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:
Apr. 06, 1982
Filed:
Apr. 09, 1979
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 braking and speed-control circuit is disclosed which prevents excessive current from being dissipated in a DC series motor. The circuit includes two free-wheeling diodes, a forward-biased diode, and a thyristor. The forward-biased diode is placed between the field coil and the armature winding of the motor. One free-wheeling diode is placed across the entire motor circuit, including the forward-biased diode. The other free-wheeling diode is placed across the forward-biased diode and the field coil. The thyristor can short across the forward-biased diode and the armature winding.