Working Principle of Capacitance Proximity Switch

The Industion surface of capacitance sensor is composed of two coaxial
mental electrodes, which from a capacitor on RC oscillation circuit,
just like an open capacitor electrode

When connecting to power supply, Rc oscillator does not wok when an object
is close tocapacitor electrode, the capacitor capacity will increase, and
the oscillator will vibrate Theough the treatment of behind stage circuit,
both signals of stop oscillation and oscillation will be converted to
switch signs for checking the existence of object This sensor can detect both metal and non-metal abject, the max action distance can be obtained, but to nonmetal object, the action distance is distance is determined by material dielectric constant, the more dielectric constant, the more action distance will be obtained.