| 摘要 |
PURPOSE:To decide the activation of a sensor correctly by detecting the voltage at the parallel joint of a referential voltage generating circuit and an oxygen concentration sensor. CONSTITUTION:O2 sensor 1 where a porous electrode is provided on a zirconia sintered member is connected in parallel with a referential voltage Vs generating circuit 5, then the output terminal voltage VIN from the sensor 1 is provided through A/D converter 4 to a microcomputor 2 for controlling the air-fuel ratio. When setting the voltage Vs in the proximity of the lean/rich decision level after activation of the sensor 1, it can be decided to be active if the voltage VIN is between the voltage Vs-DELTAV2 and the voltage Vs+DELTAV1 thereby more accurate decision is achieved. |
