摘要 |
A system for controlling the application of heat energy to a ceramic exhaust gas sensor and for linearizing the output signal from the sensor. The system compares, electrically, the resistance of a conductive heater winding against a fixed reference and permits a flow of electrical current through the heater whenever the comparison indicates that the temperature of the heater is below the desired level. By periodically establishing a flow of electrical energy through the heater and terminating that flow whenever the heater temperature reaches the desired level, the temperature of the heater may be held at the desired level with great accuracy. In order to periodically reestablish the flow of electrical energy through the heater, the system further provides an oscillator arranged to reestablish current flow through the heater a fixed time period following termination of current flow through the heater. The system also provides a linearizing amplifier connected to the sensor to provide an output signal which is linear with respect to changes in the air/fuel ratio of the mixture being combusted.
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