The Firefly Lantern
You would not believe your own eyes...
When current flows in the large coils on the outside of the lantern, a magnetic field is created around them. If the current flow alternates, so does the orientation of this magnetic field.
Faraday's law of electromagnetic induction states that a changing magnetic field creates (induces) a voltage in a conductor
placed within the field. In this case, the alternating magnetic field produced by
the large coils induces a voltage in the tiny coils on each "firefly." With a large
enough change in the field, this induced voltage is sufficient to light up the LEDs connected to the coils.
This is exactly how wireless charging works. As an alternating current flows through a coil inside the charger, a voltage is induced in a coil inside your phone . As a result, current flows through the phone's coil, charging it.
Electromagnetic induction is also leveraged in electric generators, electric guitar pickups and microphones, transformers, magnetic chips in credit cards, and induction cooktops.
