Load induction

Answer

Inductive charging is based on the Faraday-Lenz law. A changing magnetic field produces an electric field. This causes a current in a conductor. That variable magnetic field can be caused by a moving permanent magnet or by a variable current.

You place two loops close together. In one you send an alternating current. See creates a variable magnetic at the location of the second loop, where a current can flow.. .

In this way you transfer energy from one circuit to another, without electrical contact. Electric toothbrushes suffer in this way, as do pacemakers and cochlear implants.

http://micro.magnet.fsu.edu/electromag/java/lenzlaw/index.html