Capacitance position transducer
US6346818B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 9, 1999 |
| Grant date | Feb 12, 2002 |
| Priority date | — |
| Expiry date | Dec 9, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/2412
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A non-contacting capacitive position transducer comprises a stator substrate carrying two electrically conducting inverted wedge regions 14,16 whose width varies inversely in a sensing direction. A moveable pick-off 20 is capacitively coupled to both wedges. The wedges 14,16 are driven with respective distinguishable time varying periodic waveforms, e.g. a sine wave and a cosine wave, and the pick-off voltage at 20 processed to determine the position of the pick-off in the sensing direction. Various configurations of transducer are described, including those of linear, cylindrical and disc form. The pick-off voltage is preferably transferred from the pick-off 20 back to the stator by capacitively coupling the pick-off to a suitably screened pick-off track 36 on the stator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.