The touch key uses capacitive sensing technology. We know that the human body is conductive, and the circuit below the capacitive induction key can produce a uniform distribution of electrostatic field. When our finger moves to the top of the key, the capacitor on the surface of the key changes, and the relevant circuit in the notebook makes a judgment based on this capacitance change to achieve the predetermined function.
Capacitive keys are very convenient to use, only need to touch, do not need to press hard, you can operate.
The principle of touching the plastic shell switch is that the capacitor or resistance fluctuation generated by the human body is close to the switch, and the command is transmitted to the chip, and the switch circuit is controlled by the chip to realize the purpose of opening or closing the electrical appliance. In the process of switching electrical appliances, the human body does not need to contact close contact with high-voltage power sources.