Liquid level sensor for internal combustion engine
US6239709A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 11, 2000 |
| Grant date | May 29, 2001 |
| Priority date | — |
| Expiry date | Feb 11, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F23/247
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The inexpensive sensor detects a low oil or no oil condition in an internal combustion engine and shuts down the engine. The sensor includes two inductors having different resistances disposed in a sensing bridge. The inductors are heated by a steady low voltage. A periodic higher voltage is applied to the inductors by means of a power winding disposed on the same frame as the ignition coil. When at least one of the inductors is disposed in air and not in oil, an imbalance is created in the sensing circuit that is used to short out the ignition primary. Alternatively, the sensor can be used to provide a visual or audible indication of a low oil level without stopping the engine.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.