Air/fuel ratio control system for internal combustion engine having high input impedance circuit
Patent 4112893 Issued on September 12, 1978. Estimated Expiration Date: 
December 13, 1996. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
December 13, 1996. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3827237 3915135 3916170 3923016 Exhaust gas operated apparatus for continuously measuring air number of engine intake mixture Method and system for reducing noxious components in the exhaust emission of internal combustion engine systems and particularly during the warm-up phase of the engine Control system for normalizing the air/fuel ratio in a fuel injection system Patent #: 3990411 InventorAssigneeApplicationNo. 05/749909 filed on 12/13/1976US Classes:123/689, Engine fluid or engine component temperature responsive123/694, Output fed to compensating circuit73/23.32Air-fuel ratioExaminersPrimary: Myhre, Charles J.Assistant: Dolinar, Andrew M. Attorney, Agent or FirmInternational ClassF02D 41/14 (20060101)Foreign Application Priority Data1975-12-25 JPAbstractA feedback control system for controlling the air/fuel ratio of a combustible mixture fed to an internal combustion engine based on the output of an exhaust sensor includes an input circuit of a high input impedance, which serves as a prefatory circuit to a control signal producing circuit to match the high internal impedance of the sensor at low exhaust gas temperatures. The input circuit has an operational amplifier with its noninverting input terminal connected to the sensor and, optionally, two or more switchable resistors to adjust the input impedance. | |
