Dynamic liquid level indicator
US4949069A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 9, 1988 |
| Grant date | Aug 14, 1990 |
| Priority date | — |
| Expiry date | Nov 9, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B21/182
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A liquid level indicator uses a conductive probe and when the circuit is energized a logic signal indicates whether the liquid is above or below a certain level. The signal is processed by a logic circuit and the output of the logic circuit controls an indicator circuit. An inhibit circuit provides an input to the logic circuit and prevents the indicator circuit from indicating low liquid within a start time delay period after energization of the sensing circuit. The logic circuit includes a time constant circuit which interposes time delays in the logic signal output of the logic circuit to prevent false indications from momentary changes in liquid level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.