1198 results about "Field coil" patented technology

An apparatus and method for controlling a hybrid motor, The hybrid motor, uses a permanent magnet instead of a field coil for a rotor, winds a coil round a stator in a multi-phase independent parallel manner, fixes a rectifying type encoder to the rotor and connects a sensor to a driving circuit. The apparatus comprises: an encoder attached to a rotor in cooperation with a pole sensor a speed input unit for generating a speed instruction signal a power switching circuit to generate motor driving signals; a drive module receiving the speed instruction signal and the sensor signal and outputting the speed instruction signal synchronized with the sensor signal as a driving motor signal; a power supply for applying a DC voltage to the power switching circuit; A logic power supply for converting the DC voltage into a logic voltage, and applying logic voltage to the drive module. The motor has n phases, n power switching circuits and n drive modules.

A continuously variable ratio transmission including a planetary gear set having a sun gear, a ring gear, and a planet carrier having at least two planet gears carried thereon, a control element including a servogenerator capable of generating electric power, and at least one auxillary field coil adapted to be operatively connected to an output means to influence a power output level and AC power frequency of the output means, the at least one auxillary field coil being powered by the servogenerator and constituting a load to the servogenerator, the speed of the servogenerator being capable of being controlled by the load; and a means for controlling an electrical current to the at least one auxiliary field coil form the servogenerator; where the servogenerator is capable of being driven to produce electrical power by a rotation of one of the sun gear, the ring gear, and the planet carrier.

A drive control system, with PLL control, drives a rotatable multi-phase sensor-less motor by switching a current of a field coil of each phase depending on the rotating phase of the motor. When the moto is driven, a desired phase is selected as a datection phase, and a voltage induced on the coil of the detection phase is detected when power is fed for a predetermined time to the field coils other than the detection phase. A magnetic pole position is detected from the amplitude condition of the detected induced voltage. Based on this detection, the power-feeding phase of the motor drive is determined. Power feeding and pole position detection are performed alternately.

A machine includes a shaft adapted to rotate about a longitudinal axis and formed of a magnetic material and a rotor assembly rotationally engaged with the shaft The rotor assembly includes a pair of rotor disks comprising a magnetic material, each of the rotor disks having a number of magnetic poles, the magnetic poles being spaced apart circumferentially. The rotor disks are coupled to the shaft for rotation about the shaft and generation of a rotating permeance wave. The machine further includes a stator assembly that includes a magnetic core stator disposed between the rotor disks, a number of armature windings supported on the magnetic core stator, and a stationary superconducting field coil disposed between the magnetic core stator and the shaft. The stationary superconducting field coil is configured as a stationary magneto-motive force (MMF) source for the rotating permeance wave produced by the rotor assembly to produce a rotating magnetic field.

A hand-held power tool (1) includes a linear motor (2) having a rotor (3) which is movable along a percussion axis (A) in an axially limited manner between two reversal points (W) and which can be driven by the striking piston (5) of the power tool with the intermediary of an air spring (4), sensors designed for determining the actual state of the rotor (3) and connected to a computer (9) connected via power electronics (33) to at least one field coil (10) of the linear motor (2), with the rotor (3) being displaced against a contact element (11a, 11b) at least at one reversal point (W) and being pressed against the contact element electromagnetically; and a control process for the hand-held power tool.

A superconducting magnet configuration (4; 14) for generating a homogeneous magnetic field B0 in an examination volume (4b), has an interior radial superconducting main field coil (1) which is disposed rotationally symmetrically about an axis (z-axis) and an oppositely driven coaxial radially exterior superconducting shielding coil (2) is characterized in that the magnet configuration (4; 14) consists of the main field coil (1), the shielding coil (2), and a ferromagnetic field formation device (3; 18), wherein the ferromagnetic field formation device (3; 18) is located at the radially inside of the main field coil (1), the main field coil (1) consisting of an unstructured solenoid coil or of several radially nested unstructured solenoid coils (15, 16) which are driven in the same direction, the axial extent Labs of the shielding coil (2) being smaller than the axial extent Lhaupt of the main field coil (1), wherein the axial magnetic field profile (5) generated by the main field coil (1) and the shielding coil (2) during operation has a minimum of the field strength along the axis (z-axis) in the center (4a) and a maximum of the field strength on each side of the center (4a), and wherein the axial magnetic field profile (6) generated by the ferromagnetic field formation device (3; 18) during operation has a maximum of the field strength along the axis (z-axis) in the center (4a) and a minimum of the field strength on each side of the center (4a). The magnet configuration in accordance with the invention has a very simple structure.

A drive motor assembly for a power driven wheelchair comprises: a stator housing for containing field coils of a stator of the motor assembly; at least one sensor disposed in the stator housing for sensing rotation of the motor; a memory storing motor error parameter data including data of errors of the at least one sensor, the memory being embedded in the stator housing; and a connection for accessing the error parameter data of the memory from the stator housing. The motor error parameter data may be accessed from the embedded memory of the drive motor by a programmed motor controller for use in controlling the drive motor. Also, the motor error parameter data may be embedded in the drive motor by the steps of: controlling the motor through at least one predetermined drive pattern; sensing motor rotation during the drive pattern and generating signals representative thereof; deriving error parameter data of the drive motor from the generated signals; programming a memory with the derived error parameter data; and embedding the memory in the drive motor.