Wireless power transfer technology for electric iron based on multi-coils induction heating design

A wireless power transfer concept is applied to cordless ironing system by implementing induction heating techniques to enhance the mobility of traditional electric irons due to the restriction of the cable connection. The induction coils are particularly designed and the inductances of the coils in free space are also calculated and compared with measured values. The finite element method (FEM) analysis is adopted to study the inductance characteristics of the coils under the practical wireless power transfer challenge when the iron is placed above the coils at different locations on the ironing board. The comprehensive study also includes the associated driving circuit for the induction coils. The magnetic field and eddy currents distribution on the iron are then investigated based on FEM analysis under three situations, which facilitates the associated analysis of temperature rising processes on the iron. A prototype for the proposed induction iron system is developed and comprehensive experiments, including heating performance examination tests, electromagnetic interference tests as well as practical ironing work, are undertaken. The experimental results amply prove the theoretical analysis and confirm the validity and feasibility of the proposed induction iron system.