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. 29, 1988
Filed:
Jul. 22, 1986
Shigeo Kamikura, Kadaira, JP;
Yasushi Ema, Kadaira, JP;
Silver Seiko Ltd., , JP;
Abstract
A step motor control system which can control a step motor to rotate at a variable high speed like a brushless motor. A position signal indicating a position of a rotor of a step motor relative to a specific one of field windings is detected as a voltage signal which is successively compared with a reference voltage in order to detect a specific angular position of the rotor at which selective energization and deenergization of the field windings are started for a next stepping operation of the motor. The position signal may be extracted as a voltage signal from an electric current flowing through a last energized field winding by a resistor connected thereto. From the voltage signal, a back EMF induced in the field winding due to its self inductance is subtracted to detect a voltage position signal or EMF induced in the field winding by a permanent magnet of the rotor. The back EMF is produced by an electronic simulation means including an integrating circuit having a same time constant with the field winding.