Summit World Trade Corporation

Keithley Instruments, Inc.

Allen-bradley Company, LLC

John C Gibbons

Wayne C Goeke

James A Niemann

David S Vickers

Kevin Cawley

Geoffrey G Cochrane

An isolated DC-to-DC switching power supply includes an isolation transformer having a magnetic core, a first winding around the magnetic core, a first winding-shield around the magnetic core, a second winding-shield within the first winding-shield, and a second winding within the second winding-shield. There is no direct coupling between the first winding and the second winding since the second winding is enclosed within the second winding-shield and the second winding-shield is enclosed within the first winding-shield.

Isolation transformer for use in isolated DC-to-DC switching power supply

A guarded sense impedance for use in a measurement instrument includes a sense impedance adapted to have a spatially distributed electrical potential and at least one guard structure adapted to have the spatially distributed electrical potential. The guard structure is arranged to provide a spatially distributed guard potential for the sense impedance.

Spatially distributed guarded impedance

An electronic gain control is disclosed for the photomultipliers of a gamma camera which assures that all photomultipliers in the camera have uniform gain for any given ganuna event. A specific dynode in the photomultiplier is isolated from the line resistive voltage divider string in the photomultiplier which places each dynode under incremental voltages. A voltage is then applied to the isolated dynode which can vary anywhere from the voltage the isolated dynode would have had if inserted in the voltage divider string to the voltage that the immediately preceding or immediately succeeding dynode in the string has whereby the photomultiplier's gain is controlled. The applied voltage to the isolated dynode is developed electronically by a voltage to frequency converter coupled by an opto-isolator to a gain voltage divider circuit which cycles the applied voltage between two different voltage potentials tapped from the voltage divider string. The voltage to frequency converter is controlled by individual gain signals developed and stored during calibration of the camera for each photomultiplier.

Electronic gain control for photomultiplier used in gamma camera

An electronic gain control for the photomultipliers of a gamma camera assures that all photomultipliers in the camera have uniform gain for any given gamma event. A specific dynode in the photomultiplier is isolated from the line resistive voltage divider string in the photomultiplier which places each dynode under incremental voltages. A voltage is then applied to the isolated dynode which can vary anywhere from the voltage the isolated dynode would have had if inserted in the voltage divider string to the voltage that the immediately preceding or immediately succeeding dynode in the string has whereby the photomultiplier's gain is controlled. The voltage applied to the isolated dynode is established for each photomultiplier in the camera by individual gain signals developed and stored during calibration of the camera for each radio active isotope whereby all photomultipliers have uniform gain for each isotope.

Gamma camera device

An electronic gain control is disclosed for the photomultipliers of a gamma camera which assures that all photomultipliers in the camera have uniform gain for any given gamma event. A specific dynode in the photomultiplier is isolated from the line resistive voltage divider string in the photomultiplier which places each dynode under incremental voltages. A voltage is then applied to the isolated dynode which can vary anywhere from the voltage the isolated dynode would have had if inserted in the voltage divider string to the voltage that the immediately preceding or immediately succeeding dynode in the string has whereby the photomultiplier's gain is controlled. The applied voltage to the isolated dynode is developed electronically by a voltage to frequency converter coupled by an opto-isolator to a gain voltage divider circuit which cycles the applied voltage between two different voltage potentials tapped from the voltage divider string. The voltage to frequency converter is controlled by individual gain signals developed and stored during calibration of the camera for each photomultiplier.

An adapter response circuit indicates the number of adapters on a link responding to a given address and hence permits the detection of possible data collisions. Each adapter responding to the address transmitted on the link induces a current on a common conductor. The magnitude of the current unambiguously identifies the number of adapters responding to that address. The proper resistive termination of the link may be checked by inducing a similar incremental current on the conductor and evaluating a voltage variation indicating the presence or absence of a termination resistor.

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Macedonia, OH, United States of America

John C Gibbons