## How does a Universal Remote Control work?

written by: Daniel Barros•edited by: Rhonda Callow•updated: 6/30/2011

You probably use one everyday, but if you've ever wondered how a universal remote control works, today's your lucky day - we've got that ready for you here.

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Most of us pick up a remote control without so much as a stray thought to how they work or how pivotal they’ve become to our society. Purchasing a TV without the remote today is something that would be considered unthinkable, however, 50 years ago, people had to make do by getting up to press the buttons on the TV to get it to work. So how do those cool Universal Remote Controls work? Let’s take a look.

First, let’s talk basics about how a single source remote control actually works. In simplest terms, a capacitor and a circuit board draw power from a battery source to a light-emitting diode (otherwise known as an LED). Drawing power from the battery, the capacitor patiently builds up electrical charge and waits for a button to be pressed. When a button is pressed, the bottom of the button makes contact with the circuit board in the remote. When this contact is made, it triggers a specific series of 0s and 1s.

This string of 0s and 1s is then sent to the LED at the top of the remote. In order for the TV to understand the signals, the LED pulses light at variable speeds with pauses in between. A certain amount of time paused means a 0, another amount of time paused means a 1.

This way, the strings of 0s and 1s is sent to the receiver, which then decodes it into the command that you originally clicked on the remote. This all happens at the speed of light, naturally. That’s why you don’t wait once you’ve clicked a button for the TV to respond.

But what about Universal Remote Controls? How do they work with different devices? The answer lies in the “Command Codes" that every receiver or television has. In order for the receiver to not confuse a command from the LED with a command from another LED, the receiver and remote control have a specific identifier code. This code can be programmed into Universal Remote Controls.

A Universal Control takes the programmed code and assigns it to a specific button, or in the case of more modern controls, to a specific program that can be brought up by touchscreen. Once assigned, the command code for the receiver allows the generic LED of the Universal Remote to access the receiver.

The concept is simple, and yet it has such an impact on our daily lives that it becomes hard to actually measure just how much remote controls help us. Of course, the downside is that we’ve grown lazy and complacent along with the conveniences of the remote control and the personal computer.

The most interesting remote controls are those that don’t have to be pointed at anything to trigger the receiver. Take the PS3’s Blu-Ray Remote Control for instance, rather than using an LED like a conventional remote, it uses the Bluetooth protocol that is quickly permeating through society. Via BT, the remote uses radio signals at a specific frequency to access the PS3 – in this manner, you don’t have to even be in the same room as the remote to actually use it. The signal passes through people, through walls, etc. It’s a great innovation that I hope to start seeing in receivers and remotes across the board.