2277 results about "DC - Direct current" patented technology

An method and method for generating an electrical signal for use in biomedical applications, including two timing-interval generators, each optionally driving a multistep sequencer; analog, digital or hybrid means for combining the resulting timed signals into a complex electrical signal; optional filtering means for blocking direct current, removing selected frequency components from the resulting signal, and / or providing voltage step-up if needed; and conductive means for coupling the resulting signal to a human or animal body, food, beverage or other liquid, cell or tissue culture, or pharmaceutical material, in order to relieve pain, stimulate healing or growth, enhance the production of specific biochemicals, or devitalize selected types of organisms.

A tissue cutting device includes a catheter with a window at its distal tip for admitting tissue into a catheter compartment. A cylindrical cartridge in the compartment has a cutting edge that supports an electrically conductive cutting element, e.g. a band or wire. The cutting element and adjacent tissue can be heated to a selected temperature by generating an electrical current through the cutting element. The catheter is maneuverable to position its distal end near the tissue to be cut. The catheter incorporates a dilatation balloon or other feature to urge the catheter against the tissue, so that at least part of the tissue may enter the compartment through the window. Then, the cartridge is manipulated from the catheter's proximal end to move the cutting edge across the window, cutting the tissue. According to alternative embodiments, the cartridge is either rotated or moved axially relative to the catheter and, in either event may be capable of closing the catheter window when the cut is complete. Further alternatives involve either placing an indifferent electrode on the patient and providing an RF signal via a single conductor to the cutting element for ohmic heating, or providing an RF (or a DC) current through the cutting element and two separate conductors for direct resistive heating of the cutting element.

A method and apparatus for the concurrent treatment of multiple oral diseases and defects while promoting general oral hygiene utilizing direct current electricity. Electrodes are used to deliver a direct current to the gingival tissues of a mouth in order to achieve a number of therapeutic, prophylactic, and regenerative benefits. These benefits include killing oral microbes, increasing oral vasodilation, improving oral blood circulation, reversing oral bone resorption, promoting oral osteogenesis, treating gum recession, and fostering gingival regeneration. Other benefits include the treatment of gingivitis, perdiodontitis, and oral malodor while also promoting general oral hygiene.

A controlling and monitoring system for irrigation of localized areas of soil includes a water pipeline, a plurality of controllable irrigation valves, a plurality of field sensors measuring specific irrigation parameters, and a plurality of localized irrigation control units. Each of the control units has a sensor decoder connected to a specific one of the field sensors and a line decoder connected to a specific one of the irrigation valves. The system further includes a controller and power supply unit that applies a first alternating DC voltage signal to a two-wire cable interconnecting the controller and power supply unit and the control units. The cable provides power from the controller and power supply unit to each of the control units. The controller and power supply unit transmits schedules of instructions to the control units, and receives the irrigation parameters from the control units, through the cable.

The invention discloses an intelligent mobile charging automobile system and method. The system comprises a charging automobile, a large-capacity energy storage battery pack, a DC-DC direct-current converter A, a vehicle-mounted charger, a charging connection device, a charging transfer device, a ground track, a mobile phone client terminal, a scheduling center server and a charging room, wherein the scheduling center server comprises a wireless communication unit, a data receiving unit, a data processing unit and a data feedback unit; the charging automobile comprises a driving system, a whole-automobile controller, a wireless communication module, a sound-light alarm module, a tracking detection module and an obstacle avoidance detecting module. According to the intelligent mobile charging automobile system, navigation and landmark tracks are mounted and paved on the ground on the basis of the existing facilities of parking lots; the charging transfer device is mounted on the ground of the preserved charging automobile parking space; the automatic connection charging is implemented; the problem that charging stations and charging piles are inconveniently built in the existing parking lots can be solved; the system is simple and convenient; the building cost and the maintenance cost are greatly reduced; and the charging time is reduced.

