If the user of mobile technology still does not know what the famous scientist Edwin Hall is known for, then it’s time to fill this gap. Sensors, whose work is based on the opening of the hall, now stand in every third smartphone – although previously such sensors were installed only on elite gadgets.
On the list of sensors equipped with a smartphone, you can sometimes find a Hall sensor – perhaps the most mysterious of all known sensors. If the functions of, say, the heart rate monitor and pedometer are clear and obvious, then the purpose of the hall sensor is not known to every user. In this article, we’ll find out who Hall is and why the sensor named in his honor is becoming increasingly popular.
Table of Contents
A bit of physics
Edwin Hall is an American physicist. He made his famous discovery in the nineteenth century. Hall has found that if a conductor (for example, a metal plate) connected to a DC power source is placed in a magnetic field, Lorentz’s force will act on the moving electrons. As a result, the electrons move in an arc and cause one of the surfaces of the plate. On this face, the electrons will accumulate a negative charge, while the opposite – a positive charge. The potential difference at the 2 edges of the board is called the Hall voltage .
Practical application of the Hall effect was found only 15 years after the death of the scientist. Now this effect is based on the work of PC disk drives, computer coolers, car ignition systems and even jet engines. Developers have guessed relatively recently about how to apply the Hall opening on your smartphone.
Why do I need a Hall sensor on my smartphone?
The Hall sensor (also called a magnetic sensor ) is equipped with many models of popular manufacturers and some smartphones of little-known Chinese brands. This sensor is designed to capture Hall voltage.
The sensor does not measure voltage, but only determines its presence or absence, and then sends a signal to the smartphone. Upon receipt of the signal, the gadget performs a programmed action.
As a rule, using a Hall sensor on your phone boils down to solving only 2 tasks – that’s why this sensor is necessary for the gadget:
- The sensor speeds up the start of the GPS navigator and improves geographical positioning.
- The Hall sensor provides the smartphone with the ability to interact with magnetic shields.
In addition, thanks to the discovery of an American scientist, it became possible to manage gestures – a “trick” that users met for the first time on the Samsung Galaxy S3.
Of course, the potential of the Hall effect in smartphone design is not fully revealed. The reason for this is a number of technical restrictions. The use of the “fully” hole does not allow the compact size of modern mobile devices and batteries with insufficient power.
The principle of cooperation of the Hall sensor with mobile accessories
Thanks to the Hall sensor, mobile devices can cooperate with so-called “smart” cases ( Smart Case ). The magnet is mounted in the lid of such a flap. As soon as the user covers the housing cover, the Hall effect appears, the sensor sends a signal to the smartphone system – and the gadget screen is automatically locked. Of course, all this happens in a few seconds. When the owner of the smartphone opens the lid of the cover, the Hall voltage “nothing goes out”. The sensor gives the command to unlock the display.
If the gadget owner uses a window box (as in the figure above), then the Hall sensor gives the command not to completely turn off the display, but switch it from one mode to another. When the cover is closed, a clock, calendar, music player or notification list can be displayed in the available area of the screen.
Worry about the fact that the magnet of the “smart” housing will harm the smartphone stuffing, definitely not for anything. The magnetic field does not spoil the gadget – this has been confirmed by numerous professional and amateur tests.
The Hall sensor saves battery gadget – this is the main advantage of this sensor. An activated screen with a high brightness consumes an impressive amount of precious milliamps.
Which smartphones have a Hall sensor?
Unfortunately, not all manufacturers on the list of features of their gadgets indicate whether the device has a Hall sensor. In the short list of parameters such information is not exactly found. However, the user can be sure: if the original Smart Case is produced for a smartphone, this means that this device is precisely equipped with a magnetic sensor.
Final Word
Unfortunately, the “best minds” of the mobile electronics industry have not been able (for now?) To find out how to use the opening of the hall to use its full potential. Automatic display shutdown / switching – “talking to a child” compared to what can be done if technical limitations can be overcome. However, the search for ways to implement Hall observations is underway – and progress does not stand still. This may indicate, for example, the appearance of Google Card Board virtual reality glasses , the management of which is based on the interaction of a magnet and a Hall sensor.
