Thomcast Communications, Inc.

Thales Broadcast & Multimedia, Inc.

Thomson Licensing

Thales North America, Inc.

Alvin B See

Fred M Stefanik

Paulo Correa

Richard A Mitchell

A circuit to monitor ac line current through resistors employed to provide a 'step start' in a power supply, including means to monitor the current flowing through the step start resistors, comprising a peak detector, a sample and hold circuit, an analog to digital convertor and a microprocessor. The output of the current monitoring circuit may be employed to abort starting if abnormalities are sensed. The circuit may also be used to identify when the step start resistors need longer cooling time, and to continuously monitor current at times other than during starting. A timing circuit is also incorporated, which senses zero crossings of the voltage input to the power supply, so as to control the timing of the current monitoring circuit. The discrete circuits employed may be replaced by either a digital signal processor integrated circuit or a general-purpose computer implementing the same steps in a suitable algorithm.

Apparatus, method and computer program product for monitoring AC line current through the step start resistors of a high voltage power supply

A circuit to monitor AC line current through resistors employed to provide a 'step start' in a power supply, including means to monitor the current flowing through the step start resistors, comprising a peak detector, a sample and hold circuit, an analog to digital convertor and a microprocessor. The output of the current monitoring circuit may be employed to abort starting if abnormalities are sensed. The circuit may also be used to identify when the step start resistors need longer cooling time, and to continuously monitor current at times other than during starting. A timing circuit is also incorporated, which senses zero crossings of the voltage input to the power supply, so as to control the timing of the current monitoring circuit. The discrete circuits employed may be replaced by either a digital signal processor integrated circuit or a general-purpose computer implementing the same steps in a suitable algorithm.

Control and filter circuits for linear power supplies, employing resistance to limit the release of stored energy and simultaneously removing the input mains AC, so as to protect a load device from damage when a high voltage fault occurs. The circuits may be used particularly in output filters for high voltage power supplies for high power transmitting tubes, such as Inductive Output Tubes used in UHF television transmitters, which must be protected from internal arcing by a controlled release of stored energy and a rapid disconnection of input power. The use of the filter circuit combined with rapid solid state switching ensures that the load is not subject to an excessive surge when a high voltage fault occurs.

Apparatus for protection of an inductive output tube (IOT) from stored energy in a linear high voltage power supply (HVPS) and its associated filter circuit during a high voltage arc

Oil cooled multistage depressed collector high power amplifier

A lifting handle temporarily attaches to the water jacket of a plug-in liquid cooled IOT to facilitate installation, replacement, or removal of the IOT. The lifting handle includes two gripping surfaces that conform to the surface of the water jacket of a plug-in liquid cooled IOT. The gripping surfaces are hinged at their rear ends and clamped with a toggle clamp at the front ends. The gripping surfaces may be shaped to provide convenient handling during installation, replacement, or removal.

Lifting handle for plug-in IOTs

A system, method and computer program product system for evacuating coolant from a liquid-cooled device. The system includes a coolant supply path adapted to be coupled between a coolant supply pump and the liquid-cooled device; a coolant return path adapted to be coupled between a coolant supply reservoir and the liquid-cooled device; and a coolant removal path coupled between the coolant supply path and the coolant return path. The coolant removal path is configured to evacuate coolant from the liquid-cooled device using a venturi effect from the coolant supply path to evacuate the coolant through the coolant return path into the reservoir.

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Westfield, MA, United States of America

Alvin B See