Motor and drive control system thereof
AssigneeSeiko Epson Corporation
InventorKesatoshi TAKEUCHI
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Abstract
Provided is a motor having a magnetic polar unit in which a permanent magnetic polar array having arranged therein alternately a plurality of permanent magnetic polar elements in alternate opposite poles is made to face a plurality of electromagnetic coil arrays alternately excited at opposite poles, and the permanent magnetic polar array is made to move thereby; wherein the motor further comprises a sensor for detecting the periodical magnetic change accompanying the movement of the permanent magnetic polar array, the output of the sensor is directly returned as a direct drive waveform to the electromagnetic coils, and this drive circuit forms the excitation signal based on the return signal.
Claims6
A drive circuit for an AC motor, the AC motor having a stator with a combination of a coil body, a movable body with a permanent magnet and a sensor, the coil body having a plurality of coils, the permanent magnet having a plurality of magnet pole elements, the plurality of magnet pole elements being arranged to become alternating opposite poles, and the sensor being disposed at the stator, detecting a periodic magnetic field change caused by movement of the permanent magnet and outputting an analog signal,
- the drive circuit comprising:
- a frequency to voltage converter that converts a frequency of the analog signal to a voltage signal;
- a hysteresis level setting part that sets a hysteresis level based on the voltage signal;
- a window comparator that compares the analog signal and the hysteresis level, and creates the Pulse Wide Modulation signal;
- and
- a coil drive circuit that excites the plurality of coils of the AC motor with the Pulse Wide Modulation signal.
Dependencies are inferred from the claim text.