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. 09, 2010
Filed:
Jan. 24, 2007
Takeshi Omaru, Chiyoda-ku, JP;
Takeshi Omaru, Chiyoda-ku, JP;
Mitsubishi Electric Corporation, Tokyo, JP;
Abstract
When an insulated gate bipolar transistor turned on starts to transition to turn off, the insulated gate bipolar transistor has between the emitter and the collector a surge voltage caused in proportion to the magnitude of a current gradient provided when a current flowing through a coil in switching is interrupted and an electrode interconnect inductance internal to an inverter circuit. A MOS transistor is temporarily turned on within a period of time for which the insulated gate bipolar transistor turned on transitions to turn off. This can bypass a portion of the current to the MOS transistor. This can provide an alleviated apparent current gradient of the current and thus alleviate or prevent a surge voltage caused at the insulated gate bipolar transistor.