Enclosed is an active and reactive coordination control method for permanent-magnet direct-driven wind turbines in the low-voltage ride-through process. Two different control strategies are employed for a grid side converter according to amplitude change of power grid voltage: when the power grid voltage is in a normal state, the grid side converter is in an active-priority maximum power tracing control mode so that the wind turbines capture wind energy to the maximum extent; when the power grid voltage is beyond the normal range, the grid side converter is in an active priority control mode so that the dynamic reactive current which is injected into an electricity system meets the requirements of grid combining. An engine side converter is in a direct-current voltage control mode based on rotor energy storage, power unbalance of the direct-current side of the engine side converter is relieved and the direct-current voltage is stabilized by utilizing the self rotating speed of the permanent-magnet direct-driven wind turbines and the change of the kinetic energy. The active and reactive coordination control for the wind turbines before or after the sudden change of the power grid voltage is realized according to the amplitude change of the power grid voltage, the fluctuation of the direct-current bus voltage is restrained by releasing or storing the rotor kinetic energy, so that the low-voltage ride-through capability of the permanent-magnet direct-driven wind turbines is improved, reactive power support is rapidly and accurately provided for the power grid, and certain support is given to restoration of the power grid voltage.

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.

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.

A distributed power system for delivering DC power to a plurality of loads. A plurality of power converter modules having associated therewith a DC / DC power conversion operation are provided, each disposed proximate an associated one of the loads, each of said converter modules having associated therewith a switching pulse generator for generating switching pulses. A distributed power line distributes input power to each of the modules. A data communication line distributes command data between the modules. Each of the modules includes a power regulation section for receiving the input power to generate a DC output by controlling the operation of the switching pulse generator. It also includes a processing section for interfacing with the data communication line for interfacing with the commands, the processing function operating in at least a slave mode to receive commands from the data communication bus. At least one of the modules operates in both a slave mode and a master mode. In the master mode, the processing section generates commands for transmission over the data communication line to an addressed one of the other of the modules and internally for use in the local slave mode of operation. The processing section in the slave mode of operation is operable to configure and monitor the operation of the power regulation section.

This invention relates to a method for electrowinning of titanium metal or titanium alloys from electrically conductive titanium mixed oxide compounds in the liquid state such as molten titania slag, molten ilmenite, molten leucoxene, molten perowskite, molten titanite, molten natural or synthetic rutile or molten titanium dioxide. The method involves providing the conductive titanium oxide compound at temperatures corresponding to the liquid state, pouring the molten material into an electrochemical reactor to form a pool of electrically conductive liquid acting as cathode material, covering the cathode material with a layer of electrolyte, such as molten salts or a solid state ionic conductor, deoxidizing electrochemically the molten cathode by direct current electrolysis. Preferably, the deoxidizing step is performed at high temperature using either a consumable carbon anode or an inert dimensionally stable anode or a gas diffusion anode. During the electrochemical reduction, droplets of liquid titanium metal or titanium alloy are produced at the slag / electrolyte interface and sink by gravity settling to the bottom of the electrochemical reactor forming, after coalescence, a pool of liquid titanium metal or titanium alloy. Meanwhile carbon dioxide or oxygen gas is evolved at the anode. The liquid metal is continuously siphoned or tapped under an inert atmosphere and cast into dense and coherent titanium metal or titanium alloy ingots.

The invention discloses a high-focusing-capability multi-channel transcranial direct current stimulation device and a control method thereof. The high-focusing-capability multi-channel transcranial direct current stimulation device comprises a transcranial direct current stimulation (tDCS) electrode array, a power source and control units, wherein channel electrodes in the electrode array are connected with the power source respectively through independent control units, polarity and current strength of the channel electrodes are respectively controlled through the independent control units, and the tDCS electrode array is integrated into an electrode cap mode. The high-focusing-capability multi-channel transcranial direct current stimulation device can complete automatic optimization of stimulation parameters of the channels according to stimulation positions and types specified by users, and finally generates stimulation meeting users' requirements. A tDCS system of the high-focusing-capability multi-channel transcranial direct current stimulation device has the advantages of being capable of covering the whole head, having high focusing capability and multiple channels and the like, and is accurate in stimulation position and customizable in complex stimulation.

