253 results about "Ampere force" patented technology

The invention discloses a method for directly calibrating micro thrust and micro impulse. By the method, the characteristics of uniform magnetic induction intensity distribution and extremely small magnetic flux leakage in an electromagnet air gap are utilized, a current-carrying wire passes through the air gap, the action of certain ampere force is applied to the wire, and the ampere force and the acting time are measured, so that the micro thrust and the micro impulse can be calibrated. When static thrust is calibrated, a stressed coil is arranged at a stressed point of a measuring device, the position of an electromagnet is adjusted, the ampere force direction of the stressed coil is taken as the thrust direction to be calibrated, and the static thrust can be calibrated according to the linear relation between the current of the stressed coil and the stressed ampere force. When the micro impulse is calibrated, the current of the stressed coil and the acting time of the current are measured, and the impulse of the ampere force can be acquired by using the calibrated linear relation between the current and the ampere force of the stressed coil, so that dynamic impulse can be calibrated. The method overcomes the defect of the conventional calibrating method and has the outstanding advantages of small error, high precision, wide calibrating range and the like.

The invention discloses an electromagnetic energy harvesting system based on a passive suspension. The electromagnetic energy harvesting system consists of a hydraulic absorber, a speed amplifying mechanism and an electromagnetic energy harvesting mechanism. The speed amplifying mechanism is disposed between the hydraulic absorber and the electromagnetic energy harvesting mechanism and used for amplifying a vibration speed of a suspension. The vibration energy of the suspension is converted into electric energy to be stored. When a car runs on an uneven pavement, the vibration of the pavement is transferred to a car suspension by virtue of a tire to cause the up-down vibration of a car hydraulic absorber, and the vibration speed of the suspension is transferred to the electromagnetic energy harvesting mechanism by virtue of the speed amplifying mechanism, so that an intermediate rod of the electromagnetic energy harvesting mechanism and an inner drum make relative movement, an induction electromotive force is generated according to an electromagnetic induction principle, and the induction electromotive force is finally stored. Meanwhile, due to the existence of an Ampere force, the vibration absorption effect of the system is further improved. By adopting the structure, a complicated feedback system, a control system and additional power elements are not needed, so that the electromagnetic energy harvesting system is simple in structure, low in cost, wide in application range and relatively good in application prospect.

The invention discloses a two freedom degree lorentz force outer rotor spherical surface magnetic bearing. The two freedom degree lorentz force outer rotor spherical surface magnetic bearing comprises coils, magnetism isolating convex plates, a stator spherical surface magnetic conductive ring, magnetism isolating screws, epoxy resin glue, an installation pedestal, spherical surface magnetic steels, a magnetism isolating ring, a rotor magnetic conductive ring, a rotor locknut, and a rotor sleeve; the two pairs of coils are used for magnetic bearing radial direction X and Y deflection control respectively, and are fixedly arranged on the stator spherical surface magnetic conductive ring via the epoxy resin glue; the spherical surface magnetic steels are arranged on the radial outer sides of the coils; the inner spherical surfaces of the spherical surface magnetic steels and the outer spherical surface of the rotor magnetic conductive ring are arranged with spherical shell gaps so as to form air gaps. The two freedom degree lorentz force outer rotor spherical surface magnetic bearing is provided with spherical shell gaps, so that the rotor is capable of realizing wide-angle deflection, and a disadvantage of conventional columnar air gap lorentz force of magnetic bearing that, deflection angle is relatively small, is avoided. And in addition, Ampere force generated by current coil current is always tangent to the spherical surface of the coil no matter which position the rotor is deflected to, that is to say, force arm of the force couple composed of the Ampere force of each pair of coils is constant, and lorentz force control moment precision is improved.

