Wireless Mobile Charging: A Hassle-Free, Convenient And Safe Solution

Advantages of Wireless Mobile Charging

Wireless Mobile Charging platform delivers a better and much more convenient way of charging electronic devices such as mobile phones and create a hassle free environment without any use of cables or wires. The use of cables and physical connectors is not done, which allows for saving both cost and energy as well as provides better safety benefits. With the advancing technology nowadays, the wireless mobile charging system has made a huge positive impact by maintaining a hassle free charging environment and ensured continuous, safe and reliable transfer of energy and power to the handheld devices (Ahn and Hong 2014).

After completing with my secondary school, I got my Bachelor’s degree in Electronics and Telecommunication Engineering. The time duration taken to complete my Bachelor’s in Engineering had been four years and it started from July 2007 to June 2011. I also took part in various major projects related to the telecommunication industry, which further helped me a lot to gain relevant skills and knowledge about how to deal with the Wireless Charging Mobile Platform, and this had been considered as one of the major components of the project based on which the research would be conducted. As it is a research project, so the supervisor’s guidance and support have helped me a lot to conduct he research and bring out favorable outcomes with ease and effectiveness. Among the various knowledge and information that I obtained while conducting the research, I also found that there had been huge technological advancements and this had further resulted in huge innovation within the field of electronics and telecommunications. The research project is entirely based on the Wireless Charging Mobile Platform and with the help of proper support and guidance from the supervisor, the work has been conducted by the University and completed as well within the allocated time frame in an effective manner (Andersen et al. 2015).

With the advancement in technology and communication nowadays, there has been innovation in the field of Electronics and Telecommunications as well. A wide range of innovation procedures have emerged which has given rise to enormous opportunities to develop creative telecom devices as well as new products and services in the market. There were many wired telecom devices previously which had now changed to wireless devices and this had provided enough growth within the telecommunication industry too. The use of wires often leads to various complexities and issues of charging a phone or any other electronic device (Beh et al. 2014). With the rapid innovation and technological advancements, the wireless technology has gained pace and this has resulted in charging a mobile phone without using any wires. This is quite convenient as because there is not only any need of using wires but also it is portable and can be charged anywhere with a lot of ease. A static or portable mobile charging platform is quite more convenient when compared to wireless charging devices as because it can not only offer remote charging but also offers better scopes and opportunities to charge the hand held mobile device quite easily. The wireless mobile charging is also known as the inductive charging and it has utilised an electromagnetic field so as to exchange or transfer energy from one object to another through the process of electromagnetic induction (Cao et al. 2013). The process works like this where the energy is sent with the help of an inductive coupling to a particular electronic device such as mobile phones and is later used to charge the batteries of the device and make the device function properly. To develop an electromagnetic field, it is necessary to use the induction coil within the charging point while the other induction coil that is used within the portable device for the purpose of collecting the power from the electromagnetic field and then convert it into the electric current. This will support in charging the battery of the mobile phone easily. There are other situations as well when the distance between the sender and receiver can be greater though with the use of resonant inductive coupling by the Wireless mobile Charging or induction system (Freeman 2015).

Disadvantages of Wireless Mobile Charging

As the project is based on the application of wireless mobile charger, I have created project proposal report by using the Microsoft Word document and PowerPoint presentation for the purpose of presenting various graphical components and also explain the goals and objective that are needed to be achieved. By understanding the benefits and drawback of the cable system, I have learnt about how much the wireless mobile charging system has been effective and reliable and has even created a much more convenient platform for the innovation within the telecommunications industry. After the research proposal was accepted by the supervisor of the University, I finally managed to communicate with the other team members and discussed about how the project should be undertaken in the next couple of weeks. This is a group project and with the help of my other team members, I designed a planning process in order to collect necessary information about the requirements of the system as well as properly manage the process of scheduling. 

