175 results about "Electromagnetic system" patented technology

The invention provides an electric power and magnetic power dynamic joint detection method and system based on multivariable fusion, and relates to the technical field of power electronic equipment detection. According to the method, voltage, current and magnetic field sensors are arranged in a to-be-tested electromagnetic system, original physical quantity data are collected, and a multivariable time sequence data set is constructed; through preprocessing and feature extraction, a dynamic feature matrix related to electric power and magnetic power is generated; constructing a joint estimation model based on the matrix, and comparing the joint estimation model with a reference value to obtain a detection residual error; generating a state label according to the residual size and trend, and evaluating the estimation credibility in combination with a confidence interval; and a feedback mechanism is further constructed, model parameters and feature structures are optimized by adopting an adaptive algorithm, and online iteration and self-learning are realized. The method is high in detection precision, high in state recognition capability, good in adaptability and robustness, and suitable for energy flow monitoring and intelligent diagnosis of a complex electromagnetic system.

The invention belongs to the technical field of magnetic variable measurement, and particularly relates to a power driving compensation method and system for magnetostrictive load characteristic monitoring, and the method comprises the steps: obtaining a reference zero point of magnetic performance evolution in a cold state environment of an electromagnetic system according to the center frequency of the electromagnetic system; calculating a current main frequency impedance module value and a phase difference through an electrical parameter characterization method, and obtaining a thermal drift index reflecting a hysteresis loop distortion degree in combination with a reference zero point; obtaining correction factors of all orders based on the thermal drift index and the average output power at the current moment, and dynamically updating a coefficient vector of the inverse model; and constructing a pre-distortion driving voltage signal capable of counteracting nonlinear interference by using the new coefficient and the ideal guided wave voltage sequence, and inputting the pre-distortion driving voltage signal to a power amplifier to drive the magnetostrictive transducer. According to the invention, the problem of predistortion failure under a variable-temperature working condition in the prior art is solved, and the signal-to-noise ratio of high-power long-distance guided wave detection is remarkably improved.

This invention belongs to the field of curing and molding of short fiber composite materials, and discloses an apparatus and method for three-dimensional oriented curing and molding of short fibers. The orientation device of this invention includes a storage tank for holding the short fiber curing solution, a base for fixing the entire device, a horizontal rotation system for controlling the horizontal angle of the fibers, a vertical rotation system for controlling the vertical rotation angle of the fibers, and an electromagnetic system and a control system for providing an electromagnetic field. Under the command of the control system, the electromagnetic system generates an electromagnetic field, which is then used for magnetic field positioning under the drive of the horizontal and vertical rotation systems. The electromagnetic field then orients the magnetized short fibers. This apparatus and method can achieve three-dimensional orientation of short fibers in a matrix material, effectively improving the mechanical properties of short fiber reinforced composite materials and further enhancing the designability of short fiber composite materials.

The utility model relates to a relay. The relay includes: a base; the contact assembly comprises a first movable spring part, a second movable spring part, a first static spring part and a second static spring part which are arranged on the base, the first movable spring part is opposite to the first static spring part, the second movable spring part is opposite to the second static spring part, and at least part of the first static spring part can generate flexible deformation; the electromagnetic system is arranged on the base and used for driving the first movable spring part and the second movable spring part to move in the direction close to or away from the first static spring part and the second static spring part. And the stroke difference that the electromagnetic system drives the first movable spring part and the first static spring part to make contact is smaller than the stroke difference that the electromagnetic system drives the second movable spring part and the second static spring part to make contact. According to the relay, the first static spring part can absorb contact stress through flexible deformation, and the first static spring part and the first movable spring part are prevented from being damaged and deformed due to stress.

The magnetic separation column comprises an ore feeding hopper, a tailing overflow groove, a separation column body, an electromagnetic system, a concentrate opening and a water feeding pipe, the ore feeding hopper is arranged at the top of the separation column body, the lower portion of the separation column body is communicated with the separation column body, the tailing overflow groove is formed in the upper portion of the separation column body, the concentrate opening is formed in the bottom of the separation column body, and the electromagnetic system is arranged outside the separation column body in a sleeved mode. The water supply pipe is inserted into the lower part of the sorting column; the device is characterized by further comprising a magnetism gathering medium body, the magnetism gathering medium body is fixedly arranged in the separation column, and the top of the magnetism gathering medium body corresponds to the uppermost electromagnetic system. According to the utility model, the phenomenon that fine-particle magnetite moves upwards along with rising water flow and enters tailings to cause black running is effectively avoided, so that the recovery rate of iron ore concentrate is increased, and the grade of the tailings is reduced.

