Situations arise when the cable for charging a gadget cannot provide power due to the fact that there is no outlet or there is no electricity. Then on help will come wireless phone charger that works autonomously and does not take up much space.
How does a wireless phone charger work?
The operating principle of the device is based on QI technology. It involves the absence of wires or the use of contacts; its operation is based on the action electromagnetic waves. The question of how wireless charging works can be answered - according to the principle of an inductive coil, magnetic circuit. The device consists of 2 coils - transmitting and receiving, the first is needed to create electro magnetic field, and the second is for current. Interacting with each other, they create a current through the transmitter, receiver, stabilize it, bringing it directly to the smartphone.
To charge your phone, you just need to place it on a special stand. Charging can be carried out and maintained anywhere - at home, in the car, or taken with you on trips or long trips. Some countries install similar devices in cafes, when a person arrives there, and while waiting for an order, charges the phone. It turns out simple, fast, convenient.
What are the advantages of a wireless charger?
The advantages of the charger include:
- ease of use when it can be used at home, in the car or in a cafe;
- the ability to charge several gadgets at the same time;
- phones with wireless charging are increasingly being released;
- the charge is made at a distance of up to 4 cm or closer;
- charging consumes the minimum possible energy;
- its electromagnetic field is safe for humans;
- for some models it is sold immediately as a set with a cell phone, so as not to buy additionally;
- automatically turns off when reaching 100% charge;
- low cost, long shelf life.
How effective is a wireless phone charger?
Wireless phone charging is not without its disadvantages:
- Through it you can recharge only certain models of gadgets. So, you can’t charge an iPhone through it, but Samsung Galaxy or Nexus is possible.
- To charge some smartphone models, you will have to buy a special case through which the process will be performed. This includes certain costs.
- Wireless charging your phone charges at a slower rate than using a standard cable.
- While charging, the device and gadget become very hot.
- When charging, the mobile phone may receive distorted radio signals.
Where to buy and how much it costs
Portable phone chargers are sold in regular electronics chains or online stores. The range of prices in electronics stores varies depending on the manufacturer: for universal chargers the cost ranges from 2 thousand to 2500 rubles, for branded ones - from 3 thousand rubles. In online stores you can buy a device much cheaper: for universal ones they ask from 900 to 2 thousand rubles, but branded ones are not sold or are offered at the same price as in large chains.
For those who want to save money, there is the option of making such a device with your own hands. If you are well versed in electronics and radio engineering, then it will not be difficult for you to find manufacturing diagrams that are on the network or available sources, purchase parts, and make your own device. A self-made charger will cost less, and will work no worse than the factory one.
Video: DIY wireless charging
Apple has named its new iPhone 8/8 Plus and iPhone X smartphones as almost the main feature of the devices as support for the Qi standard wireless charging function. Also unveiled is the Air Power wireless charging mat, which allows you to simultaneously charge your smartphone, Apple Watch and wireless headphones AirPods. Wireless charging is slowly becoming a standard feature for A-brand flagships and beyond.
But is Apple's solution so revolutionary? How does wireless charging work in practice? About this and we'll talk in the article.
How wireless charging works
Most wireless chargers use magnetic induction and magnetic resonance. They suggest placing the gadget on a special surface for automatic charging, without the need to connect a cable to the device.
Of course, wireless charging isn't truly wireless. Your phone, smart watch, tablet does not need to be connected to the charger, but the wireless charger itself still needs to be connected by cable to the power adapter or USB port.
How Apple's opinion on wireless charging has changed
When Apple introduced the iPhone 5 without support for wireless charging, at the same time smartphones on competing Android and Windows platforms had modules built into many flagship models. But Apple's Phil Schiller that "creating a separate charger that you have to plug into an outlet is actually, for most situations, more complicated." That is, in Cupertino they didn’t even think about wireless charging, dismissing this possibility in the bud.
Five years later, Apple changed its mind. With iPhone 8, iPhone 8 Plus, and iPhone X, Apple includes support for wireless charging using open standard Qi (pronounced "shi" because it is Chinese word, which refers to " vital energy"in living things.).
Qi wireless charging
Wireless chargers in this moment use the phenomenon of magnetic induction. Simply put, they use magnetism to transfer energy. First, you place a device, such as a smartphone, on a wireless charger. Current from the wall outlet passes through a coil in the wireless charging module, creating a magnetic field. The magnetic field creates a current in a coil inside the smartphone. This magnetic energy is converted into electrical energy, which is then used to charge the battery. Devices must have the appropriate hardware to support wireless charging. That is, a device without the necessary coil inside the case cannot be charged wirelessly. 