One of the major advantages of using the wireless mobile charging device is that wires are not used and is much more convenient than wired charging devices. It is portable which allows us to carry the device from one place to another and charging is done almost anywhere. The connections are protected, due to which the electronic devices when enclosed do not suffer from any corrosion. There are lesser chances of electric faults or power fluctuations as well. Often it has been seen that the wired charging devices get torn, which hinder the proper connections and disrupt the charging of the mobile phones too ((Heys et al. 2013). This kind of issue has been overcome by the wireless mobile charging system. There is also less chance of transmitting power via a magnetic field passing through the skin and this prevent various risks related to the skin infection which may be experienced by individuals. As it is wireless, so there is also no need of plugging or unplugging the device repeatedly, which furthermore reduces the chances of wear and tear on the device’s socket (Hui 2013). It provides better convenience and offers aesthetic quality, as because there is no need of using cables or wires.

Few of the drawbacks of using the wireless mobile charging platform are slow charging speed, which makes the mobile phone heated up, though taking a lot of time to charge. The wireless charging devices are much more costly than the wired devices and this, in turn, increases the complexity for many individuals who are not tech savvy. Another major drawback of using the wireless mobile charging system is the inconvenience (Kesler 2013). While charging with the help of cable or wired device, the mobile phone can be moved to a certain distance and operated for some time or for taking calls. In the case of wireless charging mobile platform, the mobile device shall be kept on the mat for charging and thus it may not be moved from that place while it is getting charged (Khawar et al. 2014). This is a major disadvantage as because in case of taking calls or moving the mobile phone around; we need to disconnect it at first from the wireless charger and then carry out that activity. The prices of wireless mobile charging devices are also higher when compared to the wired devices, due to the increased cost of manufacturing (Ki and Lu 2013).

Working Principles of Wireless Mobile Charging

While conducting the research, the most relevant data based on the research topic has been collected from various secondary sources. The IEEE Xplore has been utilised in order to find out the most important and generic data from digital libraries and also from other journals, articles, documents, blogs and websites. Few of the research papers were Wireless Mobile Charging: A Revolution and Wireless Charger Networking for Mobile Devices, applications of wireless mobile charging device, etc. In order to maintain the codes of ethics and the quality standards of the research, the rules and regulations regarding health and safety have been maintained as well (Kim et al. 2013). The data and information used in this research have been kept confidential and all the documents that comprise the secondary research sources are authenticated, which has also prevented use of any illegal information during the research. The health and safety standards have been maintained by making the research team aware of the rules and regulations of handling the devices and make sure that any accidents are prevented (Kotte et al. 2013).

For developing a proper and reliable system according to the wireless communication system, it is important to make sure that the mobile phone that supports wireless charging is selected. Every mobile phone do not support the wireless charging system, so it is important to choose the mobile phone wisely and make sure that it supports the wireless charging mats. Few of the mobile phones that support this kind of wireless charging system are HTC, NEXUS, SAMSUNG S7 AND S8 (Le et al. 2013). The research project has been developed for understanding about the wireless mobile charging platform in details and furthermore ensure that the charging is done without any issues or complexities which may be the case for charging with the wired devices such as USB cables. There is no need to find plugs to put the USB cable, rather the mobile phone can be placed on the charging mat and within a particular amount of time, the device will be fully charged (Migneault et al. 2012).

Figure 1: Wireless charger

(Source: PowerbyProxi 2017)

The LG NEXUS wireless charging device has been considered here as most effective as it not only provides faster charging of the mobile phone but also is portable and thus it can be carried from one place to another place. The case has a protective hard outer shell that makes it quite resistant to drops (Musavi and Eberle 2014). 

As because the wireless charging is based on the inductive charging principles, so an electromagnetic field is created which allows for transfer of energy from one object to another. The energy is sent with the help of inductive coupling and it is sent to the electronic device such as the mobile phones and charges it. One of the major working principles is the magnetic resonance, also known as the inductive power transfer, that lets transmitting power or energy from one object to another object by using coils (Niu et al. 2015). This would create an electromagnetic field and allow transferring power to the handheld device as soon as it would be placed on the charger mat.   

