169 results about "Magnetic current" patented technology

The invention discloses a numerical simulation research method for a high-performance hydrogen fuel cell based on magnetic-flow-thermal multi-physics field coupling. The method comprises the following steps: globally defining geometric dimensions and physical performance parameters of the fuel cell; constructing a high-performance hydrogen fuel cell three-dimensional model with permanent magnets arranged at the cathode and anode, and creating a geometric domain; defining a magnetic field coupling equation expression; adding material attributes and physical fields, selecting a solution domain for each physical field, and setting boundary conditions and parameters according to a control equation of the added physical field; grid division is carried out on the constructed three-dimensional model, a domain probe is added, and grid independence verification is carried out; research steps are determined, steady-state calculation is carried out on the coupled model, post-processing is carried out on result data, and a state curve or image is obtained. A numerical simulation method is utilized, a coupling model of the hydrogen fuel cell, multiphase flow, solid and fluid heat transfer and the magnetic field is constructed, the action and influence mechanism of the magnetic field on other physical fields is researched, and the performance of the fuel cell is effectively improved.

An electric machine comprises a stator, a rotor, an air gap between the stator and rotor (spacing them apart), and a shielding structure to reduce capacitive coupling between the stator and rotor. The shielding structure is coupled to a reference potential. Located within the air gap, the shielding structure comprises multiple conductors. Each conductor has a first section, the longitudinal extents of which extend transversely to the magnetic flux direction of the electric machine. Each conductor also has a second section, the longitudinal extents of which extend in a comb-like or meandering pattern, interlocked transversely to the magnetic flux direction and in a direction different from the longitudinal extents of the first sections.

The utility model provides a device for visually displaying the magnetic line of force of a magnet, which relates to the technical field of magnetic line of force display, and specifically comprises a transparent shell, magnetic current liquid and a light bar arranged on the side surface of the shell, the shell is formed by attaching two plates, the inner side of each plate is sunken to form a cavity, the magnetic current liquid is smeared in the cavity, and the light bar is arranged on the side surface of the shell. And the light bar illuminates the magnetic flow liquid towards the cavity. The magnetic particles of the magnetic flow liquid are attached to the interior of the cavity of the plate due to adsorption, precipitation and movement cannot occur, the magnetic flow liquid cannot move along with the magnetic flow liquid even if the magnetic particles are influenced by an external magnet, and the free magnetic particles can only be connected under the action of a magnetic field. And the annular wave-shaped magnetic lines of force between the two poles of the magnet can be seen through 360-degree annular irradiation of the lamp strips on the periphery. The device is simple in structure, low in failure rate and low in maintenance cost, can be used for testing at any angle state, is sensitive in response, and can instantly display the change track of magnetic lines.

The invention relates to a main and collateral channel nursing instrument based on bioelectricity, which is applied to the field of physical therapy and is characterized in that a magnetic current sensor is used for monitoring the electrifying current condition of each electrode plate and skin, and when a certain area of conductive hydrogel is in poor contact with the skin, the area can be subjected to micro-regulation and control; the area is pressed downwards through the skin pressing device to be in close contact with the skin, skin burning caused by too high local current density due to poor contact is effectively avoided, and when the energizing current of the electrode plate is too high, the conductive hydrogel can be quickly separated from the skin through the magnetic attraction effect of the electromagnetic ring on the hanging barrel, so that the skin is prevented from being damaged due to too high current; in addition, when power supply current of the nursing instrument body to all the electrode plates is too high, the negative voltage electrode box can directly fall off from the skin, and compared with a direct cutting-off mode in the prior art, the situation that equipment is damaged due to sudden interruption of the current can be effectively avoided.

The invention relates to the technical field of flexible screens, and provides a magnetofluid attaching device and method for a flexible screen, and the attaching device comprises a bearing film which is used for attaching the flexible screen; the clamping and sliding assembly is used for clamping, sliding and resetting the bearing film; the telescopic magnetic fluid bag assembly is used for profiling the bearing film to which the flexible screen is attached and driving the profiled bearing film to extend into the inner wall of the curved glass cover plate; and the electromagnetic platform is used for placing the curved glass cover plate and performing magnetic current control on the telescopic magnetic fluid bag assembly. The curved glass cover plate is stably placed through the electromagnetic platform, the flexible screen and the bearing film are positioned through the clamping sliding assembly, the flexible screen and the bearing film are profiled and moved through the telescopic magnetic fluid bag assembly, and then the curved glass cover plate is stably placed by adjusting the current and the electrifying sequence of the electromagnetic platform. The flexible screen is uniformly attached to the inner circumferential wall of the curved glass cover plate through the telescopic magnetic fluid bag assembly, and the problems of unstable attachment and poor adaptability existing in a profiling silica gel attachment technology are solved.

