Capacitance measuring apparatus
US4392378A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 25, 1980 |
| Grant date | Jul 12, 1983 |
| Priority date | — |
| Expiry date | Aug 25, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F23/266
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Capacitance measuring apparatus comprises a variable capacitor VC and a reference capacitor FC. Circuits D, ID, are provided for generating a periodic waveform for application directly to the variable capacitor, and in inverted form to the reference capacitor. Switches means SM are operated by control logic CL to connect the two capacitors in sequence to the input of an integrating amplifier IA, the output of which is applied to a comparator CM to which is also applied a reference level. The output of the comparator controls the control logic. Output of the control logic is converted to an indication of the capacitance of the variable capacitor relative to that of the reference capacitor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.