Cover news reporter Xu Hai
On September 9, Vivo released the 2021 high-end flagship vivo X70 series, the top version is equipped with a 4500mAh battery and a 55W wired charge, and the wireless charging support is up to 50W;
Vivo X70 Pro+ supports 50W wireless flash charging
On August 17, iQOO released the iQOO 8 Pro, which also uses a 4500mAh battery, supporting 120W wired fast charging and 50W wireless fast charging;
The MIX4, Xiaomi's first off-screen camera phone released earlier, also uses a wireless charging combination of 120W wired charging + 50W.
Since the second half of the year, the highest power of mobile phone manufacturers' new mobile phone wireless charging has been "very tacitly" selected 50W, is the technical bottleneck limit? However, long before the release of mix4, Xiaomi had demonstrated the 120W wireless fast charging technology in a small range.
Ministry of Industry and Information Technology: The upper limit of wireless charging transmission power is 50W
The cover news reporter learned that the choice of 50W is inseparable from a regulation of the Ministry of Industry and Information Technology. On February 19, 2021, the Ministry of Industry and Information Technology publicly solicited opinions on the Interim Provisions on radio management of wireless charging (power transmission) equipment (draft for comments) (hereinafter referred to as the "Opinions"), which stipulates that mobile and portable wireless charging equipment should work in the frequency bands of 100-148.5kHz, 6765-6795kHz, 13553-13567kHz, and the rated transmission power shall not exceed 50W.
Technical requirements for wireless charging equipment of the Ministry of Industry and Information Technology
The implementation of this regulation is January 1, 2022, but in the second half of this year, whether in publicity or actual product applications, major mobile phone manufacturers have begun to consciously reduce the maximum power of wireless fast charging to 50W. Industry insiders revealed that although the document provisions are implemented next year, in fact, the second half of this year has begun to restrict manufacturers in practice. The promulgation of the opinions also means that the "inner volume" of mobile phone manufacturers in charging power has ended, at least at the level of wireless charging.
In response to this opinion, netizens also launched a fierce discussion. Most netizens choose to support the ministry of industry and information technology regulations, think that 50W wireless charging is enough, Weibo netizen @ I do not o from the heart that "wireless charging 50w is fast enough, manufacturers should put their minds on other places that need to be improved and innovated, rather than just staring at charging"; however, some netizens put forward different views on the opinion, Weibo netizen @ Zizhan neutral believes that "this kind of thing should not draw a frame, let enterprises innovate independently", Zhihu netizens believe that "no matter what, technology still has to progress, Even a small step forward, not just killing it."
Netizen discussion about the wireless charging limit of 50W
Wireless charging principle: electromagnetic induction
There are also many netizens who have questioned why they should limit the rated transmission power of wireless charging? To answer this question, we have to mention the principle of wireless charging.
In fact, the principle of wireless charging technology originated from the wireless power transmission concept of Nikola Tesla in 1890, and the main theoretical basis is electromagnetic induction. The principle is to adjust the coil of the electrical energy transmitter and the receiving end into a common magnetic resonance system, when the oscillating magnetic field frequency generated by the transmitting end is consistent with the natural frequency of the receiving end, the receiving end will resonate, thereby realizing the transmission of energy.
Tesla wireless power delivery idea
Professor Hong Xuemin, deputy dean of the School of Information of Xiamen University, in an interview with the media, took the mobile phone wireless charger as an example to explain that there is a magnetic core in the wireless charger, the outer circle is wrapped around the wire circle, and the current inside the charger will generate an induced magnetic field when it passes through the coil, at the same time, the mobile phone also has a corresponding receiving coil, which can receive the electromagnetic field emitted by the charger, and then after a certain circuit processing, it can charge the mobile phone. With the continuous development of charging technology, wireless charging has developed several ways such as magnetic resonance, electric field coupling, and radio wave transmission.
Professor Li Qingli of the School of Communication and Electronic Engineering of East China Normal University and the Shanghai Key Laboratory of Multi-dimensional Information Processing said: "Electromagnetic induction is the most mature and large-scale popularization method at present, it has a strong adaptability to the environment, and has achieved commercialization and industrialization. ”。
Reason for limiting power: maintaining the order of airborne radio waves
Why limit the maximum power of wireless charging, the opinions also made a brief explanation, the introduction of the opinions is mainly to standardize the use of wireless charging equipment, to avoid harmful interference to all kinds of radio services carried out according to law, to maintain the order of air waves, and to promote the healthy development of the wireless charging industry.
Relevant experts said that the introduction of opinions is mainly because the similar frequency bands of radio waves are very easy to produce interference, and now there are many communication equipment, and the problem of mutual interference of radio waves in the air has been very serious, and the emergence of wireless charging technology has exacerbated this complex situation.
Before the opinions were introduced, major manufacturers launched a competition on the highest power of wireless charging, and the pursuit of higher power wireless charging technology became the focus of competition. However, the actual test shows that the so-called high-power wireless charging, can not let the mobile phone always maintain high-power wireless charging, manufacturers advertised 50W, 65W, 120W, etc. is only theoretically able to achieve the peak of charging transmission power, with the change of power and other factors, wireless charging transmission power will change in real time.
Wireless flash charging for smartphones
Therefore, for users, compared with 120W wireless fast charging and 50W wireless fast charging, the experience is not a double experience on the number, but for manufacturers, it can occupy the commanding heights in the publicity; in addition, the competition of charging power will also bring hidden dangers in terms of product stability and safety.
Xia Chuanfang, hardware development engineer in the hardware department of Nubia Technology Co., Ltd., said: "Limiting the maximum power can avoid unlimited competition for higher power, so as to better work on security, performance and versatility." At present, the mobile phone products listed in batches, the maximum wireless charging power is 50W, and the Ministry of Industry and Information Technology solicits opinions based on this power, which should be passable. However, whether the final power will be fine-tuned still needs to wait for the finalization of the opinion draft. ”
At present, the provision is in the stage of soliciting opinions, and the opinions of experts, scholars, practitioners and other parties will be accepted before the formal implementation on January 1, 2022, and it is not known whether specific adjustments will be made for the formal implementation. However, as most netizens said, technology will continue to advance in the limit, and with the advancement of technology, it is not impossible for the 50W wireless charging transmission ceiling to be raised.
<b>[If you have a news thread, please report to us, once adopted, there is a fee reward.] WeChat attention: ihxdsb, QQ: 3386405712].</b>