| 摘要 |
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. |
