may be determined based on the time that elapses before the bias current decreases from an initial value to a threshold value, or determined based on the noise present on a signal which is representative of an operating condition other than the bias current magnitude.
    Type: Grant
    Filed: February 28, 2002
    Date of Patent: March 9, 2004
    Assignee: Advanced Test Products, Inc.
    Inventor: Dennis Cardinale
  • Patent number: 6696974
    Abstract: A cable composed of material capable of conducting light, sound, or electricity is inserted by appropriate means into a material to be examined. A portion of said cable having predetermined parameters is fixed internally within the material. The cable is equipped with anchors that restrict movement within the material to be examined. Displacement or deformation of the material to be examined results in displacement and deformation of the sensor cable system. The anchors preferably concentrate stress or deformation at specific points of the cable as the cable deforms. The anchors may also allow movement of the cable such that displacement and deformation of the cable within the material is reduced.
    Type: Grant
    Filed: July 28, 2000
    Date of Patent: February 24, 2004
    Inventor: James I. Mathis
  • Patent number: 6670816
    Abstract: A test coupon for measuring a dielectric constant of a memory module substrate has a plurality of test pattern layers each having a long trace and a short trace formed thereon. A first test pattern layer has an exposed surface and a second test pattern layer is formed internally. The first test pattern layer has probe pads respectively connected to the long and short traces of the first and second pattern layers. Probe pads of the first test pattern layer are connected to a via contact of the second test pattern layer by via holes. The via contact of the second pattern layer is connected to the long and short traces of the second pattern layer. The test coupon is used to measure the dielectric constant of a module board.
    Type: Grant
    Filed: December 28, 2001
    Date of Patent: December 30, 2003
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Yong-Hyun Kim, Sei-Gu Lee, Joung-Rhang Lee
  • Patent number: 6662660
    Abstract: The invention concerns an apparatus for inspecting and calculating the residual strength of an aramid fiber cable driving an elevator to determine when such cable is in need of replacement. The apparatus includes a transmitter for introducing an acoustic wave that will travel along the aramid fiber cable and a receiver for receiving the acoustic wave after its has traversed a designated section of the cable. The transmitter and receiver provide signals indicating the times the wave was sent by the transmitter and thereafter received by the receiver. From these signals, a program in the system calculates the wave velocity and the modulus, and the residual strength of the aramid cable.
    Type: Grant
    Filed: September 17, 2001
    Date of Patent: December 16, 2003
    Assignee: Thyssen Elevator Capital Corp.
    Inventor: Rory Smith
  • Patent number: 6617869
    Abstract: Given the inventive electrical circuit with a device for testing connections in electrical circuits, the change of a test signal (27) due to the effect of a long line is used for determining the quality of an electrical connection (e.g., of a pin). In particular, a determination about the terminating impedance and, thus, about the quality of the connection, is made by defining a maximum value of the test signal (28) reflected at the line end. An existing boundary scan test implementation with appropriate expansions can thereby be used, including a test controller. Standard digital signals can be employed as test signal when their propagation time is lengthened by a delay element.
    Type: Grant
    Filed: August 11, 2000
    Date of Patent: September 9, 2003
    Assignee: Siemens Aktiengesellschaft
    Inventor: Ulf Pillkahn
  • Patent number: 6538451
    Abstract: A method and system for determining the make-up of a subscriber loop having sending pulses onto a loop and acquiring data based on received echo signals. Determining from the received echoes each discontinuity on the loop and, based on each discontinuity, determining a channel transfer function for each loop section preceding the discontinuity. The transfer function is then used to synthesize an inverse filter. The inverse filter and acquired data are convolved for all the loop sections preceding the discontinuity. The method may be further improved by modeling real and spurious echoes and subtracting these echoes from the echoes generated in the loop.
    Type: Grant
    Filed: June 5, 2000
    Date of Patent: March 25, 2003
    Assignee: Telcordia Technologies, Inc.
