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Phone Wireless Chargers 5W Qi Carregador Sem Fio para Samsung S8 S9 Plus Nota 9 8 iPhone X Xs MAX XR 8 mais Rapido Carregamento para Telefone USB Carregador Pad

Posted by james021022 
With the continuous improvement of power supply quality, safety, reliability, convenience, immediacy, special occasions, special geographical environment and other requirements of electrical equipment, the contact power transmission mode cannot meet the actual needs more and more.[1]
Mobile Phone Adapter Wireless charger for charging device is the use of electromagnetic induction principle, the principle and the transformer, through the sending and receiving end each placed a coil, the sender coil in power to the outside world under the action of a electromagnetic signals, the receiver coil receive electromagnetic signals and the electromagnetic signal into electric current, so as to achieve the goal of wireless charging.Wireless charging technology is a special way of power supply. It does not need a power cord and relies on electromagnetic wave propagation, and then converts electromagnetic wave energy into electric energy to realize wireless charging.
New electronic products, especially portable electronic products such as digital camera, mobile phone, tablet computer, etc., are increasingly used in people's work and life. The matching charger also follows the traditional wired charger.However, the compatibility and universality of wired charger are poor, and it is inconvenient for users to carry and charge.At the same time, waste disposal increases the environmental pollution.Therefore, it is urgent to provide users with more reliable, convenient, convenient and timely charging equipment.The development of wireless technology makes the transmission of radio power possible, and the research and development of wireless charger will also realize the requirements of users.[3]
Figure 1 wireless charging system model
Figure 1 wireless charging system model
Mobile Phone Cables There will be three main types of battery charging in the future: visual charging, intelligent charging and wireless charging.In 2016, there were only 138 members of the international wireless charging alliance (WPC), but this year, there are more than 200 WPC technology enterprises, such as apple, samsung, HTC, huawei, lenovo, xiaomi, nokia, SONY and other mainstream mobile phone manufacturers.In general, an Qi wireless charger has a flat surface, called a charging pad, on which mobile devices can be charged.Qi specifies three different methods for coil calibration, namely: guided positioning (magnetic attraction) (as shown in FIG. 1 (a)), free positioning (moving coil) (as shown in FIG. 1 (b)), and free positioning (as shown in FIG. 1 (c)).[4]
Mobile Phone Chargers First, guide positioning (magnetic attraction) : a one-to-one charging a fixed position for placing charging equipment and achieve accurate calibration as guide, this calibration method of the advantages of simple, but it needs a series of attracted by the magnet in the charging equipment materials, therefore, eddy current power loss related to (and therefore temperature) will be induce magnetic attractor.Second, free positioning: (with a removable primary coil) is also one can locate charging devices, this method needs a mechanically movable primary coil, tuned to the location of the charging equipment coupling, however, moving mechanical parts tend to make the system reliability is reduced, in addition, the charging of multiple devices, the motor control of the primary coil is complex and expensive.Third, free positioning (coil array) : allows multiple devices to be charged without considering their location. Compared with the above two methods, this calibration method provides more user friendliness at the expense of more expensive and complex winding structure and control electronic elements.
Phone Car Chargers Wireless charging breaks the mode of direct contact transmission only by wire, which is non-contact transmission and can avoid contact sparks, sliding wear, explosive shock and other problems that may be caused by contact power transmission.The radio energy transmission mode mainly divides into three kinds: electromagnetic induction type, electromagnetic resonance type and electromagnetic radiation type.Electromagnetic induction is currently the most commonly used mode of radio energy transmission. Its technology has been mass-produced, lower in production cost than other technologies, and has been verified by safety and market.At present, there are three major alliances dedicated to Wireless charging technology development and standard setting. The three major alliances are Alliance for Wireless Power (A4WP), Power Matters Alliance (PAM) and Wireless Power Consortium (WPC).Qi standard is the "wireless charging" standard launched by WPC, which adopts the most mainstream electromagnetic induction charging technology.The Qi standard is mainly applied to portable electronic products such as cameras, video and music players, toys, personal care and mobile phones.At present, the low power wireless charger study design are mainly for mobile terminal wireless charging, USES are based on the special chip of TI company BQ500211, on a little power terminal is also special integrated chip, using special integrated chip on the early development can save development time, but in the long run consideration for cost reduction and later extended to upgrade.[5]
Phone Case Although wireless charging technology has been developed to some extent, there are still some thorny technical problems in the development process.First, the charging efficiency is not high.Once the distance is a little farther, the charging efficiency will be sharply reduced, and a large amount of time and resources need to be wasted to complete the charging, so it is of little use significance.Second, the safety of the charging process.High-power wireless charging equipment will produce a large amount of electromagnetic radiation, which will have a certain adverse impact on the health of the body, as well as interfere with aircraft and communications.Third, practicality.At present, wireless charging technology can only be realized by fixing at a certain point, which is inconvenient and impractical.Fourth, it is expensive. Because the wireless charging technology is still in the preliminary research and application stage, the research cost is relatively high, so the product price is relatively high.
