With Voltage Or Current Signal Evaluation Patents (Class 324/713)
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Patent number: 6313647Abstract: Disclosed is anew technique for measuring the resistivity of ultra-thin carbon films (less than 200 Å). The technique involves using a probe with very smooth surface, a thin layer lubricant (20-30Å)that enables the intimate and stable electrical contact between probe and the thin film, and measurement of I-V curve to determine resistance. Resistivity measurements were conducted on carbon films doped with hydrogen and nitrogen at different mixture ratios and different thicknesses, and the results were compared with those obtained on a commercially available machine that uses a mercury probe. The advantages of the present technique include simple in use, less expensive and quick measurements with reasonably good accuracy.Type: GrantFiled: November 9, 1999Date of Patent: November 6, 2001Assignee: Seagate Technology LLCInventors: Zhu Feng, Chiu-Shing Frank Poon, Tan Guo Liu, Vidya Gubbi, Chung Yuang Shih
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Patent number: 6297652Abstract: Provided are an electric resistance measuring apparatus for circuit boards, and an electric resistance measuring method using the same. An electric resistance measuring apparatus includes a one-side inspection circuit board having a plurality of connecting electrodes, and layer connector members provided on the inspection circuit board and formed of a conductive elastomer. Each of the layer connector members is brought into simultaneous contact with a plurality of connecting electrodes at one side thereof to be electrically connected thereto, and at the other side thereof, brought into simultaneous contact with a plurality of electrodes to be inspected to be electrically connected thereto. In this measurable state, two connecting electrodes are used for current supply and for voltage measurement, thereby performing measurement of electric resistance on a specified electrode to be inspected.Type: GrantFiled: February 22, 2000Date of Patent: October 2, 2001Assignee: JSR CorporationInventors: Sugiro Shimoda, Kiyoshi Kimura
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Patent number: 6288556Abstract: The invention allows for measurement at the same density as an actual device pattern and measures the level of registration of actual patterns with precision. In the measurement of the invention, a first exposure process is performed on a first-level pattern and a second exposure process is then performed on a second-level pattern. After that, the patterns are developed and etched, thereby forming two patterns of different shapes. Next, the resistance between terminals of a pattern which are obtained by means of etching is measured through a four-point measurement. An amount of misregistration of the first-level pattern and the second-level pattern is calculated from the measured resistance.Type: GrantFiled: December 3, 1998Date of Patent: September 11, 2001Assignee: Kabushiki Kaisha ToshibaInventors: Takashi Sato, Keita Asanuma, Junichiro Iba, Toru Ozaki, Hiroshi Nomura, Tatsuhiko Higashiki
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Patent number: 6278282Abstract: A method for determining quality of lubricating oil using electrodes in contact with the oil includes applying a potential having a first amplitude to the electrodes, wherein the first amplitude is sufficiently low such that substantially no solution current will flow; determining a first voltage phase lag with respect to the potential when the potential has the first amplitude; increasing amplitude of the potential to a second amplitude at which solution current flows; determining a second voltage phase lag with respect to the potential when the potential has the second amplitude; and determining the quality of the oil based on the voltage phase lags. A system for practicing the method is also provided.Type: GrantFiled: October 7, 1999Date of Patent: August 21, 2001Assignee: Detroit Diesel CorporationInventor: Gary A. Marszalek
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Publication number: 20010009374Abstract: A ratio meter and apparatus for measuring electrical components with high stability and no effect on the circuit under test. Two input signals are switched by a switching means and the inputs to two measuring means are measured while keeping the switches in a first state and a second state to find the ratio of the measurements. The ratio to be measured, which is related to the above-mentioned input signals, and which forms a bilinear equation with the two ratios, one each obtained under the first and second state, are obtained from said ratios. Accurate calibration is performed and measurement of electrical and electronic components with high stability is accomplished by connecting a front-end circuit with the ratio meter.Type: ApplicationFiled: January 17, 2001Publication date: July 26, 2001Inventor: Kazuyuki Yagi
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Patent number: 6265881Abstract: A method and apparatus for measuring impedance of grounding system wherein a transient electric current is injected at the ground system under test while measuring the a transient ground potential difference, as well as the injected electric current. The ground potential difference is measured with respect to several points on the earth's surface at small distances from the test system. These measurements are processed by computer software which filters noise, corrects voltage and current transducer errors, and estimates the test system ground potential rise with respect to remote earth. Correction algorithms are used to remove irregularities in the frequency response of the voltage and current transducers and analog filters. The filtered and corrected measurements are used to estimate the ground impedance as a function of frequency. For this purpose, a parameter estimation procedure is used which takes into consideration the geometric arrangement of the voltage and current probes.Type: GrantFiled: July 5, 1994Date of Patent: July 24, 2001Assignee: Georgia Tech Research CorporationInventors: Athanasios P. Meliopoulos, George J. Cokkinides
