How does Samsung wireless charging work? Principle of operation. Wireless charger – comfortable and reliable connection at any time

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 introduced was the Air Power wireless charging mat, which allows you to simultaneously charge your smartphone, Apple Watch and AirPods wireless headphones. 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? This will be discussed 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 the open standard Qi (pronounced "shi" because it's a Chinese word that refers to the "life energy" in living things.).

Qi wireless charging

Wireless chargers currently 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 amount 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 Note8, Galaxy S8 and Galaxy S7, in fact, support both Qi and PMA, so they can be charged from any charger. Starbucks company (global cafe chain)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 doesn't offer it on its Pixel smartphone, although some Nexus devices previously supported this feature. 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.

Hello, dear readers. I'm sure you've heard, at least remotely, that you can charge your phone without using wires. Surely many dismissed it, thinking that such modern technology is only available in very expensive devices. But no.

Almost any phone supports wireless charging, although with some reservations. Branded smartphones can receive energy through the air right out of the box, but for others you will have to purchase special accessories. Today you will not only find out whether your mobile phone supports wireless charging, but also how to ditch the wires if your device is outdated.

Wireless charging – what is it?

Before considering smartphone models that are equipped with wireless charging, you need to understand its essence. In fact, wireless energy transfer is not such a complex technology as it seems at first glance. In technical terms, wireless charging is represented by two copper coils.

One plays the role of a transmitter of energy, which it receives from the electrical network. The coil is installed in the docking station (the platform on which the smartphone is subsequently placed). The second coil is the receiver. It is equipped with devices that require energy, such as mobile phones. As a rule, the receiver is hidden from view inside the case, unless it is external.

The device's battery receives energy thanks to the magnetic field that occurs when the receiver is in the field of action of the transmitter (usually about 4 centimeters). This principle is true for the Qi standard, which is most actively used in wireless charging of wearable devices.

Smartphone with Qi icon supports wireless charging

The Qi standard was developed by the Wireless Electromagnetic Energy Consortium to transmit energy over a distance of up to 4 centimeters. Scientists, when creating the standard, used developments that had already been made by many other specialists.

In general, the idea of ​​transmitting energy over a distance appeared two centuries ago, when Marie Ampere discovered a law proving that electric current produces a magnetic field. A significant contribution was made by Nikola Tesla, who built a tower to demonstrate wireless energy transfer. Subsequently, many organizations and scientists studied technologies, but a large percentage of experiments ended in the early stages.

Until this century, wireless energy transmission remained at the testing level. So far, the technology has not become interesting to large manufacturers of portable electronics. In 2009, after the creation of the Qi standard, which became the most suitable for use in wearable technology, a number of companies began to develop concepts that support wireless charging.

The impetus for companies was the fact that the standard was free and accessible. Today, almost every flagship smartphone boasts the presence of technology, and budget smartphones boast accessories that make the function work for them.

Not a dozen companies are working on energy transmission technologies other than electromagnetic induction. For example, students at the University of Pennsylvania conducted an experiment in 2011 in which they proved that energy can be transmitted through ultrasound. And in 1945, Soviet scientist Semyon Tetelbaum described in an article the possibility of transmitting energy using microwave radiation. Subsequently, this technology was actively developed. Energy can be transmitted with a laser beam, which NASA has proven in experiments. Nikola Tesla, known for his experiments with electricity, even believed that it was possible to create a worldwide wireless system that would save people from power lines.

List of smartphones with built-in support for wireless charging (2019)

Well, you are now familiar with the theory and history of wireless energy transfer, it’s time to move on to devices that support the technology. Speaking of support, we include in the list devices that received a receiver already at the factory (you can install it separately).

To date, more than 80 smartphones have received wireless charging using the Qi standard, not counting a number of smart watch models and other devices. And this figure is growing at an enviable rate. I will try to list as many models as possible - the exact list, which is regularly updated, is presented on the Qi portal.

