| 摘要 |
PROBLEM TO BE SOLVED: To stabilize the output of an oxygen sensor by controlling the power supply to a heater which heats an element of the oxygen sensor to get a proper temperature, on the basis of a parameter correlated with an atmospheric temperature of the oxygen sensor, and a parameter correlated with an intake amount to be introduced to an intake passage. SOLUTION: In an oxygen sensor 10 mounted at a downstream side with respect to a circulated gas introduction port 8 of an intake tube 4, an element of the oxygen sensor 10 is heated by a heater 10h to get a proper temperature, because the limiting current is changed to the change of the temperature. When the heating is controlled, the basic power supply amount is determined from a map stored in a ROM 34 on the basis of the number of revolution of an engine detected by a sensor 18 for the number of revolution of engine, and the pressure of the intake tube detected by a pressure sensor 17. Then the supply power compensation amount is determined from the map stored in the ROM 34 on the basis of the intake temperature detected by an intake temperature sensor 11. Whereby the power to be supplied to the heater 10h from a power source 22, is controlled by a heater control circuit 21. |