    Inventors: Stefano Galli, David L. Waring
  • Publication number: 20030052695
    Abstract: The invention concerns an apparatus for inspecting and calculating the residual strength of an aramid fiber cable driving an elevator to determine when such cable is in need of replacement. The apparatus includes a transmitter for introducing an acoustic wave that will travel along the aramid fiber cable and a receiver for receiving the acoustic wave after its has traversed a designated section of the cable. The transmitter and receiver provide signals indicating the times the wave was sent by the transmitter and thereafter received by the receiver. From these signals, a program in the system calculates the wave velocity and the modulus, and the residual strength of the aramid cable.
    Type: Application
    Filed: September 17, 2001
    Publication date: March 20, 2003
    Inventor: Rory Smith
  • Patent number: 6512377
    Abstract: The present invention relates to a via parasitics testing and extracting method for Gigabit multi-layered PCB boards. The method of the present invention is a unique test and extraction process that utilizes a TDR measurement and processes the output data therefrom externally. The testing aspect involves obtaining a TDR module waveform and obtaining a text file with output data, whereas the extraction aspect involves analysis of the data in the text file. This method can be used directly to ascertain a Gigabit via structure without the limitations that are imposed by the conventional methods discussed above, and has been theoretically proven to be highly accurate and much faster than any of the existing methods. The method of the present invention has the potential to be included as a built-in testing feature in high-speed TDR meters, and may also be used in order to design an optimized via.
    Type: Grant
    Filed: June 29, 2001
    Date of Patent: January 28, 2003
    Assignee: Nortel Networks Limited
    Inventors: Shuhui Deng, Stephen S Brazeau, Xiao-Ding Cai
  • Patent number: 6509740
    Abstract: Methods and apparatus for determining the location of a fault or another region of interest in an electrical conductor such as an electrical cable. A preselected electrical signal is applied to the electrical conductor and a reflected signal produced thereby is generated. The reflected signal is compared to a plurality of preselected voltage values and time values are recorded representing times at which the voltage of the reflected signal crosses the preselected voltage values. Mathematical algorithms are applied using the recorded time and voltage values first to locate a suspected knee region in the reflected signal, then to confirm the presence of the knee within the suspected knee region. The location of the knee in the reflected signal is then used to calculate the distance to the fault or other region of interest. A further series of time values is recorded within the suspected knee region and used to more precisely determine the true location of the knee in the reflected signal.
    Type: Grant
    Filed: April 7, 2000
    Date of Patent: January 21, 2003
    Assignee: Jovial Test Equipment, Inc.
    Inventors: Dave Needle, Stan F. Shepard
  • Patent number: 6486676
    Abstract: A reflection measurement method and apparatus measures reflection characteristics of a device under test (DUT) when access to the DUT is through a dispersive element. The method and apparatus measure a composite reflection response of a network that includes the DUT and the dispersive element coupled to the DUT via a transmission line. A reflection response of the dispersive element is isolated from a remainder of the composite reflection response of the network. A set of transmission parameters for the dispersive element is generated from the isolated reflection response of the dispersive element and is then applied to the remainder of the composite reflection response of the network to extract the reflection characteristic of the DUT.
    Type: Grant
    Filed: March 19, 2001
    Date of Patent: November 26, 2002
    Assignee: Agilent Technologies, Inc.
    Inventor: Terrence R. Noe
  • Patent number: 6483316
    Abstract: The present invention provides a method of diagnosing a partial discharge in a gas-insulated apparatus and a partial discharge diagnosing system for carrying out the same to achieve highly accurate diagnosis through the detection of a partial discharge signal and diagnosing the partial discharge signal through multiple conditional branching. The partial discharge diagnosing system of the present invention consists: a partial discharge signal detector for detecting a partial discharge signal representing a partial discharge produced in the gas-insulated apparatus, a signal analyzer for receiving the partial discharge signal detected by the partial discharge detector and analyzing the partial discharge signal, a diagnostic unit for determining a cause of the partial discharge on the basis of results of analysis made by the signal analyzer, and a display unit for displaying results of diagnosis.
