Phase shift detection and measurement circuit for capacitive sensor

作者： Ronald A. Marker , Raymond J. Vivacqua , Delvin M. Gualtieri

DOI:

关键词: Capacitance probe 、 Electronic engineering 、 Engineering 、 Bridge (interpersonal) 、 Signal 、 Detector 、 Capacitor 、 Capacitive sensing 、 Bridge circuit 、 Wien bridge oscillator

摘要: A capacitor measurement and detection circuit (8) for monitoring changes in a sensor capacitor, comprising: bridge (20) including reference (400) the (100) generating output signals (510, 520) indicative of difference between magnitude capacitors; fixed frequency oscillator (10) connected to driving at frequency; imbalance detector (30) responsive conditioned signals; counter driven by an signal phase arm active circuit, thereby providing indication that object is positioned electric field created (50).