The utility model provides a permanent magnet type electromagnetic system and a contactor. The permanent magnet type electromagnetic system comprises a static iron core, two coil windings, a movable iron core and a magnetic conduction driving assembly. The two coil windings are arranged on the static iron core; the movable iron core is arranged opposite to the static iron core along a first direction; the magnetic conductive driving assembly is connected with the movable iron core, a first magnetic field force is generated between the magnetic conductive driving assembly and the static iron core, the first magnetic field force is used for driving the magnetic conductive driving assembly to move towards the movable iron core so as to reset the movable iron core, and a second magnetic field force is generated between the movable iron core and the static iron core so as to reset the movable iron core. And a third magnetic field force is generated between the static iron core and the coil winding. The third magnetic field force is opposite to the first magnetic field force, and the second magnetic field force is opposite to the first magnetic field force. The moving stroke of the movable iron core can be effectively improved.

The invention relates to the technical field of electrical elements, and discloses a switching-on mechanism, the switching-on mechanism is used for connecting an electromagnetic system, the electromagnetic system comprises a yoke plate and a push rod penetrating out of the yoke plate, the switching-on mechanism comprises a support, a button assembly and a limiting maintaining assembly, and the support is used for connecting the yoke plate; the button assembly is movably connected with the support and has an initial position and a switching-on position, the button assembly can move from the initial position to the switching-on position under the action of external force so as to push the push rod to switch on, the limiting and maintaining assembly is movably connected with the support, and the moving direction of the limiting and maintaining assembly and the moving direction of the button assembly form an included angle. And at the closing position, the limiting maintaining assembly abuts against the button assembly in the moving direction of the button assembly and limits and blocks the button assembly from moving from the closing position to the initial position, and convenience is provided for the power-off maintenance process of the electromagnetic relay in an integrated installation mode.

The application belongs to the technical field of wind turbine simulation, and provides a wind turbine full-closed loop simulator and method based on a field programmable gate array, which comprises a field programmable gate array chip, an ARM chip and a digital-analog interface connected with the field programmable gate array chip; the application adopts the field programmable gate array chip, and realizes transient real-time simulation of the electromagnetic system of the wind turbine by means of the powerful parallel computing capability of the field programmable gate array chip; compared with the prior art, the application can quickly verify the effect of the control strategy by using the built-in controller, and can access the actual wind turbine controller through the digital-analog interface to perform hardware-in-the-loop simulation and test the control effect; meanwhile, the ARM chip is used as a real-time operation carrier of the wind turbine controller algorithm, and the field programmable gate array chip and the ARM chip interact with real-time data through a digital-analog channel to realize a wind turbine closed loop real-time simulation platform.

The invention discloses an aluminum water filtering method and device, and relates to the technical field of aluminum water purification, and the method comprises the following steps: carrying out coarse filtration on aluminum water containing impurities; the aluminum water subjected to coarse filtration is pretreated; carrying out primary filtration on the pretreated molten aluminum; the aluminum water subjected to primary filtration enters an intermediate area and is activated by an electromagnetic coil to attract metal impurities; carrying out secondary filtration on the activated molten aluminum; and the aluminum water subjected to secondary filtration flows out of the discharge hole. The device comprises a feed port, a filter unit, an electromagnetic system, a discharge port and a control terminal. The filtering efficiency is improved, the service life is prolonged, and the maintenance cost is reduced.

This invention discloses a method and system for resampling time-domain data of electromechanical-electromagnetic simulations while preserving time-frequency domain features. It includes: constructing electromechanical and electromagnetic transient time-series trajectory samples of a new energy power grid system; processing the trajectory samples separately using an improved Proni method to obtain frequency domain response features; reconstructing the electromechanical and electromagnetic transient time-series trajectories separately using linear interpolation and adaptive resampling techniques based on the frequency domain response features; and fusing the time-domain and frequency-domain features in the reconstructed time-series trajectory data to form a comprehensive feature vector, thereby obtaining electromechanical-electromagnetic simulation time-domain data that preserves time-frequency domain features. This invention solves the asynchronous sampling problem of electromechanical-electromagnetic time-domain simulation data and can be used to support the feature analysis of inconsistent data at different time scales in electromechanical and electromagnetic systems. It has broad application prospects and significant practical implications in fields such as scheduling and control of new energy power grids.

