A modern smartphone can be so multifunctional that its owner is not always aware of all the characteristics and capabilities of his device. For example, do you know what a Hall sensor is in a smartphone? How does it work and what is it for? We suggest you learn more about this feature!
What does a Hall sensor mean in a smartphone?
We already know why the gadget needs an approximation module or a gyroscope. But what is a Hall sensor in a smartphone? It is a determinant of position whose action is based on the Hall effect. This device detects both the presence of a magnetic field and measures its intensity.
The sensor and the effect itself is named for the famous physicist E. Hall. It was this scientist who established that when a conductor plate is placed in the center of the magnetic field through which alternating current flows, Hall voltage (the transverse potential difference) will appear in it (the field).
In the described case, the electrons in the conductor are deflected strictly perpendicular to the direction of the magnetic field itself. Hence, their density on different parts of the plate will be excellent. It is this potential difference that the meter fixes.
And what is a Hall sensor in a smartphone? This is an even simpler device - it is designed to determine only the presence of a magnetic field, without measuring its strength. In addition, the gadget is probably also equipped with a magnetic sensor, which allows you to use your smartphone as a compass.
Where is it used?
We have established what a Hall sensor is in a smartphone. However, gadgets are not the only field of application of the invention, which also differs in the possibility of contactless control of any device.
I must say that the Hall effect was discovered relatively long ago - in 1879. And for the first time they put it into practice only 75 years after this event. It turned out to be useful for cars - the sensor was used to measure the angle of the crankshaft, camshaft. In older models of cars, the Hall sensor detected the moment of spark formation.
Further along the path of progress, the device began to be used in complex systems:
- proximity switches;
- systems for reading magnetic codes;
- devices used for contactless determination of current strength in conductors;
- liquid level meters;
- ion rocket engines.
In addition, it was found that the Hall sensor is able to replace magnetically controlled sealed contacts - reed switches. They have a wide scope: microelectronics, security alarms, keyboards, elevators, headphones.
Why is the Hall sensor in the smartphone?
We found out that this device determines the presence of a magnetic field. But then why do we need a Hall sensor in a smartphone today? Everything is simple - it determines whether a smart cover with a magnetic fastener is open or closed. If the magnet is far (the sensor "does not see" it at a certain distance), then a command is given to turn on the display. If the fastener is close (which means the user has closed the cover), then the sensor signals the system that the screen needs to be put into sleep mode.
This meter is also useful for bumpers for smartphones with a “window” on the display. So, for example, if you slam the cover, then the Hall sensor detects this. It gives the system a signal that you need to broadcast on the screen saver specifically designed for the "window". Most often this is the time, date, important notifications. Removed the cover of the cover - a command from the sensor to display complete information on the display.
Other features in smartphones
Interaction with magnetic caps is the most common sensor application in modern gadgets. However, it should be noted that it was successfully used in earlier models of smartphones:
- The digital compass function operated thanks to the Hall sensor. And today it is used by navigation applications for a general improvement in positioning and higher accuracy in determining the motion vector.
- Activation / deactivation of the backlight when opening / closing the clamshell device. Here, the action is similar to the current situation with magnetic covers.
Does my phone have a Hall sensor?
To answer the question in the subtitle, the easiest way is to refer to the characteristics of your gadget on the official website of the manufacturer or in the instructions for the device. However, not all manufacturers indicate whether a particular device is equipped with a Hall sensor.
But there is an easy way to verify. If “smart” covers or covers (including those with “windows”) having a magnetic fastener are produced for your smartphone model, then most likely there is a Hall sensor in the device.
Among the models popular on the market today, this module has the following:
- Lenovo Vibe S1.
- Meizu Pro5.
- Meizu M2 Mini.
- LG Nexus 5X.
- Meizu M2 Note and so on.
Unfortunately, in modern smartphones, the capabilities of the Hall sensor are greatly truncated. This is explained by minimizing the thickness of the case, the desire of the manufacturer to reduce battery consumption, the lack of need for advanced functions due to it. Today, the sensor has two tasks - interaction with a “smart” case or cover and a pocket compass.