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:
Mar. 07, 2006
Filed:
Jun. 18, 2003
Hiroshi Ito, Tokyo, JP;
Akihiko Iwata, Tokyo, JP;
Akihiro Suzuki, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
Self-quenching switching elements are connected in series in a semiconductor switching device. Snubber circuits including a diode, a capacitor, and a non-linear circuit are connected in parallel with the respective semiconductor switching elements. In the snubber circuit, the diode and the capacitor are connected in series, and the non-linear circuit is connected in parallel with the capacitor. The non-linear circuit includes an impedance element, a Zener diode, and a controlling semiconductor element and draws current through the controlling semiconductor element when applied voltage exceeds the Zener voltage of the Zener diode. The Zener voltage is larger than a divided voltage applied to the semiconductor element during a fault in a power system.