The present application relates to the technical field of geophysical electromagnetic exploration data processing, and specifically discloses a kind of orthogonal digital phase-sensitive detection time-frequency electromagnetic complex response extraction method, automatically extracts base frequency and initial phase using transmitter stored time-stamped current data, constructs zero initial phase orthogonal reference signal, carries out two-way digital phase-sensitive detection to receiver full waveform sampling data, obtains in-phase component and quadrature component, so as to calculate the complex response amplitude and phase information of target frequency.The present application does not need analog phase-locked loop and artificial phase modulation process, can stably extract complex response parameters under strong interference and strong noise background, is especially suitable for array time-frequency electromagnetic receiver full waveform sampling data post-processing, without transmitting current waveform to each receiving node in real time, improves the flexibility and scalability of time-frequency electromagnetic system.

The application discloses a small-sized circuit breaker clapping type electromagnetic system with high magnetic efficiency, which comprises a magnetic yoke, and a armature is arranged above the magnetic yoke; the armature comprises a shaft pin part and a magnetic concentration part, and a recess part is further arranged on the magnetic concentration part; wherein the recess part is recessed towards the magnetic yoke. In summary, without reducing the magnetic increase of the magnetic yoke to the static contact rod, the recess part is arranged in the normal working air gap path of the armature, the distance from the current conductor is reduced, the electromagnetic force is larger and more concentrated in the working air gap, the magnetic path surface is larger, the suction is sufficient under low current (such as 32A and below), the action is sensitive, the magnetic flux leakage is minimum, and the large current working condition is considered.

The application relates to the field of switch electric appliances, in particular to a contactor with built-in fuse. The contactor with built-in fuse comprises a first contactor and a second contactor, the first contactor comprises a first electromagnetic system, a first cover shell, a first movable contact bridge, a first static contact and a second static contact; the second contactor comprises a second electromagnetic system, a second cover shell, a second movable contact bridge, a third static contact and a fourth static contact; the contactor further comprises a fuse, the fuse comprises a third cover shell, a first fuse static contact, a second fuse static contact and a fuse body; the second static contact, the first fuse static contact, the fuse body, the second fuse static contact and the fourth static contact are connected in series. The contactor with built-in fuse has the advantages that the first contactor, the fuse and the second contactor are integrated and connected in series, the copper bars and the fuse base between devices are reduced, and the contactor has the functions of conduction and breaking under normal current and the fuse has the function of melting under short-circuit current.

The invention discloses an antenna for carrying out electromagnetic radiation and receiving by using a rotary wing of an unmanned aerial vehicle and a design method thereof, and the method comprises the steps: 101, carrying out the modeling of a rotor-antenna conformal structure, and building a rotor-antenna integrated three-dimensional parameterized model; 102, designing a rotary conduction feed structure, and designing a high-speed coaxial rotary joint according to impedance continuity, mode integrity and isolation indexes of a static end and a moving end; 103, carrying out time-varying electromagnetic modeling and optimization analysis; 104, carrying out multi-rotor collaborative design, and coordinating the phase and angle relationship of each rotor; and 105, implementing and verifying. The arrangement form of the antenna array on the unmanned aerial vehicle is innovatively provided, the antenna is deployed by highly utilizing the structure of the unmanned aerial vehicle, the formed array can realize the functions of enhancing communication, navigation interference resistance and the like of the unmanned aerial vehicle by utilizing rotation information, and the unmanned aerial vehicle can be effectively controlled under the condition that the aerodynamic performance and the structure of the unmanned aerial vehicle are not influenced. And the integration level and the stability of the unmanned aerial vehicle electromagnetic system are improved.

