4433 results about "Ac current" patented technology

A light engine comprises a pair of LED active elements mounted on a common header having first and second terminals. The first terminal is connected to the cathode of the first LED active element and the anode of the second LED active element, while the second terminal is connected to the anode of the first LED active element and the cathode of the second LED active element, thereby connecting the LEDs in an anti-parallel arrangement. A light engine having a single insulating or semi-insulating substrate having formed thereon plural LED active elements with associated p- and n-type contacts forming cathode and anode contacts, respectively, for each LED active element is also provided. The LED active elements may be mounted in a flip-chip configuration on a header having a plurality of leads. The header may include a pair of leads adapted such that two LEDs may be flip-mounted thereon with the anode of the first LED and the cathode of the second LED contacting one lead, while the cathode of the first LED and the anode of the second LED contact the other lead. In addition, the header may be adapted to permit a substrate having multiple active elements to be mounted thereon.

A modular apparatus for and method of alternating current photovoltaic power generation comprising via a photovoltaic module, generating power in the form of direct current; and converting direct current to alternating current and exporting power via one or more power conversion and transfer units attached to the module, each unit comprising a unitary housing extending a length or width of the module, which housing comprises: contact means for receiving direct current from the module; one or more direct current-to-alternating current inverters; an alternating current bus; and contact means for receiving alternating current from the one or more inverters.

An electrosurgical system for sealing vessels using capacitive (RF) dielectric heating and a method thereof are provided. The system includes an electrosurgical instrument having an end effector with parallel plate electrodes that will clamp onto a vessel and maintain a specified gap distance; however, the electrodes will be coated with a non-conductive dielectric material. Such an end effector will ensure that direct conduction between the electrodes does not occur through tissue or fluids and effectively creates a parallel plate capacitor with a dielectric, e.g., tissue and coating, in between the plates. The electrosurgical instrument will be activated with an AC signal at a specified RF frequency, e.g., a Debye resonance frequency, via an electrosurgical generator. An effective AC current will flow through the tissue and cause heating due to fictional losses from rotating polar molecules in the tissue.

A heater system may include an alternating current supply and an electrical conductor. Alternating current may be applied to one or more electrical conductors at a frequency between about 100 Hz and about 1000 Hz. The electrical conductors may be located in a formation. The electrical conductors may resistively heat upon application of the alternating electrical current. At least one of the electrical conductors may include an electrically resistive ferromagnetic material. The electrical conductor may provide a reduced amount of heat above or near a selected temperature. Heat may transfer from the electrical conductor to a part of formation.

A current sensor is described that uses a plurality of magnetic field sensors positioned around a current carrying conductor. The sensor can be hinged to allow clamping to a conductor. The current sensor provides high measurement accuracy for both DC and AC currents, and is substantially immune to the effects of temperature, conductor position, nearby current carrying conductors and aging.

An apparatus and method of control for converting DC (direct current) power from a solar photovoltaic source to AC (alternating current) power. A novel DC-to-AC power converter topology and a novel control method are disclosed. This combination of topology and control are very well suited for photovoltaic microinverter applications. Also, a novel variant of this control method is illustrated with a number of known photovoltaic DC-to-AC power converter topologies. The primary function of both control methods is to seek the maximum power point (MPP) of the photovoltaic source with novel, iterative, perturb and observe control algorithms. The control portion of this invention discloses two related control methods, both an improvement over prior art by having greatly improved stability, dynamic response and accuracy.

An apparatus for converting Direct Current (DC) to Alternating Current (AC), comprising a plurality of inverters, each inverter having a separate DC input adapted to be coupled to at least one solar cell defining an area of a solar panel.

A direct current arc fault circuit interrupter includes separable contacts and a trip circuit to trip open the contacts. The trip circuit includes a number of alternating current sensors structured to sense a current flowing through the separable contacts, a number of filter circuits cooperating with the AC current sensors to output a number of AC signals, a number of peak detectors cooperating with the filter circuits to output a number of peak current signals, and a processor cooperating with at least the peak detectors. The processor inputs the number of peak current signals as a plurality of peak current signals or inputs the number of peak current signals and determines the plurality of peak current signals. The processor also determines if the peak current signals exceed corresponding predetermined thresholds for a predetermined time, and responsively causes the contacts to trip open.

An AC controller which provides programmable switching of AC power flow, together with producing a source of DC power for operating the AC controller. The AC controller is connected in series with only one side of the AC power source and the AC load. The AC controller utilizes a thyristor for AC power control switching. During the operation, the AC controller steals a small portion of each half-cycle of the AC power to provide DC power to the AC controller. The AC controller enables the flow of AC current by providing a gate current pulse at any predetermined time during the half cycle. Once the thyristor is ON, the AC current flows through the thyristor until the AC cycle is at or near zero. To provide an OFF state, the AC controller does not provide a gate current pulse. The AC controller uses an microcontroller for the programmable capability. The AC controller can be programmed to provide a flashing light function, a time delay off mode, an automatic fade mode, a dimming function, a burglar deterrent function, and a time delay dim function. With a three-position switch which can replace existing types of wall switches, three modes of operation are achieved: ON, OFF, and MODE. The mode position initiates operation of the special function of the controller.

