How Remote Controls Work ?

In the past 20 years or so, makers of electronic devices have put a lot of emphasis on getting disconnected. But they weren’t encouraging people to stay away from television, computers, music players and so on. They were simply urging customers to abandon the many cables and wires used in the past and make the move to remote control.

Many people might think remote control is relatively new, making its appearance with cars and model airplanes that weren’t tied to the controller on the ground. But the truth is, remote control has been around for decades, with the first use attributed to Germany’s navy during World War II. The military used remote-control flying “bombs” to damage the enemy’s ships. In addition, armies used remote control to detonate explosives on the ground.

It took the application of radio signals to military tactics to make this happen. Remote control systems we use in our homes for video and audio entertainment relay on infrared light. The stream of light carries the signal from the control device in our hand to the electronic item, such as the television, DVD player, CD player etc. In essence the controller in our hands sends it signal to the other device in light pulses that are interpreted in the ever-present binary code of computer/digital language. Different codes mean different things to the device. We can turn the power off and on, change the loudness and change channels or programs.

The signals are processed inside the electronic equipment by an installed computer chip or solid-state circuitry. Remotes often have to be pointed directly at the electronic device because the element that receives the signal is on the front of the television, CD player etc. Whether or not you have to point directly depends on how strong the infrared signal is when it comes from the remote control.

A television viewer, for example, pushes a particular button on the controller, closing a circuit inside the remote control. The circuit sends a binary code command to the light-emitting diode (LED) on the front of the controller. The LED contacts the television, DVD player, CD player etc. by a specific series of pulses. The receiving equipment interprets this as a particular command and converts that to the data the equipment can use to carry out the command.

This is essentially the same method that is used for radio-controlled devices, though these other devices work with radio signals of different frequencies. But the idea is much the same. The signal, whether from light pulses or true radio signals, is converted on the receiving end to binary code that means specific things to the equipment. Differences in time between light pulses correspond to differences in signal frequency with radio-controlled devices.

 Print This Page