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. 23, 1999
Filed:
Aug. 29, 1997
Applicant:
Inventors:
Bo Bijlenga, Skultuna, SE;
Peter Lundberg, Vaster.ang.s, SE;
Assignee:
Asea Brown Boveri AB, Vaster.ang.s, SE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03K / ;
U.S. Cl.
CPC ...
327440 ; 327432 ; 327482 ; 361 90 ;
Abstract
In a method and apparatus used for detecting and handling a short circuit in a circuit having a plurality of power semiconductors connected in series the voltage is divided across the electrodes and each power semiconductor and the magnitude of a small proportion of the voltage is measured. The magnitude of the voltage is compared to a reference voltage at least from when the power semiconductor is turned on. The reference voltage is higher than the maximum voltage across the power semiconductor during normal operation. A short circuit is detected when the magnitude of the measured voltage exceeds the reference voltage.