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:
Aug. 25, 1987
Filed:
Dec. 05, 1986
Mahito Unno, Aichi, JP;
Katsuhiro Yamamoto, Aichi, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A speed detecting device for an electric motor in which the angular stopping position of a rotary shaft is controlled with a high precision. A magnet is mounted on a rotary shaft of the motor, and a position detector detects the position of the magnet as rotated by the motor, thereby producing an output signal having a linear region. A speed calculator samples this signal in the liner region at predetermined time intervals and performs a division operation whereby a difference between a present sampled value and a preceding sampled value of the output signal is divided by the time interval, thereby to produce a speed signal which is applied to the motor as a control signal.