So, wireless charging is integrated in the models (list updated in January 2019):

Apple

• iPhone 8
• iPhone 8 Plus
• iPhone X
• iPhone Xs
• iPhone Xs Max
• iPhone Xr

Asus

• Asus PadFone S

BlackBerry

• BlackBerry Passport
• BlackBerry PRIV
• BlackBerry Z30

CASIO

• CASIO G'z One Commando

Caterpillar

• Cat S50
• Cat S50C

DeWalt

• Dewalt MD501
• Dewalt MIL810G

Energy System

• Energy Phone Pro Qi

Fujitsu

• Fujitsu Arrows F-09D
• Fujitsu Arrows Kiss F-03D
• Fujitsu Arrows Kiss F-03E
• Fujitsu Arrows X F-10D

Google

• Google Nexus 4
• Google Nexus 5
• Google Nexus 6
• Google Pixel 3
• Google Pixel 3 XL

HP

• HP Elite X3

HTC

• HTC Droid DNA
• HTC Windows Phone 8X

Huawei

• Huawei Mate20 Pro

Kyocera

• Kyocera Brigadier
• Kyocera DuraForce
• Kyocera Hydro Elite
• Kyocera Torque G02
• Kyocera Torque KC-S701
• Kyocera Urbano L01
• Kyocera Urbano L03

LG

• LG G2
• LG G3
• LG G6¹
• LG G6 Plus¹
• LG G7
• LG G7 ThinQ
• LG Lucid 2
• LG Lucid 3
• LG Optimus F5
• LG Optimus G Pro
• LG Optimus It L-05E
• LG Spectrum 2
• LG Vu 2
• LG Vu 3
• LG V30
• LG V30 Plus

M.T.T.

• M.T.T. Master 4G

Microsoft

• Microsoft Lumia 950
• Microsoft Lumia 950 Dual Sim
• Microsoft Lumia 950 XL
• Microsoft Lumia 950 XL Dual Sim

Mlais

• Mlais MX69W

Motorola

• Motorola Droid Maxx
• Motorola Droid Mini
• Motorola Droid Turbo
• Motorola Droid Turbo 2
• Motorola Moto Maxx
• Motorola Moto X Force

mPhone

• mPhone 8

NEC

• NEC Medias PP N-01D
• NEC Medias X N-04E

Nokia

• Nokia Lumia 1520
• Nokia Lumia 735
• Nokia Lumia 830
• Nokia Lumia 920
• Nokia Lumia 928
• Nokia Lumia 929 (Icon)
• Nokia Lumia 930
• Nokia 8 Sirocco

Oukitel

• Oukitel U23

Panasonic

• Panasonic Eluga P P-03E
• Panasonic Eluga V P-06D
• Panasonic Eluga X P-02E
• Panasonic Eluga X1
• Panasonic Eluga X1 Pro

Philips

• Philips X723

Razor

• Razor Phone 2

RugGear

• RugGear RG730

Samsung

• Samsung Galaxy S6
• Samsung Galaxy S6 Active
• Samsung Galaxy S6 Edge
• Samsung Galaxy S6 Edge Plus
• Samsung Galaxy S7
• Samsung Galaxy S7 Active
• Samsung Galaxy S7 Edge
• Samsung Galaxy S8
• Samsung Galaxy S8 Active
• Samsung Galaxy S8 Plus
• Samsung Galaxy S9
• Samsung Galaxy S9 Plus
• Samsung Galaxy Note 8
• Samsung Galaxy Note 9
• Samsung Leader 8
• Samsung W2016

Saygus

• Saygus V SQUARED

Sharp

• Sharp Aquos EX SH-04E
• Sharp Aquos SH-07D
• Sharp Aquos SH-13C
• Sharp Aquos Slider SH-02D
• Sharp Aquos Zeta SH-06E
• Sharp Aquos Zeta SH-09D
• Sharp Q-Pot SH-04D
• Sharp SH-05D

Sony

• Sony Xperia Z3V
• Sony Xperia Z4V
• Sony Xperia XZ2
• Sony Xperia XZ2 Premium
• Sony Xperia XZ3

Techdy

• Techdy Basic Bear
• Techdy Bear Pro

Vertu

• Vertu Aster
• Vertu Signature Touch

Xiaomi

• Mi MIX 2S
• Mi Mix 3

YotaPhone

• Yotaphone 2

ZTE

• ZTE Telstra Tough Max
• ZTE Axon 9 Pro

This is not a complete list - there are also a number of models from lesser-known companies. Don't be surprised that the popular iPhone isn't on the list. It's not a mistake. Apple has not yet officially integrated wireless charging into its products. But there is a way out, more on that below.

