The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 27, 1990
Filed:
May. 19, 1988
Minoru Matsuda, Fujieda, JP;
Hiroshi Iwai, Fujieda, JP;
Abstract
A multi-phase brushless motor including a stator having a plurality of drive coils each corresponding to a specific phase and a rotor having a plurality of field magnet poles of successively alternating polarity. The stator further has a plurality of Hall generators for detecting the positions of the rotor and a speed sensor for detecting the rotational speed of the rotor. The brushless motor is driven by a drive circuit which supplies drive currents to the drive coils of the stator so as to generate torques. The drive circuit is operated under control of a control circuit which comprises a first processing circuit responsive to position signals from the Hall generators to output exciting signals to the drive circuit so that the drive circuit supplies the drive currents to the drive coils thereof and a second processing circuit responsive to the speed signal from the speed sensor and the position signal to output exciting signals to the drive circuit which in turn supplies the drive currents thereto. The first and second processing circuits are selectively operated such that the first processing circuit outputs the exciting signals to the drive circuit at startup of the motor and the second processing circuit outputs the exciting signals thereto after the startup.