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:
May. 01, 2012
Filed:
Aug. 27, 2009
Norikazu Ieda, Aichi, JP;
Yoshinori Inoue, Aichi, JP;
Hiroyuki Tsukada, Aichi, JP;
Masahiro Tanaka, Dusseldorf, DE;
Norikazu Ieda, Aichi, JP;
Yoshinori Inoue, Aichi, JP;
Hiroyuki Tsukada, Aichi, JP;
Masahiro Tanaka, Dusseldorf, DE;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
A gas concentration detection apparatus and system including a gas sensor. Voltage Vd generated across detection resistor Rd through which pump current Ip flows is differentially amplified by OPand offset voltage Vofs is superposed thereon to obtain a detection voltage Vout. The amplification factor applied to the differential amplification of the voltage Vd is changed by turning switch SWon and off. When switch SWis turned on, the input terminal potentials of the operational amplifier OPare equalized, so that voltage Vofs is output as the detection voltage Vout. The detection voltage Vout contains an error attributable to the electronic components which form the circuit. The detection voltage Vout containing the error when SWis turned on is acquired as a correction voltage for each amplification factor, and is used for correction at the time of detection of the concentration so as to cancel the error.