Agilent Technologies, Inc.

Keysight Technologies, Inc.

Hewlett-packard Company

John F Kenny

Marko Vulovic

James B McKim, Jr

Buck H Chan

Richard A Carlson

John W Hyde

Joe E Marriott

Michael Joseph Benes

Michael J Benes

Daniel Miller

Katherine Mueller

James P McKim, Jr

Embodiments are described for reducing common-mode current in electronic devices. In the various embodiments, a resonant converter is employed, for example in a power supply, and the resonant converter is driven by a DC input to generate an AC primary voltage on the primary windings of a power transformer. The DC input may be derived from an AC line voltage or a DC-to-DC converter. The AC primary voltage drives the primary winding of the transformer to generate an AC secondary voltage on at least one secondary winding of the transformer. The AC secondary voltage may then drive a rectifier, which in turn drives a low-pass filter to produce a DC output voltage. Phase-shift modulation is employed which, in conjunction with the resonant converter, applies a sinusoidal waveform to the primary of the transformer resulting in a reduced amount of common-mode current injected onto the secondary.

Resonant converter for achieving low common-mode noise, along with isolated power supply and method employing the same

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

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.

Programmable power supply having digitally implemented slew rate controller

A digital system measures cyclic disturbance signals on an electrical line that are induced by a connected unit under test (UUT). The system includes a digital to analog (D/A) converter which receives and converts a first train of digital signals to a cyclic analog test signal and applies that signal to the electrical line. An analog to digital (A/D) converter receives and converts analog cyclic disturbance signals from the electrical line to a second train of digital signals. A synch generator applies a train of synch pulses, concurrently, to synchronizing inputs of the D/A converter and the A/D converter so that their respective conversion operations are based upon a common time-base signal. A processor is coupled to the D/A converter and A/D converter and outputs the first train of digital signals to the D/A converter and receives the second train of digital signals from the A/D converter. The processor subjects a portion of the second train of digital signals to signal analysis, with the portion of the second train being representative of an integer number of cycles of the cyclic disturbance signal sensed from the electrical line. The clock frequency which causes generation of the synch pulses is selected so that the synch pulses have a precise, predetermined relationship to a predetermined number of cycles of the cyclic signal (in the case of a power spectrum analysis) or a predetermined number of half cycles (in the case of an amplitude analysis).

AC mains test system for measuring current harmonics and voltage

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Califon, NJ, United States of America

John F Kenny