An aerosol delivery device is provided that includes at least one housing enclosing a reservoir configured to retain an aerosol precursor composition, and a heating element controllable to activate and vaporize components of the aerosol precursor composition. The aerosol delivery device also includes a power source connected to and configured to provide power to an electrical load that includes the heating element, and an induction receiver connected to the power source, the induction receiver including a resonant receiver coupling device in which an alternating current is induced when exposed to an oscillating magnetic field, and a rectifier configured to convert the alternating current to a direct current from which the power source is rechargeable.

High voltage direct current systems to connect direct current energy sources to an alternating current system. In one aspect, a system includes a plurality of direct current modules having variable direct current inputs; an inverter; and a direct current bus to connect the direct current modules to the inverter, where the bus is configured to operate at a nominal voltage higher than 100 volts and to operate within 10 percent of the nominal operating voltage.

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 bidirectional active power conditioner includes a DC side, a bidirectional DC / DC power converter, a DC / AC inverter and an AC side. The DC side electrically connects with a DC source while the AC side electrically connects with a load and an AC source. The bidirectional DC / DC power converter is controlled via high-frequency pulse width modulation (PWM) switching so as to generate a predetermined DC voltage or DC current while the DC / AC inverter is controlled to convert the predetermined DC voltage or DC current into a predetermined AC voltage or AC current.

Power is transmitted from a feeding coil L2 to a receiving coil L2 by magnetic resonance. A power circuit 200 turns ON / OFF switching transistors Q1 and Q2 to feed AC current to an exciting circuit 110, whereby the AC power is fed from an exciting coil L1 to a feeding coil L2. A phase detection circuit 150 sets the switching transistor Q2 of the power circuit 200 as a measurement target and detects the phase difference between source-drain current IDS2 and source-drain voltage VDS2 from the current phase and voltage phase thereof.

A low voltage ceiling or wall mounted light fixture for residential and commercial lighting includes a plurality of high lumen white LED lights incorporated within the fixtures, a light color diffusion panel and a household current to low voltage DC converter within the fixture to convert the AC current to low voltage DC current, reducing the power required for illumination without replacement of the LED lights.

An electric power conversion apparatus includes: a channel case in which a cooling water channel is formed; a double side cooling semiconductor module that comprises an upper and lower arms series circuit of an inverter circuit; a capacitor module; a direct current connector; and an alternate current connector. The semiconductor module comprises a first and a second heat dissipation metals whose outer surfaces are heat dissipation surfaces, the upper and lower arms series circuit is disposed tightly between the first heat dissipation metal and the second heat dissipation metal, and the semiconductor module further comprises a direct current positive terminal, a direct current negative terminal, and an alternate current terminal which protrude to outside. The channel case is provided with the cooling water channel which extends from a cooling water inlet to a cooling water outlet, and a first opening which opens into the cooling water channel.

An electric arc welding apparatus comprising at least a first consumable electrode and a second consumable electrode movable in unison along a welding path between the edges of two adjacent, mutually grounded plates, a first power supply for passing a first welding current at a first low frequency between the first electrode and the two plates, a second power supply for passing a second welding current at a second low frequency between the second electrode and the two plates, where each of the power supplies includes a three phase voltage input operated at line frequency, a rectifier to convert the input voltage to a DC voltage link and a high frequency switching type inverter converting the DC voltage link to a high frequency AC current, an output rectifier circuit to provide a positive voltage tenninal and a negative voltage terminal, and an output switching network operated at a given low frequency for directing a pulsating welding current at the given low frequency from the two terminals across one of the electrodes and the plates, and a circuit for independently adjusting the given low frequency so the value of the first low frequency of the first power supply is different from the second low frequency of the second power supply.

Systems, methods and apparatus are disclosed for using renewable energy sources as broadband AC to DC conversion. In one aspect, an apparatus configured for charging an electric vehicle is provided. The apparatus includes a power supply circuit configured to convert direct current received from a renewable power source into alternating current. The alternating current is having a frequency. The apparatus further includes a power transmit circuit configured to receive the alternating current from the power supply circuit and to provide power to charge the electric vehicle using the alternating current. The power transmit circuit is further configured to substantially resonate at the frequency of the alternating current.

An electric arc welding system for creating an AC welding arc between an electrode and a workpiece wherein the system comprises a first controller for a first power supply to cause the first power supply to create an AC current between the electrode and workpiece by generating a switch signal or command with polarity reversing switching points in the first controller, with the first controller operated at first welding parameters in response to first power supply specific parameter signals to the first controller. The system has at least one slave controller for operating a slave power supply to create an AC current between the electrode and workpiece by reversing polarity of the AC current at switching points where the slave controller is operated at second welding parameters in response to second power supply specific parameter signals to the slave controller. An information network connected to the first controller and the slave controller and containing digital first and second power supply specific parameter signals for the first controller and the slave controller and a digital interface connects the first controller with the slave controller to control the switching points of said second power supply by the switch signal or command from the first controller.

