301 results about "Electric current pulse" patented technology

There is disclosed a process and apparatus for carrying out plasma electrolytic oxidation of metals and alloys, forming ceramic coatings on surfaces thereof at a rate of 2-10 microns per minute. The process comprises the use of high-frequency current pulses of a certain form and having a given frequency range, combined with the generation of acoustic vibrations in a sonic frequency range in the electrolyte, the frequency ranges of the current pulses and the acoustic vibrations being overlapping. The process makes it possible to introduce ultra-disperse powders into the electrolyte, with the acoustic vibrations helping to form a stable hydrosol, and to create coatings with set properties. The process makes it possible to produce dense hard microcrystalline ceramic coatings of thickness up to 150 microns. The coatings are characterised by reduced specific thickness of an external porous layer (less than 14% of the total coating thickness) and low roughness of the oxidised surface, Ra 0.6-2.1 microns.

An electrolytic filtration method and apparatus for the concentration and collection of suspended particulates from aqueous solutions is disclosed. The electrolytic cell contains at least an anode and a cathode, and in one embodiment contains a plurality of anodes and cathodes. The electrolytic cell also contains a filter, and in one embodiment the filter is a moving belt filter. While not bound by theory, the electrolytic filtration method and apparatus is based on the electrophoretic movement of algae particles suspended in an aqueous solution away from the filter under the influence of an electric field. In one embodiment the electric field is a pulsed waveform with unidirectional voltage or current pulses. In another embodiment, the electric field is a pulsed waveform with bidirectional voltage or current pulses.

A pulsed plasma thruster provides for an advanced lightweight design with solid propellant and predominately electromagnetic thrust in a coaxial geometry. Electromagnetic forces are generated in a plasma by current flowing from a small central electrode to an electrically conducting diverging nozzle electrode. The thruster employs a series of electric current pulses of limited duration and varying frequency between the pair of electrodes creating a series of electric arcs. The electric arcs pass over a propellant surface located between the electrodes, forming a plasma, which is then exhausted from the device to produce thrust. The thruster maintains a low plasma resistance and cavity pressure, which in turn yields strong electromagnetic body forces, resulting in a high efficiency and consistent pulse-to-pulse performance.

An electromagnetic forming apparatus for forming an essentially planar metal plate into a dish having a three-dimensional pattern, is provided. The apparatus comprises a mould having a forming surface with a contour corresponding to said three-dimensional pattern; a forming coil device; and an electric discharge circuitry for discharging a short and intense electric current pulse through the forming coil device to yield a pulsed magnetic forming (PMF) force for deforming said plate.

The invention discloses a device and a method for decomposing adipose tissue by an electromagnetic field. At least one switch, a capacitor and an excitation coil are included; the method comprises a method of decomposing excess fat with the steps of fully charging the capacitor with a power supply, switching the at least one switch; providing a current pulse having a peak current in the range of 300 A to 8000 A from the pulse capacitor to the excitation coil to generate a pulsed magnetic field through the excitation coil; and applying a biphasic sinusoidal pulse of a pulsed magnetic field to the muscle of a user for a pulse duration in the range of 50 [mu] s to 500 [mu] s to cause muscle contraction, thereby reducing adipose tissue.

A process for fine crystallization of metal liquid by electric current pulses is carried out by: smelting metal and over-heating, casting, inserting two parallel electrodes from above into molten metal, and disturbing metal liquid by 1000-4000A impulse electric current at 100-1000Hz to obtain fine-crystallized cast ingots. The disturbance is divided into both periods of core forming and solidifying. It can be used mold casting or continuous casting various metals.

A power supply device comprising an advanced harmonic current quashing (AHQ) and current pulse multiplier (CPM) (AHQ/CPM) three-phase transformer having: a primary winding placed around a magnetic core and having three primary winding input leads to connect a three phase power supply; and a plurality of secondary windings placed around the magnetic core in a predetermined winding turns configuration to generate a plurality of three phase outputs, where each three phase output of the plurality of three phase outputs has a different phase angle from all other three phase outputs, with each unique phase angle associated with a three phase output of a corresponding secondary winding being determined based on the winding turns configuration utilized for the corresponding secondary winding. A variable frequency drive (VFD) having 3N converters/inverters coupled to the secondary windings outputs exhibit substantially reduced harmonic currents and a current pulse number of greater than 6N.

