Jul 306 mins read

Communication PLUS · Industry Deep | The highest power of wireless charging is limited by 50W?

Cover news reporter Xu Hai

On September 9th, vivo released the 2021 high -end flagship vivo X70 series. The top version was equipped with a 4500mAh battery and 55W wired charging. The wireless charging support maximum 50W;

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vivo X70 Pro+support 50W wireless flash charging

On August 17, the iQOO 8 Pro released by IQOO also used a 4500mAh battery, supporting 120W cable fast charging and 50W wireless fast charging;

The MIX4, the first under -screen camera, which was released earlier, also used 120W wired charging+50W wireless charging combination.

Starting in the second half of the year, the highest power of mobile phone manufacturers' new mobile phone wireless charging has "very tacit" to choose 50W. Is it technical bottleneck restriction? However, before the release of MIX4, Xiaomi showed 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

Cover reporters learned that the choice of 50W was inseparable from a regulation of the Ministry of Industry and Information Technology. On February 19, 2021, the Ministry of Industry and Information Technology publicly collected the opinions of the "Wireless Charging (Electric Transmission) Equipment) Equipment of Radio Management (Draft for Soliciting Opinions)" (hereinafter referred to as "Opinions"). Work in 100-148.5kHz, 6765-6795kHz, 13553-13567kHz band, and the rated transmission power does not exceed 50W.

Technical requirements for wireless charging equipment of the Ministry of Industry and Information Technology

The implementation time of this regulation was January 1, 2022, but in the second half of this year, no matter in the propaganda or actual product application, major mobile phone manufacturers have begun to consciously reduce the maximum power of wireless fast charging to 50W. Relevant sources in the industry revealed that although the documents are implemented next year, in fact, in the second half of this year, it has begun to restrain manufacturers. The promulgation of the opinion also means that the "inner roll" of mobile phone manufacturers on the charging power has ended at least at the wireless charging level.

In response to this opinion, netizens also started a fierce discussion. Most netizens choose to support the Ministry of Industry and Information Technology. They believe that 50W's wireless charging is enough. Weibo netizens@我 大 大 大 大 believe that "Wireless charging 50W is fast enough, and manufacturers should put their minds in other places that need to be improved and innovative, and while It is not just staring at the charging. "However, some netizens put forward different opinions on the opinion. Weibo netizens@不 不 believe that" this kind of thing should not be drawn in frames and let the company innovate independently. " In any case, technology still has to improve, even if you move forward, instead of killing it directly. "

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Discussion on netizens with 50W of wireless charging up to 50W

Wireless charging principle: electromagnetic induction

Many netizens have questioned, why should the rated transmission power of wireless charging restricting the rated transmission power of wireless charging? To answer this question, I have to mention the principle of wireless charging.

In fact, the principle of wireless charging technology originally originated from the wireless power conveying idea of Nicholas Tesla in 1890. The main theoretical basis is electromagnetic induction. The principle is to adjust the electrical sending end and the receiving end coil to a total magnetic resonance system. When the frequency frequency of the oscillating magnetic field generated by the sending end is consistent with the intrinsic frequency of the receiving end, the receiving end will resonate to achieve energy transmission.

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Tesla radio delivery idea

In the interview with the media, Professor Hong Xuemin, deputy dean of the School of Information, Xiamen University, used mobile phone wireless chargers as an example. There is a magnetic core in the wireless charger, with a coil around the outside. At the same time, there is also a corresponding receiving coil in the mobile phone that can receive the electromagnetic field sent by the charger. After a certain circuit processing, you can charge the phone. With the continuous development of charging technology, wireless charging has developed several methods such as magnetic resonance, electric field coupling, and radio wave transmission.

Professor Li Qingli, the School of Communication and Electronic Engineering of East China Normal University, and the key laboratory of multi -dimensional information processing in Shanghai, said: "The electromagnetic induction is the most mature and can be popularized on a large scale. It has strong adaptability to the environment. And it has realized commercialization and industrialization. "

Restriction of power reasons: Maintain the order of air radio waves

Why restrict the highest power of wireless charging, the opinions have also made a brief explanation. The introduction of the opinions is mainly to regulate the use of wireless charging equipment, avoid harmful interference to various types of radio business carried out in accordance with the law. develop.

Relevant experts said that the introduction of the opinions is mainly due to the similar frequency band of radio waves. It is very easy to cause interference. Now there are many communication equipment. The problem of radio wave interference in the air is very serious, and the emergence of wireless charging technology has exacerbated this complex situation.

Before the opinions were introduced, major manufacturers launched the 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 does not keep the mobile phone keeping high -power wireless charging at all times. 50W, 65W, 120W, etc. that manufacturers can achieve the peak of the charging transmission power that can be achieved in theory, with factors such as power changes, wireless wireless changes, wireless wireless The charging transmission power will change in real time.

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Smart mobile phone wireless flash charge

Therefore, for users, compared with the 50W wireless fast charging, the 120W wireless fast charge is not a double experience in the experience. For manufacturers, it can occupy the commanding heights in publicity; It will also bring hidden dangers in all aspects of product stability and safety.

Xia Chuanfang, a hardware development engineer of the Hardware Department of Nubia Technology Co., Ltd., believes: "Restricting the highest power can prevent everyone from unlimited competition, so as to better work hard on safety, performance and generality. At present, it has been batch in batches The maximum wireless charging power of mobile phone products is 50W. The Ministry of Industry and Information Technology solicited opinions based on this power. It should be approved. But whether the final power will be fine -tuned, and you need to wait for the final determination of the opinion draft. "

At present, the regulation is in the solicitation stage of the opinion. Before the formal implementation of the official implementation of experts, scholars, practitioners and other parties, it is unknown whether it is formally implemented before the formal implementation of experts, scholars, and practitioners. However, as most netizens say, science and technology will continue to improve in restrictions. With the advancement of technology, the upper limit of the 50W wireless charging transmission is not impossible.

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