An electronic device is provided. The electronic device includes a middle frame assembly and a conductor member electrically connected to the middle frame assembly. The middle frame assembly includes a metal middle frame and a border frame. The border frame is located on an outer periphery of the metal middle frame, and at least one border frame antenna is formed on the border frame. The metal middle frame and the conductor member are stacked, and a region on the metal middle frame corresponding to the conductor member and the conductor member define a radiation cavity. At least one feed point is configured to feed the border frame antenna and the radiation cavity. The at least one feed point excites the border frame antenna to generate a radiation current, and excites the radiation cavity to generate a radiation magnetic current, to form a circularly polarized antenna.

Electric motor (16) capable of generating a total motor torque with continuously variable magnetic and reluctance torque components, the electric motor (16) comprising: a stator arrangement (26) with stator windings (26W) and a stator core (26C) with an axial length (L S ); a rotor arrangement (33) comprising a rotor shaft (17) and a cylindrical rotor hub (33R) each with respective axial lengths (L R ) includes, wherein the cylindrical rotor hub (33R) has a first end (E1) with a first mean magnetic field strength and a second end (E2) with a second mean magnetic field strength, the second mean magnetic field strength being weaker than the first mean magnetic field strength; and a return spring (64) located near the first or second end (E1, E2) of the rotor hub (33R); wherein the rotor hub (33R) is displaceable relative to the rotor shaft (17), wherein the axial length (L R ) the rotor hub (33R) the axial length (L S ) of the stator core (26C) and the rotor hub (33R) is configured to move along the axial length of the rotor shaft (17) to vary the contributions of the magnetic and reluctance torque components to the total motor torque in response to different speed and torque operating points of the electric motor (16) relative to each other; characterized by a controller (50) configured to receive a set of input signals, including a rotational speed of the electric motor (16) and a torque generated by the electric motor (16), and to displace the rotor hub (33R) along the axial length (L R) the rotor shaft (17) in response depending on the received rotational speed and torque, in order to continuously vary the relative contributions of the magnetic and reluctance torque components to the total motor torque; wherein the controller (50) is further configured to apply a magnetic flux attenuation stator current to the stator windings (26W) in order to limit the rotor hub (33R) along the axial length (L R ) of the rotor shaft (17) to be passively displaced.

The application discloses an antenna module and an electronic device, and belongs to the technical field of communication. The antenna module comprises a first radiator, a metal floor and a feed source; the feed source is electrically connected with the first radiator; a first gap is formed between the metal floor and the first radiator; a first slot is formed in the metal floor; wherein the feed source is used for exciting a first current on the first radiator and exciting a first magnetic current at the first slot; under the action of the first magnetic current, a second current is formed on opposite sides of the metal floor; and the first current and the second current are consistent in phase.

The invention relates to the technical field of magneto-rheological polishing, and discloses magneto-rheological polishing equipment with adjustable magnetic field intensity and a method thereof.The magneto-rheological polishing equipment comprises a polishing workbench, a plurality of mounting rings are distributed on the inner wall of a first mounting groove from top to bottom, a plurality of magnetic sheets are fixedly arranged on the inner wall of each mounting ring at equal intervals, and a gear ring is fixedly arranged on the outer wall of a chuck; the container is extruded through the limiting mechanism, so that the container compresses the supporting assembly and then ascends and descends in the first mounting groove, the number of the mounting rings wrapping the outer portion of the container is increased, and then the number of the magnetic sheets wrapping the outer portion of the container and conducting magnetic flow induction with the magnetic needles in the container is increased; the magnetic field intensity in the magneto-rheological polishing process is properly adjusted, the magnetic field intensity of the magneto-rheological polishing equipment is adjusted by changing the number of the magnetic sheets wrapping the container, the polishing quality of workpieces made of different materials is improved, and the manufacturing cost of the polishing equipment is reduced.

