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:
Jan. 17, 1984
Filed:
Jun. 16, 1982
Shigeki Kawada, Hino, JP;
Katsuo Kobari, Tachikawa, JP;
Fujitsu Fanuc Limited, Tokyo, JP;
Abstract
A control circuit for driving an induction motor wherein an AC voltage is converted into a direct current by a rectifying circuit and the direct current is converted into a signal having a variable voltage and frequency by a transistor inverter connected in parallel with a smoothing capacitor, and a regenerative circuit is connected in parallel with the inverter, and a first monitoring circuit is provided for comparing the terminal voltage V.sub.C of the smoothing capacitor and a first reference voltage E.sub.1 when braking is to take place. When the condition V.sub.C .gtoreq.E.sub.1 exists, the transistor inverter is disabled but the regenerative circuit is allowed to operate. When the condition V.sub.C <E.sub.1 exists, the transistor inverter is operated in the regenerative braking region. A second monitoring circuit is provided for comparing the smoothing capacitor terminal voltage V.sub.C and a second reference voltage E.sub.2 (E.sub.2 >E.sub.1). When the condition V.sub.C .gtoreq.E.sub.2 exists, both the transistor inverter and regenerative circuit are disabled immediately.