What you need to know about wireless charging
Technologies / / December 19, 2019
How did the wireless charging
In 1820, Andre-Marie Ampere provedAndré Marie AmpèreThat an electric current creates a magnetic field, and in 1831 Michael Faraday discoveredFaraday discovers electromagnetic induction, August 29, 1831 law of induction, which became the basis of the work of modern wireless charges.
In 1888, Heinrich Hertz confirmedHeinrich Hertz Produces And Detects Radio Waves In 1888 the existence of an electromagnetic field. His research helped to Nikola Tesla for the first time to transfer energy into the distance. This happenedWorld's Columbian Exposition in Chicago in 1893 in 1893 at the World Exhibition in Chicago.
Until the end of the XX century with the energy transfer at a distance of a variety of ways, many scientists experimented. Research is still going on.
Massive interest in wireless charging has arisen only after the boom of mobile devices already in the XXI century.
Today this question involved the organization of Wireless Power Consortium and AirFuel Alliance.
What are the standards for wireless charging
To charge a smartphone wirelessly, using a pair of coils, one in the charging station, which is connected to the power supply, the other device.
When the first coil current appears, it is formed around the magnetic field, which passes it to the second.
The magnetic field appears due to the use of high frequency alternating current. He converted to DC when transferred to the device.
Depending on the frequency of the current job are included in the magnetic induction or magnetic resonance.
Magnetic induction station
They transmit the energy over a distance of about 10 mm and used for AC frequency of 100-357 kHz. To charge a smartphone with such a station, it must maintain its specific range of frequencies.
The magnetic field does not pass through the metal, so the wireless charging is possible only on smartphones, the rear panel which is made of glass or plastic. In this case, even a thick protective cover can prevent charging.
According to the principle of magnetic induction wireless charging works Qi and PMA.
Qi standard development since 2008 engaged in the organization of Wireless Power Consortium (WPC), which includes manufacturers of chargers from America, Europe and Asia. Its specifications are in the public domain Qi wireless power specification.
This wireless charging standard is used iPhone 8 and newer smartphones Apple, as well as in all devices Samsung Galaxy S line of the last five years.
With them also work the company Xiaomi, Huawei, LG, Sony, Asus, Motorola, Nokia, HTC.
PMA standard development from 2012 to 2015-th was engaged in the organization of Power Matters Alliance (PMA).
He is increasingly common in the United States. There he was promotedAT & T removed Qi wireless charging in the Lumia 1520 to make room for PMA mobile operator AT & T and Starbucks coffee house chain.
Today, Power Matters Alliance composed AirFuel Alliance is engaged in the development of an alternative type of wireless charging AirFuel. But along with the Qi standard is still supported Samsung smart phones, including the latest flagship Galaxy S10, S10 + and S10e.
Magnetic resonance station
Unlike stations operating on magnetic induction, they apply increased up to 6.78 MHz frequency of the current. This allows you to expand the charge radius of up to 40-50 mm.
In such wireless charging is used as a set of two coils. But they can not be located opposite each other, so chargers need not be formed as a pedestal or mats.
On the principle of magnetic resonance wireless charging standards work Rezence and AirFuel.
Rezence development from 2012 to 2015, the first organization involved in Alliance for Wireless Power (A4WP).
By increasing the distance charging standard positioned as a more convenient alternative to Qi and PMA. Now part of the A4WP AirFuel Alliance and is working on AirFuel standard.
Rezence promoted component manufacturers Broadcom, Gill Electronics, Integrated Device Technology (IDT), Intel, Qualcomm, Samsung Electronics, Samsung Electro-Mechanics, and WiTricity.
This type of wireless charging has not yet reached the mass production. The potential of its spread is still unclear, but the company plans to HuaweiHuawei puts on a resonant wireless charging AirFuel to complete them all their smartphones.
Development of standards AirFuel, which will be a continuation Rezence, the organization does AirFuel Alliance since 2015.
In AirFuel theory can even hide under a table or other surface. Through it, the station will be able to work simultaneously with multiple devices: smartphones, headphones, laptops.
What you need to know about wireless power zaryadok
Wireless charging different in input and output power: it usually ranges from 5 to 20 watts.
Her level point on the device, on the box, on the official website of the manufacturer. It also can learn from reviews.
Some companies instead of watts Shows the voltage and amperage. Their values, you can also find out how fast you can charge the device.
Charging power in watts = voltage in volts × amperage.
Wireless charging can be supplied without a power supply. Their input power need to know to determine what is suitable for their valuable work. Standard power supply unit iPhone - 5 W, iPad - 12 W, Galaxy S10 - 25 watts.
If the input power is sufficient, the device should give the maximum output. Charging ZMI WTX10 Wireless Charger produces 18 watts, dual dock Samsung EP-P5200 - 10 Watt recommendedBelkin Boost Up Special Edition Apple charger Belkin Boost Up Special Edition - 7,5 watts.
It should be understood, with a capacity of wireless charging your smartphone operates. iPhone 8, 8 Plus and X 12 is maintained at iOS 7.5W, iPhone XS, XR and XS Max, Galaxy S10 - 10 watts.
To determine the approximate charge rate in hours from 0 to 100%, still need to know the battery capacity smartphone in watt-hours, and to take into account the efficiency (COP) of the wireless charging - usually 75–90%.
charging rate in hours = battery capacity in Wh / output charging power (or smart phone, if less) in watts / efficiency in% × 100%.
To charge the battery iPhone XS Max W at 12.08 h ∙ via ZMI WTX10 Wireless Charger, will take at least 1⅓-1⅔ hours. In this network it is possible to connect a standard power supply.
What you need to know via wireless charging
How to install on your smartphone charging station
Put the smartphone in the center of wireless charging, or at the place designated by the manufacturer.
Make sure that charging has begun. If that happens, your phone does not support this method of energy transfer, or you are using is too thick cover.
How to avoid overheating during wireless charging
During wireless charging smartphone warms more than usual. To avoid overheating, it may temporarily suspend the transfer of power when the battery charge reaches 80%.
Do not use bulky blankets that prevent the natural heat exchange. And do not put on a device that is charged, foreign objects. It is dangerous to cover it with a cloth that restrict air circulation.
How long your smartphone may be on a wireless charging
The smartphone may be on a wireless charging all night. When its battery charge reaches 100%, the energy transfer will stop.
Importantly, use high-quality charging cable and power supply to avoid short circuit.
Should I buy a wireless charging today
Wireless charging will be a good gift for a colleague or business partner, it will take a worthy place on your desktop at home or in the office.
But before buying a wireless charging it is necessary to weigh its advantages and disadvantages.
- You can simply put the smart phone on the charger, and he immediately begins to replenish energy.
- No need to look for a suitable cable connector (Lightning, microUSB, USB-C).
- Reduced wear of the power supply cables, ports and connectors.
- Wireless charging is slower than wired due to the lower efficiency.
- The charging station rarely goes complete, usually it is necessary to buy separately.
- You can not take full advantage of your smartphone while charging.
- If you accidentally move the smartphone, which lies at the station, charging may stop.
- Thick protective covers and cases with metal parts can interfere with wireless charging.
- Wireless charging is not always convenient take with you.
In wireless charging today more minuses than pluses. Until it is at an early stage of development, so we need to clearly understand where and when it is appropriate to use.
Wireless charger conveniently on the desktop. You can put it on the bedside tables and put on him a smartphone before bedtime. But it is quite inconvenient to take such a charge to travel and use on the move.
With the development of standards and AirFuel Qi wireless charging will be used throughout. But for that manufacturers will expand the radius of action, increase the charging rate and deal with the other shortcomings.
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