Abstract: Nitrous oxide (NOx) sensors and related methods and systems for use with combustion processes. The NOx sensor uses metal oxide semiconductors. The NOx sensor may have two sensing circuits that share a common electrode. The sensing circuits are differentiated by having different porous catalytic filter coatings protecting the metal oxide semiconductors: one sensing circuit has a porous catalytic filter coating that contains a Noxcat material (rhodium, ruthenium, cobalt, palladium, or nickel), while the porous catalytic filter coating of the other sensing circuit is substantially free of Noxcat material. The two sensing circuits are simultaneously exposed to the exhaust gases at a common macro location. The NOx level may be determined based on a difference in resistance between the two sensing circuits and a temperature of the NOx sensor.

Abstract: Nitrous oxide (NOx) sensors and related methods and systems for use with combustion processes. The NOx sensor uses metal oxide semiconductors. The NOx sensor may have two sensing circuits that share a common electrode. The sensing circuits are differentiated by having different porous catalytic filter coatings protecting the metal oxide semiconductors: one sensing circuit has a porous catalytic filter coating that contains a Noxcat material (rhodium, ruthenium, cobalt, palladium, or nickel), while the porous catalytic filter coating of the other sensing circuit is substantially free of Noxcat material. The two sensing circuits are simultaneously exposed to the exhaust gases at a common macro location. The NOx level may be determined based on a difference in resistance between the two sensing circuits and a temperature of the NOx sensor.

Abstract: Nitrous oxide (NOx) sensors and related methods and systems for use with combustion processes. The NOx sensor uses metal oxide semiconductors. The NOx sensor may have two sensing circuits that share a common electrode. The sensing circuits are differentiated by having different porous catalytic filter coatings protecting the metal oxide semiconductors: one sensing circuit has a porous catalytic filter coating that contains a Noxcat material (rhodium, ruthenium, cobalt, palladium, or nickel), while the porous catalytic filter coating of the other sensing circuit is substantially free of Noxcat material. The two sensing circuits are simultaneously exposed to the exhaust gases at a common macro location. The NOx level may be determined based on a difference in resistance between the two sensing circuits and a temperature of the NOx sensor.

Abstract: Sensing combustion events using a resistive based oxygen sensor exposed to exhaust gases of a periodic combustion process in a combustion engine. The oxygen sensor is disposed in the exhaust plenum of the engine and includes a metal oxide semiconductor layer bridging a gap between first and second electrodes. Spikes in the resistance of the metal oxide semiconductor layer, caused by its reaction to transient changes in the oxygen level and exhaust temperature, are indicated in a combustion signal. The combustion signal may be used to monitor for combustion misfire event(s). Further, a combustion misfire event may be detected by comparing the detected spike timing with expected spike timing, with a spike not being present at a time when a spike is expected indicating a combustion misfire event. Related devices and systems are also disclosed.

Abstract: Method and apparatus for monitoring and/or detecting combustion misfire events in periodic combustion processes in internal combustion engines, using combustion signals derived from a first oxygen sensor exposed to exhaust gas of a periodic combustion process and a second oxygen sensor exposed to the same exhaust gas. The first oxygen sensor is resistive-based, and responds relatively faster to changes in the temperature and/or composition of the exhaust gas. The second oxygen sensor is voltaic-based or ampometric-based, and responds relatively slower to changes to the temperature and/or composition of the exhaust gas. When the temperature and/or composition of the exhaust changes rapidly but transiently due to a combustion misfire event, the different response rates of the first and second combustion signals allows for the combustion misfire event(s) to be detected. Either and/or both oxygen sensors may be used to control the engine in a conventional fashion.

Abstract: A microchip oxygen sensor for sensing exhaust gases from a combustion process, and related methods. The microchip oxygen sensor includes a dielectric substrate and a heater pattern affixed to the substrate. A first electrode is affixed to the substrate and has a first plurality of fingers forming a first comb. A second electrode is affixed to the substrate and has a second plurality of fingers forming a second comb. The second electrode is disposed in spaced relation to the first electrode such that the first and second combs face each other. A semiconducting layer is disposed over the first and second electrodes so as form a physical semiconductor bridge between the first and second electrodes. The semiconducting layer comprises an n-type semiconducting material or a p-type semiconducting material. A porous dielectric protective layer, advantageously containing a catalytic precious metal, may cover the semiconducting layer.

