Square wave excitation of a transducer
US5088330A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 29, 1990 |
| Grant date | Feb 18, 1992 |
| Priority date | — |
| Expiry date | Nov 29, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L1/2256
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A device for measuring a physical quantity includes a transducer and circuitry for exciting the transducer with an a.c. square wave. The excitation circuitry includes two amplifiers, a switch and a resistor network. The excitation circuitry provides a plus one gain when the switch is in one position and a minus one gain when the switch is in a second position. A similar circuit synchronously demodulates the transducer's output signal. Another similar circuit synchronously demodulates the transducer excitation signal and provides a reference voltage to an analog-to-digital converter (ADC). The ADC converts the demodulated transducer ouptut signal into a binary word. Both demodulated signals are filtered before application to the ADC. An example of the device is a force-measuring device such as a weighing scale incorporating a strain gauge load cell.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.