Circuit and method for impedance detection
US7005865B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 6, 2002 |
| Grant date | Feb 28, 2006 |
| Priority date | — |
| Expiry date | Sep 22, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R27/26
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An electrostatic capacitance detection circuit 10 comprises a DC voltage generator 11, an operational amplifier 14 of which non-inverting input terminal is connected to specific potential, an impedance converter 16, a resistance (R1) 12 connected between the DC voltage generator 11 and an inverting input terminal of the operational amplifier 14, a resistance (R2) 13 connected between the inverting input terminal of the operational amplifier 14 and an output terminal of the impedance converter 16, and a capacitor 15 connected between an output terminal of the operational amplifier 14 and an input terminal of the impedance converter 16. A capacitor to be detected 17 is connected between the input terminal of the impedance converter 16 and specific potential.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.