Wireless charging, also known as induction charging and non-contact induction charging, is a device that uses near-field induction, that is, inductive coupling, to transfer energy from power supply equipment (charger) to power consumption.

If there is a long distance between the charger and the electric device, the resonant inductive coupling design should be used.

The ways of wireless charging include electromagnetic induction, magnetic resonance, electric field coupling and radio wave transmission. The principle of electromagnetic induction is mostly used in the wireless charging of mobile phones.

Electromagnetic induction wireless charging, when the current of the power supply passes through the coil (the transmission coil of the wireless charger), a magnetic field will be generated, and other coils (the receiving coil of the mobile phone) that are not powered on will generate current near the magnetic field to charge the mobile phone.