Why does…? #9: How does your TV remote talk to the TV?
an infrared LED blinks codes on a ~38 kHz carrier; your phone camera can see it.
How does your TV remote "talk" to your TV? 📺👀
1️⃣ INVISIBLE LIGHT: the little LED at the front flashes infrared light (about 940 nm) — your eyes can't see it. But your phone camera can! Point the remote at your camera and press a button: you'll see it blink. 📱
2️⃣ A CODE PER BUTTON: every button sends its own pattern — bursts of flashes with short and long gaps = 1s and 0s. Inside each burst the LED flashes about 38,000 times a second (38 kHz).
3️⃣ THE TV'S EAR: the TV's receiver only listens to that 38 kHz beat, so steady light from lamps and the sun can't fool it.
Invisible light, secret code!
Read the voiceover (transcript)
- How does your TV remote talk to the TV?
- It flashes infrared light you can't see. But your phone camera can!
- Each button sends its own code: bursts of flashes, thirty-eight thousand a second.
- The TV only listens to that beat, so lamps and sunlight can't fool it!
- Invisible light, secret code!
- Next: why plugs spark! Follow for more!
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