Though the mobile phone is charged wireless, the charging mat needs to be connected with a cable so as to draw in the current within the coil and create a magnetic field. When the mobile phone is placed on the charging mat, the battery of the device gets charged with the current that is produced by the coil through creation of magnetic field. The working principles include converting the main voltage into alternating current comprising of high-frequency rate (Ongaro et al. 2012). The alternating current is transmitted to the transmitter coil with the help of circuit, which further facilitate the time variations within the magnetic field that is created by the coil. The AC or alternating current then flows to the receiver coil and this process of transmission of energy from the sender to the receiver coil is termed as the resonant coupling. As soon as the current reaches the receiver coil, it gets transformed into DC or direct current and then the mobile phone is placed on the charger mat for charging. Therefore, it could be understood that the magnetic resonance is an effective working principle of the wireless charging (Ostapenko et al. 2013). 

At first, the main voltage is converted to the alternating current of high frequency and then the AC is sent to the transmitter coil. As the current reaches the transmitter, it circulates within the coil and creates a magnetic field, which in turn generates the current within the receiver coil. The alternating current is converted to direct current, which provides power to the battery through charging as soon as the mobile phone is placed over the charging mat. Few of the major advantages of the resonance wireless charging are better ability to achieve the transfer of power and coupling (Pinuela  et al. 2013). This serves better for various purposes as because the mobile phone shall be aligned on top of the transmitter and this would allow charging the device within quick time. Previously there were cases where the charging rate or speed was quite slow when compared with the wired devices. With time, various technological innovations are experienced, and this has resulted in improved rate of energy or power transfer from the transmitter to the receiver coil. This, in turn, enhances the rate f power delivery to the battery of the mobile device for the purpose of charging (Samanta and Pal 2013).            

The resonant inductive coupling is the process where the coupling increases with the resonating of the coupled coil. The two major things that are present include one drive coil and another is the resonance circuit. When the resonance occurring in the secondary side could be observed from the primary side, then the two resonances were considered as a pair known as the parallel or anti-resonant frequency (Sturcken et al. 2012). The other resonance on the other side is termed as serial resonant wireless charging frequency. The wireless charging mat works on the various working principles of resonant wireless charging and this function with the combining of the short circuit inductance and the resonant capacitor present within the secondary coil. The magnetic field is created when both the magnetic fields on primary coil and secondary coil get synchronised and this further results in production of high voltage within the secondary coil (Thomas et al. 2013). As we discussed earlier about the improved efficiency of the wireless mobile charging system, it could be understood that with the production of maximum voltage within the secondary coil, the mutual flux enhances, thereby reducing the loss of copper of primary coil and generation of heat too (Xie et al. 2013).

Resonance is a kind of distortion or fluctuations in frequencies when a system which has been vibrating or any other force that has been put from an external body makes a particular system gain some movement up or down with some high amplitude at a particular frequency. The resonance frequency is experienced when the response amplitude’s becomes relative maximum and allows for generating high power and energy through the formation of a magnetic field within the coils (Zeni et al. 2012).

The diagram below shows the wireless transmission of power or energy. There are two resonant circuits, which have been linked with the self-resonant coils and are also tuned to the same frequency of the resonant. The electronic oscillator present within the transmitter creates a high-frequency current, which allows for generating power within the coupling coil. This further facilitates or enhances the flow of oscillating current in the circuitry and a magnetic field is produced that allows transmitting the current from left hand to right-hand circuit (Zhang et al. 2012). The power is coupled out from the resonating circuit and gets turned into direct current, which has been utilised for powering the load and charging the mobile phones, as soon as it is placed on the charging mat.

The circuit of the wireless charging system consists of two transistors and these started functioning when the alternating current has been passed through these coils. The coils get distorted with the flowing current and this, in turn, results in generating a drain voltage. The drain voltage is formed at one end of the transistor Q1, which helps in turning it ON and makes the gate voltage fix to the nearest ground area (Olvitz et al. 2012). Though the Q1 transistor is ON, the other transistor Q2 remains at offline state, thereby increasing the drain voltage to a large extent on a consistent manner. On the other hand, the capacitor used within the circuit prepares the primary coil from where the alternating current will be generated afterwards. As we know that when the resonance is experienced within the tank circuit, with the increase in frequency, the inductive reactance enhances while the capacitive reactance reduces. The formula for evaluating the resonance frequency is stated below (Liou et al. 2012). 