The application relates to the technical field of electric control elements, in particular to a miniaturized high-protection DC contactor, so as to solve the problems that the process operation is complicated, time-consuming and large in space ratio when silicon rubber is generally used for internal filling of the traditional DC contactor, and finally the maintenance convenience of the internal filling structure of the DC contactor is poor and the overall application efficiency is low. The cover plate of the DC contactor is clamped with the base assembly through self-back dowel, the electromagnetic system drives the contact bridge mechanism to contact or separate from the static contact of the base assembly, the traditional screw column type base packaging structure is replaced, the space utilization rate in the shell is significantly improved by combining the up-down displacement of the contact bridge mechanism, the structural height is effectively reduced while the structural strength and sealing performance are ensured, the product miniaturization is ensured, the silicon rubber filling process is replaced by a sealing gasket, the assembly process is simplified, and the composite connection of the combined nail and rivet further guarantees the mechanical stability and sealing reliability of the overall structure.

The electromagnetic system capable of improving the electromagnetic attraction force comprises a magnetic conduction cylinder, a movable iron core and a push rod, and a cavity where the electromagnetic system is located is separated from a cavity where a contact system is located through a yoke plate; one end of the movable iron core penetrates through the magnetic conductive cylinder; one end of the push rod is fixed on the movable iron core, the other end of the push rod penetrates through the yoke plate, and a movable contact of the contact system is arranged on the push rod and can move relative to the push rod; and an elastic piece for sealing a gap between the contact surfaces of the yoke plate and the push rod is arranged on the periphery of the contact surface of the yoke plate and the push rod. The electromagnetic system can be applied to the contactor. The sealing performance of the chamber where the contact system of the contactor is located can be improved through the elastic piece, the gap between the magnetic conductive cylinder and the movable iron core is shortened, and the electromagnetic attraction is improved.

The application relates to the technical field of electrical connection devices, in particular to a contactor and a coil protection accessory. The contactor provided by the application comprises an electromagnetic system and a coil protection component, the electromagnetic system comprises a moving iron core, a static iron core and a coil, and the moving iron core is arranged opposite to the static iron core. The coil is arranged on the static iron core. The coil protection component comprises a first normally closed contact, a second normally closed contact and a time-delay operation structure. Through the cooperation of the first normally closed contact, the second normally closed contact, the time-delay operation structure, the moving iron core and the coil, the coil power supply can be cut off in time under the condition that the moving iron core is attracted abnormally, so that the overheat phenomenon of the coil and the static iron core can be avoided, the coil can be protected from the damage caused by the overheat phenomenon, the coil protection component structure is relatively simple, the cost is relatively low, a relatively high contactor and coil are protected at a relatively low cost, and the fire risk can be reduced.

The direct current contactor comprises a shell, an electromagnetic system and a contact system arranged in the shell along an axial direction, the electromagnetic system comprises an armature assembly and two coil assemblies, the two coil assemblies are arranged along the axial direction of the shell for driving the armature assembly to move linearly, each coil assembly comprises a coil framework, the contact system comprises a moving contact assembly and a stationary contact assembly, the moving contact assembly is driven by the armature assembly to contact or separate from the stationary contact assembly, the electromagnetic system further comprises a magnetic ring, the magnetic ring is located between the two coil assemblies, a moving core of the armature assembly slides up and down on the middle part of the two coil frameworks and the magnetic ring along the axial direction of the shell, and the inner ring side wall and the outer ring side wall of the magnetic ring are two magnetic poles with opposite magnetism respectively. In the utility model, the moving core is surrounded by the magnetic ring to form a surrounding magnetic loop, the moving core is uniformly stressed and deviation is not caused, local magnetic field density is avoided to be too high, the assembly process is simplified, and automatic assembly can be realized.

The utility model discloses a self -recovery formula over -voltage protection ware special -purpose magnetic latching relay with better stability. Adopted technical scheme includes: base, contact system and electromagnetic system in the base, the electromagnetic system includes framework, the iron core in the framework, the armature of being connected to the both ends of iron core and the magnetic steel spare of being cooperated with armature, the contact system includes setting on the base static contact head support movable contact head support, riveting on static contact head support static contact head, riveting on movable contact head support spring piece and riveting on movable contact head support movable contact head.

The invention relates to the field of low-voltage electric appliances, in particular to an operating system and a circuit breaker comprising the operating system, the operating system comprises an operating piece, an electromagnetic system and a moving contact mechanism, the electromagnetic system comprises a magnetic production assembly ejector rod, and the two ends of the ejector rod are in transmission connection with the operating piece and the moving contact mechanism respectively; the operating member is switched between a closing position and an opening position and drives the moving contact mechanism to be switched between the closing position and the opening position through the push rod. The electromagnetic system works when overload and / or short-circuit current flows through the moving contact mechanism to drive the ejector rod to drive the moving contact mechanism to move from a closed position to an open position; the operating system is simple in structure and small in occupied space, and the circuit breaker is simple in structure.

