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:
Jul. 12, 1983
Filed:
Jun. 10, 1981
Teruo Iwasama, Hachioji, JP;
Hitomi Tojiki, Hachioji, JP;
Olympus Optical Company Limited, Tokyo, JP;
Abstract
A motor speed control device comprises means for generating pulse output corresponding to the revolution speed of the motor, means for generating saw-tooth wave output in synchronization with the pulse output, means for generating reference voltage, a current mirror load differential amplifier including a first amplifier element having a first current mirror circuit connected as load and supplied with the saw-tooth wave output and a second amplifier element having a second current mirror circuit connected as load and supplied with the reference voltage and for supplying current to the first or second current mirror circuit corresponding to the result of comparing the reference voltage with the saw-tooth wave output, an integrating circuit to be charged or discharged by the charging current flowing through one of the first and second current mirror circuits and the discharging current flowing through the other of both circuits, and means for driving the motor by output of the integrating circuit. The motor speed control device is used for electronic apparatuses such as a tape recorder.