The invention discloses a dual-coil magnetic force driving device for a high-voltage line inspection robot. The dual-coil magnetic force driving device comprises a driving body. The driving body is composed of an upper openable driving engine body and a lower openable driving engine body which are centrally symmetric about the high-voltage lead, the driving device is characterized in that the upper driving engine body and the lower driving engine body both comprise a magnetic core, a layer, a large rectangular coil and a small rectangular coil, wherein the magnetic core and the layer are arranged in an attached mode in the axial direction of the high-voltage lead, and the large rectangular coil and the small rectangular coil are alternately wound around the magnetic core and the layer. Under the same size, compared with the prior art, the driving force of the dual-coil magnetic force driving device reaches 50% or above, a magnetic field generated by high-voltage current on the high-voltage lead is used for ampere force of an electrified coil so that a robot can move, and a traditional wheel rail type driving mode is replaced, so that the problem that the robot skids is solved; the driving mechanism is simplified, the cost is lowered, the weight, energy consumption and size of the body are lowered, and the movement speed of the robot can be improved.

The electromagnetic-magnetoelectric micro mechanical resonant beam structure consists of matrix and resonant beam in magnetic field, and the composite sensitive structure comprising elastic matrix membrane and double-ended built-in simple resonant beam realizes the resonant measurement of physical quality. Both the matrix and the resonant beam are made with SOI wafer and through epitaxial and etching process, and the matrix with low doping and the simple resonant beam of N type doping in 1x10<19> / cu cm form an integral monocrystalline silicon structure. The resonant beam with electrodes in its two ends is orthogonal with the magnetic field and produces ampere force in the thickness direction during when some current flows in and induced voltage across it during resonance. One closed-loop system is formed based on intermittent principle to eliminate coupling interference trouble. The present invention has simple structure, improved mechanical performance and high stability.

The invention discloses a magnetically-driven rotary deicing device of a deicing robot for overhead high-voltage transmission lines. Magnetic fields around high-voltage current act on an energized line to produce ampere force to drive the deicing device of the robot to rotate; the deicing device comprises two magnetic cores which are identical in structure, can be opened and closed and can be in central symmetry about the high-voltage line after being closed, and the deicing device comprises the magnetic cores and winding rectangular coils. Thus, the deicing device has the advantages as follows: 1, the deicing device of the robot can rotate due to the magnetic drive rotation toque, a traditional method that motors drive mechanisms to rotate is broken through, and problems that the robot is heavy due to multiple motors and the like are effectively solved; 2, the deicing speed of the deicing robot for the overhead high-voltage transmission lines can be increased; 3, different from the existing magnetic pole type drive principle, the device produces ampere force drive for energized coils by using magnetic fields around the high-voltage lines, and the design is novel; 4, the deicing device is small in size, light in weight and low in production cost.

A forced oscillation demonstration test instrument comprising a base frame, a displacement sensor, a spring oscillator (spring and mass block) and a propulsion unit, wherein the voltage between the two poles of the spring oscillator is in proportional to the tension force, and the spring tension force is proportional to the displacement of the oscillator mass. When the coil is powered by alternating current, the counteracting force of the ampere force exerted on the coil will be the driving force for the excitation of spring oscillator oscillating, the driving force signal can be represented by the voltage on the resistor in series connection with the coil.

The invention discloses an ampere force driving micro spraying device, and relates to a micro spraying dispensing device. The ampere force driving micro spraying device is provided with an upper magnet, upper and lower cover plates, an intermediate baffle plate, a guide plate, a lower magnet, an electrode, a flexible electric conducting actuator, a spraying nozzle, a liquid conveying pipe, a liquid storage barrel, a gas pipe, a pulse current controller and a power supply, wherein the upper magnet is fixed on the surface of the upper cover plate; the intermediate baffle plate and the guide plate are fixed on the surface of the lower cover plate; the upper cover plate and the lower cover plate are connected with each other; the lower magnet is fixed on the bottom surface of the lower cover plate; the electrode is connected with the flexible electric conducting actuator which is positioned between the bottom surface of the upper cover plate and the surface of the lower cover plate; the upper cover plate, the lower cover plate, the guide plate and the flexible electric conducting actuator surround to form an injection cavity together; the spraying nozzle is arranged on the guide plate, and is communicated with the outsider; one end of the liquid conveying pipe is communicated with the injection cavity; the other end of the liquid conveying pipe is communicated with the outlet of the liquid storage barrel; the inlet of the liquid storage barrel is connected with one end of the gas pipe; the other end of the gas pipe is externally connected with a pressure gas source; and the power supply is electrically connected with the electrode through the pulse current controller. The ampere force driving micro spraying device is simple in structure, and has a favorable electric control performance.