The smartphone models presented in the list only require the presence of a platform that is necessary for transmitting energy. As a rule, it is included with the mobile device, but not always. In this case, you will have to purchase a docking station separately.

Usually, the manufacturer produces a branded model, but you can use others - there is no special connection between the smartphone and a specific site. You can even order a cheap “noname” docking station, which in most cases will satisfy the buyer’s needs.

What to do if your smartphone does not support wireless charging

If you don’t find your device in the list of supported smartphones, don’t rush to get upset. There is an exit. More precisely, there are two of them. So, perhaps your phone is among those for which receivers (small plates with a built-in circuit) for wireless charging are specially produced. This list includes quite popular, but rather outdated models. There are exceptions, such as the iPhone 7.

Both popular and not outdated, and the manufacturer did not integrate the receiver. Receivers designed for certain models receive the appropriate designation, as well as the necessary characteristics. For example, similar receivers for the Samsung Galaxy S 5 or older solutions have unusual contacts that match those found under the device cover. Here are the most popular models that received special receivers:

• iPhone: starting with “four”.
• Samsung Galaxy: S3, S4, S5; Note 2, 3, 4, Edge.
• LG: G4, V10.
• Sony: Xperia Z3+/Z4; Experia Z5; Experia Z5 Premium.
• Huawei: Ascend Mate 7, Mate S.

The receiver for these devices usually comes with a docking station. You can buy parts separately - there is no special connection. In addition to boards (receivers), there are also special cases on the market for wireless charging of devices, which contain a copper circuit inside. For each smartphone, a correspondingly shaped case is made.

Universal solutions

There are more and more devices that support wireless charging, but manufacturers are in no hurry to “import” the technology into the budget segment. And he is the most popular. Especially cheap smartphones are loved in China, where they came up with the idea of ​​​​producing universal receivers for any model.

A docking station + receiver set costs about 500-700 rubles (you can find it cheaper), the main thing is to choose the right one for your smartphone. Pay attention to the shape and connector. A universal receiver can be found for almost any smartphone.

Docking stations

So, we figured out the support for wireless charging on smartphones. Now I would like to dwell separately on the platforms that are used to transfer energy to the device. For what?

Unlike receivers, which are either hidden inside the phone or are a faceless plate, docking stations allow the user to choose the model they like. Some companies even provide original solutions that will become part of any interior.

Particularly popular is the wireless charging dock from Samsung, made in an oval shape. It is suitable not only for charging the company’s smartphones, but also for most other models.

Among the features, it is worth highlighting support for automatic shutdown when the device is fully charged, as well as light indication. The average cost is 2,000 rubles, but in Chinese online stores you can find a cheap replica for 400-700 rubles.

The Woodpuck FAST Edition Bamboo playground model, which is made of wood, is also interesting. The manufacturer, so to speak, has combined modern technologies and natural materials. The functionality is no different from other docking stations, but it looks catchy. Cost – 40 dollars.

But Aukey QI boasts compact dimensions that allow you to take the charger with you. Yes, and the price is low - $30. Fans of purchases from China have huge catalogs to choose from, in which it will not be difficult to choose a cheap and beautiful docking station.

Among the unusual wireless charging stands, we can highlight the new TV from Asus – Designo Curve MX34VQ. More precisely, the leg on which it stands. It is made in the form of an oval platform on which the smartphone is placed for charging. It even has a backlight. Asus, following modern trends, has made the new device not only beautiful, but also useful. True, the price is steep.

Bottom line

It's safe to say that the list of devices that support wireless charging will only grow. A technology that can eliminate a lot of wires is of interest to both the user and the manufacturer, who receives additional income for its presence.

In a couple of years, every smartphone will probably support wireless charging. In addition, a dozen companies are working on developing even more advanced technology that will not be tied to a docking station. We, ordinary users, just have to wait a little to forget about the main problem of portable devices - being tied to a power outlet.

Do-it-yourself wireless charging for your phone

With the development of modern technologies, conventional wired chargers are losing their relevance. They have their own disadvantages that make them impractical. Users often encounter problems when using them, for example, the socket of a smartphone or other device may fail or the wire may fray. Today, more and more preference is given to wireless charging. They are used to recharge the battery of various electronic gadgets. The price of these products varies depending on the complexity of the circuit and the manufacturer producing a particular model.

