0 1 pioneers who have fallen one after another
When it comes to wireless charging, the first thing that comes to mind is Samsung mobile phones. Indeed, Samsung is the first mobile phone brand to widely use wireless charging. Starting from Samsung S6, almost every generation of Samsung mid-to high-end mobile phones is equipped with wireless charging. However, S6 released on 20 15 is not the first mobile phone that supports wireless charging. As early as ten years ago, there was a "magic machine" that used this function by the way.
This phone is Palm Pre released by Palm in 2009. Like the card-type task background and full-screen gesture interaction that we are familiar with now, it is left over by its airborne system webOS; There are various epoch-making hardware such as luminous point, wireless charging, positive and negative data lines, and a dedicated magnetic palm Touchstone wireless charger with charging power of 5W. No wonder Lei Jun called it magic. However, Palm was acquired by Hewlett-Packard in the following year, and the response of several products launched afterwards was flat, and finally it was gradually submerged in the trend of iOS and Andriod.
Another mobile phone that supports wireless charging is Lumia 920 released by Nokia 20 12. Lumia 920, like Palm Pre, is equipped with a number of groundbreaking technologies: the first mobile phone with optical anti-shake components in the camera in the industry, and the second mobile phone supporting Qi standard wireless charging (the first one is Sharp SH- 13C), which brings wireless charging into public view ... With the demise of the Windows Phone ecosystem, Nokia's mobile phone business has also come to an end.
In addition to these two foreign brands, the first domestic mobile phone supporting wireless charging is Gionee M7 Plus released on 20 17, namely 14W wireless fast charging. Unfortunately, after Li Jing released this mobile phone, she began to decline, gradually faded out of the mobile phone market and eventually went bankrupt.
02 AirPower, dystocia for many years.
From technology exploration to fast charging, wireless charging attracts the "dedication" of pioneers from generation to generation. It happens from time to time that the first mobile phone manufacturer who ate the crab of wireless charging sacrificed to heaven halfway. This is of course only a small probability event, which has nothing to do with technology. But on the one hand, it also implies that wireless charging is not a good way.
Apple in the post-Jobs era is relatively conservative in the follow-up of new technologies. Apple Watch released on 20 15 is the first Apple device to support wireless charging. After three generations of wireless charging on Apple Watch, it was not until iPhone X/iPhone 8 of 20 17 years that Qi 1. 1 standard 7.5W wireless charging was supported. Also in this year, Apple put forward the concept of AirPower charging pillow.
The biggest highlight of AirPower is that it can place charging devices at will, allowing users to charge devices that support wireless charging such as iPhone, Apple Watch and AirPods at the same time. In order to realize "multiple devices can be placed at will", for the first time, Apple built 22 sets of overlapping induction coils in AirPower. However, due to the mutual interference between coils, the equipment heats up. Overheating also caused AirPower to skip tickets continuously at 18 and 19, and we didn't have a chance to see it until this autumn's Apple conference.
Household wireless charging with electricity as king
Whether it's a steady Samsung or an experience-oriented Apple, the wireless charging power of mobile phones has not exceeded 1.5w for many years, and Apple is sticking to the food and clothing line of 7.5w. High power means uncontrollable heating problems and higher patent pool fees. However, domestic mobile phone manufacturers do not think so. 20 17, Gionee M7 Plus, the first domestic wireless charging mobile phone, has a dry power of 14W. Since then, the concept of the sooner the better has taken root in the hearts of domestic manufacturers.
Compared with the current 15W Qi standard wireless fast charging, the domestic wireless fast charging can be described as eight immortals crossing the sea. Almost every manufacturer can come up with their own private wireless charging protocol. Huawei's wireless SuperCharge, Xiaomi's wireless flash charging, Meizu's super wireless mCharge, OPPO's AIRVOOC, and Warp's wireless flash charging. The lowest power is 27W, and the highest power is 50W of Xiaomi 10 Pro+. Even VIVO, which has been watching, has demonstrated 60W wireless charging on APEX 2020.
Domestic mobile phone wireless charging technology can be running all the way on the road of power stacking, or will benefit from the application of charge pump technology. At present, there are two commonly used fast charging schemes: high voltage and low current, and low voltage and high current to improve charging power. Charge pump technology can realize high voltage and high current simultaneously. The principle is to use capacitor as energy storage element for voltage conversion. Xiaomi 9 adopts this wired fast charging technology to increase the wireless charging power to 20W. The charge pump technology does not change the principle of electromagnetic induction wireless charging, so it can also support the Qi wireless fast charging standard.
