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:
Feb. 26, 2008
Filed:
Jul. 28, 2005
Katsumi Ishikawa, Chiyoda-ku, JP;
Hideki Miyazaki, Chiyoda-ku, JP;
Koichi Suda, Chiyoda-ku, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
To provide a highly reliable inverter apparatus which discriminates long-cycle noise generated by the isolated signal transmission element from short-cycle dv/dt noise and induction noise. A low pass filter, band pass filter, and a switching means are provided between the input section of the gate drive circuit of the voltage-drive type power semiconductor switching element and the isolated signal transmission means that transmits the output of the control circuit; and an abnormal signal discriminating circuit is also provided which turns on and off the switching means according to the output of the band pass filter thereby eliminating long-cycle noise derived from the isolated signal transmission element, short-cycle dv/dt noise, and induction noise; and also outputs alarm signals.