A method for detecting a change in capacitance of a capacitive sensing element having a nominal capacitance value is disclosed. In an exemplary embodiment, the method includes coupling the sensing element to a first oscillator, the first oscillator generating a first frequency dependent upon the capacitance...http://www.google.com/patents/US20030071639?utm_source=gb-gplus-sharePatent US20030071639 - Method and apparatus for detecting a change in capacitance of a capacitive proximity sensor
