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Working principle of inductive proximity switch:

2022-05-16
Working principle of inductive proximity switch:
Inductive proximity switch consists of three parts: oscillator, switching circuit and amplification output circuit. The oscillator generates an alternating magnetic field. When the metal target approaches this magnetic field and reaches the induction distance, eddy current will be generated in the metal target, resulting in oscillation attenuation and even vibration stop. The changes of oscillator oscillation and stop vibration are processed by the later stage amplification circuit and converted into switching signals to trigger the driving control device, so as to achieve the purpose of non-contact detection.
Working principle of inductive proximity switch:
Capacitive proximity switch is a high-frequency oscillator and amplifier. The surface between proximity switch and capacitor participates in the detection of oscillation circuit. When it comes to the object, it detects the oscillation of proximity sensor circuit, capacitor and high-frequency oscillator. Oscillation and stop these two vibrations are converted into electrical signals and amplifiers into binary switching signals. This is the principle of capacitive proximity switch.
Detection object of proximity switch:
For different detection bodies made of different materials and different detection distances, different types of proximity switches shall be selected to make them have high performance price ratio in the system. Therefore, the following principles shall be followed in the selection of proximity switches:
When the detection body of proximity switch is made of metal, inductive proximity switch shall be selected. This type of proximity switch is the most sensitive to iron nickel and A3 steel detection body. For aluminum, brass and stainless steel detection bodies, the detection sensitivity is low.

When the detection body of proximity switch is non-metallic material, such as; Capacitive proximity switches shall be used for wood, paper, plastic, glass and water.