Wireless Power Transfer

This book describes an implementation of a wireless charger for USB consumer devices. The smart charger is able to automatically sense the presence of a nearby electronic device and detect its internal battery level. When the battery level of a USB device in proximity is dropped below a certain preset threshold, the smart charger will be initiated through an ultrasound communication system and start to charge the device. The charging process will be stopped automatically once the battery is fully charged. The automated charging capability avoids excessive charging power and makes the proposed charger eco-friendly. It is also a worry-free charge since users do not have to plug in a charger.