How wireless charging works

The presented device cannot be called completely wireless, since it is in any case connected to the electrical network. The device that requires recharging the battery is placed on top of the charger. The principle of its operation is electromagnetic induction. The battery receives voltage due to the electromagnetic field generated in the charger when electric current flows through a special induction coil.

Wireless phone chargers have recently appeared on the market.

Manufacturers of modern electronics for such models have officially adopted a single standard for wireless power supply of electronic devices - Qi. This standard sets the power of movement of electrically charged particles supplied to the coil. It is 5 watts.

The force field can operate at a distance of four centimeters. It occurs when a signal is transmitted about the appearance of one of the compatible devices. The smartphone can generate these alerts using the Near Field Communication feature. Next, energy is transferred to the battery due to the current generated by the voltage in the winding built into the device being charged.

What does a standard charger consist of?

To independently create contactless charging, you should take into account the list of elements included in its composition. So, the generator is placed on a special board. A transmitting circuit is connected to it, where a high-frequency voltage arises, affecting the receiving circuit of the device being charged. In this case, the induced alternating voltage is rectified and then smoothed using a capacitor. The stabilization unit brings it to a value equal to 5 Volts.

How to make a wireless phone charger with your own hands

Branded devices offered in stores have different prices, which are not always affordable for the average person. Sometimes a suitable solution is to create such a device yourself.

Well, already from the name of the device it becomes clear that the gadget does not require connecting wires to transfer energy

From the name of the gadget it becomes clear that the use of wires is not required to supply electricity to the smartphone battery. Power supply process steps:

1. The charger is equipped with a built-in induction coil. It produces and transmits energy to the receiver coil found in the smartphone. Typically this element is located above the back cover or battery.
2. When the phone approaches the transmitter, high-frequency electromagnetic oscillations occur.
3. A capacitor and rectifier based on a low-power semiconductor diode provide energy to the battery.

To create remote charging, you do not need to have deep knowledge of electronics. Detailed instructions and diagrams of the device are publicly available. We present to your attention one of them.

Materials and tools

List of items that will be needed to create a charger:

• a small base (board) (the remaining components will be attached to it);
• an inductor with high resistance to alternating current should have from 5 to 10 turns (wire diameter is 1 millimeter);
• a film capacitor with a capacity of 0.33 to 1 microfarad;
• two UF type rectifiers;
• soldering iron;
• several field-effect high-voltage transistors that amplify the voltage up to 10 Volts;
• two current converters with rated power dissipation up to 1 Watt;
• solder (material used for soldering and having a melting point lower than the elements being connected).

First, let's see what materials we need to build a homemade wireless charger for a smartphone with our own hands.

Let's start the process

It is recommended for a beginner not to immediately create a device for a modern smartphone model, but to practice on an old device. For example, you can collect a charger for a Nokia push-button phone that was lying around. The algorithm of actions itself is divided into several stages. The first step is to create a transmitter, which will become an independent element, and then you need to move on to developing a receiver installed in a smartphone.

The wireless charger circuit is quite simple. It contains two coils representing a receiver and a transmitter, as well as a resistor and a transistor. If you were able to prepare all the necessary elements described above, then assembling a simple contactless charger will take no more than 60 minutes.

1. Let's make a coil.

You need to wrap a contour around a piece of plastic up to 10 cm in size (or other convenient material). This is done in this way:

• a long wire is folded in half;
• five turns are wound on a piece of plastic;
• each turn should be secured around the circumference with adhesive tape or glue;
• the edge of the wire, which is a bend, needs to be cut off to make two ends;
• all resulting wire ends (4 pieces) are stripped;
• the end of the first winding is connected to the beginning of the second or, conversely, the beginning of the second winding is connected to the end of the first (in this case, a cable tester comes to the rescue).

The wireless charging circuit is very simple, consisting of two coils (transmitter and receiver), as well as a transistor and resistor

To use a multimeter, it must be switched to diode test mode. You need to bring it to each end of the winding. In this case, in one case the device may respond, but in another it may not. These ends of the wire should be located on different sides. They should be twisted together and soldered. The remaining two ends will go to the transistors.