Abstract: Method and apparatus for monitoring and/or detecting combustion misfire events in periodic combustion processes in internal combustion engines, using combustion signals derived from a first oxygen sensor exposed to exhaust gas of a periodic combustion process and a second oxygen sensor exposed to the same exhaust gas. The first oxygen sensor is resistive-based, and responds relatively faster to changes in the temperature and/or composition of the exhaust gas. The second oxygen sensor is voltaic-based or ampometric-based, and responds relatively slower to changes to the temperature and/or composition of the exhaust gas. When the temperature and/or composition of the exhaust changes rapidly but transiently due to a combustion misfire event, the different response rates of the first and second combustion signals allows for the combustion misfire event(s) to be detected. Either and/or both oxygen sensors may be used to control the engine in a conventional fashion.

Abstract: Nitrous oxide (NOx) sensors and related methods and systems for use with combustion processes. The NOx sensor uses metal oxide semiconductors. The NOx sensor may have two sensing circuits that share a common electrode. The sensing circuits are differentiated by having different porous catalytic filter coatings protecting the metal oxide semiconductors: one sensing circuit has a porous catalytic filter coating that contains a Noxcat material (rhodium, ruthenium, cobalt, palladium, or nickel), while the porous catalytic filter coating of the other sensing circuit is substantially free of Noxcat material. The two sensing circuits are simultaneously exposed to the exhaust gases at a common macro location. The NOx level may be determined based on a difference in resistance between the two sensing circuits and a temperature of the NOx sensor.

Abstract: Sensing combustion events using a resistive based oxygen sensor exposed to exhaust gases of a periodic combustion process in a combustion engine. The oxygen sensor is disposed in the exhaust plenum of the engine and includes a metal oxide semiconductor layer bridging a gap between first and second electrodes. Spikes in the resistance of the metal oxide semiconductor layer, caused by its reaction to transient changes in the oxygen level and exhaust temperature, are indicated in a combustion signal. The combustion signal may be used to monitor for combustion misfire event(s). Further, a combustion misfire event may be detected by comparing the detected spike timing with expected spike timing, with a spike not being present at a time when a spike is expected indicating a combustion misfire event. Related devices and systems are also disclosed.

Abstract: A microchip oxygen sensor for sensing exhaust gases from a combustion process, and related methods. The microchip oxygen sensor includes a dielectric substrate and a heater pattern affixed to the substrate. A first electrode is affixed to the substrate and has a first plurality of fingers forming a first comb. A second electrode is affixed to the substrate and has a second plurality of fingers forming a second comb. The second electrode is disposed in spaced relation to the first electrode such that the first and second combs face each other. A semiconducting layer is disposed over the first and second electrodes so as form a physical semiconductor bridge between the first and second electrodes. The semiconducting layer comprises an n-type semiconducting material or a p-type semiconducting material. A porous dielectric protective layer, advantageously containing a catalytic precious metal, may cover the semiconducting layer.

Abstract: A microchip oxygen sensor for sensing exhaust gases from a combustion process, and related methods. The microchip oxygen sensor includes a dielectric substrate and a heater pattern affixed to the substrate. A first electrode is affixed to the substrate and has a first plurality of fingers forming a first comb. A second electrode is affixed to the substrate and has a second plurality of fingers forming a second comb. The second electrode is disposed in spaced relation to the first electrode such that the first and second combs face each other. A semiconducting layer is disposed over the first and second electrodes so as form a physical semiconductor bridge between the first and second electrodes. The semiconducting layer comprises an n-type semiconducting material or a p-type semiconducting material. A porous dielectric protective layer, advantageously containing a catalytic precious metal, may cover the semiconducting layer.

Abstract: An oxygen sensor that has both an n-type oxygen sensing portion comprising an n-type semiconductor layer and a p-type oxygen sensing portion comprising an p-type semiconductor layer. The n-type sensing portion and the p-type sensing portion share the common electrode. The n-type semiconductor layer and the p-type semiconductor layer attach directly to the common electrode, but are not in physical contact with each other such that a lateral gap exists between the n-type semiconductor layer and the p-type semiconductor layer. The air:fuel ratio for a combustion process may be determined, using the same oxygen sensor, across a range of air:fuel values in both the rich and lean regions; as such, the oxygen sensor may act as a wideband oxygen sensor.

