8 results about "Electromotive force" patented technology

Four first electrodes are attached on the vicinity of a lower right end of a right clavicle, the vicinity of a lower left end of a left clavicle, the vicinity of a position on a right anterior axillary line at the level of a right lowermost rib, a the vicinity of a position on a left anterior axillary line at the level of a left lowermost rib of a living body, so as to correspond to limb leads of a standard 12-lead electrocardiogram (ECG). Two second electrodes are attached on such positions of the living body that correspond to a lead V2 and a lead V4 of chest leads of the standard 12-lead ECG. A first ECG data set corresponding to leads I and II of the standard 12-lead EGG with the first electrodes. A second ECG data set including the leads V2 and V4 with the second electrodes. An instantaneous electromotive force vector (a heart vector) is calculated based on the first and second ECG data sets, and predetermined first lead vectors of the leads I, II, V2 and V4. A third ECG data set including leads V1, V3, V5 and V6 of the chest leads is calculated based on the heart vector-and predetermined second lead vectors of the leads V1, V3, V5 and V6. A fourth EGG data set corresponding to leads III, aVR, aVL and aVF of the standard 12-lead EGG based on the first ECG data set The standard 12-lead EGG is derived based on the first to fourth ECG data sets.

A contactless power-receiving device, which is connected to equipment via a connection terminal and which supplies power to the load for the equipment, provided with: a secondary coil which intersects the alternating magnetic flux generated from a primary coil to which an alternating power is supplied; and a control unit which supplies induced electromotive force of the secondary coil to the load. The control unit determines the amount of charge in the load and determines whether or not to supply power to the load on the basis of the determined amount of charge.

The invention relates to a method for detecting the position of a rotor of a PMSM (permanent magnet synchronous motor) without a position sensor, and the method comprises the steps: employing a signalprocessing method for the digital processing of a change process of the back electromotive force of a three-phase winding; extracting some relatively reliable feature position of the back electromotive force in the rotating process of the motor, such as a zero point and extreme points; obtaining the position feature points, and carrying out the estimation of the rotor position information betweenthe feature points through an extended Kalman filtering method, and finally obtaining the accurate position of the rotor. The method is convenient in data collection, is small in calculation burden,is good in real-time performances, and is suitable for the implementation of various types of motor controllers.

The invention relates to the technical field of electronics, and discloses a vacuum capacitor capable of changing capacitance, which comprises an insulating rod, an upper shell, a lower shell, a fixed electrode, a movable electrode, a magnet, an insulating shell, a voice coil motor coil, a spring and a movable electrode connecting piece. The top end of the insulating rod is connected with the upper shell, and the bottom end of the insulating rod is provided with the lower shell. According to the invention, the coil of the voice coil motor is electrified, so that the coil of the voice coil motor generates a driving force magnetic field under the action of current, the magnet generates an induced electromotive force, and under the action of the induced electromotive force, the movable electrode moves in the direction perpendicular to the current direction of the coil of the voice coil motor because the current of the coil of the voice coil motor is different; therefore, the relative area between the movable electrode and the fixed electrode is changed, the capacity of the capacitor can be rapidly changed, and compared with an existing variable vacuum capacitor, the variable vacuum capacitor has the advantages of being high in adjusting speed (50-500 ms) and high in position accuracy.

A double high axial motor capable of effectively reducing back electromotive force torque pulsation comprises a sectional armature (1), a rotor disc (2), a bearing pressure plate (3), an iron core (4) and a stator bar (5), and is characterized in that the iron core (4) of the sectional armature (1) adopts an axial motor separation design, a bearing is fixed on a stator by the bearing pressure plate (3), the iron core (4) is fixed by the sectional armature (1) through the stator bar (5), and an external motor case is connected; the iron core (4) is made of a soft magnetic composite material, arc-shaped surfaces are designed in sequence according to different pole numbers, the part close to a wire inlet end is small in radian or is not arranged, and the part far away from the wire inlet end is appropriate in radian, so that the salient pole rate is improved, the influence of inter-pole resistance on counter electromotive force is reduced, and the permanent magnets can be effectively utilized; materials are saved, and power and torque are improved.

The invention discloses a three-phase 18/16-pole bearingless switched reluctance motor. According to the invention, torque windings on torque teeth are used for generating output torque, and suspension windings on the suspension teeth are used for generating radial suspension force; due to the fact that the pole arc angle of the suspension teeth is equal to a rotor periodic angle, the inductance of the suspension windings is constant, and the motion electromotive force of the suspension windings is zero, so the suspension winding does not generate torque, and then natural decoupling of the torque and the suspension force can be achieved structurally; a traditional switched reluctance motor driving mode is adopted for rotation control, and suspension control is similar to a traditional electromagnetic bearing control mode, so control is simple, and good suspension performance is obtained; only one coil is wound on each tooth, so a structure is simple, machining and assembling are convenient, and a multi-rotor-tooth-number structure facilitates reduction of torque pulsation and increase of output power; moreover, torque and suspension magnetic circuits are both of a short magnetic circuit structure, so iron core loss can be reduced; and the magnetic flux direction of a stator yoke part does not change when the motor operates, so the stator iron core loss can be further reduced.

The invention relates to the technical field of semiconductor minerals, and discloses a metal mineral powder material conductivity type rapid judgment device which comprises a working circuit, a micro electromotive force measurement circuit, an excitation circuit, an inverted T-shaped sample bracket and a sample to be detected. During measurement, K1, K2 and K3 are connected with a key above, E1, E2, R1 and R2 are adjusted, the current of the working circuit flows into the right side and flows out of the left side of the K1, the current of the excitation circuit flows into the right side and flows out of the right side of the K2, the direction of the magnetic field in the Helmholtz coil is from right to left, and mV1 is measured through the micro electromotive force measuring circuit; the K1 and the K2 are connected with a lower key, the current of the working circuit flows into the left side from the right side of the K1, the current of the excitation circuit flows into the left side from the right side of the K2, the direction of a magnetic field in the Helmholtz coil is from left to right, and mV2 is measured; and mV = (mV1 + mV2)/2 is calculated. If mV is a positive value, the conduction type is P type, and if mV is a negative value, the conduction type is N type.

The embodiment of the invention discloses an electric vehicle control method and an electric vehicle controller. The method comprises the steps of 1, when a starting signal of a user is received, outputting a first starting driving signal comprising a forward driving signal and a reverse driving signal according to the starting signal, wherein the duty ratio of the first starting driving signal isthe same as that of the starting signal, and the direction of current applied to the motor by the reverse driving signal is opposite to that of current applied to the motor by the forward driving signal; sampling a first counter electromotive force of a motor suspension phase when the forward driving signal is applied to the motor, and sampling a second counter electromotive force of the motor suspension phase when the reverse driving signal is applied; and outputting a second starting driving signal according to the difference between the first counter electromotive force and the second counter electromotive force. The accurate commutation time is obtained according to the variation trend of the difference between the two counter electromotive forces, and a starting signal is applied tostably start the motor. The problem that the motor control is out of step when a driving signal is generated by using a zero-crossing detection method in the prior art is solved.