GAS SENSOR CONTROL DEVICE

摘要

An O2 sensor includes a sensor element using a solid electrolyte layer and a pair of electrodes placed at a position to interpose the solid electrolyte layer, detects an exhaust gas from an internal combustion engine as an object of a detection, and outputs an electromotive force signal depending on an air-fuel ratio of the exhaust gas. The sensor element is connected with a constant current circuit supplying a constant current that is prescribed. A microcomputer calculates an element resistance, determines whether the air-fuel ratio is at least rich, lean, or stoichiometric, on the basis of a comparison between an electromotive force output of the electrogenic cell and a prescribed threshold. Further, the microcomputer controls the constant current supplied by the constant current circuit on the basis of the element resistance.

主权项

1. A gas sensor control device for a gas sensor which has an electrogenic cell using a solid electrolyte body and a pair of electrodes placed at a position to interpose the solid electrolyte body, and detects an exhaust gas from an internal combustion engine as an object of a detection and outputs an electromotive force signal depending on an air-fuel ratio of the exhaust gas, the gas sensor control device comprising:
a constant current supplying section supplying a constant current that is prescribed to the electrogenic cell; a resistance value calculating section calculating a resistance value of the electrogenic cell; an air-fuel ratio determining section determining whether the air-fuel ratio is at least rich, lean, or stoichiometric, on the basis of a comparison between an electromotive force output of the electrogenic cell and a prescribed threshold; and a current control section controlling the constant current supplied by the constant current supplying section, on the basis of the resistance value of the electrogenic cell calculated by the resistance value calculating section.