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. 13, 1981
Filed:
Oct. 06, 1978
Hitachi, Ltd., , JP;
Abstract
In a power converter system wherein each thyristor of a three-phase full-wave bridge circuit having thyristors connected in all of bridge arms is fired for its controlling to thereby control the dc output voltage, when the dc output voltage is low, the firing angle of a group of thyristors on the negative side is fixed to a large value and the firing angle of a group of thyristors on the positive side is rendered variable within a small range so that a period may occur through which two thyristors connected in series in the full-wave bridge circuit are fired simultaneously. When the dc output voltage is high, the firing angles of groups of thyristors on both the positive and negative sides are made equal to each other and varied simultaneously. The system improves power factor and form factor over the entire controlling range of the dc output voltage.