Method and device for processing analogue output signals from capacitive sensors

US7054778B2 · kind B2 · utility

Assignee

• Hahn-Schickard-Gesellschaft für Angewandte Forschung e. V. · DE

Inventors

• Wolfram Geiger · Gomaringen, DE
• Alexander Gaisser · Aach, DE
• Norbert Niklasch · Munich, DE

Key dates

• Filing date: Nov 30, 2001
• Grant date: May 30, 2006
• Expiry date: Apr 30, 2022

Classification

• Technology area (CPC G): Physics
• CPC primary: G01C19/5776
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An analogue output signal of a sensor which comprises a carrier signal with a carrier frequency ωC which is modulated by a measurement size is sampled with a sampling frequency ωA to receive a sampled sensor output signal. The frequency ωA of the sampling signal is set so that it is an integer divisor n of the carrier frequency ωC, wherein the phase of the sampling signal is set so that the sampling signal is synchronous to the sensor output signal. The sampled sensor output signal is filtered now to remove periodically repeated signal components from the sampled sensor output signal. Then a filtered useful signal is received, wherein its amplitude is proportional to the measurand detected by the sensor.