A Dual-Mode Wireless Charger Based on Cascaded Rectifier and Hybrid Compensation

A dual-mode wireless charger is developed by using hybrid compensations and cascaded rectifiers. The proposed system functions as a constant voltage source with passive overload protection. The AC characteristics of the resonant tank are analyzed through a circuit model, enabling the derivation of the critical load resistance and explanation of the working mechanism of normal and protection modes. Experimental results are presented to justify the voltage variation, efficiency characteristics, and dynamic response. The demonstrated 30-W system achieves a stable output voltage and 92% efficiency. Furthermore, overload protection is naturally enabled with fast transients (27 ms). Overall, the proposed system offers an efficient and reliable solution for wireless charging with passive overload protection.