Hall-effect fine resolution liquid level indicator
US6481278B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 6, 2001 |
| Grant date | Nov 19, 2002 |
| Priority date | — |
| Expiry date | Feb 6, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H36/02
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A liquid level indicator apparatus provides direct readout of liquid level at high resolution using an array of vertically disposed Hall-effect magnetic switches. To overcome the limit to closer spacing of the switches imposed by their vertical dimension, they a disposed side by side horizontally and vertically by a distance less than the vertical dimension of each switch. They are mounted on a flat flexible substrate and then bent around into a hollow cylinder or prism shape. A floating magnet of annular shape surrounds the cylinder, or a magnet corresponding to the cylindrical or prismatic shape floats inside the surrounding circuit board. Several circuits are shown for displaying a liquid level readout resulting from the actuation of the switches by the magnet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.