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. 16, 2006
Filed:
Nov. 10, 2003
Kazutaka Hattori, Okazaki, JP;
Kazutaka Hattori, Okazaki, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
An element impedance detection apparatus for an oxygen sensor is provided with a first switching device, a second resistor, first resistor, and a first condenser for application of a sweep voltage to the oxygen sensor. The first switching device is switched to ON and the sweep voltage applied; a sensor current I that flows in the oxygen sensor along with application of the sweep voltage is then detected. Element impedance is calculated based on the sweep voltage and the sensor current. The second resistor, the first resistor and the first condenser are connected to the oxygen sensor such that a time constant of the sweep voltage increases as the element impedance becomes larger.