The utility model belongs to the technical field of CVD equipment, and discloses a magnetofluid sealing device and epitaxy equipment, the magnetofluid sealing device comprises a cooling body and a magnetofluid assembly, the cooling body is provided with a first inlet and a first outlet, and the first inlet and the first outlet are communicated through a first flow channel arranged in the cooling body; the magnetic fluid assembly comprises a magnetic current cavity and a rotating shaft; the first end of the cooling body penetrates through the magnetic flow cavity, so that the first inlet and the first outlet are located outside the magnetic flow cavity, a magnetic flow cavity capable of containing the magnetic fluid is formed between the cooling body and the magnetic flow cavity, the rotating shaft is connected to the cooling body, and the second end of the cooling body can be connected with the driving part to drive the cooling body and the rotating shaft to rotate; the epitaxy equipment adopts the magnetofluid sealing device to perform heat exchange on the rotating shaft and the magnetofluid in the magnetic flow cavity, so that the temperature of the rotating shaft and the magnetofluid is reduced, and normal operation of the rotating shaft and the magnetofluid is ensured.

This invention relates to the field of energy storage technology for new energy power plants, and discloses a multi-compartment coordinated charging and discharging intelligent control device for a new energy power plant energy storage system. The device includes a container body, multiple battery clusters and a DC power control cabinet installed on its inner wall. The energy storage EMS energy management system host sends control commands to drive the drive module to synchronously energize electromagnetic coil one and electromagnetic coil two to generate a directional magnetic field. Electromagnetic coil one, in conjunction with a magnetically conductive shell, magnetizes the iron core. The iron core magnetically attracts the I-shaped armature to compress the spring one, which slides downward along the inner wall of the connecting cavity and pulls the telescopic partition to divide the upper part of the connecting cavity into independent positive and negative magnetorheological chambers that are not connected. The magnetorheological fluid in the liquid chamber flows into the corresponding chamber and, under the action of the magnetic field of electromagnetic coil two, transforms from a liquid state into a rigid solid-like state and forms a dense conductive chain, thereby forming a conductive path to ensure that the battery clusters can be independently switched on and off and coordinated across multiple compartments.

The invention discloses a variable-rigidity connecting assembly, a machine tail connecting device and a using method. The variable-rigidity connecting assembly comprises a supporting body, a permanent magnet, a magnet exciting coil, an elastic sleeve and a magnetic current layer. The magnet exciting coil located on the outer side of the permanent magnet can generate a magnetic field in the same direction or in the opposite direction with the permanent magnet after being electrified, the magnetic current layer acts on the elastic sleeve under the influence of the magnetic field, the elastic sleeve is subjected to expansion and retraction deformation, variable-rigidity controllable connection between rigidity and flexibility at the connecting position is achieved, and the variable-rigidity permanent magnet motor is suitable for different use environments and has good application prospects. The problems of force suffocation, jamming and the like or the deformation of a connecting position are avoided; according to the tail connecting device, a connecting assembly with variable rigidity is arranged in a positioning hole formed in the butt joint of a first belt frame and a second belt frame in a sleeved mode, variable rigidity connection between rigidity and flexibility between the self-moving tail belt frames is achieved, control and adjustment can be conducted according to different working conditions, and the problems of force suffocation, jamming and the like are avoided.

The invention discloses a magnetic generator based on magnetic bias current, and belongs to the technical field of generators, the magnetic generator comprises a casing, a rotating shaft and a stator, the rotating shaft is provided with a plurality of fan-shaped iron cores and fan-shaped permanent magnets, the fan-shaped iron cores and the fan-shaped permanent magnets are distributed on the rotating shaft along the circumference, the fan-shaped iron cores and the fan-shaped permanent magnets are symmetrically arranged, the fan-shaped iron cores are provided with armature windings, and the armature windings are arranged on the stator. The stator comprises four fan-shaped permanent magnets which are opposite in polarity and symmetrically distributed at the two ends of the machine shell, and the four fan-shaped permanent magnets form an axial magnetic pole pair. According to the technical scheme, the iron core and the permanent magnets are arranged in the rotor, the direction of the magnetic field of the permanent magnets is opposite to the direction of an induced magnetic field generated by an armature winding of the iron core, and the induced magnetic field hinders rotation of the rotor; meanwhile, magnetic circuit performance is optimized through magnetic biasing current, starting energy consumption is reduced, and efficient power generation is achieved through the synergistic effect of the permanent magnet and the induced magnetic field.

