4667 results about "AC - Alternating current" patented technology

The present invention provides an apparatus and a method for producing a virtual electrode within or upon a tissue to be treated with radio frequency alternating electric current, such tissues including but not limited to brain, liver, cardiac, prostate, breast, and vascular tissues and neoplasms. An apparatus in accordance with the present invention includes a source of super-cooled fluid for selectively providing super-cooled fluid to the target tissue to cause a temporary cessation of cellular or electrical activity, a supply of conductive or electrolytic fluid to be provided to the target tissue, and alternating current generator, and a processor for creating, maintaining, and controlling the ablation process by the interstitial or surficial delivery of the fluid to a tissue and the delivery of electric power to the tissue via the virtual electrode. A method in accord with the present invention includes delivering super-cooled fluid to the target tissue to cause a temporary cessation of cellular or electrical activity, evaluating whether the temporary cessation of cellular or electrical activity is the desired cessation of cellular or electrical activity, and if so, delivering a conductive fluid to the predetermined tissue ablation site for a predetermined time period, applying a predetermined power level of radio frequency current to the tissue, monitoring at least one of several parameters, and adjusting either the applied power and / or the fluid flow in response to the measured parameters.

An electro-active lens is disclosed. The lens includes at least one electro-active cell to provide a lens having at least two focal lengths, the electro-active cell capable of adjusting its focal length based on voltages applied to the electro-active cell. The voltage is supplied by an alternating current source, including a flying capacitor circuit. The electro-active lenses reduce birefringence through the use of a single cholesteric liquid crystal electro-active cell.

The present invention takes the form of a current limiting apparatus and method for limiting current flow, induced when the level of an external signal is greater than an external signal threshold signal level, in a conductive loop formed by a medical device implanted within a living organism having electrically excitable tissue. The system includes an implantable pulse generator (IPG) system having a housing, a signal generator disposed in the housing that generates an electrical signal, and at least one lead extending from the housing to convey electrical signal to the patient. To limit the induced current flow, the IPG includes current limiting componentry, an impedance increasing element, and / or alternating current blocking elements. These components provide an alternating current impedance path to the electrical ground from a lead coupled to the capacitive element. Also disclosed are techniques for reducing the effective surface area of the current inducing loop caused by the IPG system.

A lighting system for low temperature environments includes a plurality of light emitting diodes attached to a support member mounted within a refrigeration unit or the like for illuminating contents thereof. A reflector is disclosed adjacent to the light emitting diodes for dispersing the light therefrom. A light transmitting cover overlies the light emitting diodes, and preferably includes non-planar surfaces for dispersing light onto objects within the refrigeration unit. A power supply converts alternating current voltage to a lower direct current voltage for powering the light emitting diodes in a safe manner.

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.

A touch panel device includes a touch panel including first and second electrodes, an alternating-current (AC) signal source operable to input an AC signal into the first electrode, an inductive element electrically connected in series between the AC signal source and the first electrode, and a detection circuit operable to detect a change of a capacitance between the first electrode and the second electrode upon a touch of an object on the touch panel, based on a change of a signal output from the second electrode. This touch panel device can enhance detection sensitivity with a simple configuration.

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.

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.

We disclose an apparatus capable of receiving control command data for one or more electrical fixtures and modulating an alternating current by modifying firing phase angles to transmit the data corresponding to the control commands via a power line transmitting the alternating current.

The invention discloses a system and a method for supplying power cooperatively by a mains supply, a photovoltaic cell and an energy storage battery. The method comprises the steps of firstly, acquiring a maximum output power and a load required power of the solar photovoltaic cell; if the maximum output power is greater than the load required power, starting the solar photovoltaic battery to supply power and charge the battery; and if the maximum output power is less than the load required power, starting the battery to supply power or starting the mains supply to supply power. According to the system and the method, the photovoltaic cell, the mains supply and the battery used as energy sources pass through self converters to have a unified output standard, and supply power to a bus, and each load receives energy from the bus through a DC-DC (direct current) converter and a DC-AC (alternating current) converter. Based on the structure design of the bus, various loads, including AC loads or DC loads, even loads with different voltages, in a power supply system can be satisfied, so that the structure can concurrently take different power supply requirements of various loads into consideration, can facilitate the expansion of the system, and also can facilitate the application of the system in different situations, therefore, the system and the method disclosed by the invention are wide in application range.

Tumors in portions of a subject's body that have a longitudinal axis (e.g., the torso, head, and arm) can be treated with TTFields by affixing first and second sets of electrodes at respective positions that are longitudinally prior to and subsequent to a target region. An AC voltage with a frequency of 100-500 kHz is applied between these sets of electrodes. This imposes an AC electric field with field lines that run through the target region longitudinally. The field strength is at least 1 V / cm in at least a portion of the target region. In some embodiments, this approach is combined with the application of AC electric fields through the target region in a lateral direction (e.g., front to back and / or side to side) in order to apply AC electric fields with different orientations to the target region.

