There are many ways to realize wireless charging technology, each with its own advantages. Common ones are:
Wireless charging technology (English: wireless charging technology; Wireless charging technology) originated from wireless power transmission technology and is divided into low-power wireless charging and high-power wireless charging.
Low-power wireless charging often adopts electromagnetic induction, such as Qi method for mobile phone charging, but ZTE's electric vehicle wireless charging adopts induction method. High-power wireless charging often adopts resonance type (most electric vehicles charge in this way). The power supply equipment (charger) transmits energy to the electric equipment, and the electric equipment uses the received energy to charge the battery and provide it for its own operation.
Because the charger and the electrical equipment transfer energy by magnetic field, there is no wire connection between them, so both the charger and the electrical equipment can be exposed without conductive contacts.
Basic principle of electromagnetic induction wireless charging technology
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. In fact, there is not much mystery in the technical realization of electromagnetic induction solution. As early as 65438+February 2005, China BYD Company applied for the patent of non-contact induction charger, which adopted electromagnetic induction technology.
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. The research team led by Marin Soljacic, a physics professor at MIT, used this technology to light a 60-watt light bulb two meters away and named it WiTricity. The coil used in this experiment has a diameter of 50cm and cannot be commercialized. If the coil size is reduced, the received power will naturally decrease.
Radio wave type
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.
reference data
Principle of wireless charging. Baidu Encyclopedia [reference time 20 18-4-5]