The Design of a Contactless Charger for Cellular Phones Based on Power Density

• Main Authors: Nan-Kuan Lian, 廖南寬
• Other Authors: Kai-Yuen Lam
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/19698290775332031000

碩士 === 義守大學 === 電子工程學系碩士班 === 96 === Contactless chargers use a detachable transformer to transmit energy through a magnetic inductive method. It induces a high magnetic flux leakage and reduces the energy coupling coefficient in the transformer. In this study, three different ways of series capacitors were added to form resonant circuits and improve the power transmission efficiency of inductive chargers. Furthermore, a half-bridge switching circuit, high-speed switching devices, and a full-wave rectifier were utilized to design a high power-density contactless charger. With the resonant capacitors added it improved the degradation from the leakage inductances and increased the power conversion efficiency. Meanwhile, the smoothness of the switching devices reduced the occurrence of electromagnetic interference. Based on the consideration of volume and cost of the charger adding only a resonant capacitor in all the circuit topogies studied on the primary side of the detachable transformer,is a potential charger for cellular phones.