Eddy current position sensor
US5291782A · kind A · utility
Inventor
Key dates
| Filing date | Feb 16, 1993 |
| Grant date | Mar 8, 1994 |
| Priority date | — |
| Expiry date | Feb 16, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S73/05
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An Eddy current position sensor for providing an electrical signal proportional to the position of a metallic ring positioned around and movably positionable axially along the length of an elongated wire wound core. The metallic ring serves as a movable target with respect to the fixed coil/core and may be made buoyant for liquid level measurement or connected to other movable objects. The electrically conductive wire winding around the elongated preferably cylindrical ferromagnetic core has a progressively increasing spacing between each turn of wire from one end of the coil to the other. Each end of the wire is connected to a linear oscillator and signal conversion unit which serves to both input a radio frequency current through the coil and to monitor the absorption of the metallic ring around a conical shaped electromagnet field produced by the energized coil. The field absorption by the metallic ring varies linearly with the axial positioning of the ring over the coil. To increase signal output, an evenly and closely wound "Exciter" portion is also formed around the core of the same length of wire immediately adjacent the closer spaced end of the progressively wound coil.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.