Patent ID: 9625352
Date: 2017-04-18
CPC Classifications: F01N,F02D,G01M,G01N,H05K

Claim:
1. A method of determining an air:fuel ratio of a combustion process, the method comprising: supplying, from a constant current source, a constant total sensing current to an oxygen sensing portion of an oxygen sensor, the oxygen sensing portion exposed to exhaust gases from the combustion process, wherein the oxygen sensor has an n-type sensing circuit and a p-type sensing circuit that share a common electrode, the sensing current being a sum of a first current in the n-type sensing circuit and a second current in the p-type sensing circuit; wherein the n-type sensing circuit comprises an n-type semiconducting layer; wherein the p-type sensing circuit comprises a p-type semiconducting layer; wherein the n-type semiconducting layer and the p-type semiconducting layer are disposed on the common electrode with a lateral gap between the n-type semiconducting layer and the p-type semiconducting layer; determining the first current in the n-type sensing circuit; determining the second current in the p-type sensing circuit; determining a temperature value representative of a temperature of the oxygen sensor; determining a first value representative of the air:fuel ratio of the combustion process based on the first current in the n-type sensing circuit, the second current in the p-type sensing circuit, and the temperature value.