A wireless charging circuit design using MSP430F2274

　　The MSP430F2274 ultra-low power microcontroller is used as the monitoring and control core of the wireless energy transfer charger. The charging speed is selected by the switch to realize the functions of fast charging and normal charging. When the power is full, a full prompt is given and charging is automatically stopped. The wireless charging system mainly adopts the principle of electromagnetic induction, and energy is transferred through energy coupling through coils. When the system is working, the input end converts the AC mains into DC through a full-bridge rectifier circuit, or directly powers the system with a 24V DC terminal. When the receiving coil is close to the transmitting coil, an induced voltage is generated in the receiving coil. When the resonant frequency of the receiving coil loop is the same as the transmitting frequency, resonance is generated, and the voltage reaches the maximum value, which has the best energy transmission effect. Through the coupling of energy by two inductor coils, the current output by the secondary coil is changed into DC power through the receiving conversion circuit to charge the battery. The AC and DC input uses a single-pole double-gate relay. When AC is powered on, the normally open is closed, and the normally closed is opened to realize AC priority. When the AC power is off, the relay is powered off, and the normally closed is closed to realize automatic switching. When switching, the time is very short, and C1 can provide a certain amount of power for a certain period of time, which can realize non-stop switching without affecting charging.