Pressure sensitive transducer circuits
US4250452A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 1979 |
| Grant date | Feb 10, 1981 |
| Priority date | — |
| Expiry date | Apr 19, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L9/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This relates to a circuit for delivering a linear voltage (V.sub.P) which is inversely proportional to the capacitance of a pressure sensitive capacitive transducer. A constant current I.sub.O is alternately switched into a reference capacitor (C.sub.R) and the transducer capacitor (C.sub.P). When the voltage across C.sub.P reaches V.sub.P, a flip-flop is toggled to direct current to C.sub.R. When the voltage across C.sub.R reaches a reference voltage (V.sub.R), the flip-flop is again toggled directing current to C.sub.P. A duty cycle detector charges integrator capacitors until the feedback voltage V.sub.P is such as to render equal the charging times of C.sub.P and C.sub.R.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.