Diversified Technologies, Inc.

Applied Science & Technology, Inc.

Marcel P Gaudreau

Jean-Paul Dionne

Edward Merrick Hogan

Axel Sigmar

Christopher C Cunningham

Donald K Smith

Robert A Weisenseel

Evgeny Holmansky

A voltage transient suppression circuit includes a capacitor, a diode, and a voltage limiter. The negative terminal of the capacitor can be coupled to the negative terminal of a variable voltage circuit element (e.g., a switching device, a series impedance, or a load). The anode of the diode can be coupled to the positive terminal of the variable voltage circuit element, and the cathode of the diode is connected to the positive terminal of the capacitor. The voltage limiter is connected in parallel with the capacitor. When the voltage applied across the voltage limiter is above a predetermined voltage, current is allowed to conduct through the voltage limiter and a voltage potential drop across the voltage limiter is substantially independent of the current conducted therethrough. When the voltage applied across the voltage limiter is below the predetermined voltage, current is substantially prevented from passing through the voltage limiter.

Voltage transient suppression

Apparatus, and related method, for remotely measuring at 1east one environmental condition includes an electromagnetically resonant sensor having a measurable resonance characteristic (e.g., center resonance frequency, quality factor, or bandwidth) that varies in correspondence to changes in the environmental condition present at the sensor. The sensor emits an electromagnetic return signal representative of a state of the resonance characteristic when an electromagnetic excitation signal impinges on the sensor. The electromagnetic excitation signal is generated by a generator located separate and away from the sensor, and the excitation signal is then directed at the remote sensor. The sensor thus remotely detects and measures the environmental condition. In one embodiment, the sensor is an electromagnetically resonant electrical circuit. In another embodiment, the sensor is an antenna resonator (e.g., a half-wavelength antenna) made of a conductive material.

Resonant sensor system and method

A remotely-operated unmanned vehicle attached to the hull of a marine vessel by electromagnets surveys the hull for damage. The vehicle attached to the hull is electronically controlled from a remote location. An imaging system on the vehicle provides an operator with images of the vessel's hull and the surrounding environment. Once damage has been found and assessed, the vehicle applies a patch over the damaged opening in the hull to prevent cargo outflow and water inflow. The patch, which resists puncturing and tearing, is constructed from one or more sheets of flexible material having dimensions appropriate to cover most openings.

Sealing openings in hulls of vessels

Apparatus and related method for deriving, from voltage across a power switch, power for a gate drive which opens and closes the power switch in response to a control signal includes a first voltage converter connected in parallel with the power switch and a series combination also connected in parallel with the power switch. The first voltage converter converts a high input voltage which appears across the power switch when the power switch is open to a low output voltage. The series combination includes a second voltage converter for receiving the low output voltage from the first voltage converter, converting it, and providing the converted voltage to the gate drive. The series combination also includes a high-voltage switch, connected in series with the second voltage converter, for opening and closing when the power switch is opened and closed by the gate drive in response to the control signal. The high-voltage switch provides to the second voltage converter a low input voltage which appears across the power switch when the power switch is closed, and the second voltage converter converts the low input voltage and provides the converted voltage to the gate drive.

Apparatus and method for deriving power for switching a switch from

Apparatus and method for assessing damage and patching openings in hulls

A high-power modulator includes a plurality of means for limiting voltage and a plurality of controllable switches. Each of the switches is connected in parallel with a different one of the voltage limiting means to form a plurality of parallel pairs. Each of the parallel pairs is connected to each other in a series combination. A first parallel pair in the series combination can be connected to a main power source, and a last parallel pair in the series combination can be connected to a load. Each of the switches is switchable from an off or open position to an on or closed position. With the switch in the off position, voltage applied by the main power source which is above a first predetermined voltage results in current provided by the main power source being conducted through the voltage limiting means and a corresponding voltage potential drop across the voltage limiting means being substantially independent of the current conducted therethrough, and voltage applied by the main power source which is below the first predetermined voltage results in current provided by the main power source being substantially prevented from passing through the voltage limiting means. With the switch in the on position, current provided by the main power source is substantially all conducted through the switch and a voltage potential drop across the voltage limiting means is substantially zero. When voltage applied by the main power source is below a second predetermined voltage, a ratio of switches in the on position to those in the off position determines a total voltage potential drop across the series combination and thus the voltage applied to the load.

High-power modulator

A microwave plasma generator for producing an axisymmetric plasma, having a waveguide apparatus, means for introducing a microwave source into the waveguide apparatus, and means for generating a circular axisymmetric microwave field from the microwave source. There are means for tuning the field to match the impedance of a plasma load. Further included is a vacuum chamber for containing a gas to be ionized to form the plasma, means for introducing this gas into the vacuum chamber, and means for coupling the microwave field to the vacuum chamber to form the plasma.

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Lexington, MA, United States of America

Marcel P Gaudreau