1. Working with a soldering iron.

For further actions you will need material such as solder, as well as the soldering iron itself and the board that serves as the base. Stages of work:

• two transistors and diodes are soldered;
• resistors are soldered at one end to the board and the other to the diodes;
• two windings of the circuit must be tinned and then connected to the device.

1. Assembling the receiver:

• this element has a flat appearance. The coil should consist of 25 turns of wire with a thickness of 0.3 to 0.4 mm. Each turn is wound onto a plastic base and secured with glue;
• the finished contour should be carefully separated with a knife from the base that was used for winding;
• before winding when connecting, a high-frequency silicon diode is installed;
• The coil is attached to the top of the battery. In this case, a capacitor is used to smooth out voltage ripples;
• The receiver is connected to the charging connector or directly to the battery. But in the second case, the charge meter will not work. This option is suitable for those devices that have problems with the charging socket;
• Finally, you need to close the back cover of the phone and test the correct operation of the resulting device.

If making a transmitter takes a few minutes, then you will have to work hard with the receiver

The most popular wireless charger models

Not everyone has the opportunity to create their own charger. Today this is not a problem, since there are many modifications of similar accessories on sale, produced under different brands.

Overview of the characteristics of the most popular wireless charging models:

Charge your smartphone wirelessly: how wireless chargers work

One of the features of top smartphones in recent years is the ability to charge wirelessly. It is enough to place the device on a special contact pad (dock station) to restore the battery's energy supply. The charging process ends automatically when the charge level reaches 100%.

How Qi wireless charging works: energy flow through the air

The power standard for wireless charging of mobile devices is called Qi. The name reads "Qi" because the standard was named after the energy Qi - a key concept in Eastern philosophy, denoting life energy. Qi technology was developed by the Wireless Power Consortium (WPC) almost ten years ago - in 2009.

Qi wireless charging is supported by flagship smartphones from many manufacturers: Apple, Asus, HTC, Motorola, Nokia, Samsung. As a rule, all compatible chargers are marked with the official standard marking.

Official Qi logo

Qi technology allows you to transmit electromagnetic signals over a short distance (up to 4 cm). Externally, the charging process is quite simple: the charger is connected to a power source (for example, to a power outlet or USB port of a computer), the smartphone is placed on a special contact pad of the device, and the gadget’s battery begins to charge. For this purpose, there is a special transmitter in the charger, and a receiver in the smartphone.

Apple's AirPower charging can power three devices simultaneously

With Qi-enabled wireless charging, you can charge not only smartphones, but also tablets, smartwatches and other mobile devices with a Qi receiver. Some chargers have the ability to power several gadgets at the same time, depending on the number of contact pads on the device. At the current stage of technology development, there are usually two of them, although Apple last year introduced AirPower charging with three pads.

Benefits of wireless charging

The bonuses that wireless charging provides are obvious. Firstly, like any wireless device, it allows you to remove from your home a couple of extra cables that occupied sockets or PC connectors. However, there will still be a wire that connects the wireless charger to the network, but it is usually easy to hide. There are also portable power banks with Qi technology.

Secondly, smartphones with wireless charging usually support wired charging, so you will have two options for charging your gadget. If it is possible to charge the device over the air, that’s good; if not, you can always use a regular cable. In addition, wireless chargers often have additional USB or Lightning connectors to power third-party devices. You can place your smartphone on the contact pad, and connect another smartphone or, for example, a Bluetooth headset to USB.

The Nillkin Hermit charger can also be used as an external USB hub

Thirdly, using a wireless charger extends the life of your smartphone's power connector. After all, it is now used only to connect to a PC, which happens much less often than charging. Therefore, the connector becomes looser and damaged more slowly, depriving the device of power and communication with the computer.

Ferrari wireless power bank - for true car enthusiasts

Finally, a wireless charger gives a lot of room for designers' imagination. It can be given an unusual shape or color, encased in a body made of original material (metal, wood), equipped with built-in lighting, and the logo of a popular brand can be applied. Therefore, it is not surprising that many wireless chargers look more like a decorative element.

Disadvantages of wireless memory: the first alarm bells

Wireless chargers have only recently entered the market, and their effects on cell phone batteries are not well understood. Therefore, some users already began to worry in advance.

