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:
Sep. 24, 1985
Filed:
Mar. 02, 1984
Takashi Harada, Hekinan, JP;
Akio Kobayashi, Kariya, JP;
Masakazu Honda, Anjo, JP;
Susumu Harada, Okazaki, JP;
Masaya Fujimoto, Oobu, JP;
Masatoshi Suzuki, Anjo, JP;
Nippondenxo Co., Ltd., Kariya, JP;
Abstract
An oxygen concentration detector under a temperature control for an internal combustion engine. An oxygen sensor of a critical current type is held between a gas under test and a reference gas, in the vicinity of which a heater is located for heating up the oxygen sensor in a sensor activating temperature range. A first voltage is applied for a positive bias control to the oxygen sensor during a first period, and a second voltage is applied for a negative bias control thereto during a second period. Electric current flowing through the oxygen sensor is detected during the first period in order to detect the oxygen concentration in the gas under test. The current value is also detected during the second period in order to detect and maintain constant the internal electric resistance of the oxygen sensor by controlling the heater heating output.