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:
Nov. 03, 1981
Filed:
Jan. 31, 1978
Masahiko Akamatsu, Amagasaki, JP;
Ryohei Uchida, Himeji, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A transformer device comprises a saturable magnetic core having control and controlled windings, the saturable magnetic core being controlled in a feedback mode through switch means such as transistor switch means. The transformer device may comprise two magnetic cores and changes in magnetic resistance between the two magnetic cores are differentially fed back and amplified to cause an oscillative switch means to be turned on and off. A current to be detected flows in the control winding and detected by the controlled winding. The detected output corresponds to the polarity and the absolute value of the current supplied to the control winding. The transformer device not only can detect or measure the primary current but can identify the polarity thereof, differing from prior art dc current or potential transformers. The transformer device of the invention operates substantially free of slot-ripple inherent in the prior art transformer. In the transformer device of the invention, the magnetic core is driven always in an unsaturated region whereby the ripple ascribed to the exciting current is minimized. Thus the transformer device is ideal for applications where an instantaneous output in value and polarity corresponding to the primary current is desired substantially free of ripple component. The effective use of the transformer device includes current or voltage measurement, electric motors and other industrial machines, as well as inverters and choppers.