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Insight - How Remote Control Works

Written By: 

Abhimanyu Mathur

 

The Oxford Dictionary defines a remote control to be a control of a machine or apparatus from a distance by means of radio or infrared signals transmitted from a device”. So, when we decided to go inside a conventional remote control, we were stuck: which one to take? There are those for LCD TV, others for gaming consoles, for the car entertainment systems and some that work for all kinds of systems.  At the very first sight, one can notice difference in designs, features, the manner they are powered and several such features. But upon giving a slight thought, it is easy to understand that all the remotes are performing the same basic task: controlling outputs of an electric/electronic device.

So, here we are, with a Sony RMGA020 LCD TV Remote used for their 32 inch KL television series. Interestingly, Sony calls their remote to be “Remote Commanders”. Since the trend nowadays is to equip remotes with a hoard of features and create the main gadget as simple as possible, calling them “Remote Commanders” is fair enough.

Sony Remote Commander

Fig. 1: Image of Product Tag of Remote Control Device

 

How Remote Control Works

Fig. 2: Sony RMGA020 LCD TV Remote Control

Image shows the body of a conventional plastic remote. Equipped with push buttons and housing a lot many features, this Sony controller proudly commands a latest technology LED television. Upon first gaze one gets impression that the body would be housing a circuitry as complex and intelligent as the device it is attuned to.

Remote Control

Fig. 3: Shape and Structure of Outer Body of Remote

Casing and Battery Slot

Light weighted, a remote is designed with blunt corners so that it can be held for longer durations (when nothing interesting is on the television).The rubber buttons are placed in such a manner that they are able to respond to slightest pressures and do not get damaged easily when user exerts extra force on them.

Remote Cell Section

Fig. 4: Battery Casing of Remote

Majority of remotes available are powered by AA or AAA battery, and have a rechargeable NiMH battery backup. Such power sources make sure that the user never has to strive hard to control the gadget in terms of basic requirements such as power availability.

Remote Control

Fig. 5: Layers of Remote Control Body

 

A screw-less exoskeleton, the remote control easily reveals its insides to any curious mind. The upper and lower layers of the plastic body are fastened together by mechanical fixtures placed on the inside of each.

Remote Control PCB

Fig. 6: PCB and IC of Remote Control

PCB and IC

When separated, the layers reveal a rectangular PCB covering most of the area under the hood. Placed beneath the rubber buttons, the PCB is the multi-tasking part of the remote. The PCB is held to the lower layer of plastic by means of screws which have been taken out in the image above as we are going to get hold of its other side too.

Remote Control IC

Fig. 7: Circuit Arrangement of PCB

The front part of the PCB that lies just below the rubber buttons is a mesh of the connection tracks and has an IC at one end. The basic task of the IC is to decode that which button has been pressed and generate corresponding signal.

Remote Control Components

Fig. 8: Electronic Arrangement of Reverse Side of PCB

On the reverse side of the PCB, a crystal oscillator and a capacitor can be seen that facilitate the working of the IC. Proceeding towards the other end of the PCB, the marking where batteries are placed and an infrared source can be seen. The source is analogous to the output of the remote which sends the signals generated by the IC.

Hence, from managing the power requirements to taking input from the user and converting it into suitable code and then transmitting it, the PCB acts as the brain of the remote control.

 

 

Comments

do you think we are arts students and still on engineersgarage???
grow up and post something good.
i have opened TV remote control when i was in 2nd class..:-\