Patents Assigned to Doble Engineering Company
  • Patent number: 9874613
    Abstract: Test measurements on a utility power device by a switch matrix apparatus and a common voltage source as separate devices is performed. Through the switch matrix apparatus, the common voltage source selectively sends a first high voltage signal via a first lead to a first terminal of the utility power device, measures a first corresponding signal returned via a second lead of the switch matrix apparatus from a second terminal of the utility power device. While the first lead and the second lead of the switch matrix apparatus remain electrically coupled to the first and the second terminal of the utility power device, a second high voltage signal is selectively sent via the second lead to the second terminal of the utility power device, and a second corresponding signal returned from the first terminal of the utility power device via the first lead of the switch matrix apparatus is measured.
    Type: Grant
    Filed: March 13, 2017
    Date of Patent: January 23, 2018
    Assignee: DOBLE ENGINEERING COMPANY
    Inventors: Robert Clark Woodward, Jr., George Matthew Kennedy
  • Publication number: 20170289192
    Abstract: A method for protecting a mobile terminal device from cyber security threats, including the steps of: detecting that the mobile terminal device is successfully connected only through one or both of a selected physical serial interface connected to a device for facilitating the testing or a wired network interface, which is connected to an electrical utility device. Prior to executing a test routine by the mobile terminal device, switching the mobile terminal device to a test state by: disabling an internal firewall, disabling one or more remaining network interfaces and serial interfaces, such that existing communications or connections are terminated and new communications and connections are prevented. Enabling communication to one or both of the selected physical serial interface and the wired network interface, performing the testing on the at least one electrical utility device according to the executed test routines under control of the mobile terminal device until completion.
    Type: Application
    Filed: March 29, 2017
    Publication date: October 5, 2017
    Applicant: DOBLE ENGINEERING COMPANY
    Inventor: Jason Alexander Allison
  • Patent number: 9671451
    Abstract: A method for performing diagnostics on a transformer includes generating, by a voltage generator, an AC voltage and applying the AC voltage to a winding or phase of the transformer. Current flowing from the generator to the winding or phase is decomposed into a plurality of harmonic components. Respective magnitudes of the plurality of harmonic components are compared with corresponding magnitudes of harmonic components associated with one or more benchmark transformers of a known condition to determine whether the condition of the transformer matches the condition of one or more benchmark transformers.
    Type: Grant
    Filed: March 13, 2015
    Date of Patent: June 6, 2017
    Assignee: DOBLE ENGINEERING COMPANY
    Inventor: Mark F. Lachman
  • Patent number: 9632128
    Abstract: An apparatus for performing measurements on a utility power device that shares a common ground with the apparatus selectively sends a first high voltage signal via a first lead to a first terminal of the utility power device, measures a first corresponding signal returned via a second lead of the apparatus from a second terminal of the utility power device. While the corresponding first lead and the second lead of the apparatus remain electrically coupled to the corresponding first and the second terminal of the utility power device. The apparatus selectively sends a second high voltage signal via the second lead to the second terminal of the utility power device, and measures a second corresponding signal returned via the first lead of the apparatus from the first terminal of the utility power device.
    Type: Grant
    Filed: September 28, 2016
    Date of Patent: April 25, 2017
    Assignee: Doble Engineering Company
    Inventors: Robert Clark Woodward, Jr., George Matthew Kennedy
  • Patent number: 9482712
    Abstract: An apparatus for performing measurements on a utility power device that shares a common ground with the apparatus selectively sends a first high voltage signal via a first lead to a first terminal of the utility power device, measures a first corresponding signal returned via a second lead of the apparatus from a second terminal of the utility power device. While the corresponding first lead and the second lead of the apparatus remain electrically coupled to the corresponding first and the second terminal of the utility power device. The apparatus selectively sends a second high voltage signal via the second lead to the second terminal of the utility power device, and measures a second corresponding signal returned via the first lead of the apparatus from the first terminal of the utility power device.