Abstract: An oxygen sensor that has both an n-type oxygen sensing portion comprising an n-type semiconductor layer and a p-type oxygen sensing portion comprising an p-type semiconductor layer. The n-type sensing portion and the p-type sensing portion share the common electrode. The n-type semiconductor layer and the p-type semiconductor layer attach directly to the common electrode, but are not in physical contact with each other such that a lateral gap exists between the n-type semiconductor layer and the p-type semiconductor layer. The air:fuel ratio for a combustion process may be determined, using the same oxygen sensor, across a range of air:fuel values in both the rich and lean regions; as such, the oxygen sensor may act as a wideband oxygen sensor.

Abstract: A method of determining an air:fuel ratio based on information from an oxygen sensor exposed to exhaust gases of a combustion process, and related systems. A constant current is supplied to an oxygen sensor that has both an n-type sensing circuit and a p-type sensing circuit that share a common electrode. The currents in the respective sensing circuits is determined and a temperature value representative of a temperature of the oxygen sensor is determined. Then, an air:fuel ratio is determined based on the determined currents and the temperature value. The combustion process may then be controlled based on the air:fuel ratio. The air:fuel ratio may be determined, using the same oxygen sensor, across a range of air:fuel values in both the rich and lean regions; as such, the oxygen sensor may act as a wideband oxygen sensor.

Abstract: A microchip oxygen sensor for sensing exhaust gases from a combustion process, and related methods. The microchip oxygen sensor includes a dielectric substrate and a heater pattern affixed to the substrate. A first electrode is affixed to the substrate and has a first plurality of fingers forming a first comb. A second electrode is affixed to the substrate and has a second plurality of fingers forming a second comb. The second electrode is disposed in spaced relation to the first electrode such that the first and second combs face each other. A semiconducting layer is disposed over the first and second electrodes so as form a physical semiconductor bridge between the first and second electrodes. The semiconducting layer comprises an n-type semiconducting material or a p-type semiconducting material. A porous dielectric protective layer, advantageously containing a catalytic precious metal, may cover the semiconducting layer.

Abstract: A method of controlling an engine to help achieve a target air:fuel ratio based on data from an oxygen sensor, and related systems. At least one engine operating parameter and a sensed oxygen level are determined at two or more points in one of a rich and lean region based on data from the oxygen sensor. This information is used to help control engine operation in the other of the rich and lean regions without using directly sensed oxygen level data from that region. Thus, a control paradigm is developed in a first operating region based on oxygen level data from the oxygen sensor, and then used for control in a different second operating region without direct sensed oxygen level data in that second operating region. In some embodiments, the control paradigm may be adaptive based on changing conditions.

Abstract: A method of determining an air:fuel ratio of a combustion process based on information from an oxygen sensor exposed to exhaust gases of the combustion process. A first value is determined indicative of the exhaust gas oxygen content, with the value being based on a resistance of an oxygen sensing portion of the oxygen sensor. A second value is determined indicative of a temperature of the oxygen sensor, which may be based on a resistance of a heater portion of the oxygen sensor. A third value is determined indicative of the air:fuel ratio as a function of the first and second values. Thus, the oxygen level data from the oxygen sensor may be temperature compensated so as to result in a more accurate estimate of the air:fuel ratio. The third value may then be used to control the combustion process, which may be associated with an internal combustion engine.

Abstract: A releasable electrical connection and related methods use lateral compression of an electrically conductive spring to form a forced abutting solderless connection between the spring and a corresponding electrical lead, with the lead pressed between the spring and a support. The connection can be readily broken and remade for servicing related electrical equipment, such as an oxygen sensor assembly.

Abstract: A releasable electrical connection and related methods use lateral compression of an electrically conductive spring to form a forced abutting solderless connection between the spring and a corresponding electrical lead, with the lead pressed between the spring and a support. The connection can be readily broken and remade for servicing related electrical equipment, such as an oxygen sensor assembly.

Abstract: A method of controlling an engine to help achieve a target air:fuel ratio based on data from an oxygen sensor, and related systems. At least one engine operating parameter and a sensed oxygen level are determined at two or more points in one of a rich and lean region based on data from the oxygen sensor. This information is used to help control engine operation in the other of the rich and lean regions without using directly sensed oxygen level data from that region. Thus, a control paradigm is developed in a first operating region based on oxygen level data from the oxygen sensor, and then used for control in a different second operating region without direct sensed oxygen level data in that second operating region. In some embodiments, the control paradigm may be adaptive based on changing conditions.