The invention discloses a hydraulic transmission-based method and a hydraulic transmission-based device for storing energy and realizing stabilized voltage and constant frequency in wave power generation. In the device, a floating pendulum is connected with a hydraulic cylinder, high pressure oil outputted by a non-rod cavity of the hydraulic cylinder enters a high pressure energy storing device and an oil inlet of a variable motor through a control integrated valve and through a high pressure oil tube, low pressure oil outputted by an oil outlet of the variable motor enters a low pressure big-capacity energy storing device and returns to the rod cavity of the hydraulic cylinder through the control integrated valve, the main shaft of the variable motor is connected with a permanent magnet synchronous generator, and the permanent magnet synchronous generator is connected to a rectifying module and a direct-current electric energy charging-discharging control module and then connected to a stepless unload adjustable load and a storage battery. The high pressure energy storing device and the low pressure big-capacity energy storing device realize the energy storage by absorbing the fluctuation, caused by the change of transient waves, of pressure and flow rate. A controller realizes the pressure stabilization constant frequency by the stepless unload adjustable load and the displacement of the hydraulic motor respectively. The device has the advantage of making the wave power generating device output more smoothly, more free from influence of the wave impact and have higher efficiency.

The invention discloses a four-phase brushless DC motor fault-tolerant power converter and a control method thereof. The four-phase brushless DC motor fault-tolerant power converter comprises five inverting bridge arms, six bidirectional thyristors and ten fuses, a four-phase winding is connected to the midpoints of four of the bridge arms after forming two mutually-isolated channels, and the fifth bridge arms is a redundant bridge arm and only works during fault-tolerant operation; every power tube on every bridge arm is connected in series with a corresponding fuse, which can protect the system from being burnt due to short circuit faults and can convert the short circuit faults into open circuit faults for fault tolerance when the short circuit fault occur. The midpoint of every bridge arm is connected with a bidirectional thyristor for achieving fault tolerance of the power tubes; the neutral point of the winding and the midpoint of the fifth bridge arm are also connected with one bidirectional thyristor for achieving fault tolerance of the winding. The four-phase brushless DC motor fault-tolerant power converter is applicable to a four-phase permanent-magnetic brushless DC motor and a double-salient motor and can achieve open circuit and short circuit fault tolerance of power tubes and windings.

A compressor for producing compressed air, in particular for a compressed air supply system of a vehicle, includes an electric motor in the form of a brushed direct current electric motor. The compressor has at least one first and one second compressor step, which can be driven by the electric motor. The motor can be controlled by means of an electronic control module of a control device by limiting an operational flow of the motor.

The invention relates to solar photovoltaic generating applications, and in particular relates to a multi-mode photovoltaic generating system, wherein the multi-mode photovoltaic generating system mainly adopts off-grid power generation, and can release gird-connected power generation as for the surplus electric energy which is not consumed completely by a DC (direct-current) emergency load and storage batteries. The system comprises a controller, solar-cell arrays, a storage battery, the DC emergency load, a grid-connected inverter and a public distribution network, wherein a part of DC electric energy output by the solar-cell arrays is supplied for the DC emergency load by a DC bus, and the other part of the DC electric energy output by the solar-cell arrays is stored in the storage batteries. When the voltage of the DC bus is out of the normal range, the storage batteries supply the energy for the DC emergency load by a charge-discharge controller; and when the storage batteries finish the charging and the voltage of the DC bus is within the normal range, the surplus DC electric energy can be converted into AC (alternating-current) electric energy by a DC boost converter and a grid-connected inverter and then the AC electric energy is transmitted to the public distribution network. The system provided by the invention can improve the efficiency and the time of annual power generation of the system, and has good application prospects.

The invention relates to a method for recovering lead in a waste lead-acid battery filler by using a wet process, which comprises the following steps of: taking and adding sodium hydroxide and xylitol into water, agitating and dissolving at a normal temperature to prepare mixed solution; adding obtained lead paste powder in the mixed solution, reacting for 1-5 hours and taking a filtered filtrate as an electrolyte; adopting a pure lead plate or a stainless steel plate as a cathode; and adopting the stainless steel plate as an anode and switching on direct current for electrolysis. The method has the beneficial effects that the method of directly leaching lead paste is adopted; the processes of desulfurization and reductive transformation are not required, so that the process flow is simplified; the sodium hydroxide and xylitol solution are adopted when the lead paste is leached and can form a compound with lead oxide to leach the lead in the lead paste to a utmost extent, so that the sulfur dioxide and various smoke and dust generated in the pyrometallurgical recovery process are avoided, and the straight yield of the lead is improved; and volatile smoke and dust or acid mist can not be generated, so that the defect that a silicon fluorine acid electrolyte pollutes the environment and is harmful to human health is overcome.