    Type: Grant
    Filed: November 4, 2013
    Date of Patent: November 1, 2016
    Assignee: DOBLE ENGINEERING COMPANY
    Inventors: Robert Clark Woodward, Jr., George Matthew Kennedy
  • Patent number: 9313878
    Abstract: A method for mitigating voltage stress on a PCB includes applying AC voltage to a multi-terminal condenser structure of a multi-layered PCB. The terminal condenser structure is formed by overlapping a plurality of conductive traces between board layers of the multi-layered PCB. A corresponding dielectric layer is disposed between the overlapping conductive traces of the board layers. The overlapping conductive traces include a first terminal, a second terminal, a third terminal, and a fourth terminal. The first terminal and the third terminal are disposed on a first layer of the multi-layered PCB, and the second terminal and the fourth terminal are disposed on a bottom layer of the multi-layered PCB. The first terminal and the second terminal are connected to a ground point, and the third terminal and the fourth terminal are connected to the AC voltage. Voltage stresses on the PCB are mitigated utilizing the multi-terminal condenser structure.
    Type: Grant
    Filed: March 12, 2014
    Date of Patent: April 12, 2016
    Assignee: DOBLE ENGINEERING COMPANY
    Inventor: Robert Clark Woodward, Jr.
  • Publication number: 20140262445
    Abstract: A method for mitigating voltage stress on a PCB includes applying AC voltage to a multi-terminal condenser structure of a multi-layered PCB. The terminal condenser structure is formed by overlapping a plurality of conductive traces between board layers of the multi-layered PCB. A corresponding dielectric layer is disposed between the overlapping conductive traces of the board layers. The overlapping conductive traces include a first terminal, a second terminal, a third terminal, and a fourth terminal. The first terminal and the third terminal are disposed on a first layer of the multi-layered PCB, and the second terminal and the fourth terminal are disposed on a bottom layer of the multi-layered PCB. The first terminal and the second terminal are connected to a ground point, and the third terminal and the fourth terminal are connected to the AC voltage. Voltage stresses on the PCB are mitigated utilizing the multi-terminal condenser structure.
    Type: Application
    Filed: March 12, 2014
    Publication date: September 18, 2014
    Applicant: DOBLE ENGINEERING COMPANY
    Inventor: Robert Clark Woodward, JR.
  • Patent number: 8792542
    Abstract: Apparatus for processing broadband impulses signals of low repetition rate includes a tuner for receiving broadband impulsive signals of low repetition rate and providing an output signal characteristic of the amplitude and spectral content of the received input signal. Resolution bandwidth filters coupled to the tuner output each have a different bandwidth that determines the measurement resolution and influences the sensitivity and transient response to low repetition rate impulsive signals. At least one radio frequency switch selects a resolution bandwidth filter for coupling to and associated one of at least a peak detector, an average detector and an envelope generator. A gate generator coupled to the peak detector, the average detector and the envelope generator furnishes a gating signal to each to provide a peak signal, an average signal and an envelope signal respectively during a selected gating interval. A microprocessor is coupled to the peak detector and the average detector.
    Type: Grant
    Filed: March 24, 2010
    Date of Patent: July 29, 2014
    Assignee: Doble Engineering Company
    Inventors: Scott McMeekin, Brian G. Stewart, Stephen Conner, Carlos Gamio, Alan Nesbitt
  • Publication number: 20140125351
    Abstract: An apparatus for performing measurements on a utility power device that shares a common ground with the apparatus selectively sends a first high voltage signal via a first lead to a first terminal of the utility power device, measures a first corresponding signal returned via a second lead of the apparatus from a second terminal of the utility power device. While the corresponding first lead and the second lead of the apparatus remain electrically coupled to the corresponding first and the second terminal of the utility power device. The apparatus selectively sends a second high voltage signal via the second lead to the second terminal of the utility power device, and measures a second corresponding signal returned via the first lead of the apparatus from the first terminal of the utility power device.