A double-magnetic-source magnetic circuit structure of a permanent-magnet angle vibration table comprises an upper magnetic steel, a lower magnetic steel, a top cover, an outer wall, a base and an air gap between the upper magnetic steel and the lower magnetic steel, wherein the top cover is arranged on the outer wall in an erected mode, the outer wall is fixed on the base, the upper magnetic steel is fixed at the bottom of the top cover, and the lower magnetic steel is fixed at the top of the base; a moving coil is of a disc-type structure and is located between the upper magnetic steel and the lower magnetic steel, and the upper magnetic steel and the lower magnetic steel are respectively in clearance fit with the moving coil; the moving coil comprises at least one moving coil unit; each moving coil unit includes a base body and a coil assembly; each coil assembly includes a first coil and a second coil, wherein the first coil and the second coil are formed by winding one wire; each coil includes an effective wire assembly and a connection wire assembly; every two adjacent effective wire assemblies form one Ampere force generating portion; each Ampere force generating portion corresponds to a magnetic field, and the directions of the currents in every two adjacent Ampere force generating portions are opposite. The double-magnetic-source magnetic circuit structure of the permanent-magnet angle vibration table has the advantages of being simple and compact in structure, high and even in magnetic induction intensity and stable in air-gap magnetic field.

The invention relates to a device for increasing clamping force of a magnetorheological fluid flexible fixture. Magnetorheological fluid increases the clamping force of the flexible fixture in the application field of the flexible fixture to guarantee normal workpiece machining. The device mainly consists of an electromagnetic coil, a machined workpiece, an extension electric conducting ring, the magnetorheological fluid, an extension insulation container and an insulation isolation ring. When the electromagnetic coil is electrified, the magnetorheological fluid generates a magnetorheological effect, so that the magnetorheological fluid instantly changes from a low-viscosity and high-fluidity newtonian fluid to a high-viscosity and low-fluidity Bingham fluid to form a chain in a magnetic field direction to clamp the workpiece with an irregular shape; meanwhile, current is conducted to the extension electric conducting ring; an electrifying conductor is suffered from ampere force in a magnetic field; the current direction and the magnetic field direction are adjusted according to a left-hand rule, so that the generated force extrudes the magnetorheological fluid in the center direction of the device; and the chain in the magnetorheological fluid is continuously thickened by extruding, so that the workpiece is firmly clamped to guarantee normal machining.

The invention discloses a photonic crystal fiber current magnetic field sensor and a manufacturing and measuring method of the photonic crystal fiber current magnetic field sensor. At the time of manufacturing, a small segment of a photonic crystal fiber is welded between two single-mode fibers first; due to the fact that a part of air holes in the photonic crystal fiber are collapsed at the time of welding, when light is transmitted to the photonic crystal fiber, transmission between a decoring mode and a cladding mode is stimulated to form mode interference; then, the photonic crystal fiber, the single-mode fibers and an electric wire are straightened, the two single-mode fibers are bonded to the electric wire, and the electric wire is fixed on a fixture to manufacture the current magnetic field sensor. At the time of measuring, direct currents are connected into the electric wire, a magnetic field is added in the direction perpendicular to the electric wire, and therefore the electric wire drives the photonic crystal fiber to bend under the action of Ampere force. Due to the fact that the cladding mode of the photonic crystal fiber is quite sensitive to bending, interference fringes detected by a spectrograph will change obviously along with the change in the impressed currents and the external magnetic field, and sensing detection of the currents and the magnetic field is realized.