    Type: Grant
    Filed: July 31, 2001
    Date of Patent: November 19, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Tatsuro Kato, Fumihiro Endo
  • Patent number: 6477475
    Abstract: A fault point location system comprising substations 1 to send information of transmission and distribution lines, and the master station 2 to locate fault points under the information. Substation 1 detects a surge detection time and the surge current polarity. Master 2 identifies a no-branch fault section under the polarity, and identifies the fault point under a difference among detection times of substations 1 at both ends of the section, and the section length.
    Type: Grant
    Filed: November 9, 1999
    Date of Patent: November 5, 2002
    Assignees: Nippon Kouatsu Electric Co., Ltd.
    Inventors: Motokuni Takaoka, Masanori Sugiura
  • Patent number: 6385561
    Abstract: A method and apparatus (12-20, 32) for automatically locating faults in a network of signal carriers (cables) utilises an interrogation waveform which is pulse-like in form and receives composite reflected signals from the carriers which are a time distributed collection of individual reflections. These are sampled and compared using the function of an adaptive filter (52) to minimise the difference signal. The difference signals are analysed to determine significant points of departure which identify the fault location which is then represented as a distance value.
    Type: Grant
    Filed: May 13, 1999
    Date of Patent: May 7, 2002
    Assignee: University of Strathclyde
    Inventors: John James Soraghan, Wah Hoon Siew
  • Patent number: 6366095
    Abstract: The invention relates to a method for detecting at least one irregularity in the dielectric around a substantially elongate conductor, comprising of: applying a potential difference between the conductor and the earth; measuring at a first position voltage changes caused by said irregularity and moving in the direction of the first position; measuring at a second position voltage changes caused by said irregularity and moving in the direction of the second position; determining with the use of time registration the difference in arrival time of voltage changes caused by the same irregularity and measured at the first and second position; determining the position of the irregularity in said conductor on the basis of the, difference in arrival time and the length of said conductor between the first and second position.
    Type: Grant
    Filed: December 7, 1999
    Date of Patent: April 2, 2002
    Assignee: N.V. Kema
    Inventor: Dirk Marinus Van Aartrijk
  • Patent number: 6340890
    Abstract: A method and apparatus for location of partial discharges in an electric high-voltage apparatus, such as a power transformer, which is arranged in a container filled with an insulating medium is provided. At least three ultrasonic detectors are applied with mutually known positions on the outside of the container and in acoustic contact therewith. The times of arrival of a wavefront arriving at the detectors and originating from a partial discharge are determined, and on the basis of the times of arrival and on the basis of the known mutual positions of the detectors, the direction the partial discharge is determined.
    Type: Grant
    Filed: August 6, 1997
    Date of Patent: January 22, 2002
    Assignee: ABB Research, Ltd.
    Inventors: Tord Bengtsson, Mats Leijon
  • Patent number: 6313741
    Abstract: The present invention provides a sensor-fault detection circuit for use with either an inductive or capacitive-type sensor. The sensor-fault detection circuit conducts a test signal into the sensor circuit for testing such sensor circuit. A time difference measuring device is provided to analyze for correct duration of the transit time of a test signal or test pulse, respectively, passing through the sensor. In the event that the transit time does not fall within a predetermined range tolerance, a fault indication can be activated. The circuit can be used, for example, to test an inductive bar-type sensor to determine the speed of a wheel on a vehicle.
