4663 results about "AC - Alternating current" patented technology

A method and system for enhancing computer peripheral safety is provided. In accordance with various aspects of the present invention, the exemplary method and system are configured to monitor and / or isolate alternating current (A.C.) supplies with and / or from any peripheral subsystems or devices. An exemplary method and system comprises an A.C. supply, a host computer system, and a peripheral subsystem or device connected to the host computer system, such as an ultrasound imaging and / or therapy peripheral, and an isolation subsystem configured for monitoring and / or isolating the A.C. supply from the peripheral subsystem or device. In accordance with an exemplary embodiment, an isolation subsystem comprises application software and associated modules and functions that when executed continuously monitors and / or polls the host computer's hardware and / or operating system for the presence of an isolated source, such as a battery, or an unisolated power source, such as through a battery charger and / or other connection path to the A.C. main supply. In accordance with other exemplary embodiments, an isolation subsystem can comprises a wireless or other safe / isolated electrical link for connecting a patient contact device, and / or a verification link or other verification mechanisms configured between an isolation transformer and host computer to monitor or observe usage to power the host computer and peripheral subsystem.

The motor includes an E-core stator assembly with a source of alternating current and an armature portion mounted to be responsive to the stator to oscillate back and forth through an arc portion of the personal care appliance and flexure elements are connected between the armature and the mounting member, the flexure elements crossing each other, wherein the crossing point defines a pivot point about which the armature rotates. A workpiece assembly, which includes a mounting arm, is configured so that a skin brush mounted on a free end of the mounting arm has an axis of rotation about the pivot point.

Methods and apparatus are disclosed for canceling or eliminating borehole eccentricity effects on a formation resistivity measurement obtained with transmitter and / or receiver antennas which are substantially time varying magnetic dipoles with their dipole moments aligned at an angle to the axis of the borehole. Various apparatus are configured with a plurality of antennas having tilted or transverse magnetic dipole moments, at least one current sensor, means for conducting alternating current through one or more of the antennas, and means for calculating a scaling factor from signal measurements and for scaling the alternating current with the factor. One method includes scaling an alternating current and passing said current through one or more antennas to obtain the resistivity measurement. Another method includes calculating scaling factors based on spacings between antennas and / or current sensors disposed on an instrument and passing alternating currents scaled by said factors through one or more antennas to obtain the resistivity measurement. Another embodiment includes inputting a borehole fluid resistivity value to derive the formation resistivity.

A system for independent control of electric motors and electric lights includes a plurality of two-wire wallstations coupled in series via power wires between an alternating-current (AC) source and a light / motor control unit. The light / motor control unit is preferably located in the same enclosure as an electric motor and an electric light and has two outputs for independent control of the motor and the light. The light / motor control unit and the wallstations each include a controller and a communication circuit that is coupled to the power wiring via a communication transformer and communicate with each other using a loop current carrier technique. The light / motor control unit and the wallstations utilize pseudo random orthogonal codes and a median filter in the communication process.

The invention provides electronic equipment with high voltage and high power, which is used for converting alternating current (AC) voltage into direct current (DC) voltage or converting DC voltage into AC voltage, in particular a thyristor converter valve module. A whole valve module is divided into two same segments, and each segment comprises a saturable reactor, a thyristor, a DC equalizing resistor unit, an energy-extracting resistor unit, a damping resistor unit, a damping capacitor unit, a gate electrode unit and a water cooling system, wherein the reactors of the electronic equipment are connected in series to meet the requirements on different transmission powers and different power voltage grades. The equipment is core equipment for high-voltage DC power transmission and can be applied to a DC-AC converting system, meet the requirements of different voltage grades and for the DC converting system with different voltage grades, including the super high voltage of 800 kV or above.