A conductive rubber roller 10 having a conductive rubber layer 1, containing chloroprene rubber, which composes an outermost layer thereof. When an alternating current is applied to the conductive rubber roller 10 at a voltage of five and a frequency of 100 Hertz, a dielectric loss tangent is 0.1 to 1.8.

A probe instrument using room-temperature sensor(s) that can measure variations in magnetic susceptibilities. The instrument has sufficient resolution to monitor paramagnetic materials in a human body, such as iron in a human liver, by noninvasively examining patients with iron-overload diseases. The instrument includes room temperature magnetic sensors, and detects the sample, that is, the tissue response to an alternating current field applied by an applied field coil. The applied field coil dimensions are chosen so that the applied field is optimized for maximum response from the liver while minimizing the effects due to the overlying abdominal tissue and at the same time not unduly increasing the sensitivity of the instrument to the lung. To overcome variations in the sensor output due to fluctuations in the applied field, change in the ambient temperature and mechanical relaxation of the instrument, the sensor-sample distance is modulated. The detector assembly is oscillated while the examined patient remains stationary. An improved water-bag technique is employed to eliminate background tissue response. The detector assembly forms part of a probe instrument for performing noninvasively the paramagnetic concentration of a patient.

A position indicator is provided for use with a position detecting sensor that carries out position detection by detecting a change in capacitance. The position indicator includes: a first electrode configured to receive an alternating-current (AC) signal from the position detecting sensor; a signal enhancing processing circuit configured to subject the AC signal received via the first electrode to determined signal enhancing processing; and a second electrode different from the first electrode and configured to be supplied with a signal output from the signal enhancing processing circuit. An enhanced signal having a determined correlation with the AC signal received via the first electrode from the position detecting sensor is formed while the enhanced signal is sent out to the position detecting sensor via the second electrode.

A MRI system for acquiring MRI image data comprising a data acquisition means comprising a plurality of subunits for acquiring MRI image data, a power distribution means for providing the means for acquiring MRI image data with electrical power, the power distribution means comprising: a power supply unit adapted for providing direct current electrical power from an alternating current electrical mains, a power bus adapted for supplying the subunits with the direct current electrical power, control means for controlling the supply of direct current electrical power by the power bus to the subunits.

A scan driver IC for an EL element in an EL display device supplies, in a positive field, a positive polarity scan voltage and an offset voltage which is higher than ground to scan side driver ICs from voltage supply circuits, and the scan side driver ICs set voltage of scan electrodes to be the offset voltage in the positive field, together with outputting the positive polarity scan voltage to the scan electrodes during electroluminescence timing. Consequently, a voltage of Vr-Vm is applied to the scan side driver ICs, and so the breakdown voltage can be lowered by an amount corresponding to the offset voltage Vm. Circuits for providing such voltages, for providing alternating current drive voltages, and for reducing power consumption of the drive circuits are also disclosed.

The present invention provides a synchronous motor drive system designed to realize reduced vibration and noise along with high output. The system includes: inverters 101, 102, and 103 for converting a direct current to a three-phase alternating current; a current application control unit 52 that controls operations of the three-phase inverters; and a synchronous motor 41 driven by three-phase alternating currents supplied from the three-phase inverters. The current application control unit 52 determines, for each three-phase inverter, a current phase angle and a current amount of a three-phase alternating current to output, and each inverter supplies a three-phase alternating current having the determined current phase angle and current amount to a different one of three-phase coil groups 200a to 200c.

A electric motor drive apparatus comprising a voltage control unit performing voltage control processing that determines alternating-current voltage command values serving as command values of the alternating-current voltages to be supplied to the alternating-current electric motor and generates switching control signals for the inverter; and a control mode selection unit selecting a synchronous control mode in which a cycle of electric angle of the alternating-current electric motor is synchronized with a switching cycle of the inverter, or an asynchronous control mode in which the cycles are not synchronized with each other. Current detection processing is performed to detect currents flowing in coils of the alternating-current electric motor in every standard calculation cycle that is set to a half of a cycle of the carrier.

A system and method includes a controller that is configured to coordinate (i) a low impedance path for a dimmer current, (ii), control of switch mode power conversion and (iii) an inactive state to, for example, to allow a dimmer to function normally from cycle to cycle of an alternating current (AC) supply voltage. In at least one embodiment, the dimmer functions normally when the dimmer conducts at a correct phase angle indicated by a dimmer input setting and avoids prematurely resetting while conducting. In at least one embodiment, by coordinating functions (i), (ii), and (iii), the controller controls a power converter system that is compatible with a triac-based dimmer. In at least one embodiment, the controller coordinates functions (i), (ii), and (iii) in response to a particular dimming level indicated by a phase cut, rectified input voltage supplied to the power converter system.

