System for feedback control of air/fuel ratio in ic engine with means to control supply of current to oxygen sensor
A system for feedback control of air/fuel ratio in an ic engine, utilizing an oxygen-sensitive device which is provided with a heater and disposed in exhaust gas to provide a feedback signal. This device has a porous solid electrolyte layer with an outer electrode layer on one side and an inner electrode on the other side facing a substrate. There is a circuit to supply a heating current to the heater and also force a dc current to flow in the solid electrolyte layer to cause migration of oxygen ions therethrough toward the inner electrode to thereby establish a reference oxygen partial pressure on the inner side of the solid electrolyte layer. This circuit is provided with current intensity regulation means to temporarily decrease the intensity of the current flowing in the solid electrolyte layer by a predetermined value while the oxygen-sensitive device is not sufficiently heated to thereby preclude undesirable rise of the basic level of the output voltage of the oxygen-sensitive device by the effect of an increased internal resistance of the not sufficiently heated element.
- Assignee:
- Nissan Motor Co Ltd (Japan)
- Patent Number(s):
- US 4359030
- OSTI ID:
- 6586089
- Resource Relation:
- Patent Priority Date: Priority date 25 Oct 1979, Japan; Other Information: PAT-APPL-199630
- Country of Publication:
- United States
- Language:
- English
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System for feedback control of air/fuel ratio in ic engine having means for supplying controlled current to oxygen sensor
System for feedback control of air/fuel ratio in ic engine with means to control current supply to oxygen sensor