The present invention discloses an on-line monitoring method and an on-line monitoring system for an axial pressing state of an electric power transformer winding. A natural frequency of an upper layer wire cake of the winding is extracted from vibration signals of an upper surface of a transformer oil tank according to a characteristic that the natural frequency of the upper layer wire cake of the winding reduces under the action of a stable component of an axial Ampere force, a degradation of the axial pressing state of the winding, namely the reduction of a pre-tightening force, results in the reduction of the natural frequency of the wire cake of the winding, and thereby on-line monitoring the axial pressing state of the large power transformer winding by following and observing a variation trend of the natural frequency. The on-line monitoring system includes a vibration signal acquisition module, a load current acquisition module, an analysis control module, a storage module, an output display module and a sound alarm module, wherein, the vibration signal acquisition module, the load current acquisition module, the storage module, the output display module and the sound alarm module are connected to the analysis control module respectively. The on-line monitoring method and the on-line monitoring system have the advantages of a distinct physical significance and a simple realization way.

The invention discloses a cage-shaped rotor magnetic coupling capable of regulating speed. The cage-shaped rotor magnetic coupling comprises a power input shaft, a connection device, a permanent magnet outer rotor assembly, a cage-shaped inner rotor assembly, a power output shaft and a mechanical speed regulating device, the permanent magnet outer rotor assembly is sleeved outside the cage-shaped inner rotor assembly, and even air gaps are arranged between the permanent magnet outer rotor assembly and the cage-shaped inner rotor assembly. A layout mode of permanent magnets in the permanent magnet outer rotor assembly adopts a radial layout mode or a circumferential layout mode. The cage-shaped rotor magnetic coupling adopts an inside-outside-inside sleeved mode, an outer rotor adopts a structure with alternative magnetic poles, an inner rotor adopts a squirrel-cage rotor structure in an asynchronous motor, a rotating magnetic field produced by rotation of the outer rotor is used, induced current is produced in a squirrel-cage guide strip of the inner rotor, and the rotating magnetic field and the induced current drive the inner rotor to rotate under effects of ampere force. The magnetic coupling is high in reliability and operating efficiency, and reduces design and production cost.

The invention relates to a non-contact active control method for vibration of a micro thrust measurement system and relates to vibration control over a swing arm or a beam of a single-pendulum or torsional-pendulum type thrust measurement system of a space propulsion system of electric propulsion, laser micro propulsion and the like. According to the method, the ampere force between a local magnetic field and a current-carrying coil serves as the control force, a sensor is used for measuring angular displacement of the swing arm or the beam, and a closed loop feedback control method is used for controlling vibration of the swing arm or the beam so that the swing arm or the beam can be stabilized in a balance position. The method makes up the defect of an existing vibration damping method and has the outstanding advantages of being high in stabilization speed and control precision, free from additional error and the like.

An embodiment of the invention provides a heat dissipation device and communication equipment, which relate to the technical field of heat dissipation, and produce low noise while ensuring heat dissipation of an electronic device. The heat dissipation device comprises a base, a swing sheet and a magnet assembly, wherein the swing sheet comprises a fixed end and a free end, the fixed end is fixed on the base, the free end can swing relative to the fixed end, and an annular coil is arranged on the swing sheet; and the magnet assembly comprises a first magnet and a second magnet which are fixed with respect to the base, the same type of magnetic poles of the first magnet and the second magnet are opposite to each other and are located on two sides of the annular coil, and the annular coil is subjected to an Ampere force periodically changing in direction under the action of a magnetic field formed by the magnet assembly when a current periodically changing in direction is introduced into the annular coil, so that the annular coil drives the swing sheet to swing back and forth. The heat dissipation device is used for heat dissipation of a microelectronic device.

The invention discloses a low-frequency standard vibration table based on full state feedback. The low-frequency standard vibration table based on the full state feedback comprises a low-frequency standard vibration table, a grating displacement sensor, a current sensor, a power amplifier and a controller; the output channel of the controller sends a voltage driving signal, which is amplified by the power amplifier and added to the two ends of a driving coil of the low-frequency standard vibration table; the energized driving coil bears an ampere force under the action of a magnetic field anddrives the moving parts of the vibration table to generate vibration; and the grating displacement sensor is mounted on the bottom of the moving parts of the low-frequency standard vibration table. The low-frequency standard vibration table based on the full state feedback has the characteristics that the convergence process of state variables is adjustable and the suppression effect of low-frequency harmonic distortion is better.

