Apparatus and method for controlling oxygen sensor heating
US5974857A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 15, 1998 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Oct 15, 2018 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/1456
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A sensing element of an oxygen sensor is controlled to keep a target impedance for maintaining activation temperature of the oxygen sensor. As the sensing element deteriorates, its internal impedance increases and power supply to a heater for heating the sensing element increases. The oxygen sensor temperature rises excessively above an activation temperature. To restrict excessive temperature rise, the target impedance is altered when the supply power to the heater exceeds a predetermined reference. The target impedance may be increased with increase in the power supply to the heater. Alternatively, the heater supply power is limited to a predetermined maximum for restricting excessive temperature rise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.