Thus, ZDNet resource columnist Adrian Kingsley-Hughes noticed that an iPhone charged using Qi technology discharges faster. This leads to an increase in the number of recharge cycles and, as a result, can cause premature wear of the device's battery. However, the data from this experiment is not enough to speak with complete confidence about the dangers of wireless chargers.

Apple iPhone 8 and 8 Plus are the first Apple smartphones with wireless charging

Other disadvantages are also related to the newness of the technology. Qi standard chargers are not yet perfect enough - for example, for charging to work, the smartphone must lie on the platform in a strictly defined position. In addition, Qi technology is currently only available in premium devices.

Mophie battery cases add Qi support to iPhone

However, since the Qi standard is open, enterprising manufacturers have long started producing adapters that allow you to add wireless charging functions to absolutely any phone. These include battery cases with built-in Qi-to-microUSB adapters and separate adapter modules that can be glued into any case.

What types of wireless chargers are there?

Chargers based on Qi technology currently on the market differ from each other in terms of application. They can be portable or built into furniture, and are available for the home, office or car. “Home” wireless chargers work from a wall outlet or from a PC. This is the most common type of charger that looks optimal in the interior.

Wireless charging Nillkin Phantom is also an original lamp

Car wireless chargers work from the cigarette lighter in the car. They have convenient mounts for placing the charger inside the car - for example, on the windshield or ventilation grille.

Mophie car charger is attached to the grille, and the smartphone is attached to it using a magnet

Portable wireless chargers are usually combined with an external charger (power bank). This allows you to carry them with you while walking or traveling and recharge your smartphone on the go, even if there are no outlets nearby.

The capacious 8,000 mAh Harper wireless power bank is protected from shock.

Finally, the most futuristic type is built-in wireless chargers. They connect to a hidden outlet or directly to electrical wiring and are built directly into furniture: tables, bedside tables, bar counters. Starbucks coffee shops successfully use such devices, offering Powermat charging mats to visitors.

Charging mats Powermat

The future of wireless charging technology is very promising. This could be integration into a smart home, or charging points for mobile devices in public places - in cafes, subways, airports. For now, only flagship smartphones support Qi technology, but it would not be surprising if over time wireless charging becomes available to devices from the mid-range and budget segment.

How to add wireless charging support to your smartphone?

In fact, absolutely any smartphone can be equipped with Qi technology, even if it was not initially positioned as a device with wireless charging. This is a convenient opportunity for those who are used to their phone and do not want to change it for the sake of new technology.

It is enough to purchase a universal Qi module with a connector that suits your smartphone: micro-USB, USB-C or Lighting. The module is glued to the back cover of the smartphone, connected to the charging connector and hidden behind the case. After this, the smartphone can be charged wirelessly - current from the charger will flow to the battery through the adapter.

The only inconvenience of this method is that the adapter will have to be constantly disconnected in order to connect the smartphone to the PC via USB. But if you rarely connect your phone to your computer, the Qi module will definitely not bother you.

Wireless charging is one of the key innovations in the 2017 iPhone. So, it's time to understand what kind of technology this is. Since even Apple has given up.

Here are a few basic issues that any modern user should understand. We will try not to overload with scientific terms.

How it all began

The idea of ​​wireless energy transfer began to be implemented in the 19th century. The first high-profile demonstration of the new product was the World Exhibition of 1893, where Nikola Tesla lit unconnected fluorescent lamps with his own hands.

More than a hundred years later, we have just begun to receive what the Serbian genius dreamed of - the widespread introduction of revolutionary technology. Today, there are several ways to wirelessly transfer energy, but only chargers operating on the principles of electromagnetic induction have been commercialized.

What is electromagnetic induction

In a few words: if an alternating electric current is applied to one of two coils placed next to each other, then the second will generate its own current. All thanks to electromagnetic induction. By setting the voltage to the desired value, you can charge the battery.

The connection between these coils is carried out through an electromagnetic field, which made it possible to get rid of connecting wires. But the receiver must be located close to the transmitter, otherwise part of the field is wasted.

In reality, everything is a little more complicated; coils can be either magnetic inductive or magnetic resonance. There are also certain sets of parameters - standards that modern chargers must meet (for example, the well-known “Qi-standard”). These nuances affect the charging speed and the permissible field distance.

What does Qi have to do with it?

