Electrical capacitance sensors detect and measure capacitance, which is the ability to store an electrical charge. Capacitive sensors are essentially oscillators with open an capacitor that generates an electrostatic field. If there is no object nearby, the oscillator does not oscillate, and the electrical capacitance sensor remains quiet. But as an object to be detected comes closer, capacitance increases, and oscillation begins. As the oscillation increases, it is detected by a circuit that, in turn, generates an output signal that indicates the proximity of the object.
|