The invention discloses a jet flow forming device with strong magnetic driving. The jet flow forming device with strong magnetic driving comprises a liner device, a pedestal and an output end. A capacitor unit with high energy storage is used as an initial loading energy source to generate strong electric current of a megampere level, a strong magnetism loading manner is innovatively adopted to enable the electric current to flow through the surface of the metal liner and generate a toroidal magnetic field, and the metal liner stresses ampere force converging in the axial direction and then overwhelms the liner to form metal jet flow. The higher the electric current flowing through the liner, the higher overwhelming speed of the liner is, so that the speed of the head of jet flow is higher, and the penetration power of the jet flow is higher. With the jet flow forming device with strong magnetic driving, jet flow forming measures of new concepts and new principles can be enriched, thesingle mode, used for decades, of explosive driving forming jet flow is broken through, and the methods of driving jet flow forming are expanded. The jet flow forming device with strong magnetic driving can be applied to high-speed jet flow forming and hole forming power enhancement.

The invention provides an S-shaped channel solder ejecting head driven by ampere force, and relates to a solder micro-molten-droplet ejecting device. The S-shaped channel solder ejecting head is provided with a base body, a spray nozzle, a heating chamber, a heating coil, a conducting film, a pressure sensor, an air leakage pipe and an electromagnetic valve. The base body is provided with an S-shaped bent channel. The wall face of the channel is plated with a conducting film which serves as an electrode. An electrode wire lead-out hole is formed in the base body. The conducting film is electrically connected with the outer portion. The spray nozzle is arranged at the bottom of the base body and communicated with the bottom end of the channel. The heating chamber is arranged above the base body. A cover plate is arranged at the upper end of the heating chamber. The heating coil is arranged on the periphery of the heating chamber. The pressure sensor is arranged on the cover plate. The air leakage pipe is arranged on the cover plate, provided with an air leakage hole and communicated with an external air source through the electromagnetic valve. The ampere force borne by molten solder can be increased, and meanwhile the acceleration distance of the molten solder is lengthened so that ejecting can be more easily achieved.

The invention provides a composite electromagnetic type dynamic vibration absorber. According to the composite electromagnetic type dynamic vibration absorber, a shell is made of a soft magnetic material, a coil groove is formed in the inner wall surface of the shell, when a rotor is at a balanced position, in the axial direction of the rotor, the upper groove opening edge of the coil groove is located between the N-pole surface and the S-pole surface of an upper main permanent magnet, the lower groove opening edge of the coil groove is located between the N-pole surface and the S-pole surfaceof a lower main permanent magnet, a coil is installed in the coil groove, when forward current flows through the coil, the rotor is subjected to downward electromagnetic force, meanwhile, the partialwire in the middle of the coil is affected by a magnetic field facing inwards in the radial direction, the coil can bear upward ampere force according to the left-hand rule, the rotor can bear downward counter-acting force according to the Newton's third law, namely when the forward current flows through the coil, the rotor can bear downward electromagnetic force and ampere force at the same time, when reverse current flows through the coil, the rotor can bear upward electromagnetic force and ampere force at the same time, and vibration is counteracted through the combined action of the electromagnetic force and the ampere force.

The invention discloses an electromagnetic force driven automatic injection device. The device is driven by ampere force F generated by a coil electrified wire in a magnetic field. The device comprises a needle head, a needle tube, a catheter, a shell end cover, a shell, a shell bottom cover, wires, a push rod, a push rod fixing seat, a coil rack, a permanent magnet pair A, a permanent magnet pairB, a magnet yoke and a plunger. The wires at the upper end and the lower end of a coil are arranged in the magnetic field of the two permanent magnet pairs, two equal forces in the same direction aregenerated at the upper end and the lower end to drive the coil to move, and the current and the driving force are in a linear relation. The precision and sensitivity of the automatic injection devicecan be improved, and the device is stable in driving, free of noise, simple in structure, small in size and suitable for being used in various occasions.

