Autonulling AC bridge using differential and integration feedback
US5264798A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Oct 29, 1991 |
| Grant date | Nov 23, 1993 |
| Priority date | — |
| Expiry date | Oct 29, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/028
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A self-contained autonulling bridge circuit based on phase-sensitive deteon of an impedance to be measured is described. The system utilizes a feedback structure to control a variable impedance in order to establish the null of the bridge. The system utilizes a voltage-variable impedance having both resistance and capacitance and provides the phase sensitive relationship in the control means in order to provide highly accurate measurement of an unknown test impedance. The ability to measure small changes in impedance provides particularly useful application to the area of biological sensor impedance measurement or electrochemical impedance measurement using silicon-based devices.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.