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:
Nov. 18, 1997
Filed:
Jan. 11, 1996
Hayato Naito, Nagano, JP;
Nobuki Kokubo, Nagano, JP;
Kabushiki Kaisha Sankyo Seiki Seisakusho, Nagano, JP;
Abstract
A brushless motor speed detecting apparatus includes a stator having three-phase driving coils which are energized reciprocally in the positive and negative directions, a rotor having magnetic poles, three position detectors for obtaining three-phase output signals corresponding to the rotation of the rotor, a first synthesizing circuit for synthesizing the output signals of the three position detectors, mode switching circuit for forming an energizing mode switching signal according to the output signal of the first synthesizing circuit, a driving circuit for supplying currents to the driving coils by switching an energizing mode from a first energizing mode to a second energizing and vice versa according to the output signal of the mode switching circuit, and a second synthesizing circuit for synthesizing a speed signal by detecting in the non-energizing section of the first energizing mode the induced electromotive voltages generated in the driving coils as the rotor rotates to base the synthesis of the speed signal on the induced electromotive voltages.