Abstract: A stray-wire sensor includes a vertical magnetic gradiometer (VMG) carried over the surface by ground vehicles or by low-flying aircraft. The VMG has a spot of sensitivity on the ground which stays nadir to the VMG itself. A Faraday shield surrounding the VMG screens out the near field electric dipole signals, and a ferrite rod core and winding inside act as an antenna sensitive to the near-field magnetic dipole signals which radiate from horizontal lying stray wires on the ground surface in the dirt of hidden by ground cover. The VMG depends on it being moved around over the ground so that magnetic signal gradients and reversals can be measured point-by-point. The nadir points which fall over a point along a long horizontal wire will express characteristic signatures in the signal gradients and phase reversals measureable in the antenna.

Abstract: A municipal infrastructure maintenance system uses a ground vehicle to move an antenna array in back-and-forth sweeps over large areas or distances. The antenna array comprises dozens of compartmentalized radio dipole antennas arranged laterally, shoulder-to-shoulder across the width of each sweep. An antenna switch matrix is connected between the antenna array and a ground-penetrating-radar (GPR) set and provides electronic aperture switching and selection, and the ability to laterally register one sweep to the next. The antenna array is extended out in front of the ground vehicle on a pivotable boom, and the cantilevered weight is a primary concern. The antenna array is constructed with aluminum-on-aluminum honeycomb panels slotted and folded around dozens of resistive-card compartment separators. Printed circuit boards with matching baluns are also slotted to receive tabs on the resistive cards, and their dipole elements are resistive loaded to quench crosstalk and near field effects.

Abstract: Switching regulator methods and systems are provided for supplying output current at a regulated voltage level to a load. Upon determining that the output current is not below a predetermined current threshold, the regulator is operated in a continuous mode. The input voltage is monitored. If the input voltage is not below a first input threshold level, the system remains in continuous mode. Otherwise, the system enters a burst mode in which the switch mode power supply is turned OFF, thereby reducing transistor gate charge losses.

Abstract: A downhole generator comprises a turbine coaxially disposed inside a section of drillstring and that will be spun when hydraulic or pneumatic flows are pushed through to a drillbit motor on a distal end. The turbine, in turn, spins permanent magnets in an orbit around the outside of a cylindrical containment shell. Such containment shell is made of titanium or aluminum and will allow the spinning magnets fields to enter and induce electrical currents in coils within. Current from the coils is rectified and filtered to provide a DC operating voltage through intrinsically safe connectors to various loads including drillstring steering controls, radars, and telemetry circuits. The hydraulic and pneumatic flows stream past all around the cylindrical containment shell from the turbine on their way to the drillbit motor.

Abstract: A downhole generator comprises a turbine coaxially disposed inside a section of drillstring and that will be spun when hydraulic or pneumatic flows are pushed through to a drillbit motor on a distal end. The turbine, in turn, spins permanent magnets in an orbit around the outside of a cylindrical containment shell. Such containment shell is made of titanium or aluminum and will allow the spinning magnets fields to enter and induce electrical currents in coils within. Current from the coils is rectified and filtered to provide a DC operating voltage through intrinsically safe connectors to various loads including drillstring steering controls, radars, and telemetry circuits. The hydraulic and pneumatic flows stream past all around the cylindrical containment shell from the turbine on their way to the drillbit motor.

Abstract: A billing system comprises an optical system that uses a variable magnification mirror to split-off a sample of the DWDM-carrier through traffic. A pair of wedge-filters are alternatively included to add/drop particular carriers according to their respective wavelengths. The selected carrier sample is then processed through a CISCO 12000 gigabit switch router such that billing information is output that is useful to an optical Internet backbone carrier.

Abstract: A low-noise switching regulator and a method for driving an inductive load, employing current slew control and voltage slew control, is provided. Open and closed loop embodiments, as well as first and higher order slewing, are also provided.

Abstract: A current source circuit includes at least three pairs of bipolar transistors of the same polarity type. The first transistors of each pair are connected in one series circuit string emitter to collector. The second transistors of each pair are connected in another circuit string. The first-pair second transistor is connected emitter to collector with the second-pair second transistor while the emitter of the second-pair second transistor is connected to the base of the third-pair second transistor which serves as the output transistor. The first transistors of the first and third pairs have their bases connected respectively with their collector. The bases of the two second-pair transistors are cross coupled with the collectors of the second-pair transistors.