The invention discloses a sound production apparatus and a manufacturing method thereof. The sound production apparatus comprises a substrate and a vibrating diaphragm formed on the substrate in a deposition manner, wherein the sound production apparatus further comprises a coil connected to the vibrating diaphragm, the coil is combined with the vibrating diaphragm in a manner of deposition, etching or magnetron sputtering, and the coil is helical from the middle to the outer side; the sound production apparatus further comprises a first magnet component correspondingly arranged with the coil; and the first magnet component is configured to provide an Ampere force whose direction is vertical to the vibrating diaphragm for the coil. According to the sound production apparatus disclosed by the invention, when alternating current signals are input to the coil, the magnetic line of force emitted by the first magnet component penetrates through the coil, so that the coil is applied with a corresponding Ampere force and drives the vibrating diaphragm to vibrate so as to realize the sound production of the vibrating diaphragm. The sound production apparatus disclosed by the invention breaks through the installation structures of traditional coils and magnets, so that the volume of the sound production apparatus is smaller, and the sound production apparatus can be manufactured by the MEMS process.

An electromagnetic balance type acceleration sensor comprises a torquer system, a signal sensing system, a servo amplification system and an outer supporting structural body. One side of a torquer rotor is fixed to the outer supporting structural body through a wire, when accelerated speed is input in the sensitive axial direction, the torquer rotor rotates by a small angle with the wire as the fulcrum, a displacement metal sheet fixed to the edge of the torquer rotor generates relative displacement relative to the balance position, the relative displacement is fed back to the servo amplification system by being detected by a signal sensor and is converted to be current magnitude, current is fed back by a foil wire to a torquer moving coil, then ampere force is generated, and the torquer rotor recovers to the balance position under action of ampere force. The electromagnetic balance type acceleration sensor has the advantage of high-precision closed-loop control of a flexible pendulum acceleration sensor, and has the advantages of being high in zero-position stability, free of interference between shafts and the like; meanwhile, influence on material selection from temperature is relatively small, and the electromagnetic balance type acceleration sensor has a small bias temperature coefficient and has the miniaturization and low power consumption potentials.

The invention provides an electromagnetic linear damping hinge and a corresponding door and window device. The electromagnetic linear damping hinge comprises a first connecting plate and a second connecting plate, wherein the first connecting plate comprises a first plate piece and a connecting part which are connected with each other; a shaft hole is formed in the connecting part; a first magnet and a second magnet are arranged in the connecting part and are respectively arranged on two sides of the shaft hole, so that a magnetic field of which magnetic induction lines are distributed in the radial direction of the shaft hole is formed in the shaft hole; the second connecting plate comprises a second plate piece and a hinge pin which are connected with each other; the hinge pin penetrates in the shaft hole and is provided with a closed conductor device; and the closed conductor device is positioned in the magnetic field and is used for cutting the magnetic induction lines to generate ampere force when the hinge pin rotates relative to the shaft hole. According to the electromagnetic linear damping hinge and the corresponding door and window device, use safety can be improved.

The invention discloses a novel weak magnetic field sensor and a detection method based on Ampere force. Two output ends of a circulator are respectively connected with a 2*2 polarization-maintaining fiber coupler and a spectrum analyzer, the output end of the 2*2 polarization-maintaining fiber coupler is separately connected with a first polarization maintaining fiber and a second polarization maintaining fiber , the first polarization maintaining fiber and the second polarization maintaining fiber are welded in 90 degrees, a part of the first polarization maintaining fiber serves as a magnetic field induction zone, the first polarization maintaining fiber in the magnetic field induction zone and an energized electrode are wrapped by flexible materials, and the flexible materials and the energized electrode form a structure for inducting the magnetic field; the energized electrode is subjected to the magnetic field effect, generates Ampere force, and indirectly acts on the magnetic field induction zone, the polarization maintaining fibers generate stress birefringence, so that the interference light phase difference is changed and the magnitude of the magnetic field is acquired. According to the invention, the method has advantages of simple manufacture, high sensitivity, low cost, simple structure and manufacture process and the like, and the anti-interference ability of the detectable weak magnetic field and severe environment.

