Universal wireless chargers. How to buy wireless charger on AliExpress? Qi wireless charging standard. Wireless charging of smartphones on the example of Qi standard solutions

Universal wireless charger is one of the most useful gadgets existing today. Surely each of us found ourselves in an unpleasant situation when the phone had a couple of percent of the battery charge left, and there was no necessary cable at hand with which you could recharge your smartphone. In our today's review, you can see the 7 best productive models of devices of this kind.

1. Multipurpose Wireless Charging Device - Oregon Scientific Time & Wireless Charging Station QW201

Oregon Scientific Time & Wireless Charging Station QW201 is a multifunctional device that contains several useful features: Digital Watch, alarm clock, thermometer and wireless charger for mobile phone. The Oregon Scientific Time & Wireless Charging Station QW201 is priced at approximately $130.

2. Ultra-thin wireless charger - ZENS Single Wireless Charger

ZENS Single Wireless Charger is a universal wireless charger that ensures that the phone is not overloaded and automatically turns off the power supply after a full charge. The ZENS Single Wireless Charger is about $100.

3. Multifunctional wireless charger - Energizer Dual Inductive Charger

The Energizer Dual Inductive Charger is a versatile wireless charger that allows you to charge three mobile phones at the same time, two in wireless mode and one through USB cable. The Energizer Dual Inductive Charger is approximately $85.

4. Tiny Wireless Charger Stand - Nokia DT-910

Nokia DT-910 is a compact functional charger that allows you to conveniently use your phone while charging without removing it from the power source. The Nokia DT-910 costs approximately $70.

5. Universal Wireless Charging Kit - Duracell Powermat 24-Hour Power System

The Duracell Powermat 24-Hour Power System is a multipurpose charging kit that includes wireless device power supply for mobile phone. The package also includes: a case with a module and an external rechargeable battery. The Duracell Powermat 24-Hour Power System is priced around $100.

6. Dual Wireless Charger - ZENS Dual Wireless Charger

ZENS Dual Wireless Charger is a universal wireless charger, the main feature of which is the ability to simultaneously charge two mobile phones at once. The ZENS Dual Wireless Charger is priced at approximately $130.

7. Functional wireless charger - Nokia DT-901

Nokia DT-901 is a functional wireless smartphone charger made by a well-known Finnish company. Main feature device, is its design, the appearance of the gadget resembles a small pillow. It is also worth noting that the novelty is made in three colors: black, blue and red. Nokia DT-901 costs about $50.

And for those who are seriously interested in purchasing such a device, you should also take a look at the first part of our review consisting of

Qi is the Chinese word for "energy flow" (pronounced "chi" in English) and the universal standard for rechargeable batteries such as iPods, cell phones and cameras.

Power transmission occurs due to this. In this case, the receiver receives energy not through a traditional cable, but contactless way through the use of electromagnetic fields. The principle is very simple: the Qi transmitter, which is the base station, sends the necessary energy to the receiver.

Technology Description

The Qi wireless charging standard is based on magnetic induction between the flat coils of the transmitting and receiving apparatus. The primary and secondary windings form two parts of the coreless charger circuit is shielded on the lower surface of the primary and the upper secondary coil. This, and the close proximity, guarantee acceptable power transfer efficiency. Moreover, it minimizes the impact magnetic field on users.

Typically, a base station has a flat surface on which one or more mobile devices can be placed. This ensures that the vertical distance between the primary and secondary windings is sufficiently small. In addition, there are two ways to align the windings horizontally.

In the first case, the user independently sets the secondary winding opposite the primary winding on the interface surface using prompts from the mobile device.

The second method, called free positioning, does not require the active participation of a person. In one implementation, several primary windings are created for this. Another variant uses mechanical means to move the primary coil under the secondary.

Structural elements

The power transmitter consists of two main functional units, namely, a power conversion unit and a communication and control unit. The element of the first, generating a magnetic field, is the primary coil. The second changes the transmit power to the level requested by the receiver. In addition, the base station may contain more than one transmitter to serve several mobile devices, since one primary winding interacts with only one secondary at the same time. And finally system unit provides power and controls multiple transmitters.

The gadget contains an energy receiving unit, which is a secondary winding, and a communication and control unit. The latter regulates the transmitted power to a level acceptable to the subsystem connected to the power output of the receiver. An example of such a subsystem is a battery.

Stages of communication

After activating the communication and control unit of the transmitter, it sends a signal to the receiver to receive a response confirming the presence of a Q-compatible device.

