| 摘要 |
PURPOSE:To obtain an accurate negative feed back control by a method wherein at least one direct current preventing means is connected in series to the output of an air-fuel ratio detector which outputs in accordance with the density of exhaust gas component. CONSTITUTION:An air-fuel ratio operation control part 300 which receives the output from an intake air amount detecting means 2 and rotation number detecting means 7 controls a fuel supply adjusting means 4 in response to the output from a comparator 100 which discriminates lean-rich based on the output of an oxygen sensor 6. A resistor 210 and capacitor element 200 provided in series of the sensor 6 are connected to the same phase input terminal of an amplifier 230, and resistor elements 240 and 250 are connected to the inverted phase input terminal of the amplifier 230. The other end of the element 250 is connected to the output terminal of the amplifier 230 and inputted into another amplifier 100. By this, the output of the amplifier 230 is imparted with a characteristic of an AC amplifier which carries out a half wave rectification, thereby enabling a removal of temperature drift due to a low frequency of the sensor 6 and a direct current component due to an aging of the sensor 6. |
