The touch-activated switch is a simple, low-cost electronic system designed to control a device using only a finger touch instead of a mechanical switch. This project makes use of basic electronic components such as a 555 timer IC, resistors, capacitors, an LED, and touch plates to detect the small electrical charge naturally present on human skin. When the sensor plates are touched, the resulting change in voltage is processed by the circuit, which then triggers the output to turn ON or OFF. The design eliminates moving mechanical parts, improving durability, safety, and ease of operation. The circuit also incorporates signal conditioning and noise filtering to ensure stable and accurate touch detection. This project demonstrates the principle of capacitive touch sensing and provides an efficient alternative for applications in automation, lighting control, and user- friendly interfaces. Overall, the system successfully showcases how human touch can be converted into a reliable electronic control signal using minimal components and without any microcontroller.
P et al. (Fri,) studied this question.