wireless charger

Wireless charging breaks the traditional method of direct contact transmission of electrical energy through wires, and belongs to non-contact transmission, which can avoid problems such as contact sparks, sliding wear, explosion and electric shock that may arise from contact based electrical energy transmission. There are three main types of wireless energy transmission methods: electromagnetic induction, electromagnetic resonance, and electromagnetic radiation. Electromagnetic induction is currently the most commonly used wireless power transmission method, and its technology has been mass-produced, with lower production costs than other technologies, and has been verified for safety and market performance. At present, there are three mainstream alliances dedicated to the development and standard setting of wireless charging technology, namely Alliance for Wireless Power (A4WP), Power Matters Alliance (PAM), and Wireless Power Consortium (WPC). The Qi standard is the "wireless charging" standard launched by WPC, which adopts the most mainstream electromagnetic induction charging technology currently available. The Qi standard mainly targets portable electronic products such as cameras, video and music players, toys, personal care, and mobile phones. At present, the research and design of low-power wireless chargers mainly focus on wireless charging for mobile phones, using TI's BQ500211 dedicated chip. Some low-power terminals also use dedicated integrated chips. Using dedicated integrated chips can save development time in the initial stage, but in the long run, it is not conducive to cost reduction and later expansion and upgrading. 

Although wireless charging technology has made some progress, there are still some thorny technical issues in the development process. Firstly, the charging efficiency is not high. Once the distance is slightly farther, the efficiency of charging will sharply decrease, requiring a lot of time and resources to complete charging, so the use is not very meaningful. Secondly, safety issues during the charging process. High power wireless charging devices generate a large amount of electromagnetic radiation, which has a certain adverse effect on physical health and can also interfere with aircraft, communication, and other systems. Thirdly, in terms of practicality. At present, wireless charging technology can only be achieved by fixing it at a fixed location, which is inconvenient and therefore not very practical. Fourthly, the price is expensive. Due to the fact that wireless charging technology is still in the preliminary research and application stage, the cost of research is relatively high, so the prices of its developed products are also relatively high.  

The MWC (Mobile World Congress) was held in Shanghai from February 23 to February 25, 2021. At this most influential communication industry event, OPPO unveiled the X2021 scroll concept phone, which also showcased its stunning wireless charging technology across the air. Unlike wireless charging that only existed in concept in the past, this hardcore technology from "Chengdu Intelligent Manufacturing" uses the "Rui Magnetic" air gap wireless charging solution, which is the world's first mobile phone air gap wireless charging with mass production possibility.