The characteristics and classification of proximity switch performance

Proximity switch is also called the non-contact switch, it besides can complete stroke control and limit protection, or a kind of non-contact type detection device, used for detection of parts size and speed, etc., can also be used for variable frequency counters, frequency pulse generator, liquid level control and processing program of automatic connection, etc. Characteristics has reliable operation, long service life, low power consumption, high positioning accuracy, high operating frequency, and adapt to bad working environment, etc.

The performance characteristics of

In all kinds of switch, there is a kind of close to its object components - displacement sensor with the ability to "sense". Using the displacement sensor is sensitive to near the object properties for Nylon Cable Gland, the purpose of control switch on or off this is close to the switch.

MICROSONAR series proximity switch when there are objects to move to close to switch, and close to a certain distance, displacement sensor is "perception", switch to action. Usually call this distance detection distance ". Different proximity switch detection distance is also different.

Is sometimes detection test object is in a certain time interval, one by one, to move to close to switch, and one by one to leave, so repeated. Different proximity switch, responsiveness to detecting object is different. This response is called "frequency response".

species

Because displacement sensor can be according to the principle of different and different methods, and different displacement sensor method of "perception" of the object is different also, so common proximity switch has the following kinds:

1, eddy current type proximity switch

This switch is also sometimes called inductive proximity switch. It is the use of conductive objects near the can produce electromagnetic field close to switch, creates an eddy current object interior. The eddy current reaction to the proximity switch, the switch inside the circuit parameters change, thus to identify the presence of conductive objects nearer, and then control switch on or off. This approach switcNylon Cable Glandh can detect objects must be conductive.

2, capacitive proximity switch

This switch is usually measured constitute a plate of the capacitor, and the other a plate is the shell of switch. The shell in the process of measurement is usually connected to the chassis of the ground or with the device. When objects have to move to proximity switch, regardless of whether it is the conductor, due to its close, total want to make the capacitance of the dielectric constant changes, so that the capacitance changes, making and measuring head is connected to circuit state is change accordingly, which can control switch on or off. This approach switch detection object, not limited to conductor, can insulating liquid or powder, etc.

3, hall proximity switch

Hall element is a kind of magnetic sensor. Using the hall element to make the switch, called the hall switch. When magnetic objects nearer the hall switch, switch hall element on the surface of the test for producing circuit inside the hall effect and make the switch state changes, thus identify the presence of magnetic objects near, and then control switch on or off. The proximity switch test object must be metallic objects.

4, photoelectric proximity switch

A switch is called photoelectric switch using the photoelectric effect. The light-emitting device and photoelectric device in a certain direction in the detecting head is the same. When there is a reflective surface (tested object) approaches, photoelectric device receives the reflected light and the signal output, which can be "perception" is close to the object.

5, pyroelectric proximity switch

Made of temperature changes can perceive components called pyroelectric, close to switch. This switch is a pyroelectric electrical installation on the switch testing, when there are in close proximity to objects of different environmental temperature, heat release the output of the electric parts change, which can detect objects close to.

6, other types of proximity switch

When the observer or the system changes the structure of distance, close to the wave frequency offset will happen, this kind of phenomenon is called the doppler effect. Sonar and radar is made by using the principle of this effect. Using the doppler effect can be made into ultrasonic proximity switch, microwave, close to switch, etc. When there are objects move close, close to switch receives the reflected signal can produce doppler frequency shift, which can identify the presence of objects close to.