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Patent number: 6265883Abstract: An assembly of probes (1000) measures both the electrical properties and the depth of a fluid (1045). A first probe section (1040) is electrically energized, while a second probe section (1030) is de-energized. In a first measurement, the electrical properties of the fluid are measured. Low- and high-frequency, alternating potentials are used in measuring the conductivity and dielectric constant of the fluid. These potentials cause a current to flow in the fluid and also in a proximate conductor (1010), which is connected to the input of an operational amplifier (1080). The operational amplifier converts the current to a voltage whose amplitude and phase are measured using a precision rectifier (1092), a voltmeter (1096) and an oscilloscope (1094) (or alternatively with an analog-to-digital converter (1100), and a microprocessor (1150)). A similar measurement is made with a second probe section (1030) also energized.Type: GrantFiled: March 1, 1997Date of Patent: July 24, 2001Inventor: Lloyd Douglas Clark
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Patent number: 6262580Abstract: A method and a testing system for measuring contact resistance of a pin on an integrated circuit. An RC circuit is coupled to the integrated circuit, and a response signal of a testing signal input to the integrated circuit is monitored. The response signal has a time dependent voltage V′. Another time dependent voltage V1 for the testing signal through the RC circuit and a voltage drop across an internal circuit of the integrated circuit is illustrated. Comparing V′ with V1, whether the contact resistance of the pin being tested is allowable can be determined according to the ratings or specification of the integrated circuit.Type: GrantFiled: October 14, 1999Date of Patent: July 17, 2001Assignees: United Microelectronics Corp, United Silicon IncorporatedInventor: Tsung-Chih Wu
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Patent number: 6242928Abstract: The resistance of an air-fuel-ratio sensor element is determined from current detected before changing an applied voltage to the sensor and current detected when a predetermined period elapses after changing the applied voltage to the sensor. A resistance detector includes operational amplifiers, resistors and transistors. The applied voltage is changed by switching the transistors to more accurately detect a resistance value.Type: GrantFiled: January 7, 1999Date of Patent: June 5, 2001Assignee: Denso CorporationInventor: Takayoshi Honda
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Patent number: 6225814Abstract: This invention relates to apparatus for detecting the contact or nip width between two contacting surfaces. The apparatus includes first and second insulating substrates each of which has a pattern of conductive material formed on a facing inner surface thereof, which substrates are adapted to be fitted between the contacting surfaces. For a first embodiment, the pattern of conductive material on one substrate includes a pair of conductive terminals spaced by a distance greater than the contact width to be measured and the conductive pattern on the other substrate includes a conductor which extends over at least a distance greater than the maximum width W to be measured.Type: GrantFiled: April 13, 1999Date of Patent: May 1, 2001Assignee: Tekscan, IncInventors: Boris Oreper, Mark Lowe, Charles McWilliams, Charles Malacaria, Anthony Coviello, Jay Winters
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Patent number: 6218846Abstract: An innovative multi-dimensional, low frequency, impedance measurement probe array, measurement system, and method are disclosed for detecting flaws in conductive articles. The device and method provide for contacting a conductive article with an multi-probe array of current and voltage probes, injecting current sequentially through a plurality of current probe pairs and measuring absolute or relative voltages with a plurality of voltage probes and voltage probe pairs across the surface of an article for each current flow condition. The device and method further provide for constructing a voltage profile across the surface of an article where disruptions in the voltage profile enable detection of the presence, location and orientation of flaws for flaw sizes as low as 20 um.Type: GrantFiled: August 1, 1997Date of Patent: April 17, 2001Assignee: Worcester Polytechnic InstituteInventors: Reinhold Ludwig, John A. McNeill, Jennifer A. Stander
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Patent number: 6184695Abstract: A diagnostic circuit (18) for a potentiometric sensor (10) having an electrically resistive means (12) and a sliding contact (14) in connection with the resistive means and providing an output from the sensor at a sensor output terminal (16), the diagnostic circuit comprising a low pass filter (36) connectable between the sliding contact and the sensor output terminal; alternating voltage supply means (20,21,22,24) having a high impedance connectable to the sliding contact; and amplitude modulation demodulating means (30,32,34) connectable between the sliding contact and a diagnostic output terminal (38), the voltage at the diagnostic output terminal providing an indication of the contact resistance between the sliding contact and the resistive means of the sensor. Monitors the contact resistance without interfering with the sensor output.Type: GrantFiled: November 12, 1998Date of Patent: February 6, 2001Assignee: Delphi Technologies, Inc.Inventors: Michael Gläser, Jürgen Bergmann
