Capacitive digital integrated circuit pressure transducer
US4625560A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 13, 1985 |
| Grant date | Dec 2, 1986 |
| Priority date | — |
| Expiry date | May 13, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L15/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A highly accurate and miniaturized pressure transducer is disclosed which includes first and second capacitors as a part of the integrated circuit, which also includes an Eccles-Jordan astable multivibrator. The miniaturization of both the capacitors and the entire multivibrator circuit in an integrated circuit establishes all components so that they are very closely matched on the two halves of the multivibrator, and so that whatever environmental disturbances, e.g., electrical, thermal, noise, etc., are encountered, are shared by both halves, and hence negated, so far as output drift is concerned. The multivibrator has a rectangular wave output and the duty cycle thereof is proportional to the force or pressure applied. This duty cycle is changed upon applied pressure, which changes one of the capacitors, and measurement of the duty cycle is a measurement of the applied force or pressure. The entire output circuit of the transducer is a digital output to provide digital processing through to a digital display. The foregoing abstract is merely a resume of one general application, is not a complete discussion of all principles of operation or applications, and is not to be construe…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.