    Type: Grant
    Filed: December 22, 1994
    Date of Patent: November 6, 2001
    Assignee: WABCO Standard GmbH
    Inventor: Klaus Glabe
  • Patent number: 6300768
    Abstract: The present invention provides a method of diagnosing a partial discharge in a gas-insulated apparatus and a partial discharge diagnosing system for carrying out the same to achieve highly accurate diagnosis through the detection of a partial discharge signal and diagnosing the partial discharge signal through multiple conditional branching. The partial discharge diagnosing system of the present invention comprises: a partial discharge signal detector for detecting a partial discharge signal representing a partial discharge produced in the gas-insulated apparatus, a signal analyzer for receiving the partial discharge signal detected by the partial discharge detector and analyzing the partial discharge signal, a diagnostic unit for determining a cause of the partial discharge on the basis of results of analysis made by the signal analyzer, and a display unit for displaying results of diagnosis.
    Type: Grant
    Filed: January 24, 2000
    Date of Patent: October 9, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Tatsuro Kato, Fumihiro Endo
  • Publication number: 20010024125
    Abstract: A method for fault detection in the operation of sensors with at least two decoupled signal-transmitting elements with contacts and with a closed conductor loop includes delaying, a first test output by a defined switching delay with reespect to a second test output and evaluating the input channels in accordance with a defined expectation. Faults being inferred from deviations between actual and expected signal variations and time intervals.
    Type: Application
    Filed: January 29, 2001
    Publication date: September 27, 2001
    Applicant: Siemens AG
    Inventors: Heiko Groenewold, Ronald Hauf
  • Patent number: 6259255
    Abstract: A surge locating system and a method thereof which can accomplish the surge locating with high accuracy and with relatively simple structure. When the surge occurs, the voltage is generated on the neutral point of Y-connected three-phase alternating current transmission line because of losing a voltage balance on the three-phase alternating current transmission line. The surge locating can be accomplished by detecting the voltage generated in the neutral point. The neutral point is grounded, and the surge locating system according to the present invention is installed between the neutral point and the grounding point. The voltage generated in the neutral point is introduced into the surge locating system and the detecting time thereof is stored. This detecting time is stored in the respective stations, and the surge point can be located based on the detecting time difference between the stations.
    Type: Grant
    Filed: December 8, 1998
    Date of Patent: July 10, 2001
    Assignees: Tohoku Electric Power Co., Inc., Kyokuto Boeki Kaisha, Ltd.
    Inventors: Sakari Ohira, Masaaki Ozawa, Toshiaki Kojima
  • Patent number: 6194902
    Abstract: A method and system for detecting corrosion on a pipe or a pipeline. An electrical or electromagnetic pulse is transmitted into a pipe or pipeline to travel as a propagating electromagnetic wave along the pipeline to a receiving location. Both the distance traveled from the transmitting and receiving location, and also the time interval for such travel are measured. Velocity of the wave is detected as a means of ascertaining whether corrosion is present. Various embodiments, using both multi-channel and single cables, are used to transmit the detected waves, and the waves are received at a plurality of spaced locations along the length of the pipe or pipeline. For an insulated pipeline, the signals can be received by a directional antenna, and the pulses can be transmitted into the pipeline by means of either an antenna placed directly adjacent to the pipeline or a magnet electrical contact member in direct contact with the pipeline.
    Type: Grant
    Filed: February 27, 1997
    Date of Patent: February 27, 2001
    Inventors: John T. Kuo, Gale D. Burnett
  • Patent number: 6037780
    Abstract: The object of the present invention is to offer a transmission line propagation delay time measuring device capable of reducing the measurement errors due to attenuation in transmission lines and allowing precise measurement of the transmission line propagation delay time.
    Type: Grant
    Filed: July 16, 1997
    Date of Patent: March 14, 2000
    Assignee: Ando Electric Co., Ltd
    Inventor: Toshiyuki Ohtaki
  • Patent number: 5991338
    Abstract: The invention relates to a method for pinpointing an interruption in a link for transmitting digital signals between a first station and a second station on the basis of the times of occurrence of signal changes on the link. In accordance with the invention, the method is characterised by generating signal changes after the link has been restored. Preferably, the time of restoration is determined on the basis of data signals received, and a detection signal is fed to the link after the determination of the time of restoration. On the basis of the difference in time of observing restoration and of receiving a detection signal, the location of the interruption is determined. For this purpose, the length of the link need not be known.
