Other

Ltx Corporation

Innerspec Technologies, Inc

Stephen William Smith

William Robert Creek

Philip Haywood Cox

A high-voltage pulser circuit for Electromagnetic Acoustic Transducer (EMAT) coils using a Capacitive Discharge push-pull converter. The present invention relates in particular to the operation of the converter into an Electromagnetic Acoustic Transducer (EMAT) differential coil. The present invention reduces ringing of the coil current resulting in a smaller blind zone and a well-defined broadband ultrasonic wave from the coil. The pulser can be used to generate one or more cycles and work in either pulse-echo (same transmitter and receiver) or pitch-catch (different transmitter and receiver).

Capacitive discharge push-pull converter pulser for electromagnetic acoustic transducer

Circuitry for high-power, high-frequency excitation of electromagnetic acoustic transducers (EMAT) without the use of a matching transformer is described. This circuit contains at least 4 switching devices, arranged in an H-Bridge configuration to drive EMATs over a range of frequencies. The switching devices can be connected in parallel with respect to the H-Bridge and switched in sequence for greater power output and variety of wave forms including, Churp, Hemming window tone burst, rectangular tone burst and Barker Code wave forms. A circuit for driving sensor coils of an EMAT to correct the disadvantages of conventional pulsers. A plurality of switching devices are connected in parallel and augmented with support circuitry to provide increased power output, stability, reduced noise and complex output wave forms. This design provides for the application of modulated pulses such as multi-pulse, multi-frequency bursts with peak power outputs over 20,000 watts and frequencies over 10,000 Hertz.

H-bridge pulse generator

An apparatus for testing radio frequency (RF) and/or mixed signal semiconductor devices and or modules is described. specifically described is how the distributed stimulus for RF automatic test applications, unified testhead for automatic test applications, reverse card backplane for automatic test applications, direct coaxial interface for automatic test applications, cable-free interface for automatic test applications, micromachine switch matrix for automatic test applications, device specific module high speed date for RF automatic test applications may be used within tester apparatus described herein or in other test applications. Additionally a high speed date communications test apparatus which may be used in a variety of device testers is described herein.

Apparatus for high density low cost automatic test applications

A phase shifted H-bridge resonant converter with symmetrical currents includes, a DC storage cap (), four switches (-) with a parallel turn off network consisting of diodes (-), capacitors (), (), (), (), resistors (), (), (), (). The subsequent output of switches (-), is arranged in series with DC blocking caps (-), connected to a low mutually coupled inductor (), an AC resistive load, capacitor (), resistor () across inductor (), with capacitors (), () that comprise a resonant tank circuit, and is connected to the primary of transformer (21) wherein the interaction between the two coils of the low mutually coupled inductor () provides symmetrical currents within the switches and resonant tank circuit. Further, output rectification may be arranged by use of secondary winding of transformer (), diodes (-), filter inductor (), filter capacitor (), and load resistor ().

Phase shifted H-Bridge resonant converter with symmetrical currents

A method and apparatus for a micromachine relay is provided. A pin controller comprises at least one spring pin designed to movably couple the pin controller to a device under test (DUT) to provide signals to the DUT. The pin controller further includes a micromachine relay coupled to the at least one spring pin to control the movement of the at least one spring pin and an integrated circuit for controlling the micromachine relay.

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Appomattox, VA, United States of America

Stephen William Smith