A system and method are provided for attracting a magnetically responsive substance inserted in a subject's body towards a target area within the body to treat the area. The system generally comprises a medical device having a proximal end, a distal end, and at least one magnetic element disposed at the distal end of the medical device for orienting the distal end in a desired direction to place an aperture against the opposite wall of the vessel. The system further includes a voltage that may be applied to a coil that is disposed on the side of the medical device and proximally spaced from the magnetic element. A voltage is applied to the coil to attract the magnetically responsive substances inserted into the body around the coil. A high frequency alternating current voltage is applied to an adjacent transducer to ultrasonically disperse the collected magnetically responsive substances into the surrounding target tissue.

The invention may be broadly conceptualized as an approach in which a intelligent controller (102) is in communication with appliances (116-122) over the alternating current home wiring and is in communication with a user profile (204) contained in a database (202) at a web server (104) via a modem (206) enabling configuration and programming of the appliances (116-122) to occur over a web device (112) in addition to time synchronization of the clocks in the intelligent controller (102) and appliances (116-122) with the web server (104) in order to maintain the correct time.

A switching regulator includes a switching transistor, an inductor, a feedback voltage generator, a hysteresis comparator circuit, and a feedback loop circuit. The switching transistor alternately switches on and off. The inductor charges when the switching transistor is on. The feedback voltage generator generates a first feedback voltage by dividing an output voltage. The hysteresis comparator circuit has a voltage comparator to compare the first feedback voltage against a reference voltage to output a comparator output signal as a result of the comparison. The feedback loop circuit feeds the comparator output signal back to the feedback voltage generator to generate a second feedback voltage. The first feedback voltage has an alternating current component substantially dependent on the second feedback voltage varying with the comparator output signal.

An apparatus for DC fast charging of an electric vehicle includes an active front end AC-DC converter and an isolated DC-DC converter. The active front end AC-DC converter is adapted to rectify a medium voltage alternating current (AC) from a utility grid to a high voltage direct current (DC). The isolated DC-DC converter is adapted to transform the high voltage DC to a low voltage DC for charging the electric vehicle.

An image forming apparatus, includes an image bearer to bear a toner image; a transfer member to transfer the toner image; a transfer bias applicator to apply a transfer bias to the transfer member, the transfer bias applicator including a direct current voltage source to apply a direct current transfer bias constituted by a direct current voltage to the transfer member; and a superimposed voltage source to apply a superimposed transfer bias in which an alternating current voltage is superimposed on a direct current voltage to the transfer member; and a controller to switch between a direct current transfer mode during which the direct current transfer bias is applied to transfer the toner image and a superimposed transfer mode during which the superimposed transfer bias is applied to transfer the toner image while the direct current voltage source and the superimposed voltage source are off.

A soft-load power distribution system includes a transfer switch having a first input to a utility power source with a utility alternating current (AC) voltage, a second input to a generator power source with a generator AC voltage, and an output to a load. A first switch is electrically connected between the first input and the output and a second switch is electrically connected between the second input and the output. The transfer switch has a third input, such as a go to emergency input, controlling the first and second switches. A bypass switch is electrically connected between the second input and the output. First and second sensors, such as potential transformers, sense the utility and generator AC voltages, respectively. A controller closes the bypass switch when the utility AC voltage is within a predetermined range of the generator AC voltage, and includes an output controlling the third input.

An object of the present invention is to detect characteristics of images such as blurring and the like without expanding compressed and stored image data. And, the above-described detection is realized by detecting image characteristics on the basis of attached information of an image, such as relation between low frequency components and high frequency components of alternate current components and contents of a quantization table of image data compressed by a compression system for converting image data into spatial frequency components. In addition, for example, as a result of detection, an image discriminated to be in a blurred state is controlled so as not to be inserted into an album template or to be inserted into a small area inside the album template. Thereby, a user can omit work of picking and choosing images to insert into an album template while taking a look at a lot of images.

An AC power source is connected to a write coil mounted on a head slider for determination of contact of a head slider with a storage medium. The AC power source outputs the alternating current having a specific frequency. A measuring circuit measures a sequence of indices for the alternating current supplied to the write coil. A component corresponding to the specific frequency is extracted from the sequence of the indices. This serves to eliminate components corresponding to frequencies other than the specific frequency, namely noise. A detecting circuit detects contact between the head slider and the storage medium based on a change in the amplitude of the sequence appearing at the specific frequency. The contact can thus reliably be detected between the head slider and the storage medium.