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. 30, 1981
Filed:
Dec. 20, 1978
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02P / ;
U.S. Cl.
CPC ...
318721 ; 318722 ; 318723 ; 318802 ;
Abstract
A control device for a thyristor motor is disclosed by which the advance angle is switched at a predetermined slow rate of change in order to avoid an abrupt change in the motor torque. The thyristor motor comprises a thyristor frequency converter for a frequency conversion and a synchronous motor driven by the frequency converter, and in the thyristor motor the advance angle is switched at low and high speeds of the motor.