Electricity is a naturally occurring force that exists everywhere and it is used to power many things that are used in our everyday life. Without electricity, peoples lives would be very different and in many cases more difficult. There are many ways to generate electricity; one way in producing electricity is the use of solar cells. Solar cells or photovoltaic cells are made of semiconductor materials such as silicon and designed to convert light energy into electrical energy by the photovoltaic effect. Photovoltaic effect is the basic physical process through which a solar cell converts light into electricity. Light is one of the most abundant forms of energies and by using this energy in a proper way an eco-friendly form of energy can be produced. When light energy strikes, it absorbs photons of light and releases electrons these free electrons then forms an electric current that can be used to power a load. According to The World Factbook, the world has over 5 billion mobile phone users.
In the Philippines alone, there are 92,227,000 mobile cellular telephone subscribers, placing the country in the 11th position of most number of mobile phone users in the year 2010. This fact shows that mobile phones are essential therefore the batteries are needed to be charged and one way to charge it, is through solar energy. For its commercial purpose, the solar powered mobile phone charger is designed to have a coin timer that will recognize the coin to activate the timer and the mobile phone charger. The time that it will take for the mobile phone to charge depends on the amount of money that will be inserted in the device. Through this, the materials used for the machine, like the solar calls, will be recovered. The convenience of the machine lies in its capability to be installed either indoor or outdoor locations as long as there is light that can be absorbed by the photovoltaic cells. Background of the Study
From the survey given randomly to some students and employees most of them frequently use¦. try dn to.. From the survey that was gathered, most people frequently usetheir mobile phones and sometimes forget to charge their phones at home; such causes them to run out of battery charge when they need to use it outside, especially in emergency purposes. The places where they need to charge their phones the most in case of emergency are schools, hospital, mall, offices, bus stations and other terminals. For the past years, a mobile phone charger coin-operated machine already exists in the Philippines and this was stated from the article of Rey Gamboa from Philippine Star. However, this machine is usually available on public and indoor places like Ministop and 7-eleven and are powered by power grids.
Therefore, the proposed design is a mobile phone charger vending machine that uses solar cells to produce electricity that will power the device without the need for outlet plugging(the power in the outlet¦ try to¦ ). It can be used on both indoors and outdoors as long as light is available.It may also payback the expense of the material used and the good thing is that the time span of a solar cell is about 30 years according to the studies done in 2007 by International Journal of Environmental Technology and Management. It may also payback the expenses for the materials used in having solar cells and it has a time span of more than thirty years according to the studies of the International Journal of Environmental Technology and Management in the year of 2007. trydn¦
Statement of the Problem
This project study dealt in the development of using free energy caused by light that produces electricity for the mobile phone charger. This form of transforming energy will help lessen the environmental problem such as pollution, global warming, acid rain or smog.At the same time, it paybacks the causeof the solar cells itself by using it as a solar powered mobile phone chargervending machine. The study specifically aims to answer the following questions: 1. What type and how many solar cells are needed to produce electricity that is enough to power the mobile phone charger vending machine? 2. How to design the power supply circuit necessary to power the mobile phone charger vending machine? 3. What is the position and alignment of the solar cells and also the time in which it can produce electricity efficiently? 4. How to design and develop the mobile phone charger circuit that can accommodate 2 units of mobile phones? 5. Howlong is the payback time in using solar cells to power the mobile phone charger vending machine?
Objectives of the Study
The researchers main objective is to design and develop a solar powered mobile phone charger vending machinethat can maximize the profit of the investors that operates it. This means that this device can be installed in any areas as long as the solar cells can be exposed to sunlight which will eliminate the need of an outlet.In order to address the main objective, the following also need to be achieved: 1. To determine the type and number of solar cells needed to produce electricity that is enough to power the mobile phone charger vending machine. 2. To design the power supply circuit necessary to power the mobile phone charger vending machine. 3. To determine the position and alignment of the solar cells and also the time in which it can produce electricity efficiently. 4. To design and develop the mobile phone charger circuit that can accommodate 2 units of mobile phone. 5. To determine thepayback time in using solar cells to power the mobile phone charger vending machine.
