Book 3, Question 98
Why Do Remote Controls Work?
Inside, a chip turns your finger press into a pattern of on-and-off pulses, and the TV's sensor listens for that pattern. The same idea works for garage doors, drones, ceiling fans, and toy cars!
From the book
Page from A Million Whys Book 3
More fun facts
- Most TV remotes send invisible infrared light to the device they control.
- A typical TV remote uses infrared light with a wavelength of about 940 nanometers, just beyond what our eyes can see.
- Point a remote at a phone or digital camera and press a button, and the camera may show a pulsing light you cannot see with your eyes.
- Each remote sends its own pattern of infrared flashes, which is why your TV remote does not control a car stereo.
- A few kinds of remotes, like garage door openers, use radio signals instead of infrared light.
Sources: Exploratorium, NASA, NASA Science
Questions kids ask
Can you see a remote's light?
Not with your eyes, because it is infrared. But a phone camera can often show it as a pulsing light.