04 consumes 47% more power than wired charging.
Wireless charging uses the principle of electromagnetic wave induction to charge, and the principle is similar to that of transformer. There is a coil at the sending end and the receiving end, and the coil at the sending end is connected with a wired power supply to generate electromagnetic signals, and the coil at the receiving end induces the electromagnetic signals at the sending end to generate current. There are four ways to realize wireless charging technology: electromagnetic induction, magnetic field vibration, radio wave and electric field coupling. However, due to the limitation of technology and cost, all mobile phone wireless charging technologies are based on electromagnetic induction.
When it comes to wireless charging, the problem of conversion efficiency is unavoidable. Based on electromagnetic induction wireless charging, the theoretical charging efficiency reaches 80%. But this is only theoretical efficiency, and the actual situation must be discounted. On-line test data show that under the condition of 220 AC V, when 30W wireless VOOC flash charging is turned on, the output power of the charging terminal is as high as 42.62W, which is far lower than the conversion efficiency of 80%. This brings the problem of power consumption.
According to the latest estimation of OneZero and iFixit team, the power consumption of wireless charging method is much lower than that of wired charging method. After comparing the wireless and wired charging of Pixel 4 for many times, it is found that wireless charging uses 47% more power than wired charging on average. Average demand14.26 wh; Fully charge the mobile phone by wired means. Wireless chargers need an average of 2 1.0 1 Wh. This amount of electricity seems insignificant, but if many devices and terminals use wireless as the main charging method in the future, the power consumption will be very considerable.
05 wireless charging, which one is only enough for mobile phones?
According to IHS data, it is estimated that by 2020, the shipment of wireless charging receivers will exceed 654.38+billion pieces, and the transmission end will reach about 500 million pieces in 2026.5438+0. It is predicted that the global wireless charging market will grow from 15 to1500 million in 2024, with a compound annual growth rate of 27%. Of course, most of these 654.38 billion wireless charging receivers are not mobile phones, among which small Internet of Things devices such as smart wearable devices and new energy vehicles are the main ones.
As far as mobile phones are concerned, the main application scenario of wireless charging has never been from minimum charging to Wally, but "keeping enough power at any time". Pick up your mobile phone occasionally at work, and don't worry about the power of your mobile phone when you get off work; Put down your mobile phone before going to bed, and you can sleep peacefully. To sum up, wireless charging of mobile phones has three advantages: one is to keep the device fully charged by debris time, the other is to protect the "chrysanthemum", and the third is that there is no wire binding, so it can be carried around.
So no matter how high the wireless charging power of the mobile phone is, it is actually a chicken rib function for most people. Moreover, the general wireless charging function is only carried on the flagship model, and even fewer users can be covered.
Wireless reverse charging and NFC charging can be expected in the future.
Contrary to mobile phones, the demand for wireless charging of wearable devices is very strong at present. Smart watches and TWS headset charging boxes are basically equipped with wireless charging function as standard. Most of these products have limited battery capacity, so they are not so sensitive to charging power, and even charging with NFC can satisfy them. Now Android phones basically support wireless reverse charging. Xiaomi 10 Pro+ achieves the reverse charging power of 10W, which can easily charge small IOT devices such as TWS earphone box, and can also "fast charge" Apple wirelessly.
Instead of engaging in high-power private wireless charging standards, I think the introduction of NFC charging standards is of greater significance to the entire wireless charging ecology. The NFC charging standard introduced in May adopts the basic frequency of 13.56 MHz, and supports four power transmission levels of 250, 500, 750 and 1000 MW. The power of 1W can be ignored, but the usability problem is solved.
NFC charging standard is very suitable for small IOT devices with small battery capacity. Wireless charging can be realized without additional coils and peripheral circuits, which reduces the cost and makes the equipment smaller. For mobile phones, the NFC charging standard can also reduce the wireless charging function to a thousand yuan level. At present, the mobile phone equipped with NFC function has great popularization significance, and it also makes wireless reverse charging easier. The combination of wireless reverse charging and NFC charging should accelerate the popularization of wireless charging. Future wireless life can be expected.
By the way, is your mobile phone wirelessly charged?