Exhaust emission control for IC engine - has gas probe esp. for oxygen to help regulate mass ratio of mixture fed to engine

摘要

Exhaust emission control for internal combustion engine uses an exhaust gas probe, esp. an oxygen probe to determine the composition of the exhaust gas and hence help regulate the mass ratio of the fuel mixture supplied to the engine. The output signal from the probe is fed to a variable gain amplifier for controlling the mixture adjusting unit. The signal is fed via a threshold circuit (3) whose control position determines the integration direction of the amplifier. The time lapse between two successive operations of the threshold circuit is detected by the charging or discharging of a store whose charging condition influences the time constant of the amplifier (4).