Wireless phone charging: how it works, how to use it? How wireless phone charging works and works

What is wireless charging for a smartphone, how does it work and how to choose it

IN lately on the market mobile devices everything appears more smartphones with wireless charging function. In this article we will try to tell you a little about it, how it works, its pros and cons, how to use it and how to choose it. So let's get started!

Operating principle

Let's start with the fact that this technology is based on the principle of electromagnetic induction, in which an electromagnetic field is formed around a current-carrying conductor. If another conductor is placed within the range of this field, current will also begin to flow through it. The radiation power can be adjusted using inductors, allowing the energy to be concentrated on the required area.

In our case, wireless charging technology is implemented through a special docking station (powered by USB port or a regular outlet) and receiving device– i.e. the smartphone itself. Each of them is equipped with an induction coil, which allows the Google Phone placed on the station stand to receive electromagnetic radiation station and replenish your battery charge level.

Wireless charging standards

There are two standards of wireless charging technology in the consumer market today. The first of them (the most popular) is called Qi, the second is PMA. However, some manufacturers support both standards, which gives their gadgets some versatility.

You can find out which standard a particular smartphone supports from the documentation that came with it or from the description of its characteristics published on the manufacturer’s website.

How to choose a wireless docking station

1. Power

If you decide to purchase a docking station with fast charging, then be sure to check the charger specifications. So, for example, with an output voltage of five volts, the current can range from several hundred milliamps to one ampere and higher. At the same time, wired charger the output has a current strength of one to two amperes. Thus, the most suitable model would be a model with an output current of one ampere or higher. If given value If the docking station is too low, you will spend much more time charging your smartphone.

2. Number of charging circuits

It is also worth paying attention to the number of coils of the wireless charger you want. The fact is that most docking stations are equipped with only one coil, which is why they have a very limited range and require precise placement of the phone on the stand. At the same time, today on the market you can find stations with two or even three coils, thanks to which the accuracy of the gadget’s location on the platform has almost no effect on its charging speed.

3. Brand.

You should not buy completely “incomprehensible” devices. Chinese auctions today are replete with a huge number of various models of wireless chargers, but you need to understand that when buying a pig in a poke, you will not receive any guarantees that the output power will correspond to the declared indicators. And this is the most important indicator.

Today there are enough brands that produce good products, and not always for a lot of money: Samsung, Nokia, Belkin, Anker, Mophie, Skyway, etc.

Use the "correct" power supply, the power of which meets the manufacturer's recommended specifications.
For most chargers, especially those with single coils, the position of the device matters. These can be either drawn outlines of the recommended location of the smartphone, or specific recommendations in the instructions. If the charger is made in a docking station form factor, there are often only one or two possible positions (vertical and horizontal, if there are two coils)
Do not place anything between the smartphone and the charger. Magnetic mounts, magnetic cases, metal plates in car mount cases can all reduce the performance of the charger.
Also, do not forget to take it out of the case. credit cards, electronic passes, and other things that have magnetic stripes or RFID radio frequency identification chips, because possible electromagnetic radiation can damage them.
A very thick case can also reduce charging efficiency by moving the device away from the charging circuit.
Vibrating the smartphone, for example when receiving a notification, can move the device from its original position, which can reduce efficiency
Slight heating during charging is normal. But only a small one.

Pros and cons

What are the pros and cons of wireless charging for smartphones? Let's start with its advantages:

Pros:

Convenience. I think no one will argue that this is much more convenient than connecting a cable. Especially if the device periodically has to be used during charging, for example, for calls.
You won’t have to connect the cable every time, which means the smartphone’s interface connector will last much longer.
Today, many establishments, including StarBucks and McDonalds, have equipped their customer tables with built-in Qi docking stations, which can be useful if you urgently need to charge your gadget and don’t have a charger on hand. Furniture has also already appeared (for example, in IKEA) with built-in charging panels, and automakers are increasingly installing them in premium cars.
While at home, you can keep your device on the docking station all the time, so it will always be fully charged. In this case, the controller built into the device will automatically stop charging as soon as its level reaches 100%.
Safe to use. Any cable begins to wear out with constant use, which can lead to damage and, as a result, a short circuit. Wireless charging has no such disadvantages.