The present invention discloses a composite ultra-wideband director, which is composed of a director vane and a magnetic current loop. The director vane is placed above the radiation surface of the oscillator, and the magnetic current loop is placed below the radiation surface of the oscillator with its vertical axis coinciding with that of the oscillator. In particular, by designing a double-layer director vane and a spiral magnetic current loop, the above-mentioned composite director realizes ultra-wideband plane wave conversion and gain improvement. The invention combines the plane wave conversion characteristic of the director vane with the characteristic of the magnetic current loop to improve the axial gain, providing a solution for a composite ultra-wideband and high-gain director, so as to better meet the requirements of current 5G ultra-wideband antennas. The present invention also provides a high-low frequency nested array.

Dry-running electromagnetic valve (1) comprising a valve housing (2) in which an electric coil (3) and an armature (5) are arranged, and a valve spool (8) which can be operated by the armature (5) in an axial operating direction for opening and closing the electromagnetic valve (1), the coil (3) generating a magnetic flow when the electromagnetic valve (1) is operated, which magnetic flow flows via a magnetically conductive valve housing outer wall (2c) of the valve housing (2) to the armature (5), in order to reduce the friction of the electromagnetic valve, it is provided according to the invention that in the valve housing (2) a magnetically conductive magnetic flux element (12) is provided, which introduces at least 80%, preferably at least 90%, particularly preferably 100% of the magnetic flow flowing through the valve housing outer wall (2c) into an armature end face (5B) of the armature (5) facing the coil (3).

The invention relates to the technical field of active vibration reduction, in particular to a triaxial damping controllable magneto-rheological damper and a vibration reduction method thereof.Compared with a conventional magneto-rheological damper, the triaxial damping controllable magneto-rheological damper can cope with excitation in the vertical direction and the horizontal direction at the same time, and the vibration reduction effect is good. Vibration in different directions can be effectively suppressed; the magnetic field intensity is controlled by the magnetic current coil, so that damping force in different directions can be accurately adjusted; the response speed of the magnetorheological fluid to the magnetic field change is high, the damping force can be adjusted in a short time, and different vibration conditions can be adapted; according to the magneto-rheological damper, the damping force can be changed by adjusting the current signal according to different damping requirements, the magneto-rheological damper is suitable for various different application scenes, and therefore the engineering applicability of the magneto-rheological damper in the field of electronic equipment is improved.

The invention belongs to the technical field of magneto-rheological polishing, and particularly relates to a magneto-rheological polishing device and a polishing method. The magnetorheological polishing device comprises a sleeve made of a non-magnetic material and fixedly arranged, a magnetic piece capable of generating a magnetic field, a first driving assembly connected with a workpiece and used for driving the workpiece to rotate and a second driving assembly connected with the magnetic piece, and the sleeve is provided with a polishing hole used for containing the workpiece. A polishing medium is arranged between the outer surface of the workpiece and the inner wall of the polishing hole, and the second driving assembly is used for driving the magnetic part to reciprocate in the length direction of the sleeve so as to generate a gradient magnetic field on the polishing medium. The magneto-rheological polishing device can polish the roller mold, and meanwhile the structure of the magneto-rheological polishing device is simplified.

This invention belongs to the field of computational electromagnetics numerical simulation and provides a simulation method for electromagnetic scattering of thin-coated targets based on Schur complement preconditions. First, for the IBC scattering target to be solved, equivalent surface current and equivalent surface magnetic current are introduced as independent unknowns. The electromagnetic scattering solution equation is established using SDIE and then discretized. Next, the impedance matrix is ​​decomposed into near-field and far-field matrices using an octree structure. For the near-field matrix, key operator sub-blocks are explicitly assembled and extracted. Then, approximate operators in block diagonal form and Schur complement operators are constructed and approximately inverted. Simultaneously, the diagonal product of intermediate blocks is pre-calculated and stored based on the approximate operators. Finally, the constructed preconditions are applied to the GMRES iterative solver. When the iteration error reaches the preset convergence criterion, the current and magnetic current distributions on the target surface are output. Further calculations of radiation characteristic parameters such as the target's radar cross section are then performed, achieving low-cost, high-efficiency, and easily parallelizable electromagnetic simulation solutions.