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Patent number: 6175239Abstract: A process and apparatus are provided to determine the characteristic impedance of a transmission line coupled to the output of a buffer. To achieve this, an output resistance of the buffer is initially set to a relatively high value to underdrive the transmission line. The output resistance of the buffer is then decreased until the buffer overdrives the transmission line. The characteristic impedance of the transmission line can then be determined from a ringback voltage which occurs due to the overdriving of the transmission line. In accordance with an embodiment of the invention, the ringback voltage can be detected by noting when a reference voltage is crossed twice during the same time of the driving pulse on the transmission line (the second crossing being the ringback voltage). The characteristic impedance of the transmission line can then be used to set the output resistance for the buffers on the operational buses.Type: GrantFiled: December 29, 1998Date of Patent: January 16, 2001Assignee: Intel CorporationInventor: Stephen Hall
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Patent number: 6172511Abstract: A device for measuring a crack in a workpiece or sample (3) comprises a resistive layer (1) arranged to be fixed to the workpiece so that the layer is fractured by the propagation of cracks in the workpiece or sample (3) to change the impedance of the layer (1). Two elongate electrodes (2) are provided on the resistive layer (1) and arranged to pass a current through it, and, measuring means are provided for measuring the impedance of the resistive layer (1), and for thereby determining the size of cracks in the workpiece or sample (3). Preferably another resistive layer (6), is provided adjacent the resistive layer (1), which is arranged not to be fractured by the propagation of cracks in the workpiece or sample (3). This enables environmental effects to be compensated for.Type: GrantFiled: July 29, 1998Date of Patent: January 9, 2001Assignee: Cranfield UniversityInventors: John Rayment Nicholls, Roger David Tidswell
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Patent number: 6127830Abstract: In a method of monitoring an output module to which a number of inductive loads are connected and in which the current flowing through these inductive loads is regulated by clocked driving of the output stages, the current created in the blocked phases of the output stages by the inductively stored energy is partially or temporarily conducted across a common current measuring device and evaluated for testing the output stages, including the inductive loads.Type: GrantFiled: September 21, 1998Date of Patent: October 3, 2000Assignee: ITT Manufacturing Enterprises, Inc.Inventors: Mario Engelmann, Michael Zydek, Olaf Zinke, Wolfgang Fey
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Patent number: 6124143Abstract: Process monitoring circuitry according to the invention incorporates additional routing structures that approximate signal delays due to long metal routing paths. The additional process monitor circuitry builds upon existing approaches without increasing the die size of an integrated circuit through the utilization of excess silicon space available between the bonding pads and the scribe lines of an integrated circuit wafer. More specifically, supplemental metal routing lines and vias are included in the delay paths of process monitor circuitry and located on the integrated circuit such that impact to other metal signal lines/vias used in the actual design is minimized. The supplemental metal routing lines are disposed in unused routable silicon space, such that no silicon area penalty is suffered as a result of having long metal routing lines.Type: GrantFiled: January 26, 1998Date of Patent: September 26, 2000Assignee: LSI Logic CorporationInventor: Emery O. Sugasawara
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Patent number: 6107811Abstract: An automated coupon monitor for detecting the electrical parameters associated with a pipe, a coupon and a reference electrode utilized with a cathodic protection system. A voltage detector circuit has its output applied to a pair of sample and hold circuits, one for recording E.sub.OFF and the other for recording E.sub.ON. Series connected between the coupon and the pipe is a zero resistance current detector circuit and an interrupter switch for measuring the pipe-coupon current and periodically interrupting that current to permit measurement, sampling and storing of E.sub.OFF. The sample and hold circuits and the interrupter switch are controlled by a microprocessor controller. The circuit provides DC level outputs which can be easily read by a digital multimeter or stored in a data logger for subsequent reading or transmission to another location.Type: GrantFiled: February 12, 1998Date of Patent: August 22, 2000Assignee: CC Technologies Laboratories, Inc.Inventors: Dan L. Caudill, Neil G. Thompson, Kurt M. Lawson
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Patent number: 6083272Abstract: A method of adjusting drive currents on a semiconductor device having transistors of various densities is disclosed. Consistent with the invention, off-state currents and drive currents associated with non-dense transistors on a first semiconductor device formed by a fabrication process are determined. Off-state currents associated with dense transistors on the first semiconductor device are also determined. Using the determined off-state and drive currents associated with the non-dense transistors and the off-state currents associated with the dense transistors on the first semiconductor device, drive currents associated with the dense transistors on the first semiconductor device are estimated.Type: GrantFiled: June 13, 1997Date of Patent: July 4, 2000Assignee: Advanced Micro Devices, Inc.Inventors: John L. Nistler, Derick J. Wristers
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Patent number: 6084418Abstract: An air-fuel ratio sensor generates linear air-fuel ratio detection signals proportional to concentration of oxygen in exhaust gas from an engine in response to a command voltage from a microprocessor. A bias command signal generated by the microprocessor is provided to a D/A converter which converts it to an analog signal. Thereafter, the signal is provided to an LPF for removing the high frequency components of the analog signal. Output voltage of the LPF is provided to a bias control circuit. A single AC signal which has a predetermined frequency and which is provided with a predetermined time constant (about 159 .mu.s) by the LPF is applied to the air-fuel ratio sensor. Element resistance of the air-fuel ratio sensor is detected based on the voltage of the AC signal and the change in the current level of the air-fuel ratio sensor caused by the application of the AC signal.Type: GrantFiled: March 11, 1998Date of Patent: July 4, 2000Assignee: Denso CorporationInventors: Masayuki Takami, Tomomichi Mizoguchi, Satoshi Haseda, Kazuhiro Okazaki, Koji Jono
