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:
Jul. 04, 1978
Filed:
Jul. 30, 1976
Hiromi Inaba, Hitachi, JP;
Seiya Shima, Katsuta, JP;
Korefumi Tashiro, Hitachi, JP;
Takeki Ando, Nakamachi, JP;
Hitachi, Ltd., , JP;
Abstract
In order to control a DC motor, a main circuit is constructed in such a manner that a unidirectional thyristor converter is connected to the armature of the motor, while a bilateral thyristor converter is connected to the field system of the motor. Provided is a speed controller which is impressed with a speed command signal and a speed feedback signal so that the speed controller produces an error signal representing the difference between the speed command signal and the speed feedback signal and the error signal is applied to a function generator which in turn produces a field current command signal and an armature current command signal. The field current command signal assumes a value proportional to the error signal when the error signal is less than a predetermined value. The armature current command signal is kept constant when the error signal is below a predetermined value, while it increases, when the error signal exceeds the predetermined value, in proportion to the amount of the excess. These current command signals are used to phase-control the thyristor converters in the field circuit and the armature circuit.