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:
May. 19, 1981
Filed:
Sep. 07, 1978
Applicant:
Inventors:
Shigeki Kawada, Hino, JP;
Yoshiki Fujioka, Hino, JP;
Mitsuhiko Hirota, Tokyo, JP;
Naoto Ohta, Hino, JP;
Assignee:
Fujitsu Fanuc Limited, , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02D / ;
U.S. Cl.
CPC ...
318434 ; 318332 ;
Abstract
A system for controlling DC motors of the type employing permanent magnets as field poles. The firing phase angle of a thyristor is controlled in response to an error signal representative of an error between a commanded motor speed and an actual motor speed. For preventing demagnetization of the permanent magnets due to the armature reaction, the clamp level of the error signal is changed in accordance with the actual motor speed.