New Localized Charging Principles for Planar Inductive Battery Platform for a Wide Range of Portable Electronic Loads

The large variety of battery chargers for portable electronic products such as mobile phones, MP3 players etc has led to huge amount of electronic waste in recent years and users’ inconvenience. One solution that can drastically reduce the number of chargers and unify the charging protocol is to develop a universal wireless battery charging platform (charging pad) on which more than one portable electronic device can be placed and charged simultaneously. The Principal Investigator previously developed an inductive charging pad that provides uniform magnetic flux over the entire charging surface of the charging pad and successfully demonstrated basic principle of this wireless battery charging pad concept. This project further studies a “new localized charging principle” that (a) enables only the local areas on which the loads are placed to be energized for energy transfer and (b) provides load detection, identification and battery charge monitoring functions. Such new localized charging principle can ensure maximum energy efficiency, minimized electromagnetic radiation and meet various international regulations for safety and human exposure to RF radiation.Planar contactless battery charging platform is an emerging technology that has the potential of unifying the charging protocols of portable consumer electronic products. This project involves:the theory on the optimal geometry and design of a planar winding array structure;a new matrix switching inverter system that can detect the loaded areas and select the appropriate windings for energy transfer; andnew bidirectional communication channel between the charging pad and the portable electronic equipment for load identification, compatibility check, data exchange and battery charge monitoring.The nature of the project is both basic and applied. It covers fundamental geometry problems of the windings, circuit topology and control, communication techniques, electromagnetic compatibility study, battery charging and monitoring.It is envisaged that this project will lay down the foundation for the design of a new generation of wireless battery charging platforms. The features of the charging pad developed in this project has the potential of forming an international charging protocol for future portable electronic products and open a door for designing water-proof products that cannot be charged by conventional chargers.