Faraday’s Legacy

In 1831, Michael Faraday discovered that moving a magnet through a coil of wire creates electricity. This principle, Electromagnetic Induction, is exactly what happens when you drop your iPhone on a Qi charger.

The Two-Coil Dance

Wireless charging requires two copper coils:

1. The Transmitter (Base): Connects to the wall and creates a rapidly changing magnetic field.
2. The Receiver (Phone): Sits inside your device and “catches” that magnetic field, turning it back into electrical current to charge the battery.

Resonance: The Efficiency Key

Early wireless chargers were slow and picky about alignment. Modern chargers use Resonant Inductive Coupling. By making both coils vibrate at the same frequency, we can transfer energy more efficiently and over slightly larger distances.

The Future: True “Over-the-Air” Charging?

We are currently moving toward RF-based charging, where your devices could charge from a hub across the room. It’s no longer just induction; it’s the future of a world without cables.

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References & Further Reading

• Khan Academy: Faraday’s Law
• Wireless Power Consortium: How Qi Works
• Popular Science: The Future of Charging