Wireless charging technology originated from wireless power transmission technology and can be divided into two ways: low-power wireless charging and high-power wireless charging. Electromagnetic induction is often used for low-power wireless charging. High-power wireless charging often uses resonance mode to transmit energy from power supply equipment (charger) to electrical equipment, which uses the received energy to charge the battery and provide it for its own operation.
fundamental principle
1, electromagnetic induction type
Alternating current with a certain frequency in the primary coil generates a certain current in the secondary coil through electromagnetic induction, thus transferring energy from the transmitting end to the receiving end. At present, the most common charging scheme is electromagnetic induction. As early as June, 5438+February, 2005, BYD Company in China applied for the patent of non-contact induction charger and used electromagnetic induction technology.
2, magnetic field * * * vibration
It consists of an energy transmitter and an energy receiver. When two devices are tuned to the same frequency or vibrate at a specific frequency, they can exchange each other's energy. This is a technology being studied before a project. A research team led by a physics professor at Massachusetts Institute of Technology (MIT) used this technology to light a 60-watt light bulb two meters away and named it WiTricity.
3. Types of radio waves
This is a mature technology, similar to the crystal receiver used in the early days. It is mainly composed of microwave transmitter and microwave receiver. It can capture the energy of radio waves bouncing off the wall and keep a stable DC voltage while adjusting according to the load. This method only needs a transmitter installed on a wall plug and a "mosquito" receiver that can be installed on any low-voltage product.