| 摘要 |
PURPOSE:To enable to control the air-fuel ratio always accurately, by using a smoothed voltage obtained by adding or subtracting a prescribed voltage to and from the output of an O2-sensor as a reference comparison voltage in judging the air-fuel ratio whether it is rich or lean. CONSTITUTION:An output Vs of an O2-sensor is applied to a comparator 10 via an amplifier 9 and compared with a reference voltage S/V at the comparator 10. In case of Vs>S/L, a rich signal is produced while in case of Vs<S/L, a lean signal is produced from the comparator 10. The output of the comparator 10 is afforded to an amplifier 11 via a resistance 14 or to an amplifier 12 via resistances 14, 15 and voltages -VR, VL are produced respectively from the amplifiers 11, 12. These voltages -VR, VL are added to the output Vs of the O2-sensor at an adder section consisting of a feedback amplifier 13, resistances 18, 19 and a feedback resistance 21. The sum output is smoothed by charging it in a capacitor 23 via a resistance 22, and the smoothed voltage thus obtained is used as the reference voltage S/L of the comparator 10. |
