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:
Mar. 30, 2004
Filed:
Feb. 27, 2001
Yuji Kimoto, Aichi, JP;
Toshiya Matsuoka, Gifu, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
A control system for a gas sensor element capable of lessening the effect of variations in sensor properties among gas sensor elements as well as the effect of environmental factors, such as temperature and humidity, to thereby accurately detect variation in the concentration of a specific gas. In a control system for a gas sensor element whose sensor resistance Rs varies with the concentration of NOx gas, a pulse signal Sc which alternates between 0 V and +5 V is input to a pulse input terminal When a voltage of 5 V is applied to the pulse input terminal a capacitor is charged via a fixed resistor having a resistance Rc and a diode When a voltage of 0 V is applied, the capacitor discharges via the gas sensor element An output voltage Vout is A/D-converted and processed by means of a microcomputer thereby controlling an electronic control assembly The potential Vout at an operating point Pd varies with the sensor resistance Rs as well as with the duty ratio DT of the pulse signal Sc. Thus, the output voltage Vout can be maintained within a predetermined range by adjusting the duty ratio.