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Patent number: 6078182Abstract: An instrument for measuring the resistance of liquid paints and the surface resistance of articles to be coated electrostatically, includes a voltage multiplier circuit that multiplies a periodic low voltage signal to generate a resistance measuring voltage applied to first and second electrodes for resistance measurements. The electrodes are coupled to differential inputs of an A/D converter having an oscillator output for supplying the periodic low voltage signal to the multiplier circuit. Resistance, voltage and current measuring circuits are alternately switchable between the electrodes and the differential inputs of the A/D converter for measuring resistance, voltage and current, the results of which are displayed visually.Type: GrantFiled: April 21, 1998Date of Patent: June 20, 2000Assignee: Illinois Tool Works IncInventor: Brian Gorrell
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Patent number: 6014030Abstract: Current-level monitoring circuitry incorporating a full-time coarse monitor and a part-time fine monitor and capable of generating control signals when the current-level being monitored reaches certain predetermined thresholds. In its preferred embodiment the invention is incorporated into battery-protection circuitry, guarding against both excess charging currents and excess discharging currents. A key concept of the invention is a hierarchical monitoring system incorporating a full-time coarse monitor that activates the fine monitor only when the battery current level enters a certain range and then deactivates it once the level falls out of that range again. Should the current level continue to rise up to the threshold of unsafe battery current, the fine monitor will disconnect the battery. In the preferred embodiment of the invention, the fine monitor operates by comparing, with a predetermined reference voltage, the voltage drop across a fine sensing resistor through which battery current is directed.Type: GrantFiled: March 30, 1998Date of Patent: January 11, 2000Assignee: National Semiconductor Corp.Inventors: Gregory J. Smith, David J. Kunst, Paul M. Henry
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Patent number: 6008662Abstract: Conditions in a fluidized bed are measured with a probe and a circuit. The bed can be a polymerization reactor's reaction chamber, and the conditions can result in "sheeting" which is the build up of polymer on the chamber walls. The probe protrudes into the bed and detects a current which generally is a function of at least the impact and charge of particulates in the bed. The current detected by the probe is related to the conditions in the bed. The circuit measures the detected current. The probe has an inner probe piece of metallic material within an insulator of polymeric material. A portion of the insulator protrudes a first distance into the bed, and a portion of the inner probe piece protrudes a second distance into the bed. The first distance is less than or equal to the second distance. The insulator typically does not extend as far into the bed as the inner probe piece.Type: GrantFiled: October 31, 1996Date of Patent: December 28, 1999Assignee: Oxford Instruments America, Inc.Inventors: Robert E. Newton, David R. Day, Ron L. Swartzentruber
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Patent number: 5999002Abstract: A contact resistance check circuit and method for verifying that a sufficient electrical connection is established between a source and a sense lead of a Kelvin connection. The circuit includes a microprocessor for driving a transformer that is connected to the source/sense probe (i.e., contact resistance) with an input pulse. The input pulse is altered in relation to the magnitude of the contact resistance to produce a check pulse. A comparator is used to compare the check pulse with a threshold voltage and for generating a fault indication signal. A flip flop then stores the fault indication signal so that the fault indication signal may be monitored by the microprocessor.Type: GrantFiled: October 10, 1997Date of Patent: December 7, 1999Assignee: Keithley Instruments, Inc.Inventors: Glenn Fasnacht, Wayne Goeke
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Patent number: 5991707Abstract: A method and system diagnoses system reliability problems and/or system failure in a physical system through the predictive identification of errant fluctuations in one or more operating parameters of said physical system. The values of at least one kind of operating parameter of physical system are determined. A data stream of the parameter values are divided into one or more sets, and the sets are associated into one or more series. Through a series of mathematical calculations, it is determined whether an N0, Nx or N1 condition exists. An N0 condition indicates that the values are probably within a good operating range. An Nx condition indicates the probability of approaching a point outside of a good operating range condition. An N1 condition indicates the entering of the range of possible system failure.Type: GrantFiled: March 9, 1998Date of Patent: November 23, 1999Assignee: Hydrotec Systems Company, Inc.Inventors: Warren W. Searles, Brett W. Searles
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Patent number: 5978197Abstract: Circuitry for testing and comparing ESD protection structures is provided on a semiconductor integrated circuit. Analysis of charge transmitted to a test capacitor on board the chip provides for improved accuracy in evaluating performance of the ESD protection structure. Moreover, multiple ESD structures can be implemented and accurately compared to one another on a test chip as described. The disclosed methods and apparatus are usefull in reduced turn-around time and more accurate evaluation and comparison of ESD protection structures in integrated circuits.Type: GrantFiled: November 18, 1997Date of Patent: November 2, 1999Assignee: LSI CorporationInventor: Victer Chan
