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. 17, 1982
Filed:
Dec. 10, 1979
Applicant:
Inventors:
Assignee:
Janome Sewing Machine Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02P / ;
U.S. Cl.
CPC ...
318812 ; 3183 / ; 318441 ; 112275 ;
Abstract
An electric sewing machine has an A.C. driving motor controlled by a triac; a controlling circuit for the triac includes a thyristor powered by a lower-voltage battery via an adjustable RC-circuit; the controlling circuit is electrically insulated from the A.C. power-supply circuit by an optoelectric coupler, the optical part of which is connected to the A.C. circuit and the electric part of which controls the gate of the thyristor in synchronism with the A.C. voltage; the thyristor in the controlling circuit is coupled to the triac by means of an insulating pulse transformer.