Agilent Technologies, Inc.

Keysight Technologies, Inc.

Marko Vulovic

Peyman Safa

John F Kenny

Richard A Carlson

Buck H Chan

Benjamin D Hoover

John W Hyde

James B McKim, Jr

Daniel R Schwartz

Bryan D Boswell

Michael Joseph Benes

Michael J Benes

Edward Brorein

Robert Zollo

James P McKim, Jr

A switching converter has a first converter output for connection to a user load and a second converter output for connection to the user load. A first direct current rail power negative terminal has a first positive output and a first negative output connected to the second converter output. A second direct current rail power negative terminal has a second negative output and a second positive output connected to the first positive output. A first switch has a first positive terminal connected to the first positive output, a first negative terminal and a first control terminal. A second switch has a second positive terminal connected to the first negative terminal, a second negative terminal connected to the second negative output, and a second control terminal. A pulse width modulator has a first modulator output connected to the first control terminal, and a second modulator output connected to the second control terminal. An inductance is connected between the first converter output and the first negative terminal. A comparator controls the first pulse width modulator based on a voltage difference between a current measurement voltage that varies based on current through the inductance and a first set point voltage.

Switched-mode, high bandwidth, high impedance power supply

In accordance with one illustrative embodiment, a system for determining a self-discharge current characteristic of a storage cell (or a bank of storage cells) includes a voltage source, first and second voltage measurement circuits, a current measurement circuit, and a processor. The voltage source provides a potentiostat voltage to the storage cell coupled to the system. The first voltage measurement circuit provides a first voltage resolution for measuring an open circuit voltage across a pair of terminals of the storage cell. The second voltage measurement circuit provides a second voltage resolution that is significantly higher than the first voltage resolution for measuring a terminal voltage at one of the pair of terminals of the storage cell. The processor executes a test procedure by using the voltage source, the first and second voltage measurement circuits, and the current measurement circuit, to determine the self-discharge leakage current characteristic of the storage cell.

Systems and methods for determining a self-discharge current characteristic of a storage cell

Disclosed is a continuous broken sense lead detection system ('CBSLDS') for use with a Kelvin-connected device under test ('DUT'), a power source, and detection system stimulus configured to provide a periodic stimulus voltage. The CBSLDS is configured to detect a discontinuity in a first sense lead, second sense lead, or both, that are in signal communication with the DUT. The CBSLDS includes a first transformer, second transformer, first DC-blocker, second DC-blocker, first detection module, and second detection module.

Continuous broken sense lead detection system

An energy dissipating device configured to connect to a power supply and to dissipate excess energy from a direct current (DC) rail in response to a change in power supply settings or operating characteristics. The energy dissipating device is connected to the DC rail, which conducts current generated by an AC/DC converter to at least one DC/DC converter. When power demand to the DC/DC converter is reduced, the DC/DC converter generates a supplemental current surge on the DC rail. A rail current monitor monitors the current level on the DC rail and generates the DC rail power signal indicative of the supplemental current surge level generated by the at least one DC/DC converter. The supplemental surge current is used to control dissipative elements connected across the DC rail to modulate a current sink path across the DC rail to dissipate the excess energy from the DC rail.

Energy dissipating device for DC power supplies

An apparatus and method for synchronous communications using a serial data stream employs a housing with a controller and a back plane. The housing accepts one or more modules for interconnection with the back plane. The back plane distributes power to the modules and provides a communication link from the controller to each module. Each communication link includes a data out line, a data in line and a clock line, where each clock line is derived from one clock source.

Communications system for implementation of synchronous, multichannel, galvanically isolated instrumentation devices

In one embodiment, a measurement apparatus has an input stage, an output stage and a multiplexer. The input stage has a signal input, a plurality of measurement range outputs, and a plurality of selectable gain stages, with each of the selectable gain stages being coupled between the signal input and a respective one of the measurement range outputs. The output stage has a measurement acquisition path between an analog measurement input and a digital measurement output. The measurement acquisition path includes an analog-to-digital converter. The multiplexer has i) a plurality of data inputs, at least two of which are coupled to respective ones of the plurality of measurement range outputs, and at least one of which is a reference input configured to receive a signal to which signals appearing at the measurement range outputs are commonly referenced, ii) a data output coupled to the analog measurement input of the output stage, and iii) a control input.

Methods and apparatus for acquiring measurements and performing an auto-zero process using a multi-range measurement apparatus

An electrical current measurement system. A sense impedance and a composite amplifier are in electrical communication and together define a trans-impedance circuit that presents a frequency-compensated impedance lower than the sense impedance to an input electrical current to be measured. A sense amplifier in electrical communication with the sense impedance provides an output indicative of a magnitude of the input electrical current. A current bypass circuit may parallel the trans-impedance circuit and bypass the input electrical current around the trans-impedance circuit when the current reaches a predefined magnitude. The system may be combined with another current sensor to form a dual-range current measurement instrument.

Dual-range measurement of electrical current

An electrical current measurement system. A first low-range current gauge receives a current to be measured and provides a first intermediate value indicative of the amplitude of the current up to a first maximum current. A second low-range current gauge receives any portion of the current having a magnitude that exceeds the first maximum current and provides a second preliminary value indicative of the amplitude of the portion of the current having a magnitude that exceeds the first maximum current up to a second maximum current. An arithmetic unit or a digital processor receives the first intermediate value and the second preliminary value and provides a second intermediate value indicative of the amplitude of the current. A full-range current gauge may also be provided. A selector or the digital processor selects one of the values for display or other output.

Multi-range electrical current measurement

A power supply programmable for a constant current mode and a constant voltage mode and selectively operable in either mode. Respective circuits associated with each of a constant voltage loop and a constant current loop track a control voltage of the other loop when the other loop is operating closed loop and maintains a control voltage of the open loop at a tracking offset value from the control voltage of the closed loop, allowing the open loop to rapidly assume control of the power supply during a mode transition. The tracking offset value is briefly increased during a mode transition to interrupt oscillation tendencies, resulting in faster mode cross-over and reduced overshoots, while maintaining stability.

Programmable power supply with dual mode cross over clamps

A digitally implemented slew rate controller for a power supply and a power supply having the same. An output up-programming signal is provided that enables the power supply to change an output voltage and current at a maximum rate which does not engage the protection circuits which are employed to protect components of the power supply. The maximum rate of change decreases as the output voltage increases. The up-programming speed of the power supply output optimizes the output by considering that an amount of output current available for charging an output capacitor of the power supply will decrease as the output voltage increases for a resistive load. An output down-programming control signal enables a discharge device to dissipate heat with a constant power characteristic, which will minimize a time required to reduce the output voltage while not exceeding a maximum power dissipation rating of the discharge device.

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Columbia, NJ, United States of America

Marko Vulovic