Sensors in smartphones(part 2)

Sensors in smartphones(part 2)

In the previous post we have learned all about  " Different Sensors Available In Phone" and Here comes Part 2 of previous post .If you have not seen the part 1 then head over to previous link .

1.Hall Sensor:

A Hall effect sensor is a transducer that varies its output voltage in response to a magnetic field. Hall effect sensors are used for proximity switching, positioning, speed detection, and current sensing applications.

The main function of this proximity sensor is to detect how close your smartphone's screen is to your body. When you use your smartphone, it detects the position of ear with respect to screen and turns off the light of screen and saves battery. Also proximity sensor stops the accidental touch, unwanted input during talk. This sensor also detects the signal strength, interference sources and amplify or filter by use of Beam Forming Technique. Thus, in a nutshell, proximity sensor detect the presence of body like cheek, face or ear and stops the web surfing, music or video during talk/calling and save the battery. After the conversation, it resumes the same function which was stopped earlier during talk.

It was discovered by Edwin Hall in 1879.
wikilink for Hall effect: Wikipedia



2.Accelerometers:

Accelerometers  are  devices that can measure acceleration (the rate of change in velocity),  but in smartphones, they're able to detect changes in orientation and  tell the screen to rotate. Basically, it helps the phone know up from  down.

All accelerometers have two fundamental parts: 
1. A housing attachment to the object  whose acceleration we want to measure.
2. A mass that, while tethered  to the housing, can still move. 

For example assume a spring and a heavy ball. If you move the housing up, the ball lags behind stretching the spring.  If we measure how much that spring stretches, we can calculate the force  of gravity.

Inside the smartphone accelerometer chip, engineers have created a tiny accelerometer out of  silicon. It has, of course, a housing that's fixed to the phone, and a  comb-like section that can move back and forth. That's the seismic mass  equivalent to the ball. The spring in this case is the flexibility of  the thin silicon tethering to the housing. Now clearly, if we can  measure the motion of this central section we can detect changes in  orientation.
The motion of the springs causes a change in value of capacitance which is sensed by a sensor which scales it to current signals to communicate with the brain of the smartphone.
And all of this happens in a matter of a microseconds.


3.Gyroscope:

The gyroscope is a sensor that can provide orientation information as well, but with greater precision. Thanks to this particular sensor, Android's Photo Sphere camera feature can tell how much a phone has been rotated and in which direction. It is also used by Google's Sky Map for telling what constellation you're pointing a phone at.


4.Thermometer:

There's a thermometer in pretty much any smartphone, and some handsets might have more than one of them. The difference is that they're used to monitor the temperature inside the device and its battery. If a component is detected to be overheating, the system shuts itself down to prevent damage.

Nearly all of the main sensors are explained in previous part and this part . Biological sensors like heart rate senors , Iris Scanner etc will be explained in different part.If you have any queries about any sensor , comment below. Thanks for Reading...!!  : )