The invention discloses a star contactor module, a star-delta contactor module and a star-delta starting switch, and the star contactor module comprises a star module housing, a first electromagnetic system, a first contact support, and a first contact assembly. The first contact assembly comprises three first moving contacts and three groups of first static conductive structures, and the three first moving contacts are in short circuit through short circuit pieces; each first static conductive structure comprises a first wiring section, a contact section and a second wiring section, and the first wiring section, the contact section and the second wiring section in the same first static conductive structure are always kept in a connected state on a circuit; the first electromagnetic system comprises a first armature which is arranged in a sliding mode, the first contact support and the first armature are arranged in a synchronous movement mode, the three contact sections are located below the three first moving contacts respectively, and connection and disconnection of a first contact assembly are achieved through sliding of the first contact support; the star contactor has the characteristic of independent modularization of the star contactor module.

The present application relates to a laser speckle reducer and a projection device. The laser speckle reducer comprises: a stator part, a vibration assembly, a first diffuser, a mover part, and a second diffuser; the stator part comprises a substrate; the vibration assembly is disposed on the substrate; the first diffuser is disposed on the substrate; the mover part comprises an elastic assembly, and the elastic assembly is connected to the substrate; the second diffuser is disposed on the elastic assembly, and the second diffuser is arranged opposite to the first diffuser; when the vibration assembly vibrates, the elastic assembly drives the second diffuser to vibrate by means of resonance, and the second diffuser is configured to move relative to the first diffuser. The present application can reduce or eliminate the effect of laser speckle, without the need for an electromagnetic system, thereby reducing the number of components and simplifying the structure.

The application discloses a multiple-input multiple-output antenna decoupling performance prediction method based on deep learning, belongs to the technical field of computer-aided electromagnetic system design and prediction, is used for antenna decoupling performance prediction, and comprises the following steps: determining key size parameters of an antenna to be optimized; performing parameter scanning on the variation range of the key size parameters to obtain full-band S parameter simulation data and form an original data set; the data amount of the original data set is expanded by using an SMOTE algorithm to generate an enhanced data set; an antenna decoupling performance prediction model is constructed and trained, the antenna to be optimized is input, and corresponding full-band S parameter curve final prediction results are output. The application effectively expands high-dimensional data by introducing the SMOTE algorithm, solves the problem that small sample data in the electromagnetic simulation field cannot support deep learning model training, constructs a DNN model to establish a nonlinear mapping of a continuous S parameter curve, and can comprehensively evaluate the S parameters of the antenna, instead of being limited to discrete frequency points.

The application provides an electromagnetic system and a clapper circuit breaker, and belongs to the technical field of electrical equipment. The electromagnetic system comprises a magnetic yoke and an armature. A first side plate, a connecting plate and a second side plate in the magnetic yoke are sequentially connected to form a U-shaped structure, and the side wall of the first side plate and the second side plate away from the connecting plate is a first air gap surface. The armature comprises a body part and two connecting parts, the body part is located on one side of the first air gap surface, the two connecting parts are connected to the first end of the body part, one connecting part is rotationally connected to the outer side of the first side plate, and the other connecting part is rotationally connected to the outer side of the second side plate. When the electromagnetic system is in a released state, the distance between the second air gap surface of the body part and the part close to the first end of the body part tends to zero, and when the armature rotates relative to the magnetic yoke to the second air gap surface and the first air gap surface are attracted, the electromagnetic system is attracted. The two connecting parts are located on both sides of the body part, which can reduce the gap between the connecting part and the body part, thereby reducing the air gap between the armature and the magnetic yoke.

The invention discloses a contact system of an electromagnetic relay, which comprises a ceramic bottom plate and is characterized in that the contact system is arranged on the ceramic bottom plate, a plurality of grooves are formed in the side edge of the ceramic bottom plate, metal sheets are fixed in the grooves, and the contact system is fixed with an electromagnetic system of the relay through the metal sheets; a mounting groove is formed around the edge of the lower end face of the ceramic bottom plate, a metal welding ring is fixed in the mounting groove, and the ceramic bottom plate and a housing of the electromagnetic relay are sealed and fixed through the metal welding ring. Conductive parts in the relay are effectively isolated from the outside by adopting the insulating ceramic bottom plate, and the conductive distance between the conductive parts in the relay is increased, so that the use safety of the relay in a high-voltage environment is ensured, the dielectric voltage resistance of the relay is improved, the insulating property and the arc extinguishing capability of the relay are further improved, and the service life of the relay is prolonged. And meanwhile, the load voltage of the relay is also improved.

