In accordance with an embodiment, a flywheel includes a rotary shaft which is rotatably provided to the flywheel, a rotor which is fixed to the rotary shaft and rotatable with the rotary shaft, and an unrotatable stator arranged so as to face the rotor. The rotor includes first permanent magnets provided on a first surface facing the stator. The stator includes second permanent magnets which are provided on a second surface facing the rotor in correspondence with the first permanent magnets respectively and have the same polarity as that of the first permanent magnets.

A temperature acquisition section (acquisition module) acquires a temperature of an environment in which a printer device is used. A printing condition acquisition section (acquisition module) acquires information relating to printing conditions of the printer device. A conveyance load estimation section (estimation module) estimates a conveyance load when a stepping motor (motor) provided in the printer device conveys a printing paper (print medium) based on the information acquired by the temperature acquisition section and the printing condition acquisition section. A current value setting section (setting module) sets a current value to be applied to the stepping motor based on the conveyance load estimated by the conveyance load estimation section. A motor control section (control module) controls the stepping motor by applying the current value set by the current value setting section to the stepping motor.

A device for forming and applying accessory elements to a continuous band of absorbent material, includes a unit for feeding a continuous strip to a conveyor roller, a unit for cutting the strip in a continuous and alternating succession of first and second pieces, a first and a second roller rotating about respective axes parallel to the first direction, each including a movement device acting along a circumferential direction around the respective axis and configured for imparting to each unit a respective motion between positions for picking up and releasing the pieces. A unit for applying a pair of pieces to the band is equipped with a separating unit equipped with a spacer device for moving first and/or second carriages along a separating direction between close and far axial positions, wherein the spacer device includes a plurality of linear actuators each associated with a respective first carriage.

A method for power conversion generally includes a step of generating a drive current in a first winding of an electromagnet in a motor mode. The electromagnet may be mounted spatially proximate a rotor and has a bifilar coil. The bifilar coil may have a pair of conductors that form the first winding and a second winding. The second winding may be spatially parallel to, spatially separated from, and electrically isolated from the first winding. The rotor may be rotatably mounted and has a plurality of permanent magnets. Further steps generally include rotating the rotor in response to the drive current, removing the drive current from the first winding in a generator mode and inducing a load current through the second winding to an electrical load in response to a torque applied to the rotor.

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.

A driving device for a stepping motor includes a motor driving circuit configured to generate a current waveform representing an electrical angle in synchronization with a mechanical angle of the stepping motor, and excite the stepping motor using the current waveform; a memory configured to store a value of the electrical angle; and a controller configured to: when a power supply to the stepping motor and the motor driving circuit is stopped, store a first value of the electrical angle held by the motor driving circuit in the memory; and when the power supply is resumed, replace a value of the electrical angle of the motor driving circuit with the first value while suppressing a rotational operation of the stepping motor.

A driving device for a stepping motor includes a motor driving circuit configured to generate a current waveform representing an electrical angle in synchronization with a mechanical angle of the stepping motor, and excite the stepping motor using the current waveform; a memory configured to store a value of the electrical angle; and a controller configured to: when a power supply to the stepping motor and the motor driving circuit is stopped, store a first value of the electrical angle held by the motor driving circuit in the memory; and when the power supply is resumed, replace a value of the electrical angle of the motor driving circuit with the first value while suppressing a rotational operation of the stepping motor.

A moving body includes: a plurality of linear motors including a first linear motor driven by magnetic interaction with magnetic flux of a magnetic pole path; a position detection sensor configured to detect a position of the moving body; a first electrical angle detection sensor disposed at a position different from the position detection sensor in a path direction of the magnetic pole path and configured to detect an electrical angle of the first linear motor; and a control unit configured to, when one of the position detection sensor and the first electrical angle detection sensor is positioned at a magnetic pole absent section, use the other of the position detection sensor and the first electrical angle detection sensor both to detect a position of the moving body and to detect an electrical angle of the first linear motor.

A method and a circuit arrangement for damping stepper motor resonances during operation of a stepper motor (M), in particular in the medium und high speed range, is described, wherein the coils (A; B) of the stepper motor (M) are each connected into a bridge circuit (Br1; Br2) comprising semiconductor switches (Sw1, . . . Sw4), in order to impress into the coils (A; B) a predetermined target coil current (I.sub.SollA; I.sub.SollB). The resonance damping is essentially achieved by activating a passive FD-phase in the zero crossing of the target coil current (I.sub.SollA; I.sub.SollB), during which all 10 semiconductor switches (Sw1, . . . Sw4) are opened or switched blocking, in order to thereby feed a coil current flowing in the related motor coil (A; B) back into the supply voltage source either via inverse or body diodes and/or via diodes (D1, . . . D4) connected in parallel to the semiconductor switches (Sw1, . . . Sw4) in the reverse direction between the positive supply voltage (+V.sub.M) and ground potential.

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.