Wireless charging history

As early as the 1930s, Michael Faraday discovered that changes in the surrounding magnetic fields would generate currents in the wires. In the 1990s, Serbian scientist Nikola Tesla applied for the first patent.

Unfortunately, this research has been delayed for a century. The biggest obstacle is the low transmission efficiency and danger. Electromagnetic radiation is only suitable for transmitting information and is not suitable for transmitting energy. Because radiation is not directional, energy will be wasted in useless space. Some people think of the use of directional electromagnetic radiation, such as lasers, but their operability is not strong and dangerous.

Prof. Xu Shuyuan of the Department of Electronic Engineering of City University of Hong Kong successfully developed the “Wireless Battery Charging Platform” in the early years. Several electronic products can be placed on a charging platform. No external wires are needed. Automatic charging through low-frequency electromagnetic fields, charging The time is no different from traditional chargers. However, this technology still requires the product to contact the charger. It mainly uses the near-field electromagnetic coupling principle.

Researchers at the Massachusetts Institute of Technology have made new progress in wireless power transmission. They used a power source two meters away and lit a 60-watt bulb across the "ground".

Sorjačić's design has limited distances for non-radiative wireless energy transmission. The smaller the receiver, the shorter the distance. He calculated that laptop-sized objects can receive wireless power transmission within a few meters, so that installing an emitter in each room would power the entire home's laptop.

Soryacchi hopes to increase efficiency to 70% to 80% through the use of different materials and improved technologies. They believe that the improved device will wirelessly charge laptops, mobile phones and other devices in 3 to 5 years.