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Patent number: 5977777Abstract: A device in a motor vehicle, with which signals which are generated by a sensor and represent a physical magnitude are transmitted on signal lines. The device includes a voltage divider which is composed of the sensor and at least two impedances which are connected each at one end of the sensor. The signals generated by the sensor are guided, via signal lines connected at its terminals, to a differentiator, by which the usable signal is obtained, and interference signals coupled onto the signal lines are eliminated. Alternatively, the device can also be used for transmission on a signal line pair of any desired potential difference present at an impedance.Type: GrantFiled: March 23, 1998Date of Patent: November 2, 1999Assignee: Robert Bosch GmbHInventor: Peter Jueliger
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Patent number: 5972198Abstract: It is an object of the present invention to provide a corrosion resistance test process, wherein the estimation of the corrosion resistance of an article formed of a metal material and a coating can be carried out synthetically and in a short time. In carrying out a corrosion resistance test, the article is immersed into an electrolytic solution and then, a voltage is applied to the metal material to carry out a metal material corroding step and a coating peeling-off step alternatively and repeatedly. The voltage applied to the metal material is a superimposed voltage Vd+Va resulting from superimposition of a DC voltage Vd and an AC voltage Va. A voltage condition of Vd<0 and Vd+Va>0 is established at the metal material corroding step, while a voltage condition of Vd<0 and Vd+Va<0 is established at the coating peeling-off step.Type: GrantFiled: May 5, 1998Date of Patent: October 26, 1999Assignees: Mitsuba Corporation, Honda Giken Kogyo Kabushiki KaishaInventors: Toshihiro Takeuchi, Tadashi Imanaka, Keiji Kiuchi, Hidemichi Ohta
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Patent number: 5963044Abstract: A method for acquiring measured values in electronic analog circuits having at least one measurement point, in particular safety-relevant circuits for passenger protection systems in motor vehicles. The electrical potentials generated at the measurement points are each compared as measured quantities with a ramp voltage that rises in steps, where the number of steps required to reach the voltage value of the measured quantity at the respective measurement point is provided as a unit of measurement that is proportional to the measured quantity. This allows the comparison of all measured quantities with the ramp voltage to be performed simultaneously, the ramp voltage being selected to cover the entire range of measurement.Type: GrantFiled: August 22, 1997Date of Patent: October 5, 1999Assignee: Temic Telefunken microelectronic GmbHInventor: Gerhard Schafer
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Patent number: 5912561Abstract: Any voids in the divider walls of multichamber packages, and in particular, multichamber tubes, can be detected by applying a potential difference across the divider walls of the package. If there is a void, there will be an arcing of current from one electrode to another with a measurable difference in the potential difference between the electrodes. There also may be a visual and/or audible indication. This change in potential difference can be used to determine the integrity of the divider walls of the package. In a preferred mode, the electrodes also are the mandrel mold sections that are used for the compression molding of the shoulder and nozzle onto the body of a tube package. In this embodiment the integrity of the divider walls can be determined prior to the forming of the shoulder and nozzle onto the tube body or after the shoulder and nozzle is formed onto the tube body.Type: GrantFiled: October 1, 1997Date of Patent: June 15, 1999Assignee: Colgate-Palmolive CompanyInventor: Robert Mack
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Patent number: 5881130Abstract: Method and apparatus for detecting whether load coils are attached to a telephone line. A stimulus waveform having multiple frequency components is applied to the line. The current and voltage at the near end of the line are coherently sampled and transformed to the frequency domain. The frequency spectra are used to compute auto and cross power spectra of the current and voltage. These power spectra are then used to compute the impedance on the line as well as a coherence function that indicates the extent to which the computed impedance was influenced by noise. If the coherence values indicate that the computed impedance is sufficiently reliable, load coils are detected by finding peaks in the magnitude of the impedance function or sign changes in the phase of the impedance function. Calibration, offset adjustments and ensemble smoothing are used to increase the accuracy of the results. The computation is fast because computing the spectra avoids the need for individual measurements at multiple frequencies.Type: GrantFiled: September 15, 1997Date of Patent: March 9, 1999Assignee: Teradyne, Inc.Inventor: Yun Zhang
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Patent number: 5844406Abstract: The porosity and integrity of a nonconductive material is determined using electron beams and electronic instrumentation. The electric corona discharge from holes in the nonconductive material is detected and analyzed in order to determine the presence of viral and sub-viral sized voids or holes, as well as other material anomalies such as blisters and bubbles.Type: GrantFiled: August 21, 1996Date of Patent: December 1, 1998Inventors: Gregory J. Gormley, Robert Griebel
