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:
Aug. 20, 1985
Filed:
May. 24, 1983
Susumu Matsumura, Osaka, JP;
Masao Yano, Kobe, JP;
Nobuo Sashida, Kobe, JP;
Yoshihiko Yamamoto, Amagasaki, JP;
Susumu Jatsumura, Osaka, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A thyristor apparatus employing light-triggered thyristors comprises forward voltage detecting circuits (15) and a thyristor number detecting circuit (17). The forward voltage detecting circuits (15) detect forward voltages applied to light-triggered thyristors (13) to provide detected signals. The thyristor number detecting circuit (17) is responsive to the detected signals to cause light-triggered thyristors in a thyristor arm (U) to be turned on simultaneously in the case where the number of the light-triggered thyristors being supplied with forward voltages is one or more but not more than a predetermined number. Accordingly, if and when an overvoltage is applied to the thyristor arm (U), overvoltage suppressing elements (14) are prevented from being damaged even if partial commutation failure occurs in the light-triggered thyristors.