Linear capacitive pressure transducer system
US4398426A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 2, 1981 |
| Grant date | Aug 16, 1983 |
| Priority date | — |
| Expiry date | Jul 2, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L9/125
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A capacitive pressure transducer system includes a reference capacitor and a capacitor which varies with pressure; and circuitry which involves alternately charging one of the capacitors to a reference voltage level, and then switching to charge the other capacitor; and circuitry for producing an output voltage which varies as the duty cycles of the two capacitors shift; and the output is therefore substantially proportional to the pressure changes. Feedback is provided to incrementally change the capacitor charging and switching timing or duty cycles by changing the charging current or the reference voltage at which switching occurs, to substantially eliminate deviations from linearity in the voltage versus pressure characteristic.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.