The invention discloses a suction type bistable magnetic latching contactor, which comprises an electromagnetic system and a contact system below the electromagnetic system, and is characterized in that the electromagnetic system comprises a bottom plate, and the bottom plate is provided with a door-shaped magnetic conductive frame and a yoke located in the door-shaped magnetic conductive frame; a magnetic conductive plate is arranged at the open end of the yoke, a coil assembly is arranged in an inner cavity of the yoke, one end of the coil assembly is installed at the closed end of the yoke, and the other end of the coil assembly is installed on the magnetic conductive plate. Magnetic steel is arranged between the top of the yoke and the n-shaped magnetic conductive frame. An iron core movably penetrates through the center of the coil assembly, a first armature and a second armature are arranged at the two ends of the iron core respectively, the first armature is located between the n-shaped magnetic conductive frame and the closed end of the yoke, the second armature is located between the n-shaped magnetic conductive frame and the magnetic conductive plate, and working air gaps are formed between the first armature and the n-shaped magnetic conductive frame and between the second armature and the n-shaped magnetic conductive frame. The lower end of the push rod is connected with the contact system. The magnetic holding force of the armature is provided through the magnetic steel, the coil does not need to be continuously powered up, and the impact vibration resistance and reliability of the contactor are improved.

The utility model provides a control module of a contactor, which comprises a control module shell, a static iron core and a coil are arranged in the control module shell, the coil is arranged between a movable iron core and the static iron core, the movable iron core is arranged on a movable iron core supporting piece, the movable iron core supporting piece is connected with the control module shell in a sliding mode, and the static iron core is arranged on the movable iron core supporting piece. The movable iron core supporting piece is provided with a first linkage part, and the first linkage part is detachably connected with the contact support. Through modularized design of the electromagnetic system, the number of parts can be reduced, management is convenient, disassembly and replacement are convenient after the contact breaks down, and cost is saved.

A computer-implemented method of predicting a response of an electromagnetic system to electromagnetic radiation from an illumination configuration. The system includes an aberration element located in the radiation path and an object interacting with the electromagnetic radiation at an object plane on the radiation path, the aberration element causing an aberration of the electromagnetic radiation transmitted along the radiation path described by an aberration function. The method includes various steps.

The invention relates to the field of low-voltage electric appliances, in particular to an operating system which comprises an operating part, an electromagnetic system, a moving contact mechanism, a control system and a trigger mechanism. When the operating piece moves to the closing position, the triggering mechanism is triggered by the operating piece moving to the closing position to output a first closing signal to the control system, and the control system controls the electromagnetic system to work after receiving the first closing signal so that the ejector rod can drive the moving contact mechanism to move to the closing position. The moving contact mechanism is driven by the electromagnetic system to move towards a disconnection position; the operating system is simple in structure and small in occupied space.

The utility model provides a permanent magnet type electromagnetic system and a contactor. The permanent magnet type electromagnetic system comprises a static iron core, two coil windings, a movable iron core, a contact supporting piece, a reset piece and a magnetic conduction driving assembly. The two coil windings are arranged on the static iron core, the movable iron core is arranged opposite to the static iron core in the first direction, the contact supporting piece is connected with the movable iron core, and the magnetic conduction driving assembly is connected with the contact supporting piece. A first magnetic field force is generated between the magnetic conduction driving assembly and the static iron core, a second magnetic field force is generated between the movable iron core and the static iron core, and a third magnetic field force is generated between the static iron core and the coil winding. The reset piece is arranged on the side, away from the contact supporting piece, of the magnetic conduction driving assembly and exerts reset force in the direction of the movable iron core on the magnetic conduction driving assembly. The first magnetic field force is the same as the reset direction, the third magnetic field force is opposite to the first magnetic field force, and the second magnetic field force is opposite to the first magnetic field force. The moving stroke of the movable iron core can be effectively improved.