Principle of capacitive proximity switch

Capacitive proximity switch is a kind of position sensor with switch output. Its measuring head is usually one plate of the capacitor, and the other plate is the object itself. When the object moves to the proximity switch, the object and the proximity switch The dielectric constant changes, so that the state of the circuit connected to the measuring head also changes, so that the switch can be controlled on and off. Capacitive proximity switches can detect any medium, including conductors, semiconductors, and insulators, and can even be used to detect liquid and powdery materials. For non-metallic objects, the operating distance is determined by the dielectric constant of the material. The greater the dielectric constant of the material, the greater the available operating distance.

Proximity switch, also known as non-contact proximity switch, is an ideal electronic switch sensor. When the metal detector is close to the sensing area of the switch, the switch can quickly issue electrical commands without contact, pressure, sparks, and accurately reflect the position and stroke of the motion mechanism. Even if it is used for general stroke control, its positioning accuracy and operation Frequency, service life, ease of installation and adjustment, and adaptability to harsh environments cannot be compared with general mechanical limit switches. It is widely used in medical equipment, electronic equipment, machine tools, metallurgy, chemical industry, textile and printing industries. . It can be used as limit, counting, positioning control and automatic protection link in automatic control system. Its characteristics are mainly manifested in:

1. Liquid, powder, non-metal, metal and other special bodies can be detected.

2. The detection distance and sensitivity can be adjusted.

3. It is not affected by bubbles or liquid color when detecting liquid.

4. There are a variety of shapes such as square, round, pipe type, etc. to choose from.