While the Qi standard's operating range was originally limited to a small magnetic field range, it now also supports the use of magnetic resonance phenomenon. It works in a similar way, but the gadget being charged can be located up to 45 mm from the surface of the wireless charger, and not touch it, as was before. This method is less efficient than the magnetic induction method, but there are some advantages - for example, the wireless charger can be installed under the surface of the table, and you can place the gadget with the receiver on the table to charge it. It also allows you to place multiple devices on one charging pad and each of them will be charged in parallel.
A little about the system's power consumption. When gadgets are not charging, the Qi charger does not consume a large number of electricity. A special low-power module monitors this moment and turns off the current to the coil, but when it detects that a gadget that requires charging is placed on the charger pad, it increases the output power of the magnetic field.
Competitors of the Qi standard
Wireless charging is becoming more common and more thoroughly standardized. And this time, Apple didn't create its own wireless standard. Instead, it decided to support the existing Qi standard, which also supports many third-party devices.
Power Matters Alliance (PMA)
However, Qi run by the Wireless Power consortium, the most widespread at the moment, but it is not alone. In second place -Power Matters Alliance, or PMA standard. It uses magnetic induction, just like Qi. However, these two standards are incompatible. New iPhones and other Apple products cannot be charged using the PMA wireless charger.
But some devices on the market are compatible with both standards. Modern smartphones such as Galaxy Note 8, Galaxy S8 and Galaxy S7, in fact, support both Qi and PMA, so they can be charged from any charger. Starbucks ( world wide web cafe)previously relied on PMA, but now there is an option that it can rethink the situation, since the iPhone only supports Qi.
Apple is confident that in the near future many airports, hotels and other public places will also rely on Qi. That is, most likely there will be devices from other manufacturers that support wireless charging of this standard. As practice shows, this will probably actually happen.
Alliance for Wireless Power (A4WP)
There is a third competitor to the Qi standard. This Alliance for Wireless Power (A4WP), which uses Rezence technology in its work. The essence of the operating principle of the standard is to use the magnetic resonance effect, which will expand the charging area for several devices. You can place multiple gadgets on one charger, move them around, and even charge them through an object such as a book. Rezence technology requires a Bluetooth connection to your device to work.
AirFuel Alliance
Realizing that the Qi standard is the most popular on the market, the competitors decided to unite. This is how a new education appeared AirFuel Alliance, which has been promoting its wireless charging technologies since 2015. The consortium included 195 companies. The most interesting thing is that the AirFuel Alliance has secured the support of Intel, which suggests that everything is serious and here to stay. Well, competition is always good for users, because it is the engine of progress.
What devices can you use wireless charging with today?
I am sure that many users ask themselves this question. After all, everyone wants to try how wireless charging actually works, and whether it is as convenient as the developers say.
I have quite a lot of experience using wireless charging. You will be surprised, but it’s been almost 5 years. My good old Nokia Lumia 820 supports wireless charging. Back in December 2012, when I purchased a smartphone, I received an additional accessory that made it possible to use wireless charging for this smartphone.
True, in order for the Nokia Lumia 820 to be charged wirelessly, it was necessary to buy a special back cover. From personal experience I can say that using wireless charging is very convenient and practical. Place your smartphone on a special surface and it will begin to receive energy to charge the battery. It is worth noting that there are also unpleasant sides to using wireless charging from Nokia. Let's start with the fact that in this case the smartphone body heats up quite noticeably, and the charging process itself is much slower than when charging via a cable.
Unfortunately, the story of Microsoft smartphones seems to be over. But you still have the opportunity to try wireless charging.
Over the past few years, Android smartphone manufacturers have been increasingly installing wireless charging in their devices. For example, Google does not offer it on its Pixel smartphone, although previously some devices in the Nexus line supported this function. Of the A-brands, only Samsung has retained wireless charging capabilities in its latest flagship models.
But with Apple's move to give the Qi standard a vote of confidence, wireless charging may become more common, including on Android devices.
However, you can already buy a smartphone that supports wireless charging. This Samsung Galaxy Note8 and Galaxy Note 5,Galaxy S8, S8+, S8 Active, S7, S7 Edge, S7 Active,LG G6 (US and Canada version only) and LG V30,Motorola Moto Z, Moto Z Play, Moto Z2 Force, Moto Z2 Play (only with wireless charging module), and of course the new iPhone 8, 8 Plus, X (10). As you can see, there is quite a large selection, from different brands and on different platforms.
