| 摘要 |
PURPOSE:To keep the temperature of a detector in constant and control an air- fuel ratio surely even upon the starting of the engine or the like by a method wherein a heater is annexed to the air to fuel ratio detector. CONSTITUTION:A temperature detector 7 is connected electrically to an air-fuel ratio control circuit 4 while the electric heater 8, arranged at the part of the air- fuel ratio detector 3 which is facing to the inside of an exhaust pipe 2, is also connected electrically to the air-fuel ratio control circuit 4. According to this connection, the temperature detector 7 detects the temperature of the air-fuel ratio detector 3 and sends the output signal thereof to the air-fuel control circuit 4. This control circuit 4 decides the output signal and heats the electric heater 8 by conducting it when the temperature of the air-fuel ratio detector 3 is lower than a predetermined value, while stops the heating by cutting a current for the heater when the temperature thereof has exceeded the predetermined value. |