A radial flux electric motor comprises a stator with a radially inner stator surface and stator windings arranged on it. The motor also includes a rotor, which is mounted inside the stator and configured to rotate about an axis relative to it. The rotor has a core defined by an outer surface and magnetic poles configured to generate a magnetic flux and define leakage flux zones. The motor additionally includes a selective permeability sleeve, which is circumferentially mounted on the rotor and attached to the outer surface, creating an air gap between the sleeve and the stator. The sleeve reinforces the core and magnetic poles and contains regions of relatively high and relatively low magnetic permeability that alternate around the outer surface of the rotor.The areas with relatively low magnetic permeability are arranged radially outwards and opposite the stray flux zones in order to control the distribution of the magnetic flux in the motor.

The present invention provides an inrush current suppression method for a core-type transformer, which includes obtaining the magnetizing current value of the transformer; modeling the data in the DC magnetizing process to calculate the closing angle; obtaining the relationship between the closing angle and the magnetizing current, establishing a magnetizing model, and outputting the magnetizing current and the optimal closing angle after the transformer parameters are input; judging whether the output magnetizing current exceeds the overcurrent protection value; calculating the voltage value of the transformer element according to the magnetizing current to judge whether it exceeds the overvoltage protection value; and performing phase-controlled closing according to the closing angle output after the magnetization is completed, so that the bias magnetic energy generated by the closing is offset by the residual magnetism in the iron core after magnetization, thereby suppressing the inrush current. The present invention calculates the relationship between the magnetizing current and the transformer magnetic flux, uses the magnetizing current to control the three-phase iron core magnetic flux of the transformer within a specified range, and then controls the transformer to close at a specific angle, thereby achieving the suppression of the three-phase inrush current.

This application discloses a high-isolation terminal antenna system, relating to the field of antenna technology. It combines current-loop antennas and / or magnetic flux-loop antennas with different location characteristics to provide good radiation performance while maintaining good isolation. Specifically, the terminal antenna system includes a first antenna, a second antenna, and a third antenna. The first antenna, the second antenna, and the third antenna are either current-loop antennas or magnetic flux-loop antennas. When the current-loop antenna is working, a uniform magnetic field is distributed between the radiator of the current-loop antenna and the reference ground. When the magnetic flux-loop antenna is working, a uniform electric field is distributed between the radiator of the magnetic flux-loop antenna and the reference ground. The first antenna is disposed on a first side of the electronic device, the second antenna is disposed on a second side of the electronic device, and the third antenna is disposed on a third side of the electronic device. The first side and the third side are opposite each other, and both the first side and the third side are adjacent to the second side.

The application belongs to the technical field of electromagnetic modeling of targets in layered media, and specifically provides a plane multilayer medium electromagnetic scattering modeling method based on layered medium Green function, which is used to solve the problems of large number of unknown quantities and low calculation efficiency when analyzing the electromagnetic scattering characteristics of targets in layered media; first, the medium target in the plane multilayer medium is meshed; then, the layered medium Green function is calculated based on the space list and interpolation method, and the matrix equation of the target current and magnetic current is constructed by solving the surface integral equation of the target by using the method of moments; finally, the improved stacked non-diagonal low-rank matrix is used to solve the matrix equation to calculate the target scattering field. The application adopts a direct solving calculation method, effectively solves the problem of ill-conditioned matrix difficult to converge in the conventional iterative method, especially for the multi-port excitation problem, without the need for repeated calculation, improving the solving efficiency of large-scale problems and reducing the consumption of calculation resources.

This invention refers to a magnetic anti-scaling device that can be coupled around piping with fluid flow inside it, comprising an external tube; and a plurality of magnetic arrangements, wherein each magnetic arrangement is formed by a cylindric support and a plurality of magnets circumferentially positioned on the cylindric support: where—in the plurality of magnetic arrangements comprises a sequency of magnetic arrangements placed side by side, and likely to be longitudinally coupled around the piping in an axisymmetric arrangement, so as to form, at least, a concentration plan of magnetic field; and wherein a spacer and an absorber are positioned at each end of the axisymmetric arrangement, and the external tube surrounds the axisymmetric arrangement. The application of a high-density magnetic flow orthogonally to the speed of the fluid to be treated inhibits formation of scales at the internal wall of piping, thus reducing scaling at the equipment upstream.

A method includes receiving, from a sensor proximate a first conductor, a sensor signal representing a measurement of a magnetic field produced by a first current flowing in the first conductor and a second current flowing in a second conductor. The first current includes first and second current components having different frequencies, and the second current includes third and fourth current components. The third current component is phase shifted from, and has the same frequency as the first current component. The fourth current component has a different frequency from the third current component. The method also includes determining reference values of the first and second currents, and, based on the sensor signal and the reference values of the first and second currents, determining for the sensor, a plurality of coupling coefficients representing magnetic field coupling between the first and second conductors.