A power supply device to supply power to a micro server includes a plurality of power supplies configured to be redundant and supply DC power, and an output unit to output the DC power output from the plurality of power supplies to the micro server, wherein one of the plurality of power supplies operates in a master mode and the remaining power supplies operate in a slave mode, and wherein if a load of the micro server is less than or equal to a first predetermined load, at least one of the power supplies that operate in the slave mode does not output the DC power.

A portable integrated self-contained rechargeable with AC-DC direct current battery system mounted within an instrument case for housing a foldable keyboard, a display and plurality of medical test and treatment modules. It optionally includes a suitable DC to AC inverter to supply AC power. The system includes at least one USB port for adding external test and treatment modules on ad hoc basis. It also includes full duplex data and information input, processing output and communications interface to and from sensors, transducers, networks and other data / information generation or consumption modules, devices and subsystems. It is also known by its three trademark names “Hospital-in-a-Box”, RK Ruskat (Stylized) and SCOMET.

The invention discloses a system and a method for controlling the speed PID of a direct current (DC) motor, belonging to the field of DC motor control. The structure comprises a controller, a power drive unit, a controlled object and a speed detection sensor, wherein, the controller comprises a comparator, a proportioner, an integrator and an adder; the controlled object comprises a DC motor and a mechanical load; the control method of the control system comprises the steps as follows: an equivalent damping parameter K and an equivalent inertia parameter A of the controlled object are recognized; furthermore, an proportion control parameter KP and an integral control parameter KI of the controller are adjusted. During the debugging process of the control system, the controller parameters can be adjusted effectively, the blindness of adjusting the PID controller parameter is avoided so that the time and energy are saved, and the best speed control effect can be obtained.

The invention discloses a multifunctional solar-powered intelligent monitoring traffic signal unmanned directing post. The multifunctional solar-powered intelligent monitoring traffic signal unmanned directing post includes a square umbrella seat, a hollow-core support main rod, a solar energy amorphous silicon film cell panel and a plurality of plumbic acid storage batteries connected in series, the hollow-core support main rod is mounted on the square umbrella seat, is square and is made of stainless steel, the square umbrella seat is internally equipped with the plumbic acid storage batteries and a control box, and an LED illuminating lamp, vehicle traveling arrow lamps, traffic lights, network monitoring cameras, a traffic prompt sound box, a detachable direct current electric fan, a charging interface and a traffic prompt screen are arranged on the hollow-core support main rod in sequence from top to bottom. The multifunctional solar-powered intelligent monitoring traffic signal unmanned directing post provided by the invention is light in weight, foldable and movable, automatically starts a passing signal, provides clean electric power energy, obtains power supply anytime anywhere, and can be used by traffic police, border guards and personnel on duty at intersections.

The invention discloses an electric bicycle control method based on a permanent magnet brushless direct current motor. According to the method, subdivided rotor position information is used for directly starting the motor, and the switching procedure from square wave starting to sine wave starting in a traditional control method is omitted. The electric bicycle control method relates to a rotor section calculation module, a speed calculation module, an angle subdivision module, a phasing adjustment module, a speed control module, a current-limiting control module, a waveform modulation module, a three-phase inverter and a motor starting module. By the adoption of the method, control efficiency and control performance are improved, and currents passing through a motor winding are in a sine wave mode when the motor operates; compared with a traditional square wave control method, torque pulsation is small, motor running noise is low, and the service life of the motor can be prolonged; compared with a traditional space vector control method, the algorithm is simple, implementation is easy, the requirement for a microprocessor is low, and high cost performance is achieved.

The invention provides a method for preparing carbon nanohorn, belonging to the technical field of carbon nanohorn synthesis. The carbon nanohorn is prepared by the DC (direct current) arc method in the reaction atmosphere of air, CO2, CO or a gas mixture of CO / N2. The method of the invention meets the requirements for mass production and has the advantages of simple equipment and low preparation cost; moreover, the product of the method has high purity, particularly, the purity of the carbon nanahorn simply subjected to ignition and purification is higher than 94%; and the diameter of the carbon nanohorn prepared by the method of the invention is approximately 25 nanometers, and the carbon nanohorn can be aggregated into a spherical aggregate with the diameter of 50 to 80 nanometers.