Significance of the Study
People who are using mobile phones frequently are the main recipients of the benefits in this study. The need of people to charge their mobile phone because of work, emergency, or any other condition will lead them to find a mobile phone charging station. Hence, a mobile phone charging station that is powered by light energy will be a good way to harness energy from light efficiently and productively. For the environment, the device uses only the photons of light to produce electricity which means that it doesnt need to be plugged into a power source. It can also be used inside anenclosed area where there is artificial light like bulbs or fluorescent light. However, for higher gain of electricity and efficiency it is recommended to harness sunlights energy because it is brighter than any other artificial light that is common in commercial and public areas. For the investors, after the device is produced, it in itself will produce electricity for it to work.
Consequently,the device doesnt need intensive maintenance, and the cost of maintenance will be less. For the future researchers, energy sources has so many forms; the way of harnessing it to its full potential is the only difference. This device is an example of harnessing light energy in a way that will help the producer, consumer and environment. This will help future researchers to think of topics that will not only benefit one party, but all those who are going be involved or affected by their proposed project. For the researcher, this device is another innovation in the field of harnessing solar energy. This simply shows that solar energy can be used as an alternative source of energy in many ways.
Scope and Limitations of the Study
The researchers main concern is to design a solar powered mobile phone charger vending machine that is efficient on harnessing solar energy and can convert it to electrical energy to charge mobile phones. The device must be economically sound in a way that when it has achieved its payback period, the only thing that must be put into concern is the cost of maintenance. Since solar cells are easy to maintain, the maintenance cost is not high. The devices main part is the power supply that will act as the source of electricity for the device. Solar cells effective life span is 25-30 years, which makes it a very good alternative source of energy for the device to work. To design the devices main part, the position and slope of the solar cells must be considered depending on the location where it will be installed so that the solar cells can produce the maximum amount of electricity.
This is because the amount of electricity that a solar cell can produce depends on the intensity of sunlight that is being absorbed within the semiconductor material. The number of solar cells must also be enough to produce electricity that is needed to power the device. The rated total power output of all the solar cells must also be sufficient for the mobile phone vending machine. It must also be placed on top of a roof or any high position so that shadowing, vandalism and stealing can be prevented. A battery will serve as a storage device so that the electricity that will be generated by the solar cells will be stored whenever it is not in use and the electricity that will charge the mobile phones will be constant and not fluctuate. The power supply circuit will regulate the voltage and current to its rated value that the mobile phone charger vending machine needs. The devices second main part is the mobile phone charger vending machine.
This is composed of a mechanism that recognizes the coin that is inserted and starts the process of charging the mobile phone and also the timer. It recognizes the diameter, thickness and weight of the coin so that it can distinguish the value of the coin. The timer is programmed to start whenever a coin is inserted and it depends on the value of the coin that is inserted on how many minutes the timer will countdown. At the same time, the charger will start charging the mobile phone until the timer ends the countdown. The devices third main part is the mobile phone charger circuit. This charger can charge multiple mobile phones at the same time. It is composed of different plug-ins that is commonly used for the user to choose of the plug-in that fits in his/her mobile phone. It is operated by the timer so when the timer starts to countdown, it starts to get electricity from the power supply. Theamount of voltage and current output that is needed to charge the mobile phones is suitable for nearly all brands of mobile phones.
Limitations of the study
The device is subjected to the following limitations:
1. In outdoors, the device only operates during daytime, approximately 6:30am 5:30pm depending on the location as long as sunlight is available. 2. It can also be used inside a mall or commercial area that has artificial lighting system,however the amount of electricity that the solar cell can produce is not as high compared to what sunlightcan produce. 3. The plug-in that will be used to charge the mobile phones are those of Nokia. 4. Since the device only recognizes 1Php and 5Php, it can only be used in the Philippines. 5. It cannot be used outdoors when sunlight is not present specifically during rainy days or in cases when the clouds are very gloomy. 6. It cannot be used outdoors when there is a natural catastrophe or disaster. 7. The researchers will not consider the charging time of the Deep cycle battery. 8. The researcher will not consider if the mobile phone user doesnt ends the countdown of charging his/her mobile phone.