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:
Jun. 26, 1984
Filed:
Nov. 30, 1981
Kazuo Watanabe, Hachioji, JP;
Hachiro Makabe, Fussa, JP;
Akira Orii, Sagamihara, JP;
Michio Hisatake, Hino, JP;
Kazuji Yamamoto, Koganei, JP;
Janome Sewing Machine Co. Ltd., Tokyo, JP;
Abstract
A speed-control circuit for a motor of the sewing machine is disclosed. The circuit includes a controller, thyristors for controlling the rotation of the motor in dependence upon the operation of the controller, operational amplifiers activated in dependence upon the operation of the controller to produce a speed designating voltage, a frequency - voltage converter which receives a frequency representing the speed of rotation of the main shaft of the sewing machine, a comparator for comparing that speed designating voltage with the voltage of the frequency-voltage converter to detect a motor drive phase, and a light emitting diode and a phototransistor activated by the motor drive phase and operative for controlling the ignition phase of those thyristors.