Patents Assigned to KEITHLEY INSTRUMENTS, LLC
  • Publication number: 20180259562
    Abstract: A test and measurement instrument for performing multiple operations, including a port to receive a signal from a device under test; and a processor. The processor configured to, based on a parallel trigger model, execute a first process associated with first functionality of the test and measurement instrument, and execute a second process on the signal from the device under test, the second process associated with second functionality of the test and measurement instrument. The second process commencing prior to completion of the first process.
    Type: Application
    Filed: December 29, 2017
    Publication date: September 13, 2018
    Applicant: Keithley Instruments, LLC
    Inventors: Brian P. Frackelton, George J. Polly
  • Publication number: 20180261072
    Abstract: A data acquisition system, including an input configured to receive a signal on a port and a processor. The processor determines, during an initial scan, a first measurement value of the signal on the port, sets at least one alarm value based on the first measurement value, the at least one alarm value being within a predetermined amount of the first measurement value, receives, during a subsequent scan, a second measurement value of the signal on the port, and generates an alert when the second measurement value violates the at least one alarm value.
    Type: Application
    Filed: September 20, 2017
    Publication date: September 13, 2018
    Applicant: Keithley Instruments, LLC
    Inventors: Brian P. Frackelton, George J. Polly
  • Publication number: 20180259401
    Abstract: Embodiments described herein include a data acquisition unit having a plurality of ports that are each configured to receive a signal from a respective temperature sensor of a device under test. Each of the temperature sensors is associated with a location with respect to the device under test. The data acquisition unit also includes a processor configured to determine a temperature corresponding to each temperature sensor, based on the signal received from the respective temperature sensor. The processor can then generate a thermal gradient for the device under test based on the temperature and the location of each of the temperature sensors. This thermal gradient can then be output for further analysis. Additional embodiments may be described and/or claimed herein.
    Type: Application
    Filed: December 21, 2017
    Publication date: September 13, 2018
    Applicant: Keithley Instruments, LLC
    Inventor: George J. Polly
  • Publication number: 20180259579
    Abstract: Disclosed is a test and measurement instrument including a plurality of ports. The ports are configured to source a test signal into a device under test (DUT), and receive a signal response from the DUT. The test and measurement instrument also includes a measurement unit configured to measure the signal response. The test and measurement instrument further includes a processor configured to compare the signal response to a data structure. The processor also determines a classification of, and/or connections to, at least one DUT component coupled to at least one of the ports based on results of the comparison.
    Type: Application
    Filed: September 29, 2017
    Publication date: September 13, 2018
    Applicant: Keithley Instruments, LLC
    Inventors: Gregory Sobolewski, Justin R. Noble, F. Joseph Frese, IV
  • Patent number: 10044136
    Abstract: A cable strain arrestor assembly that protects equipment from damage due to pulling forces on attached cables is disclosed. The assembly comprises a mounting bracket that attaches to an equipment enclosure and converts pulling forces on the cables into compressional forces on the cables in order to break the cables before any damage can be transferred further through the cables. The assembly is able to convert these pulling forces by utilizing a tapering slot and a complementary shaped clamping collar with a channel that contracts as the clamping collar is moved in the direction of the taper of the slot.
    Type: Grant
    Filed: August 7, 2017
    Date of Patent: August 7, 2018
    Assignee: Keithley Instruments, LLC
    Inventors: Joseph A. Peters, Vladimir V. Genkin
  • Patent number: 9983228
    Abstract: Embodiments of the present invention provide an improved two-cable connection system for connecting electrical test instrumentation to a device under test (DUT). In one embodiment, a single pair of equal-length triaxial cables each has a desired characteristic impedance. Each cable has a center connecter, intermediate conductor, and outer conductor. The proximal end of each cable is connected to the test instrumentation, and the distal ends are located at the DUT. At the distal end, the center conductors are connected to the DUT, the intermediate conductors are allowed to float, and the outer conductors are connected to each other. The proximal end of each cable is connected to the device using an appropriate connection for the test that will be performed. This allows the test instrumentation to perform different types of tests without changing connections to the DUT.
    Type: Grant
    Filed: September 4, 2015
    Date of Patent: May 29, 2018
    Assignee: Keithley Instruments, LLC
    Inventors: Wayne C. Goeke, Gregory Sobolewski
  • Patent number: 9847724
    Abstract: Embodiments of the present invention provide improved techniques and devices for reducing transformer commutation distortion caused by large load currents. Traditional power supplies which have two or more phases typically commutate a transformer during the end of each phase. When the load current is large, energy stored in the transformer's leakage inductance can cause undesirable effects during commutation. Embodiments of the present invention reduce these effects by lowering the voltage across the primary side of the transformer prior to commutation. In one embodiment, a capacitor is added to the primary side of the transformer. A switch directs current through the capacitor prior to commutation, allowing the capacitor to absorb the transformer's leakage inductance energy and lower the primary side voltage. Other suitable components, such as resistors, diodes, transistors, or additional transformer windings, may also be used to reduce the primary-side voltage prior to commutation.
