International Business Machines Corporation

Other

Michael Allen Weed

Steven Michael Douskey

Frank William Angelotti

Wayne Allan Britson

David W Collins

Kerry T Kaliszewski

A method for discharging an industrial lifting magnet quickly without producing a high voltage transient is presented. Most of the stored magnetic energy is dissipated in the magnet itself by connecting a diode across the magnet in the appropriate direction at discharge time using switching devices. One variation, suitable for smaller magnets, discharges the remaining energy using DC capacitors and a diode switching network. Another variation, suitable for magnets of any size, discharges most of the remaining energy in a power resistor of modest size using a system of diodes and switching devices in conjunction with a relatively small AC capacitor across the magnet.

Method and apparatus for discharging a lifting magnet

An electronics systems having variable interconnections among major components is tested by dynamically identifying the locations and types of all system components at the time the test is to be performed, for building a global model describing the interconnections among these components. Specific tests appropriate for this model are then dynamically generated and executed. Data on the components themselves identifies them. The tests employ boundary-scanning techniques to locate failing drivers, receivers, and bidirectional driver/receivers, as well as open and shorted interconnections.

Testing system interconnections using dynamic configuration and test

Phase difference demodulator for measuring the phase difference between two signals of the same frequency, time multiplexed onto a single analog input, and providing a precision digital output signal representing the phase difference. The most significant part of the signal, the upper bits, is determined by digital processes while analog-to-digital processes determines the lower bits. The analog-to-digital processes utilize an integrating capacitor and current sources for demodulating servo bursts for obtaining phase difference. The current sources are a coarse current and a fine current 1/16 in value of the coarse current source. The capacitor is switched in a differential scheme by the integrator to determine error during the digital approximation of the upper bits in analog to digital conversion. The same capacitor and current sources are utilized in the error acquired in analog form and then during the analog-to-digital conversion.

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Spring Valley, MN, United States of America

Michael Allen Weed