    Type: Grant
    Filed: October 14, 1997
    Date of Patent: November 23, 1999
    Assignee: Koninklijke PTT Nederland N.V.
    Inventor: Eric Simon Trommel
  • Patent number: 5920195
    Abstract: An apparatus and method for the moisture content measurement of compressible materials using pressure to firmly hold surface probes against the material to be measured. The apparatus uses moisture measurement circuitry employed in frequency domain impedance or time domain reflectometry devices to obtain moisture content readings from materials. These moisture content readings are based on the apparent dielectric constant of the measured material. Subsurface air voids or gaps found in loose, layered materials undesirably influence moisture measurement readings by reducing the apparent dielectric constant of the measured material. Pressure is supplied through the apparatus to the material in the proximity of the surface probes, thereby reducing air voids to enhance measurement accuracy. The apparatus and method are especially useful for compressible organic materials such as forest duff, hay and soil.
    Type: Grant
    Filed: December 18, 1996
    Date of Patent: July 6, 1999
    Assignee: The United States of America as represented by the Secretary of Agriculture
    Inventors: Peter R. Robichaud, Roger D. Hungerford, David S. Gasvoda
  • Patent number: 5903155
    Abstract: A method of measurement for fault distance determination on two or more parallel HVDC lines connected between two stations with a line fault locator is provided. The fault distance determination is performed by determining the difference in time, via synchronous clocks at each station, between travelling waves, which arise when a fault occurs, reach the two stations. The difference in time is determined by measuring the current associated with the travelling waves and detecting the current at the two stations and on each of the parallel connected lines.
    Type: Grant
    Filed: August 26, 1997
    Date of Patent: May 11, 1999
    Assignee: Asea Brown Boveri AB
    Inventor: Hans Bjorklund
  • Patent number: 5903157
    Abstract: In a measuring system for an enclosed high-voltage switchgear having at least two poles, each of which is phase segregated, and with sensors for dielectric noise and a detector device connected to them for outputting a signal in the event of an noise, a time comparator is provided that blocks the output of a signal if the time difference between two noise signals from sensors of different phases is less than a certain interval of time, in particular an adjustable interval.
    Type: Grant
    Filed: December 8, 1997
    Date of Patent: May 11, 1999
    Assignee: Siemens Aktiengesellschaft
    Inventors: Norbert Achatz, Jorg Gorablenkow
  • Patent number: 5889405
    Abstract: A method of detecting a fault of an electromagnetically-actuated intake/exhaust valve is disclosed. A valve body is supported in neutral position by the energizing force of an elastic member, and the electromagnetic force generated by supplying a current to the coils arranged on the two sides of a plunger is applied to the plunger thereby to operate the valve. A fault is detected based on a change of the current flowing in one coil attracting and holding the plunger with the inductance change of the same coil when the plunger is switched from the position of the same coil to the position of the other coil. This method improves the fault detection accuracy for the electromagnetically-actuated intake/exhaust valve over the prior art.
    Type: Grant
    Filed: May 23, 1997
    Date of Patent: March 30, 1999
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Akihiro Yanai, Takashi Izuo
  • Patent number: 5877631
    Abstract: An evaluation method for a test semiconductor device having at least two wiring patterns disposed in parallel, wherein: at least one wiring pattern is grounded; a pulse voltage is applied between the grounded wiring pattern and an adjacent wiring pattern; a time required for the pulse to reciprocate along the wiring patterns and a value of a voltage including a reflected voltage between the wiring patterns are measured to judge a presence/absence of a wiring breakage or a wiring short circuit and to locate a wiring breakage point or a wiring short circuit point.
