IC for producing an output voltage related to fuel composition in a capacitive fuel sensor
US5343156A · kind A · utility
Inventors
Key dates
| Filing date | Apr 15, 1992 |
| Grant date | Aug 30, 1994 |
| Priority date | — |
| Expiry date | Apr 15, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A circuit for responding to the output of a capacitive fuel sensor that can distinguish gasoline from methanol and produces an output that is related to the methanol proportion. The response is independent of the conductivity in the sensor resulting from fuel contamination. A square wave is employed to excite the sensor and the circuit provides for stabilizing the square wave amplitude. The circuit includes an amplitude modulation detector that converts the square wave transients into a fuel composition related voltage output that can be applied to an engine control mechanism that will adjust the automotive engine to operate efficiently with the fuel being supplied. Circuits are shown for linearizing the fuel composition to voltage response and a charge dispenser amplitude modulation detector is described wherein the detection occurs only during the square wave transient interval.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.