Electromagnetic induction
This is the most common way of wireless charger. It USES the principle of electromagnetic induction to generate current through the electromagnetic induction between the primary and secondary coils, so as to realize the transfer of energy in the space.This wireless charger implementation has been promoted by the wireless charging alliance.[2]
Radio waves
Phone Screen Protectors Radio wave is a mature wireless charging method developed by wireless charger at the present stage. Its working principle is to capture radio waves in space by means of micro-efficient receiving circuit, and then convert electromagnetic energy into stable electric energy.Already, companies claim to be able to wirelessly charge electronic devices a few metres away that are smaller than cellular phones.[2]
Figure 2 wireless charger
Figure 2 wireless charger
Magnetic resonance
This is a kind of is still in the development of wireless charging technology, the technology is mainly composed of professor of physics at the Massachusetts institute of technology study team, led by Intel engineers to the technology as the foundation, to the power supply in the distance about 1 meters place lit up a 60 watt light bulb, but also the transmission efficiency of 75%.Intel engineers say the next goal will be to use this wireless charging technology to charge modified laptops.But to achieve that goal, the interference and impact of electromagnetic fields on other components of the computer needs to be addressed.
Phone Wireless Chargers In order to make the products of different brand can share the same charger, improve Wireless charger generality, the world's first promote organization for standardization of Wireless charging technology, the Wireless charging alliance (Wireless Power Consortium, hereinafter referred to as the "union"winking smiley launched the "charging" standard, Wireless charging alliance (WPC) under the standard, Wireless transmission of Power consumption is only 0 ~ 5 w.Systems that meet this standard range use inductive coupling between two flat coils to transmit power from a power transmitter to a power receiver.The distance between the secondary coils is generally 5mm, and the output voltage is regulated by a global digital control loop, where the power receiver communicates with the power transmitter and generates power consumption.The communication is a one-way communication from the power receiver to the power transmitter by backscattering modulation.In backscatter modulation, the power receiver adjusts the load to change the current consumption of the power transmitter.These current changes are monitored and demodulated to the information needed for the two devices to work together.Communication protocols include analog, digital acoustic pulse (ping), identification, configuration, and power transmission.[3]
The typical starting sequence when the power receiver is placed on the power transmitter is as follows: [3]
(1) the simulated ping from the power transmitter detects the existence of the object.
(2) the digital ping from the power transmitter is an extended version of the analog ping and gives the power receiver time to respond to a signal strength packet.If the signal strength packet is valid, the power transmitter will energize the coil and proceed to the next step.
Figure 3 wireless charger
Figure 3 wireless charger
(3) in the identification and configuration stage, the power receiver will send some packets to identify them and provide configuration and setting information to the power sender.
(4) in the power transmission stage, the power receiver sends control error packets to the power transmitter to increase or decrease the power.Control error packets are sent every 250ms during normal operation and every 32ms during large signal changes.In addition, during normal operation, the power transmitter will send power packets every 5s.
(5) in order to terminate the power transmission, the power receiver sends a "stop charging" message or does not communicate within 1.25s, so that the power transmitter enters a low-power state.Under the Qi standard, mobile phones, cameras, computers and other products can be charged with Qi wireless charger, and large-scale wireless charging will be possible.
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