    Type: Grant
    Filed: October 6, 2015
    Date of Patent: December 19, 2017
    Assignee: Keithley Instruments, LLC
    Inventor: Wayne C. Goeke
  • Patent number: 9829520
    Abstract: A method for measuring the impedance of a DUT having a capacitance of less than 1 pF includes applying a voltage or current signal to the DUT, the voltage or current signal including an AC component having a non-zero frequency of less than 1 kHz; monitoring a current or voltage signal, respectively, through the DUT in response to the voltage or current signal; digitizing the voltage signal and the current signal synchronously; and calculating the impedance from the digitized voltage and current signals.
    Type: Grant
    Filed: August 22, 2011
    Date of Patent: November 28, 2017
    Assignee: Keithley Instruments, LLC
    Inventor: Gregory Sobolewski
  • Patent number: 9778666
    Abstract: A dynamic current limiter circuit is disclosed. The dynamic current limiter includes an input node an output node. The dynamic current limiter also includes a current control valve coupled between the input and output nodes, the current control valve being configured to limit current flow between the input and output nodes based on a control input. The dynamic current limiter also includes a current change detector coupled between the input and output nodes, the current change detector being configured to detect a change in current through the input and output nodes and generate a control signal configured to drive the control input. The current control valve is configured to limit current flow between the input and output nodes in response to the current control signal.
    Type: Grant
    Filed: August 22, 2012
    Date of Patent: October 3, 2017
    Assignee: Keithley Instruments, LLC
    Inventor: Gregory Sobolewski
  • Patent number: 9742379
    Abstract: A voltage clamp circuit which operates using a voltage controlled current source where the change of the polarity of the voltage controlled current source controls whether it is clamping or not. While clamping, the stability of the control loop uses the capacitance of the output to create and single pole roll-off of the loop gain and while not clamping, uses the capacitance of the circuit which sets the clamping voltage to produce the roll-off. The circuit operates in a linear fashion both while clamping and not clamping, which allows for a faster response when clamping is needed.
    Type: Grant
    Filed: December 10, 2014
    Date of Patent: August 22, 2017
    Assignee: Keithley Instruments, LLC
    Inventor: Wayne C. Goeke
  • Patent number: 9680300
    Abstract: A switch protection circuit includes a discharging circuit and, optionally, a clamping circuit. The discharge circuit operates prior to the switch completing the switching action to discharge capacitance from a signal line of a cable connected to a device under test to a ground voltage. When not discharging, the discharge circuit presents low leakage to a measurement circuit so as not to interfere with such measurement. If present, the clamping circuit clamps a signal line of the cable to a guard structure of the cable so that the discharge circuit can couple both the signal line and the guard structure to ground. The protection circuit operates without significantly worsening low current performance of the measurement instrument.
    Type: Grant
    Filed: April 22, 2014
    Date of Patent: June 13, 2017
    Assignee: Keithley Instruments, LLC
    Inventors: Matthew A. Holtz, Gregory Sobolewski, Jerold A. Williamson
  • Patent number: 9645193
    Abstract: An impedance sourcing circuit for a measurement device configured to measure a device under test (DUT) and method are disclosed. The impedance sourcing circuit includes a voltage/current source. An electrically controlled variable resistance having a control input is configured to adjust the variable resistance is coupled to the DUT. A loop gain controller is coupled to the control input of the electrically controlled variable resistance. The loop gain controller is configured to drive the control input of the electrically controlled variable resistance to adjust the variable resistance to generally match the impedance of the DUT. The impedance sourcing circuit may also include a voltage detector configured to detect a voltage across the DUT and a voltage reference. The loop gain controller may be configured to drive the control input of the electrically controlled variable resistance based on the voltage detected across the DUT and the voltage reference.
    Type: Grant
    Filed: October 23, 2012
    Date of Patent: May 9, 2017
    Assignee: Keithley Instruments, LLC
    Inventor: James A. Niemann
  • Patent number: 9501085
    Abstract: A method and apparatus for generating a desired pulse waveform including: dividing the desired pulse waveform into a plurality of line segments; assigning to each line segment at least a segment identification, a segment initial value, and a segment duration to form a waveform description; providing the waveform description to a pulse generator. The pulse generator is operable to produce a waveform corresponding to the waveform description and to output the produced waveform.
    Type: Grant
    Filed: February 1, 2007
    Date of Patent: November 22, 2016
    Assignee: KEITHLEY INSTRUMENTS, LLC
    Inventors: Pete Hulbert, Michael Rayman, Trish Gottlob, Rajat Mehta, John Lilie