Upon receiving the request, the receiver enters the selection phase. If the offered voltage is high enough, then the ping phase begins.

Upon receiving a response from the transmitter, the mobile device sends a signal strength packet and enters the identification and configuration phase, or sends a power transfer complete packet and remains in the ping phase.

Then an identification packet and control packets are sent. The receiver enters the charging phase. At the same time, it controls the transfer of energy by transmitting control packets. base station, which contain information about adjusting the current of the primary winding, about the received energy, about the charging status, about the completion of the transfer.

What is a wireless charging point?

Qi-charging is universal because it ensures the compatibility of mobile phones and different manufacturers. The only condition is that both parts - transmitter and receiver - must comply with the Qi standard.

Thus, any Qi wireless charger will fit any Qi mobile receiver, regardless of brand or model. A bunch of cell phones different manufacturers, including Samsung, Nokia, LG, Sony, HTC and Motorola, are already Qi-compliant and therefore can be connected to any charging station that meets its requirements. The number of compatible gadgets continues to grow as technology wireless transmission energy is supported by everything a large number companies. This makes it possible to charge battery-powered electronics with a single power source.

How it works?

The mobile charger is not the latest invention. Electric toothbrushes have been using inductive power for many years. The process uses a resonant inductive coupling of the base station transmitter and mobile phone receiver. The primary coil continuously sends a test signal to the sender to check for a change in capacitance or resonance indicating the presence of a compatible phone. The transmitter modulates the charge and checks if the Qi wireless charging standard is supported.

Once compatibility and energy requirements are taken into account, the process of inductive energy transfer begins. In this case, the contact between the receiver and the transmitter is maintained. Once the battery is fully charged, they will go into standby mode. Universal charging is activated and transfers energy only if the connected gadget is on it.

Coils transmitting and receiving energy are specially shielded in order to reduce electromagnetic radiation.

The main features of the technology

• A method of non-contact power transmission from a base station to a mobile device, which is based on the near field magnetic induction that occurs between the coils.
• Transmission of about 5W of power using a suitable secondary coil (having a typical outer dimension of about 40mm).
• Operation at frequencies from 100 to 205 kHz.
• Support for two methods of placement on the surface of the base station:
  • guided positioning, where the user is assisted to correctly position the mobile device in a location providing power through one or more fixed points;
  • arbitrary placement on the surface of the charging station.
• A simple one that lets your phone or tablet take the lead.
• Significant design flexibility to integrate the system into a mobile device.
• Low standby power consumption (depending on implementation).

One for all

How convenient would it be to have one Qi charger for all phones, players, cameras without a lot of tangled cables?

While countless new smartphones are sweeping the world, the battery life battery getting shorter. And every manufacturer and even every gadget has its own charger. And with each purchase, their number increases. Ultimately, the user is lost in a pile of various power adapters. Thanks to Q-technology, they become unnecessary, and tangled tangles of cables disappear, and this is not all the advantages of this technology.

Just as Wi-Fi became the global standard for wireless Internet connections and Bluetooth eliminated the need to hold your phone in your hand, so Qi is becoming the global standard for inductive charging of battery-powered gadgets.

Is electromagnetic radiation harmful?

Expert opinion is divided. On the one hand, many scientists confirm that a small amount of electromagnetic radiation from wireless charging does no harm. Others talk about great danger to which the human body is exposed.

So how much electromagnetic energy is emitted by the Qi system? Very little. The Qi principle has been used in electric toothbrushes for many years without affecting people's health. The scheme of the charger is such that due to the small area of ​​​​its action, electromagnetic radiation is extremely limited. It exists only in the immediate vicinity of the wireless transmitting station and only when the gadget is on it. Electromagnetic radiation further reduced by additional shielding in the transmitting and receiving coils.

Wireless Power Consortium

The Wireless Power Consortium (WPC) was founded on December 17, 2008. At the same time, a unified program for the development of this technology was approved.

The Qi wireless charging standard ensures its versatility for all Qi-compatible electronic gadgets. This means that every device compatible with it can be charged at any Qi-compatible station. The WPS has 250 members, including market leaders Samsung, Nokia, LG, Panasonic, HTC, Sony, Microsoft and Motorola, making it the largest association of manufacturers supporting wireless types chargers.

