What is the working principle of Hall proximity switch?

Speaking of switches, the first thing you think of may be the basic ones at home that turn on the lights when you press them. It is also a switch. The one Xiaotu is going to introduce today has a cool name - Hall proximity switch. There are many types of proximity switches, and Hall proximity switch is one of them. It has a very wide range of applications in the field of aviation technology, aerospace technology research and development and some industrial production fields. Although it is inconspicuous, it plays an indispensable role and can be said to be an important part of scientific and technological production.

Working principle of Hall proximity switch:

When a metal or semiconductor sheet carrying current is placed vertically in a magnetic field, a potential difference will occur at both ends of the sheet. This phenomenon is called the Hall effect. The potential difference between the two ends is called the Hall potential U, and its expression is U=K·I·B/d, where K is the Hall coefficient, I is the current passing through the sheet, and B is the external magnetic field (Loren Cili Lorrentz) magnetic induction intensity, d is the thickness of the sheet.

It can be seen that the sensitivity of the Hall effect is directly proportional to the magnetic induction intensity of the external magnetic field. Hall element belongs to this kind of active magnetoelectric conversion device and is a magnetic sensitive element. It is made based on the principle of Hall effect and using integrated packaging and assembly processes. It can easily convert magnetic input signals into electrical signals for practical applications, and at the same time it is easy to operate and reliable for practical applications in industrial applications. requirements.

The Hall proximity switch is made using this characteristic of the Hall element. Its input end is characterized by the magnetic induction intensity B. When the B value reaches a certain level (such as B1), the Hall proximity switch The trigger inside the Hall proximity switch flips, and the output level state of the Hall proximity switch also flips. The output end generally uses a transistor output, and is similar to other sensors, including NPN, PNP, normally open type, normally closed type, latch type (bipolar), and dual signal output. The Hall proximity switch has the characteristics of no electric shock, low power consumption, long service life, and high response frequency. It is integrated inside with epoxy resin sealing and potting, so it can work reliably in various harsh environments.

When a magnetic object moves close to the Hall proximity switch, the Hall element on the detection surface of the switch changes the internal circuit state of the switch due to the Hall effect, thereby identifying the presence of a magnetic object nearby, and then Control the switch on or off. The detection object of this proximity switch must be a magnetic object.

After reading Xiaotu’s introduction, do you have a certain understanding of Hall proximity switches and their working principles? Don't think that such high-end components only appear in research fields such as aerospace and aviation. In fact, we often come into contact with Er-type proximity switches in our daily lives. For example, it can be found in some automatic doors in garages and hotels, anti-theft equipment in banks and filing agencies, and in some measurement technologies. The role it plays in our lives is really not small!