The invention discloses an MEMS sound production apparatus and an electronic device. The MEMS sound production apparatus comprises a substrate provided with a hollow inner cavity and a vibrating diaphragm formed above the substrate in a deposition manner, the vibrating diaphragm comprises at least one magnetized magnetic material layer, and the vibrating diaphragm further comprises a first coil arranged to align to the magnetic material layer; and the first coil is configured to provide a driving force whose direction is vertical to the vibrating diaphragm for the magnetic material layer. According to the sound production apparatus disclosed by the invention, the first coil and the magnetic material layer are correspondingly arranged together, when alternating current is input to the first coil, the magnetic materials of the magnetic material layer penetrates through the coil, the magnetic material layer generates vibration vertical to the direction of the vibrating diaphragm under the counterforce of an Ampere force of the coil, and thus the vibration sound production of the vibrating diaphragm is realized. This sound production apparatus disclosed by the invention can be used in telephone receivers or loudspeakers, and breaks through the installation structures of traditional coils and magnets, so that the volume of the sound production apparatus is smaller, and the sound production apparatus can be manufactured by the MEMS process.

The invention discloses a loudspeaker, relates to the technical field of terminal devices and solves the problem of a poor loudspeaking effect caused by an insufficient sound pressure level in a light and thin terminal device. The loudspeaker comprises a diaphragm and a magnetic circuit system. The magnetic circuit system comprises a first magnet and a second magnet which are arranged in a sleeving manner, an interval exists between the first magnet and the second magnet, and annular magnetic steel is arranged in the interval. A first sound coil is arranged in a first interval formed between annular magnetic steel and the first magnet, a second sound coil is arranged in a second interval formed between the annular magnetic steel and the second magnet, the first sound coil and the second sound coil generate Ampere forces in the same direction to drive the diaphragm to vibrate. The loudspeaker provided by the invention is used in the technical field of terminal devices.

The invention provides an aerodynamic electromagnetic simulation test device. The aerodynamic electromagnetic simulation test device comprises an electrifying solenoid, a model fixing device, a loading snap ring, a power switch and a programmable power supply; the electrifying solenoid which is in a hollow cylindrical shape is used for generating axial uniform magnetic fields with identical magnetic induction line directions; the model fixing device which is arranged at one end of the electrifying solenoid is used for fixing a test model within a hollow range of the electrifying solenoid; the loading snap ring comprises a snap ring and a lead; the snap ring is a concave groove which is made of non-conducting materials and can be snapped under the test model; a plurality of leads pave inside the concave groove in a parallel mode; the directions of the leads are perpendicular to those of the magnetic induction lines; every lead is divided into a transverse lead section which paves on the bottom surface of the concave groove and a vertical lead section which paves along the concave groove wall; the leads are connected with the programmable power supply through the power switch after being in parallel connection. The aerodynamic electromagnetic simulation test device achieves real simulation of dynamic aerodynamic loads of an aircraft through Ampere force.

The invention relates to an aluminum alloy semi-continuous cast electromagnetic stirring device and method. The aluminum alloy semi-continuous cast electromagnetic stirring device comprises a launder used for holding melt, a crystallizer is arranged blow the launder, a cooling water spray zone is arranged at the lower outlet of the crystallizer, permanent magnets are arranged at the outer side of the crystallizer in pairs, a graphite electrode is inserted in the melt, a plurality of sliding electrodes are arranged below the cooling water spray zone, and the graphite electrode and sliding electrodes are respectively connected with two electrodes of a pulse direct current power supply. The aluminum alloy semi-continuous cast electromagnetic stirring device uses the principle that current undergoes ampere force in a magnetic field and combines direct current with permanent magnets, the flow modes and flow intensities of different melts in the crystallizer region are designed according to sizes, shapes and material components of aluminum ingots, and segregation behaviors of alloying elements and growth patterns of dendritic crystals are controlled to realize microstructure homogenization and refining.