Heater control system for an air-fuel ratio sensor in an internal combustion engine
US6083369A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 11, 1998 |
| Grant date | Jul 4, 2000 |
| Priority date | — |
| Expiry date | Feb 11, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/4067
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A heater control system for an air-fuel ratio sensor for an internal combustion engine is provided to supply power to a heater in order to activate the air-fuel ratio sensor quickly at the time of starting the engine. The system comprises an air-fuel ratio sensor arranged in the engine exhaust system for detecting the air-fuel ratio, a heater for heating the air-fuel ratio sensor, a power supply including a battery and an alternator for supplying power to the heater, a power switch for operating a power line for transmitting power from the power supply, a capacitor circuit charged by the power supply and adapted to discharge through the heater the electricity stored therein by the charging, a first switch connected in series with the heater for supplying or cutting off the current flowing to the heater, and a control unit for controlling the first switch to close after the power switch is closed. The system further comprises another capacitor circuit adapted to be connected in parallel to the power supply at the time of charging and to be connected in series with the power supply at the time of discharging to thereby apply to the heater a high voltage obtained by superimposing the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.