Cons:

Higher cost.
Most docking stations have a very limited range and require precise positioning of the phone on the stand.
Less energy efficient. On average, wireless charging takes 1.5-2.5 times longer than conventional charging.

What to do if your smartphone does not have wireless charging functionality?

The lack of wireless charging technology on a smartphone does not mean that it cannot be used. Today, to solve this problem, some manufacturers offer additional accessories that can add the missing function to the device.

One such method is plate receivers. It's so thin plastic card with a built-in inductor, which is connected to the smartphone via a special contact cable, after which it is placed under the cover. As a more comprehensive alternative, you can purchase a special charging case with a similar plate already built-in, which, after installation, replaces back panel gadget.

Technologies make life more convenient for the modern user of mobile devices in the most different aspects. If until recently the main competitive positions concentrated in the devices themselves, today manufacturers are paying more and more attention to accessories and peripheral components.

One of them is How it works this device and how it can be useful to the modern user? The answers to these questions lie in the concept of communication itself, which excludes a wired connection. Wireless contact is designed to save people from the hassle of inconvenient connectors. In many ways, this idea was realized, but such devices were not without their drawbacks.

Features of wireless chargers

In the first years of the spread of telephones for cellular communication manufacturers had to make reservations when positioning such gadgets as mobile. The fact is that they were and remain mobile only conditionally, since they are dependent on the charger cable. Remove all conventions of such designation mobile phones and smartphones allowed wireless charging.

How does this device work? All technologies on which such charging are based are based on distance principles. It is important to note that the spread of technology wireless communication and the transfer of information has not been something new and surprising for a long time. Radio signal modules, Bluetooth and Wi-Fi sensors, network access points - all of this, to one degree or another, allows the transmission of information signals.

However, the novelty and fundamental difference exactly with wireless principle The actions consist precisely in the possibility of transmitting energy over a distance to power the batteries.

Operating principle

The most common design of such devices involves the presence of induction coils in the filling. In fact, they act as receivers as well as translators. electrical signals. When the charger itself is connected to the mains, a voltage is generated, after which a magnetic field is formed around the transmitting coil. Actually, after entering this field of the phone, wireless charging is activated.

How does recharging work? Due to the transformation of electromagnetic waves, which are transferred to the battery as electricity. In this case, the target object for power supply can be not only a phone or smartphone. Developers are guided by broad standards of batteries and batteries, which also apply to some models of tablets, cameras, players and other equipment.

Depending on the device model and its characteristics, it is possible different conditions maintaining charging. For example, to understand how it works, you should familiarize yourself with the Qi energy transmission standard. Such a transmitter is capable of replenishing the battery capacity at a distance of 3-5 cm, that is, practically the mobile device must be in contact with the charger.

Wireless charging safety

The ability of chargers to transmit energy over distances rightly raises questions regarding their safety for users who, in any case, will be in the range of the induction coils. However, manufacturers claim that such devices do not cause any harm to health.

Examples include electric shavers and brushes that operate on the same principle of electromagnetic fields as wireless phone charging. How does the charging panel work in contact with other equipment and does it harm it? This question is also raised, but the manufacturers deny such a danger.

The point is that maximum power, at which such devices operate is no more than 5 watts. This is not enough to have a negative impact even on devices sensitive to electromagnetic fields.

Devices from Samsung

One of the most successful developments in the segment of Korean wireless charging is the Wireless Charging Pad. This is an optimized version of the basic family, which has eliminated common problems of most similar devices first generation. One of the main advantages of this model is the ability to interact with the phone’s battery regardless of its position relative to the functional platform.

In its commercial form, this version is represented by wireless charging for Samsung Galaxy S6, which supports the WPC standard. This technology differs in that it is suitable not only for Galaxy smartphones, but also for most others Samsung phones. In addition, as the manufacturer notes, charging can replenish energy to half the capacity in just a few minutes.

Apple devices

It must be said right away that Apple products do not support wireless charging technologies. However, the manufacturer is looking for alternative ways providing this opportunity to its users.

In particular, he recommends using accessories in the form of cases from Duracell. Therefore, the question of whether wireless charging works through a case will have a positive answer in the case of iPhones. If this method does not suit you, then you can use an iQi format receiver card. It connects via a special Lightning connector and is also hidden under a standard smartphone case.

