Wireless charging methods include electromagnetic induction, magnetic vibration, electric field coupling and radio wave transmission. Most wireless charging of mobile phones uses the principle of electromagnetic induction.
In electromagnetic induction wireless charging, when the current from the power supply passes through the coil (the power transmitting coil of the wireless charger), a magnetic field will be generated, and other non-energized coils (the power receiving coil on the mobile phone) will generate a magnetic field when they are close to it. current to charge the mobile phone.
1. Advantages of wireless charging: Safety: No energized contact design can avoid the risk of electric shock. Durable: The power transmission components are not exposed, so they will not be corroded by moisture, oxygen, etc. in the air; there are no contacts, so there will be no losses caused by mechanical wear and flashover during connection and separation. Convenience: No need to connect with wires when charging, just place it near the charger, no need to occupy multiple power sockets, and no need for multiple wires to be entangled with each other.
2. The disadvantage of wireless charging is that the efficiency is slightly lower: Generally, there is a transformer in the charger, but the wireless charging transformer composed of a transmitting coil and a receiving coil has structural limitations, so the energy transmission efficiency will theoretically be slightly lower. Lower than the average charger. Slow charging speed: Since most current receiving devices such as mobile phones limit the input power, the charging speed is slow. High cost: The charger needs an electronic circuit to drive the coil, and the power receiving device needs an electronic device for power conversion. Both need coils, and high-frequency filter circuits are needed to meet electromagnetic compatibility, so the cost ratio is direct Charging is higher.