The present invention discloses a Ku-band antenna array for drone communications, relating to the field of antenna design. The antenna array comprises a plurality of metasurface antenna units, wherein the metasurface antenna units comprise a metasurface layer and an SIW waveguide layer; a rectangular patch group arranged in an array with equal spacing is laid on the surface of the metasurface layer, the patch group comprising a first rectangular patch etched with slits in the same direction, a second rectangular patch etched with two short slits facing each other, and a third rectangular patch etched with short slots representing magnetic currents, wherein the second rectangular patch is symmetrical about the third rectangular patch; the SIW waveguide layer is pre-set with short-circuit vias and arrayed metal vias, which are used to couple and excite the characteristic modes of the metasurface layer after connecting the SIW feed layer and the slotted ground layer. The antenna array provided by the present invention is not only compact in structure, but also has broadband, high gain, and excellent directivity, and also has good polarization purity and anti-interference capabilities.

The invention discloses a power transformer multi-physics coupling simulation analysis method and a related device, and the method comprises the steps: constructing a corresponding geometric model and a multi-physics coupling model according to the obtained transformer data of a power transformer, and further determining a target simulation model; inputting a preset direct-current magnetic bias current into the target simulation model to simulate a direct-current magnetic bias state, and performing finite element analysis to obtain vibration displacement change distribution and sound pressure distribution; and according to the vibration displacement change distribution and the sound pressure distribution, determining the weak position of the power transformer influenced by the preset direct-current magnetic bias current. Therefore, accurate analysis and prediction of vibration and noise characteristics of the power transformer in the direct-current magnetic bias environment are realized by establishing a multi-physics field coupling model for analysis.

The invention discloses a phase-free electromagnetic source inversion positioning method and device based on adaptive sparse sampling, and the method comprises the steps: determining the position of an adaptive sparse sampling point for a to-be-measured electromagnetic source on a near-field scanning plane, so as to obtain the near-field distribution data of the corresponding sparse sampling point; recovering the near-field distribution data into uniform distribution data through an interpolation method, and extracting amplitude information to obtain phase-free data; establishing a forward radiation model of the equivalent electromagnetic source according to the electromagnetic field integral equation model and the mirror image effect, and constructing a corresponding error minimization objective function based on the phase-free data and the forward radiation model; performing iterative optimization on the phase-error-free minimization objective function by using an LM algorithm so as to perform inversion on the electromagnetic source to be measured to obtain equivalent magnetic current source distribution; and reconstructing a magnetic field according to equivalent magnetic current source distribution obtained by electromagnetic source inversion. According to the scheme, efficient reconstruction of the near-field radiation characteristics of the radio frequency circuit can be realized while the number of sampling points is reduced and the inversion precision is ensured.

This invention discloses a millimeter-wave wide-beam DRA, a wide-angle beam scanning phased array, and their design methods. The DRA consists of a DR and a microstrip coupling slot located directly below the DR. This invention enables the non-exciteable DRA to achieve TE by setting the dimensions of the slot and the DR. 112 The resonant frequency of the mode is close to that of the slot operating mode, and the field inside the DR will exhibit a similar behavior to that of the TE mode. 112 The field distribution of the mode forms an equivalent magnetic current parallel to the ground plane, thereby achieving wide beam characteristics in the E-plane and H-plane; moreover, arranging multiple such small-sized DRA units at equal intervals can form a linear phased array in the E-plane (H-plane), whose beam can be scanned from -72° to +72° (-65° to +65°), with a gain ripple of 2.5dB (0.5dB), and the present invention does not require any parasitic structures or additional active control circuits.

A rotation angle detector includes a magnet arranged to rotate, and a magnetic detection circuit provided with a first pair of magnetic detection elements arranged to be in combination sensitive to a first magnetic field in circumferential direction to the first surface and to a second magnetic field in normal direction to the first surface and arranged away from the rotation axis, and configured to detect magnetic flux of the magnet. A second pair of magnetic detection elements are arranged to be in combination sensitive to the first magnetic field in circumferential direction to the first surface and to the second magnetic field in normal direction to the first surface. A signal processing unit is configured to output a signal representative of a rotation angle of the magnet based on outputs of the first and second pair of magnetic detection elements.