Capacitive Touch Switch

Touch sensing is fast becoming an alternative to traditional pushbutton switch user interfaces, because it requires no mechanical movement and it enables a completely sealed and modern looking design.

Capacitive touch switches basically work on Charge Detector (CD) technology. Capacitive switch is basically a pair of adjacent plates. Small edge to edge capacitance is present, the intent of the switch layout is to minimize the capacitance between these plates.

When a conductive object like finger is placed in proximity to the two plates, there is a capacitance between one electrode and the conductive object and a similar capacitance between the conductive object and the other electrode.

The most common form of capacitance switch array is a set of capacitors where one side of each is grounded. Thus the active capacitor has only one assessable side, the switch is grounded variable capacitor. The presence of the conductive object increases the capacitance of the switch to ground. The switch action is determined by measuring the charge in the capacitance.

Capacitive switches offer infinite life time due to its solid state nature. Key operations through all kind of dielectric material like Wood, Glass, Acrylic, etc. Capacitive switches are very much suited for harsh environments. Backlit option is possible in capacitive touch switch.