Modern research in the field of wireless power transmission has consolidated two large groups: the Wireless Power Consortium and the AirFuel Alliance. Of course, there are other teams working on their own, unique technologies, but their widespread use is still a long way off.

Today, the main specification has become the one developed by the Wireless Power Consortium. It was she who received the name “Qi” (read “qi”).

In theory, Qi provides charging power of up to 5 W and a current of 1 or 2 A, at a voltage of 5 V. These parameters are comparable to wired chargers, but the power supply is much slower.

At the same time, the receiver and transmitter can exchange information about supported standards and charge level. For example, this allows you to turn off the transmitting device when the battery is fully charged.

A magnetic field is not radiation, and it affects the human body no more than Wi-Fi or a mobile signal. In any case, 5 watts of power is not enough to have a negative impact.

5 centimeters is not the limit

Two Qi-aware coils are not the only option for wireless energy transfer. There are many working prototypes that can charge devices at a distance of several meters.

Here are some of them:

• WiTicity
  The idea came to the mind of an employee of the University of Massachusetts, Marin Soljacic. The two coils are tuned to resonate with each other. When alternating current is applied to one coil, the magnetic field is transferred to the other coil. This method is patented and all details are kept secret. It is known that it has already been possible to transmit energy over a distance of about two meters, with a theoretically possible seven meters. The company already cooperates with such giants as Delphi, Toyota, IHI, Audi, Haier or OSRAM.
• PoWiFi
  Guys from the University of Washington have come up with a way to use Wi-Fi as an energy source. They reflashed the Asus RT-AC68U router in order to transfer charge through unoccupied channels. Sensors located at a distance of up to 8 meters from the router successfully converted the energy of the electromagnetic wave into direct current. This way we were able to supply power to the CCTV camera and even charge the Jawbone Up24.
• DCRS
  Another system called Dipole Coil Resonant System works at a distance of up to 5 meters. This also uses coils and is relatively compact. The experiment showed that using this method it is possible to power even an LCD TV (40 W) at a distance of up to five meters. But the larger the gap, the lower the efficiency, for example, when transmitting 40 watts over 5 meters, you will have to “pump out” 400 watts from the power grid. But without wires between the receiver and transmitter.

But all these methods are not ready for the mass market. Therefore, we are content with wireless charging according to the Qi standard. As it turned out, even such a limited method of energy transfer is enough for its widespread distribution.

From theory to practice. There are fewer and fewer wires around

A couple of years ago I declared war on all the wires in my apartment and mercilessly HID them. Everything was used, from hidden wiring in the wall to neat routing of cables using Velcro from IKEA. But no matter how hard I try, the cords for charging gadgets are still visible, they are either used for their intended purpose or patiently await their voracious “consumers.”

With every new device that “understands” wireless charging, the little perfectionist inside me rejoices. Very soon it will be possible to throw out this entire bundle of wires, replacing them with one charger for all devices. Which I will not be too lazy to build into the table.

Wireless power transfer can do much more than conveniently charge your smartphone at home. It’s now possible to stay in touch all the time, all you have to do is upgrade the infrastructure. And this is already happening:

1. Entrepreneurs were the first to jump on the wave. Today, the presence of wireless charging platforms in cafes, restaurants and cinemas is an example of good form and a good way to add another competitive advantage to your piggy bank.
2. Car manufacturers are not far behind. For example, in the dashboard Volvo XC40 They built in a platform for wireless charging - you got into the car, put your smartphone in a specially designated compartment and you don’t even think about the remaining percentage.
3. Yes, even IKEA sells interior items with built-in wireless charging. The Swedes offer both ready-made lamps with additional platforms and separate modules built into furniture. You can put together a nice desk for your office.

It turns out that now you can stay connected to the network around the clock: at home, on the way to work, in the office and while walking. This is enough for even the most voracious Android smartphone.

Wireless charging is the future

The era of different connectors is passing, the time of unification is coming. Judge for yourself, more and more gadgets receive the same USB Type C, and now wireless charging according to the Qi standard.

So, you don’t have to connect your smartphone or watch to a wire at all. I wouldn’t be surprised if in a couple of years, next to the router that distributes Wi-Fi, a box appears that distributes charge. And it will be enough just to enter the room, and the smartphone will start charging itself.