Even if your smartphone does not support wireless charging, you can add support for this function using a special case. Also, in some cases, it is possible to use a wireless charging adapter, which is attached to the back of the gadget and connected to the power port.
And now the most important thing. In order to charge your smartphone using wireless charging, of course, you first need to purchase a charger that will support the Qi standard. You can find such devices in various online stores, such as, Aliexpress, eBay and others. After purchasing a device in a store, connect it to a power outlet and place your smartphone on a special platform. Now it will charge wirelessly, just like you wanted.
Results
Something tells me that the appearance of wireless charging functions in the new iPhones will give impetus to the development of this segment of the IT industry. Very soon we will see a situation where all flagship smartphones will begin to support wireless charging technology by default. And then it may come to budget devices. So we're in for some interesting times.
Science fiction writers assumed that beginning of XXI century, humanity will easily leave the atmosphere, and in Everyday life use flying cars. Their calculations were quite fair, because having first taken off in an airplane in 1903, on April 12, 1961, a man made the world’s first flight in space. But life decreed otherwise, and humanity took the path of developing personal electronics, a thing that not a single “dreamer” could guess.
Essential devices
Behind a short time phones have turned into completely futuristic and irreplaceable devices that help a person in all aspects of life, with which he does not part even in his sleep.
But one thing has always made the idyllic picture of the new wonderful world harsh satire and parody of it - this, of course, is a battery. If in the era mobile phones Somehow we managed to keep the device alive for a week, but today the smartphone barely manages to maintain its functionality during the day. And these modest figures are achieved only thanks to breaks in using the smartphone.
The actual operating life of a phone today does not exceed 3-4 hours. Initially, manufacturers followed the most logical path to increasing battery capacity, but it turned out to be a dead end, because buyers did not want brick phones that looked like walkie-talkies for war heroes, but wanted the weightless, thin devices of Star Trek heroes.
Then the manufacturers took a different path: since we can’t increase the battery life, they thought, let’s make charging so effective that people will be happy once again charge the phone.
The Birth of Wireless Charging
This is how Quick Charge and wireless charging technologies were born. And, if the first technology did not provide a fundamentally new experience, then the second, at least outwardly, finally became the breakthrough that everyone had been dreaming about for so long. After all, charging the phone by simply placing it on the table brought us closer to the future.
Let's see what the essence of this technology is. And we will learn about its disadvantages, because the advantages are obvious.
The first phone with wireless charging appeared back in 2009. It was the legendary Palm Pre (a phone that claimed to be the phone of the future, but ultimately buried Palm). Since then, technology has changed significantly, but the principles of inductive charging, familiar to users of electric toothbrushes 27 years ago, have not gone away.
These are still two induction coils connected to a power source, in which a magnetic field appears perpendicular to the turns of the coil. Thus, if you place two coils within the range of the magnetic field (and at the same time connect one of them to a power source), then voltage will appear in the second coil. It is important to take into account the fact that the two induction coils should never touch each other. This elementary principle underlies the operation of all devices.
Wireless Electromagnetic Energy Standards
The basic operating principles of wireless devices have been standardized by the Wireless Power Consortium. As a result, the Qi wireless communication standard emerged (in Russian it is read as Qi or Chi, in Japan they say Ki or Ke). This name was not taken by chance, since in Eastern philosophy it expresses the idea of space-time and vital-energy substance, which underlies the structure of the Universe. Which perfectly describes the essence of this phenomenon. Most manufacturers (Samsung, LG, Google, Motorola, Microsoft, HTC and Nokia) follow these standards so users can charge their phones in different points peace.
Along with this Consortium, there is also the Power Matters Alliance (PMA), founded in 2012 by Procter & Gamble and Powermat Technologies. This alliance opposes the Qi standard. And he also has support large companies, including Samsung, Sony, HTC, LG, Asus, Qualcomm, ZTE and AT&T. And yes, you didn’t think so, some manufacturers want to sit on two chairs at once.
There are few differences between competitors. Both use inductive charging, but the Qi wavelength is in the range of 100-205kHz, while the PMA is in the 277-357kHz range. The charging method itself is absolutely identical (a merger with the Alliance for Wireless Power, which promoted Rezence technology based on magnetic resonance, the meaning of which is the opposite of charging using magnetic induction, used by competitors, has not yet brought serious dividends), the only tangible advantage of RMA is the support of Starbucks coffee shops.
Today, PMA is an example of a “pull-out strategy”, when the company installs wireless charging of its standard in order to create de facto consumer demand.
