Touch sensors are used in many applications, from remote controls, LED light controls to appliance control panels. This is a simple solution to replace the mechanical buttons and can be implemented in a wide variety of applications. The sensor provides great user experience. It is easy and more convenient to use as it has no moving mechanical parts. The circuit consumes very low current. Circuit has been designed using AT42QT1012 IC from microchip. This IC has many features. The circuit shown here is just Touch On/Off Toggle switch. You can read data sheet of the IC to use the timer function. The circuit provides TTL toggle Output which can be interfaced to Microcontrollers or BC847 output that is capable to drive 5mm white LED. Use Output Pin and VCC pin to connect 5mm LED. Small Pad on PCB helps to detect the finger touch.
Capacitive Touch Sensor Toggle Switch – [Link]