Remote Controls the incredible saga of invisible light by Samuel Bradshaw and Ryan Roose (of 7 th )

The process, as observed Point a small handheld object, called a remote control, at a TV. Boink! At the press of a button, the TV illuminates itself!

Inside said device

Description of components The buttons send signals to the circuit board by pressing them. The circuit board receives these signals and translates them into electric pulses. Capacitors help by storing energy that can be used by the remote. The LEDs (Light-Emitting Diodes) receive electric pulses and give off light.

Behind the scenes (1/2) As you know, there are many kinds of light, both visible and invisible.

Behind the scenes (2/2) A remote control uses infrared light, which comes just after red in the electromagnetic spectrum, to send signals to the TV.

Transmitting the signal When a button is submitted to pressure, the circuit board transmits an electrical signal to the LEDs. The LEDs emit an intermittent transmission of light - all in 7-bit binary code (ones and zeros).

About binary code Binary code uses ones and zeros to say “on” and “off” in continuous sequences at given times to make an electronic device do something. With the remote’s LEDs, a short beam of light represents “0”, and a long beam of light represents “1”. The TV then translates this binary signal into an action. For example, “ ” means “Volume up” (this can vary in different brands).

Interference? There are many other things that emit infrared light, from the sun to fluorescent lights (and back again). The TV can distinguish remote control signals from other sources because the remote control only sends a particular wavelength of infrared light (usually 980 nanometers).

A tad of history (1/2) The first TV remote controls were not wireless. They simply sent electric signals straight to the TV. Eugene Polley, an engineer, invented the first wireless TV remote in It was called “Flashmatic” and was essentially a flashlight that shined light on one of four photo cells around the TV screen. Each photo cell did something when light struck it.

A tad of history (2/2) The next development used high-frequency sounds to send a signal. By the early 1980s, the companies switched to infrared signals, which are what we use today.

Parenthesis: Credits Samuel: Presentation, images, aesthetics Ryan: Ideas, research, suggestions ("How Remote Controls Work") ("About Zenith") ("Television History") ("Light-emitting diode") ("The Nervous System") ("Native Village Media Library") ("Binary")

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