Qi standards
There are two varieties of the Qi standard. The first involves charging at low power - 5 watts, and the second at high power - 120 watts. High-power Qi is currently not produced by manufacturers due to imperfect technology (to receive such an amount of energy you will need a bulky induction coil, which is comparable to the thickness of a smartphone).
Using Qi at 120 watts, you can charge your laptop. Qi at 5 watts is used to replenish the battery capacity of tablet computers and phones. It should be noted that a tablet and a smartphone require different current strengths, which correlate with general principles wired charging.
From here we learn that fears about health risks from wireless charging are completely unfounded. The fact is that magnetic radiation is not ionizing in its effect on the body; it is similar to a Wi-Fi signal. Moreover, charging at a power of 5 watts is safe for humans in any form.
Today, of course, phone charging is conditionally wireless, as it requires a special charging platform. In many ways, this spoils the impression of this method, but, fortunately, manufacturers know about it. And in 2015, the famous furniture company IKEA presented furniture with a built-in wireless charging module at the Mobile World Congress (MWC) exhibition.
Cons of wireless technology
A very favorable picture is spoiled by various shortcomings of wireless technology, largely due to the immaturity of the technology. The first and main point is, of course, the range of action. The phone is tightly tied to the charging pad. If you want to read a message sent to you or answer a call, charging will be interrupted immediately. Which will lengthen the already long charging time.
And here we come to the second point: wireless charging is a long process. 30% slower than wired. It also turned out that using this type of charging “kills” the phone’s battery much faster.
Of course, wireless charging is the future, but some (Apple in particular) believe that this future has not yet arrived, and wireless charging is just a fashionable toy.
And beautiful, it has attracted the eyes of astronomers since ancient times. Even then, many of its features were noticed: phase changes, sunrise and sunset times, duration lunar month. Ancient scientists also noticed the constancy of the face of the night star. True, in those days they did not ask the question of why the Moon turned one side to the Earth. For them, this was the only possible position, fully consistent with the prevailing beliefs about the structure of the sky.
Today things are a little different. Our ideas about movement and interaction space objects, supported by numerous observations, are very different from those that existed in ancient times. And almost everyone knows from school why the Moon is turned to the Earth on one side.
The beginning of the story
Today, one of the secrets that the Moon stubbornly refuses to reveal to us is its origin. Various studies, carried out in order to obtain a final answer to this question, have so far given rise to several versions. According to one of them, the Moon and Earth are sisters, formed at approximately the same time from a common protoplanetary cloud. This is supported by the results of radioisotope analysis, which made it possible to determine the same age of two cosmic bodies. However, there is also evidence indicating large differences in the composition of our planet and its satellite. A version has been put forward to match them: the Moon was formed somewhere far in space and, approaching the Earth, was captured by it. Close to it is the hypothesis that suggests that several cosmic objects were attracted, which after some time collided and formed the Moon. Finally, there is a theory according to which our planet is more like a mother for its satellite: the Moon appeared as a result of the collision of the Earth with a huge body. The knocked out part subsequently began to rotate in orbit around the “progenitor”.
Satellite-planet system
Be that as it may, all that is known for certain is that the Moon is natural satellite Earth. According to astronomical data, the night star at the time of its formation was located much closer to our planet. Moreover, it flew around the Earth faster and turned first one way or the other. This situation is typical for initial stage evolution of the satellite-planet system. An example of the result of the development of such “relationships” is Pluto and its accompanying Charon. Both cosmic bodies always turn the same side to each other, their rotation is synchronized. But first things first.
Tidal acceleration
The young Moon immediately began to affect the Earth. This was expressed in the formation of tidal waves in the newly formed oceans, as well as in the crust. This effect has two main consequences. Firstly, as a result of certain features and its rotation, the tidal wave is ahead of the Moon. The entire mass of our planet contained in like waves, in turn, affects the satellite, gives it acceleration, and the Moon begins to move faster, gradually moving away from the Earth. Secondly, in this process an oppositely directed force appears, inhibiting the movement of the continents. As a result, the speed of rotation of the Earth around its axis decreases, and the length of the day increases.
The Moon is moving away from our planet by about 4 cm per year. However, this is not an eternal process, and the probability of the Earth losing its satellite is negligible. The “escape” of the Moon will end at the moment when the rotation of the Earth around its axis is synchronized with the movement of the satellite in orbit. In this case, our planet will always look at the night star with the same side.
Similar process
It is easy to assume that the answer to the question of why the Moon is turned to the Earth on one side is associated with a similar phenomenon. And indeed, the Earth causes similar tidal waves. Since our planet is more massive, the force of its impact is much more noticeable. Obeying her, the Moon has long synchronized its rotation with its movement around the Earth. As a result, an always visible and invisible side of the Moon appeared.