Devices from Cota

Cota employees are also developing interesting proposals. They are not just mastering the concepts of specialized charging panels for mobile devices, but are striving to expand their range of action as much as possible. For example, in addition to phones and tablets, such a device can fill wearable electronics with energy. Moreover, for this it is not necessary to bring the device close to the active panel.

A small device the size of a bread box works at a distance of 10 m. The question arises: “How does wireless charging work with such a radius? Is it effective enough?” And here it’s worth returning specifically to wearable technology, including: smart watch, bracelets and wristbands, since it is in working with these gadgets that the device demonstrates the most impressive performance. Obviously, phones and smartphones require more time.

Disadvantages of wireless charging

Like all technologies that radically change approaches to the use of technology and electronics, wireless devices charging also has many disadvantages. Of course the user gets significant advantage, since he does not have to tinker with wires and connectors, but the efficiency of filling the power supply with this method is noticeably reduced.

Most devices provide a charge over a longer period of time compared to the classical method. In addition, there are ergonomic inconveniences that modern wireless charging cannot yet get rid of. How does a wired charging system work? It requires connection to the device, after which it can be used for the same 30-60 minutes required to replenish energy. However, in the case of wireless technologies not only does the charging time increase, but it also eliminates the possibility of using the device during this period.

Directions for further development

Actually, all directions of development of chargers operating without wires are aimed at eliminating the above-mentioned shortcomings and generally improving the basic characteristics.

Also big problem there remains a considerable weight of such devices. In the mid-segment, the average device is a platform that can hardly be called mobile. However, it is worth noting here how wireless works. Samsung charger S6 and devices for younger versions of the smartphone from the Charger Kit line. These are panel charging accessories that are fixed to phones by type protective devices and covers. This interface configuration minimizes the size of the charging infrastructure, but is not highly efficient.

Conclusion

It cannot be said that the emergence of wireless chargers has caused a stir in the market of accessories for mobile devices. Despite the novelty of the concept, the spread of this product is hampered not only by ergonomic shortcomings, but also by the cost at which wireless phone charging is sold.

You can make a similar device with your own hands at a lower cost. To do this, it is enough to organize a blocking generator with the function of an energy transmitter. As experienced craftsmen note, such a circuit will only require a homemade copper-based coil and one transistor with the accompanying wire infrastructure. Another thing is that in terms of reliability and safety, such a device will be noticeably inferior to the same branded models from Samsung.

In order to equip your favorite smartphone with the flagship wireless charging function, you don’t need much.

Firstly, the base, also known as the charger. Most often it is made in the form of a small round platform with an outlet for a charger. For the experiment, let's take an unnamed model with a pleasant blue backlight. Powered by a 5 V, 2 A power supply ( regular USB), is powered via a standard microUSB port. At the output, the device produces a current with parameters of 5 V, 1 A, which is enough to charge most devices even in operating mode.

The second necessary element of modernization is the antenna, with the help of which the smartphone is charged from a distance. Usually this distance is minimal, by the way, but the convenience of using wirelessly can be significant for someone. For example, the database can be embedded in dashboard car or put it on the chest of drawers near the bed: came, put it down, went to bed. And no searching for wires.

There are a lot of different universal antennas for smartphones on the market. They are also suitable for other equipment, but here you need to think about placement. The antenna (we have an unnamed Chinese copy) is a coil with a circuit board hidden in a paper-like envelope. A wire with a microUSB plug comes out of it, although if desired, it can be soldered to any other one. It is worth paying attention: the coil only works in one position in relation to the charger. Since the cable for connecting to a smartphone is flat, you may need to open the bag and flip the coil over for the antenna to work (as in our case). The coil should face the open side towards the charger.

Attention: the charging base shows the necessary parameters of the power supply (in the case of the used one - 5 V, 2 A). They need to be provided for. At lower current levels, charging will occur very slowly. For adequate operation, you may need to replace the cord included with the charger, since not every USB cable can pass a full 2 A. As you can see,

In order to equip your favorite smartphone with the flagship wireless charging function, you don’t need much.