    Type: Application
    Filed: November 4, 2013
    Publication date: May 8, 2014
    Applicant: Doble Engineering Company
    Inventors: Robert Clark Woodward, JR., George Matthew Kennedy
  • Publication number: 20120077444
    Abstract: Apparatus for processing broadband impulses signals of low repetition rate includes a tuner for receiving broadband impulsive signals of low repetition rate and providing an output signal characteristic of the amplitude and spectral content of the received input signal. Resolution bandwidth filters coupled to the tuner output each have a different bandwidth that determines the measurement resolution and influences the sensitivity and transient response to low repetition rate impulsive signals. At least one radio frequency switch selects a resolution bandwidth filter for coupling to and associated one of at least a peak detector, an average detector and an envelope generator. A gate generator coupled to the peak detector, the average detector and the envelope generator furnishes a gating signal to each to provide a peak signal, an average signal and an envelope signal respectively during a selected gating interval. A microprocessor is coupled to the peak detector and the average detector.
    Type: Application
    Filed: March 24, 2010
    Publication date: March 29, 2012
    Applicant: Doble Engineering Company
    Inventors: Scott McMeekin, Brian G. Stewart, Stephen Conner, Carlos Gamio, Alan Nesbitt
  • Patent number: 6633169
    Abstract: Monitoring a leakage current from an isolator for a high voltage conductor to ground includes directing the leakage current through a primary wire inductively coupled to a secondary winding energizing an amplifier.
    Type: Grant
    Filed: April 8, 1999
    Date of Patent: October 14, 2003
    Assignee: Doble Engineering Company
    Inventor: George A. Cavigelli
  • Patent number: 6177803
    Abstract: A group of bushings receives voltage in parallel to produce a current output from each bushing. Cumulatively combining the current outputs from the bushings vectorially furnishes a vector sum bushing current. Reference voltage devices also produce reference current outputs. Cumulatively combining the reference current outputs vectorially provides a vector sum reference current, and differentially vectorially combining the vector sum reference current with the vector sum bushing current delayed by 90° provides a difference signal representative of a bushing condition. As an alternative to the reference voltage devices, a second group of bushings may be used. In this case, a delay of 90° is not required. The invention may also be used to monitor the condition of other capacitive devices, for example, high voltage current transformers.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: January 23, 2001
    Assignee: Doble Engineering Company
    Inventors: David Train, Philip A. von Guggenberg, George A. Cavigelli
  • Patent number: 5818245
    Abstract: Impedance of a power system adapted for operation at a predetermined line frequency is measured by providing a test signal of frequency different from the predetermined line frequency by an increment significantly less than the predetermined line frequency to provide an impedance measurement signal representative of the impedance of the power system at the test frequency. The impedance measurement signal is processed to provide a line impedance signal representative of the power system impedance at the predetermined line frequency.
    Type: Grant
    Filed: December 30, 1996
    Date of Patent: October 6, 1998
    Assignee: Doble Engineering Company
    Inventor: Lars P. Allfather
  • Patent number: 5635871
    Abstract: The invention features an apparatus and technique for amplifying a signal without creating a phase error. The apparatus is an active device with a restricted band width selected to include desired frequencies of operation. The apparatus includes at least one amplifier with a local feedback loop, formed by a network, constructed and arranged to exhibit a high forward gain at the operating frequencies. The amplifier and the network are constructed and arranged to provide substantially 180 degree phase shift between an input voltage and an output voltage at the operating frequencies. The apparatus also includes a signal input node adapted to introduce the input voltage to the inverting input of the amplifier, a signal output node adapted to obtain the output voltage from the output of the amplifier, and a resistive global feedback loop that connects the signal input and signal output nodes and controls the closed loop gain of the amplifying apparatus.