A little more than half
An attentive amateur astronomer can quickly discover that the face of the night star does change somewhat. Visible side The moon does not occupy exactly half of it. The orbit of the night star deviates from the plane of rotation of the Earth around the Sun (ecliptic) by approximately 5º. In addition, its axis is shifted by 1.5º relative to the trajectory of the Moon. As a result, up to 6.5º above and below the poles of the satellite are available for observation. This process is called lunar latitude libration. The satellite's longitude fluctuates similarly. It is caused by a change in the speed of the Moon depending on the distance to the Earth. Due to this, the part of the satellite hidden from view is reduced, and the other side of the Moon, illuminated, increases to 7º longitude. So it turns out that in total Up to 59% of the lunar surface can be observed.
In the distant future
So, the question of why the Moon always faces the Earth with one side finds an answer in the peculiarities of the influence of the planet’s gravitational force on the satellite. However, as stated, a similar process later certain time will lead to the fact that the Earth will look at the night star with only one part of itself, regardless of what phase the Moon is in. According to the calculations of John Darwin, the grandson of the founder of the theory of evolution, the length of the day at this moment will be equal to fifty days familiar to us. The distance separating the Earth and the Moon will increase by about one and a half times. This will be the same ideal condition satellite-planet systems.
Solar tides
There is, however, some probability that the Moon will never be destined to reach sufficient distance. The reason for this possibility lies in solar tides. daylight has a similar lunar effect on both the planet and the satellite. If in theoretical construction The future of two cosmic bodies include this fact, it turns out that at a certain distance from the Earth the Moon will begin to approach again. This reduction in distance will have devastating consequences. When the Moon is at a distance of 2.9, it will be torn apart by gravitational forces.
One more “but”
However, this picture may not be realized. The fact is that according to forecasts, the removal of the Moon, then its approach and, finally, death will take several trillion years. During this time, a catastrophe on a more serious scale may occur, at least for all life on the planet. The Sun will go out, having exhausted all its reserves of stellar fuel. Following this, all conditions of interaction in planetary system luminaries
Study
The other side of the Moon, inaccessible to direct observation, long time was a mystery, literally shrouded in darkness. It only gave me the opportunity to get to know her better. First aircraft The one that photographed about 70% of the surface of the hidden part was the Soviet Luna 3. Images transmitted to Earth showed that the relief reverse side somewhat different from the nature of the visible surface. There were practically no plains of seas here. Only two such formations were discovered, later named the Sea of Moscow and the Sea of Dreams.
Giant crater
In 1965 he headed to the Moon spacecraft"Zond-3". He completed filming the invisible part of the satellite. The image of the remaining 30% of the surface only confirmed the earlier conclusions: the surface in this part is covered with craters and mountains, but there are practically no seas on it.
The most impressive size is one of the craters, located exactly on dark side Moons. Its length is 2250 km and its depth is 12 km.
Hypotheses
Today the mysteries have largely been solved. However, it is common for the human mind to fantasize about those things and phenomena that are inaccessible to direct observation. Therefore, on the Internet it is easy to come across the most bizarre hypotheses related to the entire Moon as a whole or only to its hidden side. There are assumptions about the artificial origin of the satellite, its population by extraterrestrial intelligence and the deliberate concealment of one of the parties. There are also references to the mysterious space base, placed on the dark part of the satellite. Such versions are quite difficult to both confirm and refute. No matter how true or false they may be, they are based on the same reason that prompted people to explore space: the hope of finding fellow humans in the vast expanses of the Universe, the desire to touch the unknown.
However, today it is known quite precisely why the Moon is turned to the Earth on one side. And the assumption of artificial origin did not receive any serious continuation. The answer to this question became as obvious as the understanding of what phase the Moon is in today and why. It is impossible, however, to say that we know about earth's satellite everything and no discoveries are expected in the future. On the contrary, the night luminary matches the ancient deities who personified it, remains mysterious and is in no hurry to share secrets. Humanity still has to learn a lot of interesting things about the satellite of our planet. Maybe, new stage The study that began quite recently will bear fruit in the near future. It's absolutely certain that great value In this sense, the implementation of some NASA projects has. Among them is Avatar, which consists of developing a telepresence suit. It will allow, while on Earth, to conduct experiments on the Moon with the help of robots. Great hopes are also placed on the colonization project, the implementation of which will result in the placement scientific base on the satellite of our planet.