Design Of The Wireless Charging System For Mobile Phones

With the screen of phones getting bigger and functions more integrated, powerconsumption of mobile phones grow higher, so charging for mobile phones becomemore frequent. Cluttered wires and data lines have made the charging process veryannoying, so we need to find a more convenient way of charging. Wireless chargingtechnology for mobile phones is a technology that depends on magnetic coupling in thespace to transmit electrical power from power supplies to mobile phone batteries. Thisis a brand new way of charging, which overcomes the disadvantages of traditionalcharging methods, and enables users to make full use of fragments of time to chargetheir phones, so it makes the charging process more flexible, convenient and safe. Thisnew charging method has broad develop and implement prospects, so far it hasreceived extensive attentions from research institutions and enterprises, and there areeven some relevant products on the market now. Based on the researches of thewireless charging technology, this thesis designed a wireless charging system formobile phones. The research works in this thesis have some promoting effect onpopularizing and implementing the wireless charging technology, and can providesome references for the designing of wireless charging systems in the future.The main work and achievements are summed up as followed: described theworking principle of the wireless charging system, analyzed the functional andperformance requirements of the system, and brought up the design specifications;designed the main circuit and resonant circuit of the system and selected the control IC;designed a simplex communication between the power receiver and power transmitter,which enables the power receiver to send back communication signals to inform thepower transmitter about battery power needs and state of charge, the one waycommunication also formed a negative feedback closed loop in the system, whichenables the controller to take more precise control and therefore improve the transferefficient, and analyzed the modulation circuit in the Simulink to verify the modulationeffect; in order to overcome the disadvantages of wire-wound coils like high cost,inconvenient to assemble, complicated production process, bad consistency and so on,the paper designed a kind of PCB coils, which cost less, easier to produce and morelight and compact; designed an experimental wireless charging system for testing, thetest results indicated that the designed wireless charging system has met the engineering requirements.