A stepping motor includes a rotor, a stator and three coils. The rotor is two-pole magnetized in a radius direction. The stator is provided with a rotor receiving section for receiving the rotor. The three coils are magnetically connected with the stator. At least one of the three coils is an integrated coil which is integrally formed with the stator by winding a coil around a part of the stator.

An X-Y movable stage with rotation is described. A fixed base comprises a magnetic bed with a checkerboard pattern of alternating north and south poles on a grid. A movable puck moves and rotates on the base. The puck comprises three or more nodes where each node may be energized for a north, south, or off magnetic field, with varying field strength. The nodes are arranged on an X-Y motion grid on the puck that are rotated 45 from the magnetic base grid. A first set of node locations on the puck may be each centered between a pair of opposite poles on the magnetic base. One arrangement of nodes is at the corners of a rectangle aligned with the motion grid. An optional second set of one node locations on the puck may be each centered between a pair of opposite poles on the magnetic base, when the first set of nodes is aligned over poles. Methods of mapping node locations, controllers, and applications are described.

An X-Y movable stage with rotation is described. A fixed base comprises a magnetic bed with a checkerboard pattern of alternating north and south poles on a grid. A movable puck moves and rotates on the base. The puck comprises three or more nodes where each node may be energized for a north, south, or off magnetic field, with varying field strength. The nodes are arranged on an X-Y motion grid on the puck that are rotated 45 from the magnetic base grid. A first set of node locations on the puck may be each centered between a pair of opposite poles on the magnetic base. One arrangement of nodes is at the corners of a rectangle aligned with the motion grid. An optional second set of one node locations on the puck may be each centered between a pair of opposite poles on the magnetic base, when the first set of nodes is aligned over poles. Methods of mapping node locations, controllers, and applications are described.

An example actuator control system includes a variable differential transformer (VDT) configured to measure displacement of a motor, and a motor controller configured to control the motor based on displacement data from the VDT. A circuit card assembly (CCA) interconnects the VDT to the motor controller. The CCA includes memory storing configuration data of the VDT, and the CCA is configured to provide the configuration data to the motor controller to calibrate the motor controller for use of the VDT. A method of configuring a motor controller is also disclosed.

Aspects of the invention provide methods and systems for moving a plurality of moveable stages relative to a stator. The stator comprises a plurality of coils shaped to provide pluralities of coil trace groups where each coil trace group comprises a corresponding plurality of generally linearly elongated coil traces which extend across a stator tile. Each moveable stage comprises a plurality of magnet arrays. Methods and apparatus are provided for moving the moveable stages relative to the stator, where a magnet array from a first moveable stage and a magnet array from a second moveable stage both overlap a shared group of coil traces. For at least a portion of the time that the magnet arrays from the first and second moveable stages overlap the shared group of coil traces, currents are controllably driven in the shared coil trace group based on the positions of both the first and second moveable stages. The positions of the first and second moveable stages may be ascertained by feedback.

A displacement device comprises a stator comprising non-parallel stator-x and stator-y elongated traces. The device comprises a moveable stage comprising a first magnet array comprising first magnetization segments linearly elongated in a stage-x direction and having magnetization directions generally orthogonal to the stage-x direction. The first magnet array comprises a first pair of adjacent first magnetization segments comprising two first magnetization segments adjacent to one another in a stage-y direction non-parallel to the stage-x direction. Each first magnetization segment in the first pair has a corresponding magnetization direction oriented at a corresponding angle .sub.n about a corresponding stage-x axis as measured from a positive stage-z direction that is generally orthogonal to both the stator-x and stator-y directions. The corresponding angle .sub.n is one of 45+n90 where n is any integer. Each first magnetization segment in the first pair has a different magnetization direction.

A control device (303) for controlling the feeding of electrical power to electromagnets (12) of an electric drive, in particular a linear motor stator (300), has a control device (303) comprising a first control component (306a) that is adapted to cause, in accordance with a drive desired value, the generation of first PWM control signals for controlling the energization of the electromagnets, and a second control component (306b) that is adapted to cause, in accordance with information to be transmitted, the generation of the first PWM control signals to be converted into a generation of other second PWM control signals.

A displacement device comprise a stator having a plurality of electrically conductive coils shaped to provide: a first plurality of coil traces generally elongated in a stator-x direction and distributed over at least a first portion of a first layer; a second plurality of coil traces generally elongated in a stator-y direction and distributed over at least a second portion of a second layer. The first and second portions of the first and second layers overlapping one another in a stator-z direction. The displacement device also comprises a moveable stage having one or more magnet arrays. The moveable stage is moveable relative to the stator within a two-dimensional working region. The one or more magnet arrays include a first magnet array comprising a plurality of first magnetization segments, each having a corresponding first magnetization direction. The displacement device comprises one or more amplifiers connected to drive a plurality of currents in the plurality of electrically conductive coils; and a controller configured to control the currents driven by the one or more amplifiers and to thereby cause the moveable stage to track a desired position, (x.sub.r,y.sub.r), within the working region.

Aspects of the invention provide methods and systems for moving a plurality of movable stages relative to a stator. The stator comprises a plurality of coils shaped to provide pluralities of coil trace groups where each coil trace group comprises a corresponding plurality of generally linearly elongated coil traces which extend across a stator tile. Each movable stage comprises a plurality of magnet arrays. Methods and apparatus are provided for moving the movable stages relative to the stator, where a magnet array from a first movable stage and a magnet array from a second movable stage both overlap a shared group of coil traces. For at least a portion of the time that the magnet arrays from the first and second movable stages overlap the shared group of coil traces, currents are controllably driven in the shared coil trace group based on the positions of both the first and second movable stages. The positions of the first and second movable stages may be ascertained by feedback.

Aspects of the invention provide methods and systems for moving a plurality of moveable stages relative to a stator. The stator comprises a plurality of coils shaped to provide pluralities of coil trace groups where each coil trace group comprises a corresponding plurality of generally linearly elongated coil traces which extend across a stator tile. Each moveable stage comprises a plurality of magnet arrays. Methods and apparatus are provided for moving the moveable stages relative to the stator, where a magnet array from a first moveable stage and a magnet array from a second moveable stage both overlap a shared group of coil traces. For at least a portion of the time that the magnet arrays from the first and second moveable stages overlap the shared group of coil traces, currents are controllably driven in the shared coil trace group based on the positions of both the first and second moveable stages. The positions of the first and second moveable stages may be ascertained by feedback.