Development history of wireless charger

As early as the 1830s, Michael Faraday discovered that the magnetic field around him changed.

Chemistry will produce a current in the wire. In the 1890s, Serbian scientist Nikolai Tesla applied for the first patent.

Unfortunately, the research has been delayed for a century. The biggest obstacle is that the transmission efficiency is too low and dangerous. Electromagnetic radiation is only suitable for transmitting information, not for transmitting energy. Because radiation is directionless, energy will be wasted in useless space. It is envisaged to use directional electromagnetic radiation, such as laser, but its operability is not strong and it is very dangerous.

Professor Xu Shuyuan, Department of electronic engineering, City University of Hong Kong, has successfully developed a "wireless battery charging platform" in early years. He can put several electronic products on one charging platform without external wires, and charge them automatically through low-frequency electromagnetic field. The charging time is the same as that of traditional chargers. However, this technology still needs the product to contact with the charger, which mainly uses the principle of near-field electromagnetic coupling.

Researchers at the Massachusetts Institute of technology have made new progress in wireless power transmission. They use a power source two meters away to "separate" a 60 watt light bulb.

Soliacci's design, non radiation wireless energy transmission has a distance limit, the smaller the receiver, the shorter the distance. He calculated that objects the size of laptops can receive wireless energy transmission within a few meters, "so that a transmitter can be installed in each room, which can power the whole residential laptop. "

Soliacic hopes to increase efficiency to 70-80% by using different materials and improving technologies. They believe the improved device will charge laptops, mobile phones and other devices wirelessly within three to five years.