As the number of Qi-enabled products increases, it's important to make sure every mobile charger works correctly with all Qi-supported gadgets, said WPC Chairman Menno Treffers. This is facilitated by a constantly updated database created by Testronic, which makes it easy to determine whether New Product compatible with previously certified products. The Qi wireless charging standard has become one of the most important technical developments for users of phones and tablets, which are now used daily in work and life.

A couple of months ago I became the owner of a very interesting smartphone- TCL Idol X S950 (aka Alcatel One Touch 6040D). Today, having one of best ratio price quality. I will not list all the characteristics - Google knows them. I will stop only at 5" - FullHD(Sharp) - 140.4 x 67.5 x 6.99 - 120 gr.

And everything would be fine, but I had to charge it all the same, in the old fashioned way, by everyday wear of a small microUSB connector.
The wires have long been tired, and the manufacturers still did not reach the standardization of wireless memory. And here the Nexus 7 appeared in use, with the possibility of wireless charging, and it turned out that finally the standardization arrived in time. So it was decided to upgrade your smartphone like this convenient function like wireless charging.

Since the phone is only 7mm thick, it was doubtful whether a QI-standard receiver would fit inside the device.
Therefore, for a start, I took a universal receiver, since our eastern neighbors quickly responded to the growing demand and released one. It is designed for CIP installation in any smartphone with a removable back cover. It was made quite competently, but the experimental back cover is non-removable and when connected to the phone it all looks like this:

In principle - not bad, nothing sticks out. But there are two buts:
1) to connect the cord - you need to pull out the charge, and the firmware that I like (MIUI) is not yet stable, i.e. will have to do it often;
2) I don't wear covers; it would be necessary to fix the receiver on the back cover, but with the possibility of removal if necessary.

Therefore, I decided to check the charging process itself, and then open the phone - and implant the receiver inside. Checked - charging, it's time to move on.

I measured the actual thickness of the receiver itself: in the main part - 0.8 mm, in the region of the components there is a maximum thickening of 1.26 mm. This led to sad thoughts (with a phone thickness of 7 mm), but the decision has already been made, and there is nowhere to retreat.

We open the phone. (Here, even those who already know how to do it with their left hand with their eyes closed - keep in mind that the plastic is quite soft, and the fastening ears are very thin, so open it very carefully. I did it.)
How it looks inside, I have seen more than once in the photos and videos posted on the network. An autopsy confirmed that nothing had changed there since the filming, so only one question arose - where is it easier to solder the receiver? At first I thought to the microUSB connector, but there is a rather large polygon on the positive contact, apparently in the lower layer, and it was not very convenient to solder there. Then I rang the contact pads and found the contacts I needed, displayed on the TP.
See the photo, marked the positive and negative contacts:

Then I unsoldered the connector from the receiver and soldered its conductors to the phone's TP (the lead wires in the receiver are flat, which in this case very handy). I soldered without disconnecting the battery, which is NOT CORRECT !!! If you repeat - be sure to disassemble upper part and disconnect the battery.

... but I did not want to do this, plus I decided to check the straightness of the hands and the reliability of the circuitry used in the phone. All in all, everything went well. Soldered, made a coup of the receiver and voila:

A few words why this is so. The thing is that you intuitively try to put the phone in the center of the charging station, respectively, the receiver antenna is also desirable to be in the center as much as possible. When soldering in that place - the receiver just lay down perfectly after the coup. And the second reason is those 1.26 mm that I mentioned. At the end of the battery (where its electronics are) there is a slight thickening, and the battery itself is slightly thinner, and the phone's electronics are flush with the battery. This thickening is just where it is desirable to place the antenna. So it turned out that it is ideal to put the soft part of the antenna on the thickening, and 1.26 mm will be above the electronics, which is quite acceptable.

Well, then - assembly and verification. Here MIUI reports that it is charging:

In addition to the receiver, which was built into the phone, you need a QI standard charging station. There are many different ones, both cheap Chinese and expensive branded ones (made in the same China). I settled on this one (it has a built-in 10A battery):

Although the CVC to indicate the data of 10000mA was clearly filmed by Chinese devices. In fact, the capacity differs downward. But for a couple full charge enough, and thanks for that, as they say.

In general, I am satisfied. It takes longer to charge than from a cord (the receiver is limited by a current of 500mA), but the phone usually charges overnight, so it's not critical at all. At the end of the charging process, both devices are disconnected from each other.
On the other hand, if you put the station at the workplace, then you can take the phone from the station and put it on it, respectively, the energy consumption in work time may tend to 0 if the work is not on the road. And if it is an exit station, then a similar station, only 12V, can be connected to a car. And after talking, send the phone not in your pocket, but on a stand.