An electric spark servo control method based on current pulse probability detection is characterized in that a current signal is adopted as a sampled signal; the current pulse occurring probability in a sampling period is acquired through a sampling circuit, so as to obtain a sampled current pulse probability; the sampled current pulse probability is calculated and stored by adopting a microprocessor, and is compared with a set current pulse probability, so as to obtain a scaling factor serving as servo control reference and control the feeding of an electric spark machine tool; when the sampled current pulse probability is larger than the set current pulse probability, the present feeding speed is multiplied by the scaling factor; and when the sampled current pulse probability is smaller than the set current pulse probability, the present feeding speed is multiplied by the scaling factor, so that the practical current pulse probability gets is changed to be equal to the set current pulse probability step by step. The method has the advantages that the controlling precision is high, the phenomena of over feeding and lack of feeding can be avoided; suitability for various electric spark processing forms of metal, semi-conductors, and heterogeneous composite materials containing conductive substances is realized; and the processing stability and the processing quality can be improved.

The invention discloses a charging method of power lithium ion batteries, and belongs to the field of power lithium ion battery technology. The charging method comprises three steps: step one, precharge, wherein when the voltage of a power lithium ion battery is lower than a threshold voltage, the power lithium ion battery is charged with electric current I1=0.1C so as to increase the voltage to the threshold voltage; step two, variable current charging, wherein the power lithium ion battery is charged by using different electric currents according to the battery level so as to increase the battery level to 80% of the battery capacity at last; and step three, pulse current charging, wherein pulse intermittent charging of the power lithium ion battery is realized by using current I7=1C, charging time Tc=1s, and then charging is stopped; when the battery voltage reduces to an upper limit voltage, and is equal to 4.2V, the power lithium ion battery is charged by using current I7=1C, and charging time Tc=1s; charging and stop charging operations are repeated continuously as above; in the charging process, the time of stop charging is gradually prolonged because that the power lithium ion battery is gradually fully charged; and when pulse charging is as small as 5% to 10%, charging is stopped. The charging method is capable of increasing charging speed and battery service efficiency.

The invention discloses a wide-range magnetostrictive displacement sensor measuring device and method. The wide-range magnetostrictive displacement sensor measuring device mainly comprises a magnetostrictive displacement sensor signal emitting and receiving circuit and a magnetostrictive displacement sensor measuring device; the magnetostrictive displacement sensor signal emitting and receiving circuit is connected with the magnetostrictive displacement sensor measuring device; and the magnetostrictive displacement sensor signal emitting and receiving circuit is used for emitting current pulse signals and receiving magnetostrictive echo signals, and the magnetostrictive displacement sensor measuring device is used for measuring the transmission time of the magnetostrictive echo signals. The wide-range magnetostrictive displacement sensor measuring device can finish the displacement measurement in dangerous environments.

The invention discloses a negative electrode material of a high-power lithium battery, a preparation method and the lithium battery. The negative electrode material is of a granular structure, and comprises an inner core and a coating layer coating the inner core. The inner core is artificial graphite with a porous structure on the surface after being corroded by oxidants; and the coating layer comprises amorphous carbon and a conductive agent, wherein the coating layer is uniformly dispersed on the surface of artificial graphite particles, and the conductive agent is uniformly distributed ordistributed in the coating layer in an island shape. The negative electrode material disclosed by the invention is premixed by a special premixing process, and a negative plate is prepared by a special slurry mixing process from low viscosity to high viscosity; the lithium battery prepared from the negative plate has the advantages of high specific power and high-rate charge-discharge performance,and being capable of reaching 25C or above current continuous charge and discharge, 35C or above current pulse charge and 40C or above current pulse discharge; the power density of the battery can reach 5,000 W/kg or above, and the working temperature range is wide and can reach -30 DEG C-65 DEG C; and the battery can realize 2C or above current charging and discharging at the low temperature, and the battery has the excellent low-temperature cycle life.

The invention discloses a power battery self-heating method and device and a readable storage medium. The method comprises the steps: acquiring the battery temperature, the current electric quantity and the capacity attenuation mean value of a power battery; acquiring corresponding charging internal resistance, discharging internal resistance and negative electrode temperature coefficient according to the battery temperature; calculating a charging current according to the charging internal resistance and the charging voltage, and calculating a discharging current according to the discharginginternal resistance and the discharging voltage; calculating pulse charging time according to the current electric quantity, the capacity attenuation mean value, the charging current and the negativeelectrode temperature coefficient; calculating pulse discharging time according to the charging current, the discharging current and the pulse charging time; carrying out charging and discharging on the power battery by taking the charging current, the discharging current, the pulse charging time and the pulse discharging time as pulse parameters, so that the power battery is self-heated, negativeelectrode lithium precipitation is not caused, the self-heated battery has no obvious capacity attenuation, and the reduction of the service life of the battery caused by cyclic charging and discharging can be avoided.

A method of producing a high-density abrasive compact material includes the steps of providing an electrically conductive mixture of a bonding powder material and abrasive particles or grit; compressing the electrically conductive mixture; and subjecting the compressed electrically conductive mixture to one or more high current pulses to form the abrasive compact is provided.