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Patent number: 5841282Abstract: Device for measuring soil conductivity is comprised of a frame adapted to be conveyed over a ground surface and plurality of soil engaging coulters insulated from each other and insulatively mounted to this frame. This device also includes means for passing a current between a first pair of coulters through the soil and means for measuring this current. It further comprises means for measuring the resulting voltage between a second pair of coulters. This device for measuring soil conductivity also is comprised of electrical contact members which provide consistent electrical contact from the coulter to the means for measuring current and voltage. An electrical signal received by a coulter travels to a mounting flange and then to a dust cap. The dust cap passes this electrical signal to the spindle by way of a spring-loaded plunger. This electrical signal travels from the fixed spindle to the means for measuring current and voltage.Type: GrantFiled: February 10, 1997Date of Patent: November 24, 1998Inventors: Colin Christy, Eric Lund
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Patent number: 5818243Abstract: An impedance meter includes a floating type ammeter which measures a voltage across a current detection resistor and determines a current flowing therethrough. A balun eliminates the common mode voltage component in the high frequency range; and a differential amplifier eliminates the common mode voltage component in the low frequency range. The common mode rejection (common mode elimination) effect of the balun and differential amplifier crosses over at a crossover frequency where the impedance of an capacitor and the impedance of the balun are equal. As a result, the impedance meter is capable of measuring a broad range of impedances across a wide range of frequencies, both the low frequency and high frequency range.Type: GrantFiled: May 20, 1997Date of Patent: October 6, 1998Assignee: Hewlett-Packard CompanyInventor: Hideki Wakamatsu
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Patent number: 5811979Abstract: A protective grounding jumper cable tester is provided which includes a housing; a pair of jumper attachment terminals on the housing for attachment of a jumper cable therebetween; a dc voltage applying circuit disposed in the housing and connected to the pair of jumper attachment terminals for applying a direct current through a jumper cable attached between the jumper attachment terminals; and electronic means in the form of a PC board and microprocessor disposed in the housing and interconnected to the dc voltage circuit for applying a predetermined mathematical relationship to measure a resistance value of at least a portion of the jumper cable attached between the jumper attachment terminals. The electronic means in applying the predetermined mathematical relationship to measure the resistance value includes means for taking different voltage readings in accordance with Kelvin's measurement procedure and calculating the resistance value from the voltage readings in accordance with Kirchoff's current law.Type: GrantFiled: August 9, 1996Date of Patent: September 22, 1998Assignee: Hubbell IncorporatedInventor: David A. Rhein
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Patent number: 5808461Abstract: A circuit arrangement for air quality measuring having at least one sensor element which has resistors the resistance of which changes depending on the air composition. The circuit arrangement has an evaluation circuit for the sensor signals and includes a logarithmic circuit.Type: GrantFiled: July 29, 1996Date of Patent: September 15, 1998Assignee: Robert Bosch GmbHInventors: Thomas Weigold, Heiner Holland
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Patent number: 5804979Abstract: A circuit for measuring alternating current (a.c.) and direct current (d.c.) in a conductor without breaking the conductor is provided. A modulated current source is coupled in parallel with a segment of the conductor to inject a test current. A synchronous demodulator is also coupled in parallel across the segment to separate the test voltage drop induced by the test current from the voltage drop due to the current in the conductor. The test voltage drop and the voltage drop are measured by a voltmeter and the resistance of the segment and the current flowing through the segment can then be calculated.Type: GrantFiled: May 13, 1997Date of Patent: September 8, 1998Assignee: Fluke CorporationInventors: John M. Lund, Steven Dennis Swift
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Patent number: 5793195Abstract: Ion-beam probes of the planar, screened, and multilayer types are shown and described. These probes can detect the arrival of energetic ions and, in the latter type, also detect the arrival of energetic neutral molecules. A specific improvement is the use of a multilayer collection surface behind an aperture to measure the angular distribution of the etching contributions of energetic ions and/or energetic neutral molecules. After use, this multilayer collection surface provides a permanent record of the measurement. The improvement is also suitable for the adverse thermal and ion-etching environment of an energetic ion beam. In one embodiment, the aperture size and distance from the collection surface are such that a theoretical analysis of etch depth behind a straight-edge mask can be used to analyze the experimental results. The etch contour can be accurately reproduced from the measurement of half-maximum half angle, as long as the assumed distribution is incorporated in the measurement process.Type: GrantFiled: August 30, 1995Date of Patent: August 11, 1998Assignee: Kaufman & Robinson, Inc.Inventors: Harold R. Kaufman, Raymond S. Robinson, James R. Kahn
