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WHYWhy does…? · #16EP.182 · 24 s

Why does a laptop charger have a box in the middle?

Cover of the lesson: Why does a laptop charger have a box in the middle?▶ Tap to play
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// WHAT YOU WILL LEARN

The box is the power supply: it turns 230 V / 120 V AC from the wall into about 20 V DC, and keeping it outside keeps its heat out of the laptop.

// LESSON NOTES

Why does a laptop charger have a box in the middle of its cable? 🔌💻

📦 That box is the real charger — a power supply.
⚡ IN: 230 V AC (India, UK, Europe) or 120 V AC (USA, Canada) — most work on 100–240 V.
🔁 Inside, it switches the power on and off tens of thousands of times a second through a tiny transformer.
🔋 OUT: about 20 V DC — just what the laptop needs.
🔥 Why outside? Heat! A charger turns a few watts into heat — inside, it would cook the laptop.
✅ Bonus: a thinner laptop that works in any country.

Read the voiceover (transcript)
  1. Why does a laptop charger have a box in the middle?
  2. That box is the real charger: a power supply!
  3. In: two-thirty volts AC, one-twenty in the US.
  4. Out: about twenty volts DC, just what the laptop needs!
  5. Guess: why keep it outside?
  6. Heat! Inside, it would cook the laptop.
  7. Thinner laptop, works worldwide!
  8. Next: why you should eject a USB stick. Follow for more!

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