English: An Apple iPhone whose battery is being charged on a wireless charging plate. Wireless charging is being used in the latest generations of smartphones to eliminate the need to plug a cable into the phone. The phone is simply placed on the charging plate. The plate senses the phone and begins the charging process. A high frequency alternating current flows through a coil of wire in the plate, creating an oscillating magnetic field that induces an alternating current in a second coil in the phone. This current is rectified to direct current and charges the phone's battery.