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Patent number: 5786700Abstract: A process determines a linear interconnection resistance R between two external access points of an electronic device. The device comprises a chip, a chip carrier and wiring between the chip and carrier. The chip comprises an ESD device such as a diode which is electrically connected between the two access points. To begin the process, various currents are injected from one of the access points to another and corresponding voltages are measured across the two access points. Alternately, various voltages are applied from one access point to the other and corresponding currents are measured. The applied voltages and injected currents all forward bias the ESD device. These current-voltage relationships are applied to an interconnection model algorithm to yield the interconnection resistance.Type: GrantFiled: May 20, 1996Date of Patent: July 28, 1998Assignee: International Business Machines CorporationInventors: Keh-Chee Jen, Jan Obrzut
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Patent number: 5749986Abstract: Methods and apparatus for detecting and utilizing a voltage produced by a variety of materials for process control and analysis purposes.Type: GrantFiled: August 1, 1995Date of Patent: May 12, 1998Assignee: Tracy A. WyattInventor: W. Tison Wyatt
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Patent number: 5719526Abstract: A load monitor module for measuring voltage and current supplied from an amplifier to a load is provided within an amplifier and includes a device for calculating an impedance of the load and an amount of power delivered to the load from the amplifier. The load monitor module includes a voltage measuring device and a current measuring device for accurately measuring the voltage and current of a generated test signal or an audio signal input the amplifier signal path without substantially altering the signal. The monitor module also includes a controller for controlling the performance of the amplifier and load according to the calculated load impedance and power input to the load from the amplifier.Type: GrantFiled: November 16, 1995Date of Patent: February 17, 1998Assignee: Crest Audio, Inc.Inventor: Dennis Fink
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Patent number: 5714875Abstract: An electron beam stop for use with high power electron beam accelerators can be used to measure beam parameters including energy, current, scan width, scan offset and scan uniformity. The beam stop is split in two segments in the direction of electron travel, with the first segment closest to the beam source absorbing a portion of the electrons incident thereon and the second segment farthest from the beam source absorbing all of the electrons that pass through the first segment. The ratio of charges deposited in the two segments is a sensitive index of the energy of the primary electrons, i.e., a measure of beam energy. The sum of the charges in the two segments is a direct measure of the number of electrons incident on the absorbing medium, i.e., a measure of the beam current.Type: GrantFiled: February 23, 1995Date of Patent: February 3, 1998Assignee: Atomic Energy of Canada LimitedInventors: Courtlandt B. Lawrence, M. Aslam Lone, John W. Barnard, Dennis L. Smyth, Wlodzimierz Kaszuba
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Patent number: 5703492Abstract: In a fault analysis of large-scale integrated (LSI) circuits, a potential distribution image of a non-defective product and another potential distribution image of a defective product are displayed alternately and continuously in time, so that it is possible to acquire in real time an image of any location within a whole surface of the LSI chip. As a result, it can be viewed as if the potential distribution image of the non-defective product and the potential distribution image of the defective product are overlapped or superimposed with over time. Accordingly, a different portion between the non-defective and defective potential distribution images can be seen distinguishably from a coincident portion between the non-defective and defective potential distribution images, so that it is possible to trace the different portion in real time.Type: GrantFiled: January 10, 1995Date of Patent: December 30, 1997Assignee: NEC CorporationInventors: Toyokazu Nakamura, Yasuko Hanagama, Tohru Tsujide, Kenji Morohashi
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Patent number: 5694047Abstract: A method and system for measuring programmed antifuse resistance in an FPGA without disturbing the antifuse resistance. The method includes estimating a plurality of subparts of the programming path connecting low and high programming voltage sources on the FPGA device, measuring the path as a whole, and subtracting the sum total of the subparts from the whole path measurement, thereby deriving the antifuse resistance. If the derived antifuse resistance is higher than desired, programming and measurement may be repeated to ensure device longevity and accurate timing for implemented designs.Type: GrantFiled: August 9, 1995Date of Patent: December 2, 1997Assignee: Xilinx, Inc.Inventors: F. Erich Goetting, Venu Kondapalli, David P. Schultz
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Patent number: 5691644Abstract: A method of use and system for determining the longitudinal active resistance of a neutral conductor of an underground electrical cable, while the electrical cable remains in service. The method is conducted by applying a selective frequency test current signal to the neutral conductor of the underground cable connected between a pair of grounded structures, e.g., power transformers, from a test signal generator that is connected across the neutral conductor using first and second bifilar winding signal-voltage cables. The method utilizes indirect voltage determination to obtain the voltage drop across the neutral conductor while mitigating induced voltage effects which occur when direct voltage measurement is used. A plurality of selective frequency test current signals are used to obtain a plurality of longitudinal active resistance values. Any conventional extrapolation method is then used to obtain a longitudinal active resistance value at 0 Hz.Type: GrantFiled: May 10, 1996Date of Patent: November 25, 1997Assignee: Henkels & McCoyInventor: Boris M. Danilyak