    Type: Grant
    Filed: October 9, 1996
    Date of Patent: March 2, 1999
    Assignee: Yamaha Corporation
    Inventor: Yasuji Takahashi
  • Patent number: 5818237
    Abstract: Arcing faults in an ac current are detected by apparatus which is responsive to a predetermined randomness in step increases in the current to eliminate false tripping caused by regularly occurring discontinuities produced by loads such as dimmers. A signal conditioner generates a bandwidth limited di/dt signal having pulses produced by the step increases in current. In one embodiment, a first tracking circuit tracks the envelope of the di/dt signal with a first time constant. A second tracking circuit also tracks the di/dt envelope, but with a second, shorter time constant. An arcing fault is indicated if the second tracking signal falls to a predetermined fraction of the fist tracking signal. This circuit may be used alone to detect arcing faults or to increase the sensitivity to arcing faults over dimmers of a circuit which responds to a time attenuated integrated valve of the pulses in the di/dt signal.
    Type: Grant
    Filed: June 10, 1996
    Date of Patent: October 6, 1998
    Assignee: Eaton Corporation
    Inventors: Joseph C. Zuercher, Raymond W. MacKenzie, Steven C. Schmalz
  • Patent number: 5814998
    Abstract: A device and a method for locating partial discharges in dynamoelectric high-voltage machines and/or high-voltage systems, comprising at least two coupling units (16, 17, 18) which are coupled to mutually spaced measuring points (MP1, MP2, MP3, ES, TS, AKV) of a conductor (2) of the high-voltage machine and/or high-voltage system, and couple out a high-frequency electromagnetic signal produced upon the occurence of partial discharges. The device further comprises an evaluation device which is electrically connected to each coupling unit (16, 17, 18) and records the temporal sequence of the signals coupled out by each coupling unit (16, 17, 18). The place of origin of the partial discharges can be determined from the temporal sequence of the signals, it being possible to enhance the accuracy by additional measurements at further measuring points.
    Type: Grant
    Filed: May 30, 1996
    Date of Patent: September 29, 1998
    Assignee: Siemens Aktiengesellschaft
    Inventors: Peter Gruenewald, Juergen Weidner, Gerhard Schimmelpfennig, Reinhold Koziel
  • Patent number: 5751149
    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.
    Type: Grant
    Filed: December 8, 1995
    Date of Patent: May 12, 1998
    Assignee: Tempo Research Corporation
    Inventors: Arthur E. Oberg, Charles H. Wissman
  • Patent number: 5729144
    Abstract: A power line fault locating system employing combinations of conducted electrical transient signals recorded at specific points in the power delivery network, radiated electromagnetic signals produced by the air-gap arc preceeding the fault current or by the lightning discharge causing the fault, and knowledge of the power line path associated therewith. The arrival time of conducted transient signals produced by the fault are detected with microsecond accuracy through use of a fault recording sensor (FRS). The low level electromagnetic radiation (VHF/UHF) caused by arcing associated with power line faults is detected at at least one arc detection sensor (ADS) located at some distance from the power line. The ADS senses the time of arrival of the radiated signal associated with the fault.
    Type: Grant
    Filed: December 2, 1996
    Date of Patent: March 17, 1998
    Inventor: Kenneth L. Cummins
  • Patent number: 5726577
    Abstract: Series arcs in an ac circuit are discriminated from other phenomenon by analyzing the timing between pulses in a second derivative of the current signal. A first timer starts timing upon detection of a first pulse in the second derivative of current signal. Time out of the first timer starts a second timer which times a second interval or window during which a series arcing fault will generate a second pulse of opposite polarity to the first pulse. Detection of the first pulse followed by a second pulse of opposite polarity during the window sets a flip-flop to record the event. When a predetermined number of events are counted by a counter within a given time-period set by a third timer, an output signal indicating an arcing fault is generated. If the second pulse is generated before the window opens, or a third pulse occurs during the window, the flip-flop cannot be set so that other events such as the switching of a dimmer do not generate a false output signal.
    Type: Grant
    Filed: April 17, 1996
    Date of Patent: March 10, 1998
    Assignee: Eaton Corporation
    Inventors: Joseph C. Engel, Raymond W. Mackenzie