The invention relates to a drive circuit for driving an LED array. In order to allow driving the LED array based on an AC current supplied by an electronic ballast circuit for driving a fluorescent lighting device, the invention provides for a power supply sub-circuit converting the supplied AC current to a DC current and at least partially storing energy of the converted DC current for driving the LED array. Further, the power supply sub-circuit is connected / disconnected to / from at least one of first or second terminals in response to the presence / absence of the AC current supplied via a terminal of at least one of the first or second terminals. Accordingly, the power supply sub-circuit is connected to the first and second terminals only when the supplied AC current is simultaneously supplied via a terminal of each of the first and second pair of terminals.

A photovoltaic (PV) energy system includes a pulsed bus defined by a non-zero average value voltage that is proportional to a rectified utility grid AC supply voltage. The PV energy system also includes a plurality of PV modules, each PV module including a bucking circuit configured to convert a corresponding PV voltage into a pulsing current, wherein the pulsating bus is configured to sum the pulsing currents produced via the plurality of PV modules such that a resultant pulsing current is injected into the pulsating bus in phase with the non-zero average value voltage. A current unfolding circuit is configured to control the amount of AC current injected into the utility grid in response to the resultant pulsing current.

A method for coupling at least one of a wall mount and a ceiling mount adjustable IR driver with a two way IR network of a home automation system controlled by a main controller selected from a group comprising a dedicated controller, a video interphone and a shopping terminal, the IR driver includes a plurality of adjustable IR transmitters and at least one IR receiver for propagating IR commands to at least one of hand held IR remote control units, electrical appliances and devices selected from a group comprising a remotely operated relays, an AC current sensors and a keypads, and for receiving from at least one of the devices a status data, said IR commands include at least a power on-off command for switching an appliance on and off and the status data pertaining to the on and off statuses of a commanded appliance.

The invention discloses an adapter. A mobile terminal is charged through a data line, and a source end connector is used for receiving required charging voltage and required charging current from the mobile terminal. A control unit is used for obtaining the charging voltage and the charging current. The control unit is used for comparing the charging voltage and the charging current with the required charging voltage and the required charging current respectively, and a control signal is generated when the charging voltage and the charging current are different from the required charging voltage and the required charging current. A PWM (Pulse-Width Modulation) driving module is used for adjusting an output pulse signal according to the control signal so as to control the start frequency of a switch unit and change a third alternating current, and thus the charging voltage and the charging current are adjusted to the required charging voltage and the required charging current. In the charging process of the adapter, the adapter outputs voltage and current matched with the required charging voltage and the required charging current of the mobile terminal, and thus the charging effect of the mobile terminal is better.

An induction choke in a petroleum well where a voltage potential is developed across the choke to power and communicate with devices and sensors in the well. Preferably, the induction choke is a ferromagnetic material and acts as an impedance to a time-varying current, e.g. AC. The petroleum well includes a cased wellbore having a tubing string positioned within and longitudinally extending within the casing. A controllable gas lift valve, sensor, or other device is coupled to the tubing. The valve sensor, or other device is powered and controlled from the surface. Communication signals and power are sent from the surface using the tubing, casing, or liner as the conductor with a casing or earth ground. For example, AC current is directed down a casing or tubing or a lateral where the current encounters a choke. The voltage potential developed across the choke is used to power electronic devices and sensors near the choke. Such induction chokes may be used in many other applications having an elongated conductor such as a pipe, where it is desirable to power or communicate with a valve, sensor, or other device without providing a dedicated power or communications cable.

The present invention provides a highly reliable electric power converter reduced in parasitic inductance.An electric power converter that includes a capacitor module which has a DC terminal, an inverter which coverts a direct current into an alternating current, and heat release fins which cool the inverter, is constructed so that: the inverter has a power module including a plurality of power semiconductor elements; the power module further has a metallic base, a dielectric substrate provided on one face of the metallic base, a power semiconductor element fixed to the dielectric substrate, and a DC terminal; the metallic base has the heat release fins on the other face; the DC terminal in the power module and the DC terminal in the capacitor module are each formed by stacking flat plate conductors via an insulator; the two positive and negative DC terminals have respective front ends bent in opposite directions; a plane including the bent sections is used as a surface for connecting the power module and the capacitor module; and the insulators overlap each other at the connection surface.

An integral method for realizing parallel generation and network reactive power compensation at the same time is based on the transient reactive power theory applying park transfer to transform a three phase inverter output current to a rotation dq coordinate to realize separation of active current and reactive current to convert the DC current of the photovoltaic to AC current by controlling the currents and directions carry out reactive power compensation to the local network. When a photovoltaic battery has enough energy to output, it realizes parallel generation and reactive compensation at the same time, when it stops the output, the inverter compensates the network independently.