Everything is working, appearance not violated. A place with a thickening of 1.26 mm is felt, but since there is a screen under it, and then a silumin frame, it does not affect the screen. Well, we'll see...

Actually opening can be avoided by those who wear the phone in a NOT hard case. There should be enough space between the case and the back cover for outdoor installation of the receiver. In addition, the external installation of the receiver reduces the heating inside the device, which is more favorable for life cycle batteries. But the interior is aesthetically much more pleasing.

In general, it is not so scary and expensive to adapt almost any smartphone to the world of wireless charging technologies.

P.S. everything you do - do it at your own peril and risk, if you are not confident in your abilities - it's better not to start. Illiterate opening of the device entails a possible withdrawal from the warranty, any traces of soldering inside the device - 100% deprive you of warranty service.

In short: take it!
The purpose of this review is to provide the main specifications rather than write a novel. In Russian and literature, I had fours, I did not like compositions. Find errors, write, correct. And in general, as the Chukchi would say: "Yours want to buy a product, mine is yours to write a review."

Background. Order
I decided to get a wireless charger for my Chinese phone(Samsung clone Galaxy Note II). Choose the cheapest options. As a result, I ordered separately universal charging and a receiver with a connection via micro USB. They came in regular bubble bags. The charger-transmitter comes with a white USB cable, 80 cm.


Specifications

Charging-Transmitter:

Input voltage: DC 4.6-5.5V
Input current: 1000-2000mA
Driven load: 5W
Charging efficiency: 75%
Operating temperature: 0-45
Humidity range: 45-85%RH
Charging frequency: 100-200KHz
Power distance: 5mm
Dimension: 155 x 84 x 9mm
Electric energy transition: 72%
Weight: 104g
Light status: 1.Red led: standby; 2.Blue(or Green) led: charging; 3.Flashing: voltage/current/temperature anomalies

Receiver:

Input: 5V
Output: 1000 mA
Size: 69x44mm

Testing:
First of all, I decided to measure the current during normal charging of the phone. For this, I used a folk USB tester and the Ampere program. To my surprise, the results were different. I don’t know what to sin on, maybe the program makes incorrect measurements.

I don’t know who to believe, but I will be guided by the testimony of the program.
In Standby mode, the red LED is barely noticeable, the tester shows zero current consumption (in fact, it is less than 50 mA, there is nothing more accurate to measure). Therefore, you can safely leave charging in standby when there is no need to charge the phone.
When the phone is put down, charging is activated and a moderately bright blue LED lights up.
In charge mode, the transmitter consumes about 780 mA (according to the tester).

At the same time, the phone receives about 540 mA (according to the program).

For my phone, the difference is not great, so it does not take much more time to charge wirelessly. For those whose phone directly consumes about 1 A, for those the wireless option will be twice as long. During operation, charging and the phone do not heat up significantly, it feels warm, about 30-40 degrees.

A few words about the receiver.
Achtung! When buying, pay attention to which way the micro USB connector on your phone is turned. On aliexpress, I met the receiver in two variations.

The thickness of the receiver is not uniform. The main area has a thickness of 1 mm, at the location of the microcircuit 1.45 mm (measured with a caliper). Fits perfectly for my phone. The lid closes tightly, nothing sticks out. True, I had to cut the latch on inside so as not to pinch the cable. The cable is very thin, only 0.2 mm. I can’t show pictures with the phone, because the only camera is the phone itself.

At the end of the charge, the transmitter continues to glow, consumes about 600 mA and remains warm. Since the phone stops consuming energy, everything goes to an unwanted electromagnetic field.

Total:

Pros:
- cheap
- Universal
- Fairly thin receiver
- There are no problems with positioning, charging does not stop from a slight displacement of the receiver and transmitter.

Minuses
- No automatic shutdown at the end of the charge
- Short USB transmitter cable, only 80 cm.
- The receiver outputs about 500 mA instead of the declared 1000 mA.
- USB is constantly busy. To connect something to the phone, you have to remove the cover. It will be problematic to recharge the phone via cable. To transfer files, you have to use Bluetooth or WiFi.

I am satisfied with the purchase, now there is no need to reach for the cable and try to get into the phone connector in the twilight. I recommend it to everyone who is not critical of the charge time.

P.S. No cats, dogs, cockroaches or other pets!