With the increase in voltage and frequency, there might be chances of getting damaged due to the excessive heat produced. Therefore, in order to maintain a good circuit, the heat sink is used with the MOFSET, which can further prevent excessive heat generation and furthermore ensure that the circuit functions properly for the wireless mobile charging system. The metal–oxide–semiconductor field-effect transistor or MOSFET is a type of field effect transistor used for the purpose of assuming the device conductivity with the help of produced voltage (Musavi et al. 2012). This kind of transistor is also useful for changing the conductivity of the device as well as switches the electronic signals that are transmitted within the circuit. This is because with the excessive heat, not only the wireless charging device may get damaged but also the mobile phone when placed over the charging mat. The insulated copper wire helps in preventing any electronic faults and power fluctuations too (Shimizu and Takahashi 2012).  

Here S is the source, G is the showing gate, body is represented as B and the terminals through which the electronic signals are drained have been shown as D.

The power receiver includes the coil that receives the direct current, circuit that can resolve any circuit issues and the IC used for regulating the voltage. The transmitter coil sends the alternating current and thus the magnetic field produced increases with the large gap between the sender and receiver coil. The flow of alternating current or AC voltage leads to activating the wireless charger. The rectifier plays a major role here because it converts the AC voltage into the direct current or DC voltage, though there may be certain power fluctuations during this time period (Suh and Kim 2013). In such case, the IC voltage regulator maintains a steady flow of DC voltage and produces the output voltage, which is then used to charge the handheld device.  

The IC Voltage regulator is used to maintain the voltage that is produced as output in a consistent manner by ensuring a constant value all throughout. The IC voltage regulator 7805 delivers a +5 volts regulated power supply by using a heat sink as well so as to prevent excessive heat production. The input voltage ranges in between 7 V to 35 V. The output voltage is maintained at a constant value, as a result of which the voltage will not be more than 5V. The output voltage can be managed to the extent of maximum of 25 degree Celsius while the line regulation and load regulation are 0.01% and 0.3% respectively (Ahn and Hong 2014).

Wireless transmitter and receiver sections have been used as a pair in order to manage the wireless communication with ease and effectiveness. The wireless transfer of data has been done with the help of 433 MHz Radio Frequency signals that have been afterwards modulated with the utilisation of Amplitude Shift Keying (ASK) Modulation technique (Andersen et al. 2015).

The step down transformer has its own significance in the circuit because here the secondary voltage is lesser than the primary voltage. Moreover, it can be said that the step down transformer converts high voltage low current power to a low voltage and high current power. 

Conclusion

The research topic revolved around the concept of wireless mobile charging system and was conducted by some group members by working in coordination and as a team. All the codes of conduct that were set up by the IEEE had been fulfilled and the rules and regulations had been maintained. The contributions of each member of the group have helped in deriving good outcomes from the research as well as understand how the wireless mobile charging system has contributed to the Electronics and Telecommunications. The research conduction had also helped me to enhance my skills and level of knowledge for progressing in my career as well as lead a successful professional life in the future. Proper guidance was provided by the supervisor, which had further helped in following the most relevant research methods and maintenance of good research values and ethics as well. The course that I undertook was bachelor’s in Engineering.

The research was conducted with the focus on wireless mobile charging system and this included various communication disciplines as well as how the wireless charging system had become a major part of innovation in the Telecommunication industry nowadays. The data and information had been collected from different kinds of secondary sources such as journals, documents, articles, blogs, etc. The benefits of wireless charging along with few examples of mobile phones that supported wireless charger had also been included in this research. The circuit composed for the particular system had been shown here along with relevant equations of calculating the resonance frequency and inductance. The various components of the receiver unit like the voltage regulator IC LM 7805 and how it had been designed for supporting the wireless mobile charging system were also important portions of this research topic. All these important aspects had been covered here for deriving a good conclusion at the end of this report.  

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