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Patent number: 5684408Abstract: A protective grounding jumper cable tester basically includes a housing, a direct current power supply, a pair of jumper attachment terminals, a pair of test probe terminals, a current applying circuit connected between the direct current power supply and the pair of jumper attachment terminals for applying a direct current through a jumper cable attached between the jumper attachment terminals, and a resistance sensing circuit connected to the test probe terminals for sensing resistance to the flow of the direct current through the jumper cable by using a pair of test probes connected to the test probe terminals.Type: GrantFiled: December 18, 1996Date of Patent: November 4, 1997Assignee: Hubbell IncorporatedInventor: Clayton C. King
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Patent number: 5680055Abstract: A system to sense changes in the state of an ion exchange resin bed which includes first and second current electrodes spaced from each other, a first electrical circuit electrically connecting the current electrodes and designed to be connected to a source of alternating current, and also including first and second voltage probes spaced from each other and located approximately between said first and second current electrodes with a wire connecting voltage probes. A second electrical circuit consists of the first and second voltage probes, the wire and the portion of the resin bed lying between said voltage probes so that when the first electrical circuit is energized by the source of alternating current a voltage is induced in the second electrical circuit which corresponds to the state of the resin bed located between the first and second voltage probes.Type: GrantFiled: July 19, 1995Date of Patent: October 21, 1997Assignee: Marquette UniversityInventors: Martin A. Seitz, Charles J. Koehler, Richard W. Hirthe, Patrick J. Dupies, Don D. Vaughan
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Patent number: 5680054Abstract: The position of a break in at least one of a pair of rails in an electrically isolated rail segment of a railroad is carried out by measuring current across the ballast between the rails of the segment from one end of the segment when one of the rails in the segment is not broken and subsequently when the rail is broken. A position of the break can be calculated as a function of the ballast current. A linear approximation using the ratio of the ballast current when the rail is broken to the ballast current when the rail is not broken multiplied by the distance of the rail segment from the one end gives a satisfactory approximation of the location of the rail break.Type: GrantFiled: February 27, 1996Date of Patent: October 21, 1997Assignee: Chemin de fer QNS&LInventor: Cyprien Gauthier
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Patent number: 5663651Abstract: The present invention provides a test pattern and method for separately measuring a plug resistance and interfacial resistance of a contact resistance with high precision including the steps of: (a) providing on a semiconductor chip a test pattern as described above; (b) applying a predetermined voltage between the electrode pad patterns of one of a pair of first and second electrode pad patterns and a pair of third and fourth electrode pad patterns and measuring a current flowing between the electrode pad patterns of the one pair in an open state between the electrode pad patterns of the other pair; (c) repeating this measuring method between the electrode pad patterns of each pair; and (d) determining a first plug resistance of the first or fourth contact hole and a second plug resistance of the second or third contact hole from the voltage and the first to third currents.Type: GrantFiled: October 11, 1995Date of Patent: September 2, 1997Assignee: NEC CorporationInventor: Hiromitsu Hada
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Patent number: 5661406Abstract: Methods are provided for detecting and locating leaks in liners used as barriers in the construction of landfills, surface impoundments, water reservoirs, tanks, and the like. Electrodes are placed in the ground around the periphery of the facility, in the leak detection zone located between two liners if present, and/or within the containment facility. Electrical resistivity data is collected using these electrodes. This data is used to map the electrical resistivity distribution beneath the containment liner between two liners in a double-lined facility. In an alternative embodiment, an electrode placed within the lined facility is driven to an electrical potential with respect to another electrode placed at a distance from the lined facility (mise-a-la-masse). Voltage differences are then measured between various combinations of additional electrodes placed in the soil on the periphery of the facility, the leak detection zone, or within the facility.Type: GrantFiled: September 27, 1995Date of Patent: August 26, 1997Assignee: Leak Location Services, Inc.Inventors: William D. Daily, Daren L. Laine, Edwin F. Laine
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Patent number: 5656939Abstract: An apparatus for measuring hardness of an ultraviolet curing transformation agent comprising a stain of the present invention comprises a light source device for emitting beams including ultraviolet rays, an optical filter member through which the ultraviolet rays having a predetermined wavelength among the beams emitted from the light source device pass, and a measuring device for measuring electric conductivity of the ultraviolet curing transformation agent comprising the stain, provided at a location where the ultraviolet rays having the predetermined wavelength irradiate. Further, the measuring device comprises an electrode portion including electrodes on which the ultraviolet curing transformation agent is applied, and the electrodes are connected through a power supply and a measuring device for measuring the electric conductivity.Type: GrantFiled: May 25, 1995Date of Patent: August 12, 1997Assignee: ORC Manufacturing Co., Ltd.Inventors: Izumi Serizawa, Masahiro Kurano, Yasusuke Takahashi