Wireless Charging Coils
1. How do Wireless Charging Coils Work?
The wireless charging coil realizes energy transmission based on the principle of electromagnetic induction. The transmitting coil generates an alternating magnetic field through alternating current, and the receiving coil couples the magnetic field and converts it into current output. The system usually contains a resonant circuit (such as a parallel resonant structure) to improve the efficiency and stability of energy transmission. High-frequency carriers (such as 2MHz) are often used to optimize long-distance transmission performance.
2. What are the Main Components and Characteristics of Wireless Charging Coils?
1) Material and Structure
Usually wound with copper wire because of its good conductivity and low resistance loss;
Common forms include air-core coils and magnetic core coils, with typical sizes such as 30×10×0.52mm elliptical design;
The receiving coil integrates a rectifier circuit to convert AC power into DC output.
2) Key Parameters
Inductance Value: Typical range 10–50μH, directly affects the resonant frequency matching;
Quality Factor (Q value): Reflects the energy storage and loss ratio, the higher the better the efficiency;
Self-resonant Frequency (SRF): Needs to be higher than the operating frequency to avoid the influence of parasitic capacitance;
Output Power: Covers 5–100W, suitable for scenarios from mobile phones to electric vehicles.
3. What are Wireless Charging Coils Used for?
Consumer Electronics: Mobile phones, smart watches, TWS headphones and other portable devices;
Industrial Equipment: Drones, AGV automatic guided vehicles;
Automotive Electronics: On-board wireless charging systems and electric vehicle charging bases.
4. Technical Standards and Optimization Directions of Wireless Charging Coils
Compatible Standards: Support WPC Qi, AirFuel, NFC, and other protocols;
Multi-coil Array: Improve the fault tolerance of the charging position through a multi-coil layout;
Safety Mechanism: Integrated overcurrent/overheating protection circuit to ensure charging safety.
5. Development Trends of Wireless Charging Coils
Reducing energy loss through resonant coupling technology and introducing intelligent control algorithms to achieve dynamic power adjustment will further expand the application of medium and long-distance wireless charging.