Capacitive Touch Sensor Design

Application Note Abstract   This application note considers the possibility of using springs as sensors. A comparison with solid conductive sensors and recommendations for the practical usage of springs are also discussed.   Introduction   CapSense™ may be used in several applications. However, some applications cannot install printed circuit boards with a set of sensors directly under the overlay or attached to the device case. Examples of such applications are “white goods” (that is, cooktop, washing machines, refrigerators, microwave ovens, and others) and various vehicle electronics, such as radio sets, TV tuners, dash boards, seat occupant detection, and so on.   Metallic spring sensors may be used as an alternative to solid conductive sensors. Th...