Firstly, the base, also known as the charger. Most often it is made in the form of a small round platform with an outlet for a charger. For the experiment, let's take an unnamed model with a pleasant blue backlight. Powered by a 5 V, 2 A power supply (regular USB), powered via a standard microUSB port. At the output, the device produces a current with parameters of 5 V, 1 A, which is enough to charge most devices even in operating mode.

The second necessary element of modernization is the antenna, with the help of which the smartphone is charged from a distance. Usually this distance is minimal, by the way, but the convenience of using wirelessly can be significant for someone. For example, the base can be built into the dashboard of a car or placed on a chest of drawers near the bed: come, put it down, go to bed. And no searching for wires.

Nowadays, a person without a smartphone is a person cut off from life. It's hard to imagine that a few years ago a mobile phone was used only for communication. Now this little helper gives us both access to the Internet and many applications, and wakes us up in the morning. The list of benefits provided by a smartphone can be continued endlessly. It is not surprising that for modern phones invented large number gadgets. One of them is a wireless charger, which we would like to talk about in more detail.

How can I tell if my phone supports wireless charging?

From the name it is clear that this is a gadget that allows you to charge your smartphone without using wires. It is a small stand connected to the network. There is an induction coil inside, which creates a small magnetic field around itself. If there is a smartphone within the radius of this field, it will receive electricity literally through the air. But there is one caveat - the smartphone must also have a built-in induction coil. It will serve as a kind of energy receiver from the charger.

The purpose of creating this device was to get rid of modern smartphones from the charger connectors, and also allow all devices in the house to be charged from one platform. The idea was a success, but why then don’t we see this technology in every home and don’t use it ourselves? The answer is simple - despite all the advantages, this miracle device also has disadvantages.

Pros and cons of a wireless charger

Wireless charging has a lot of advantages, but they all have their own cornerstone.

No wires

Without a doubt, this is a big plus. Wires have always been a weak point in chargers. With frequent kinks, the wire was easily damaged and tangled. Frequent recharging would loosen the USB port on the phone, and sooner or later the phone would need repairs. But there is also reverse side medals. Refusal of wires reduced efficiency (efficiency) from 90% to 60–75%. Simply put, when using wireless charging, your smartphone will charge approximately 2-3 times longer.

Range of use

It would seem that there are no wires - there are no restrictions, and you can charge your phone simply while in the apartment. But no - the radius of use of the wireless charger is very modest (3–5 cm) and the phone will have to be placed on a stand. Another significant drawback will be the inability to use the smartphone while charging.

Price

The cost of a charger is quite variable, but it will always be more expensive than the usual charger.

Standards

I would like to talk about the standards that made the use of technology for transmitting electricity through the air possible.

Qi (“Qi”, after the term of Eastern philosophy) was developed by the WPC (Wireless Power Consortium - Wireless Electromagnetic Energy Consortium). It is the most widespread and is supported by such giants of the mobile industry as Asus, Motorola, HTC, Huawei, LG, Nokia, Samsung, Blackberry, Sony and others. You can find out more about the standard and the list of supported devices on their official website.

The PMA standard also uses the principle of electromagnetic induction, but cannot boast as much big list manufacturers supporting their technology, like Qi. It was developed by Powermat, which at the moment trying to fight unhealthy competition from Qi.

This standard uses Rezence technology, which is fundamentally different from PMA and Qi. The strange thing is that the most unpopular standard has many advantages in comparison with its competitors. The advantages include:

the ability to charge through interference (if you put a book between the smartphone and the charger, nothing will change);
one platform can provide energy to several devices;
work in close proximity to metal objects, etc.

Get acquainted with full list smartphones that can use wireless charging right out of the box can be found on the official website https://www.wirelesspowerconsortium.com. I would like to note that most manufacturers have made sure that their product supports the use of this technology.

What if your smartphone is not on the list of supported devices, but you need to use wireless charging? If you have this question, then most likely you are a happy user of Apple products. The iPhone does not yet have the ability to receive electromagnetic signals. However, there is an alternative - purchasing an auxiliary accessory that will do this for your phone. It fits under a standard case and does not cause any discomfort.

Is wireless charging harmful to health?

Like any new technology, the wireless charger raises many questions. One of the most pressing is whether it harms health. Let’s immediately dispel this far-fetched myth. It will do you no more harm than an electronic razor using the same technology. The developers of the WPC standard themselves claim this.