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. 09, 1977
Filed:
Jan. 13, 1976
Masayoshi Sunada, Hitachi, JA;
Kuniaki Kubokura, Hitachi, JA;
Hitachi, Ltd., , JA;
Abstract
A control circuit for controlling the shaft speed of a motor having clutch and brake devices comprises a speed detector for detecting the actual rotating speed of the motor and generating a first pulse signal having a period in inverse proportion to the actual rotating speed, a speed selector for setting the desired-speed of the shaft, a signal generator for generating a second pulse signal having a period in inverse proportion to the desired-speed from the speed selector, a first means for detecting the ratio of the period of the first signal to the period of the second signal, and a second means for controlling the operation of the clutch and brake devices in response to the detected ratio.