Winding structure and circuit design of contactless power transfer platform

Universal contactless battery charging platform is an emerging technology for charging different portable electronic devices simultaneously. In this paper, a simple winding method using a single winding is proposed to achieve a near uniform magnetic field distribution above the charging surface. Circuit analysis for identical multi-loads application is performed, through which characteristic curves of different parameter variations can be obtained. Based on the analysis, a design method that can help to achieve a high power factor with different load number is proposed. The detailed design procedure is given. Finally the winding structure and the design method are experimentally tested by a prototype.