    Type: Grant
    Filed: December 15, 1992
    Date of Patent: June 3, 1997
    Assignee: Doble Engineering Company
    Inventor: George A. Cavigelli
  • Patent number: 5541827
    Abstract: A switching amplifier circuit includes a tri-state switching circuit receiving a DC voltage signal and having first electrical switches responsive to first control signals and providing a differential AC voltage waveform at a predetermined frequency alternating between a positive DC voltage, negative DC voltage and a zero voltage. The switching amplifier further includes a rectifier circuit having second electrical switches responsive to second control signals for receiving the differential AC voltage output waveform from the tri-state switching circuit and providing a desired output signal. The second control signals are applied to switch the second electrical switches only when the first electrical switches of the tri-state switching circuit are in the zero voltage state.
    Type: Grant
    Filed: May 17, 1995
    Date of Patent: July 30, 1996
    Assignee: Doble Engineering Company
    Inventor: Lars P. Allfather
  • Patent number: 5317277
    Abstract: The invention features power amplifying apparatus with controllable frequency characteristic of the gain. The apparatus includes a band pass network of two cascaded amplifiers and multiple resistors and capacitors arranged to form multiple feedback loops. The feedback loops stabilize the output A.C. signals and establish a predetermined bandwidth of the network. The apparatus also includes a capacitor resistor feedback loop, connected to the output of the second amplifier and input of the first amplifier, with the capacitor and the resistor selected to maximize the loop gain at a desired frequency.
    Type: Grant
    Filed: December 8, 1992
    Date of Patent: May 31, 1994
    Assignee: Doble Engineering Company
    Inventor: George A. Cavigelli
  • Patent number: 5287065
    Abstract: Automatic bridge balancing apparatus includes a reference impedance and a measuring terminal pair for receiving an unknown impedance. A source of a test signal is coupled to the reference impedance and the measuring terminal pair. A measuring detector is connected in series with the unknown impedance when connected to the measuring terminal pair to provide a measured signal. A reference detector is coupled to the reference impedance to provide a reference signal. A combiner combines the measured signal with the reference signal to provide an error signal. The reference detector includes an up/down counter coupled to a digital attenuator that provides the reference signal. A controller responds to the error signal to control the count in the up/down counter so that the associated digital attenuator provides a signal to the combiner that reduces the error signal so that the count in the up/down counter is characteristic of the unknown impedance.
    Type: Grant
    Filed: October 4, 1991
    Date of Patent: February 15, 1994
    Assignee: Doble Engineering Company
    Inventor: Lars P. Allfather
  • Patent number: 5068636
    Abstract: A current shunt device has main and auxiliary windings which are located in substantially the same position and are connected in series.
    Type: Grant
    Filed: October 26, 1989
    Date of Patent: November 26, 1991
    Assignee: Doble Engineering Company
    Inventor: George A. Cavigelli
  • Patent number: 5021648
    Abstract: A motion transducer includes a rotatable wheel, a drive assembly that engages a movable rod in contact with the circumference of the rotatable wheel, and an encoder that measures the rotation of the rotatable wheel and that encodes information relating to the rotation of the rotatable wheel. Linear motion of the movable rod causes rotation of the rotatable wheel, the angular displacement of the rotatable wheel being proportional to the linear travel of the rod.
    Type: Grant
    Filed: February 28, 1990
    Date of Patent: June 4, 1991
    Assignee: Doble Engineering Company
    Inventor: Donald R. Jones
  • Patent number: 4973919
    Abstract: A signal is amplified with a plurality of amplifiers, each amplifier having a reference port, a reference node coupled to the reference port, and a signal port, and each amplifier being supplied by a power source with operating potential with respect to the reference node that is coupled to the reference port of that amplifier. The amplifiers are cascaded in a manner selected so that the output of a first amplifier (which receives the signal to be amplified at its input port) drives the reference node of a second amplifier, and the reference node of the first amplifier provides an input at the signal port of the second amplifier, whereby the first and second amplifiers are directly coupled together to amplify the applied signal.
    Type: Grant
    Filed: March 23, 1989
    Date of Patent: November 27, 1990
    Assignee: Doble Engineering Company
    Inventor: Lars P. Allfather