The invention belongs to the technical field of treatment of non-biodegradable organic wastewater, and in particular relates to a bipolar three-electrode coupling technology. A bipolar particle electrode is formed by loading one or more than one of common metal oxides such as MnO2, CuO and Fe2O3 on gamma-Al2O3 which as taken as a carrier; and the bipolar particle electrode, as well as a negative electrode and a positive electrode which are normal conductive carbon fiber felts, so as to form a bipolar three-electrode coupling reactor; and by using ozone, catalytic oxidation is strengthened; water is discharged through a hollow fiber separating membrane; therefore, non-biodegradable wastewater organic pollutants are degraded efficiently and biodegradability of wastewater is improved. The technology is low in operation cost, easy in installation and low in working pressure; meanwhile, due to application of a direct-current electric field which is lower than 10V, the coupling treatment device effectively strengthens an electrochemical reaction, and enhances adaptability to acidic, alkaline and high-temperature wastewater; chemical oxygen demand (COD) of wastewater is reduced for more than 80%; and the coupling treatment device obviously improves solid-liquid separation efficiency, remarkably improves effluent quality and stabilizes effluent quality.

The invention relates to a device and a method for repairing ground cracks of a coal mining loess subsidence area. The method comprises the steps of during repairing, firstly, detecting the depth of all the ground cracks formed on a coal mining working surface and judging the type; filling the ground cracks with a filler, and arranging grouting pipes and electrodes at the ground cracks; adding a microorganism bacterial liquid into the grouting pipes, and introducing a direct current between the grouting pipes and the electrodes; adding a nutrient solution into the grouting pipes; when the ground cracks are filled with mixed size of the microorganism bacterial liquid and the nutrient solution, stopping grouting; and after the injected mixed size is solidified, planting plants on the ground. According to the invention, the method is simple and easy to implement, the method is more environment-friendly through microorganism grouting, the distribution of microorganism products can be made more uniform through electric traction, as a renewable matter, microorganisms can be continuously utilized on a large scale, different prevention methods are utilized for cracks in different coal mining positions, and the limitation of one method is avoided.

The invention provides a method for diagnosing common disconnection faults of a brushless direct current motor inverter. The diagnosing process includes detecting currents of a current stage, and determining a conducting state matrix of the current stage; outputting fault bit signals according to current detection signals of the current stage; calculating a sum matrix Q of a conduction matrix in a period before the current stage, and diagnosing the number and positions of fault tubes by judging the number and positions of 0 elements in the sum matrix Q; and outputting fault types, fault tube positions and fault bits as diagnosis results. According to the method for diagnosing common disconnection faults of the brushless direct current motor inverter, faults can be detected in time and fault positions can be diagnosed when disconnection faults happen to the brushless direct current motor inverter, maintenance and changes for fault switching tubes by technical staff are facilitated, a system can be switched to a fault-tolerant operation mode to operate continuously, and the method has high practical application values in industrials of aviation, aerospace, automobiles and the like with high reliability requirements.

The invention discloses a hybrid direct current power transmission system control method and device. The hybrid direct current power transmission system adjusts in real time the total number of used submodules of a modular multilevel converter, and the output level polarity of the used submodules according to the direct current voltage of a rectifier station at the other end; or adjusting in real time the total number of used submodules of a modular multilevel converter, and the output level polarity of the used submodules according to direct current or direct current power; or adjusting in real time the total number of used submodules of a modular multilevel converter, and the output level polarity of the used submodules meanwhile according to the direct current and the direct current voltage of a rectifier station at the other end. The method can effectively control system direct current voltage and direct current, and avoid power transfer interruption of a hybrid direct current power transmission system.

The invention relates to a device and a method for generating a pulsed (intermittent), cold, atmospheric pressure plasma, preferably a thread, for precise antimicrobial plasma treatment (antisepsis, disinfection, sterilization, decontamination) of very small surfaces and cavities, including on living human and animal bodies, preferably in the field of medicine, by means of a negative direct-current corona discharge, the device comprising at least one electrode for generating high field strengths, through or around which electrode the gas to be ionized flows in a gas channel, wherein the electrically conductive structure (surface, cavity) to be treated is used as the counter-electrode. Said plasma can also be used in general for cleaning, coating, activating, and etching surfaces.