Group Design Project – B202

Product feasibility study

USE CASE SCENARIO

Demand in buying items needed 24 hours a day

Shops are placed for people to go and buy something that they need. Unfortunately, they cannot go there at night as the premises will definitely close. So, how can we solve this problem? What people might think is we can have a 24 hours shop in order to solve the problem. Yes, by having 24 hours shop, we can solve this problem but we need to think about other factors that might raised as a result of having 24 hours shop like the electricity usage factor, labour factor, security at night factor and many other factors associate with that. One of the solutions of replacing a 24 hours shop is by implementing a vending machine.

What is vending machine?
Vending machine is a notes or coins operated machine that provides various snacks, drinks and other products to customers.

Why we need vending machine?
The idea of having vending machine is to vend product without a cashier.

For instance, Japan is one of the countries that use many vending machines. So, we can easily found vending machines all over the cities, towns and even in the countryside. Even, you can buy rice from vending machine! It is said that almost none of them are vandalised, meaning that people there are really appreciate this technology.

http://shw.keytoe.fotopages.com/20350345/P1.html
Picture 1. Vending machine that sells various kinds of rice.

http://shw.keytoe.fotopages.com/20350346/P2.html
Picture 2. Vending machine that sells eggs from farm.

http://shw.keytoe.fotopages.com/20350347/P3.html
Picture 3. Vending machines that sell foods and drinks.

By having vending machines, we found that labour cost can be reduced. For instance, by referring to Picture 3, we can see that many vending machines are installed in the restaurant. People still can buy their food and drinks, eat in the restaurant and clean the table themselves after they finish having their meal, but the difference is that they buy their food from the machines.

Second, by having vending machines, we are able to buy the things that we need at anytime as it does not require us to go and buy from the shop. For instance, by referring to Picture 1 and Picture 2, we found that we can even buy rice and eggs from the vending machines. So, if you feel hungry at night and suddenly you realised that your rice or your eggs has finished, you do not need to worry as you can easily buy them from the vending machines. This proof that vending machines give a lot of benefits to us and that is why Japanese really appreciate this technology.

Third, by having vending machines that can sell almost everything, we found that we are able to reduce space. What we mean is instead of erecting new shop which definitely requires lots of space; we can replace them by allocating the vending machines.



However, this technology also requires power. So, it can be said that this machines contribute to increment the power usage, which this not sounds good for our earth as high power usage will contribute to global warming.

According to an article entitled “production and consumption of nuclear energy” that can be found from this URL, http://www.planete-energies.com/content/nuclear-energy/production-consumption.html, it says that up to year of 2006, the amount of electricity generation from nuclear energy throughout the world is 2,660 GKWh. The fraction of it can be viewed from the Table 1 below.

http://shw.keytoe.fotopages.com/20350437/Table1.html
Table 1. World electricity generation from nuclear energy by country (2006) and the share of nuclear energy in total electricity generation

According to an article that can be found from the URL, http://www.absenergyresearch.com/cmsfiles/reports/Hydro-Power-Report-Ed-2-2009.pdf, it says that hydropower which also contributes in generating power, has increased from under 50GW in 1950 to an estimated 929GW in 2008.

We could also look at Picture 4 which shows the rate of world energy usage (in Terawatts) which can be found from this URL, http://en.wikipedia.org/wiki/World_energy_resources_and_consumption.

http://shw.keytoe.fotopages.com/20350348/P4.html
Picture 4. Rate of world energy usage in Terawatts from 1965 to 2005.

This shows that, people are using too much power nowadays. Again, how can we solve this problem?



People now have start thinking of finding alternative energy sources as to avoid an extreme serious energy shortage in the future. Solar power can play a role as an alternative energy source.

What is solar cell?
Solar cell is a panel which convert sunlight into DC electricity without moving any parts, noise pollution and even radiation.

http://shw.keytoe.fotopages.com/20350349/P5.html
Picture 5. Solar panel

Lots of people are using solar cell in their daily living as an alternative method to reduce the power usage from mains i.e. solar cell water heater and solar cell hand phone battery charger. There are several reasons why you will think that solar cell is a perfect solution,

1. You will save most of your money every time you get your power bill
2. You will save the environment and your children will thank you for it
3. You will know that you are doing your part to protect our planet
4. You are able to spend your savings on more important things

Hence, it is a good idea to combine the solar feature into a vending machine as it would reduce more problems coming from domestic power usage. Even we can found many equipment that uses solar power nowadays. For instance, we can find one section called Greenshop at Dixons webpage where it is a section of selling energy saving products. This URL shows solar-powered radio is been sold by Dixons (http://www.dixons.co.uk/martprd/store/dix_page.jsp?BV_SessionID=@@@@1343874277.1238110843@@@@&BV_EngineID=cccfadegldkkfhdcflgceggdhhmdfho.0&chain=Dixons&int=hp-greenshop&channel=WEB&page=GenericEditorial&genericeditorial=Greenshop-home).

What is solar-powered vending machine?

Solar-powered vending machine is a vending machine that powers its vending and refrigeration mechanisms with solar power. It is equipped with a battery that able to stores energy which sufficient enough for the machine to use it back whenever it does not receives any sunlight (at night or cloudy day).

Why we need solar-powered vending machine?

These are some benefits of having solar-powered vending machine,
1. To reduce the energy usage which comes from the mains (plant)
2. To vend a product without a cashier
3. To sell various products in 1 place (in one vending machine)
4. To save space (vending machine does not require lots of space compared with ordinary shop)
5. To buy items wanted anytime (day and night)

Apart from that, by using solar power, implicitly we can have another benefit which is this machine can be put anywhere! (Mobility feature is added).

What do we mean by mobility?

Mobility means the ability to move freely. We called this machine a mobile machine because we can put this machine at any place that able to receive sunlight. Hence, this machine will no longer be stagnant in one place.

Where are the possible places to place this machine?

As mentioned earlier, we can put this machine anywhere as long as it able to receive sunlight. Below is the list of possible places that we think it might be useful to put the machine,
1. Beach
2. Golf course
3. Highway
4. Places of interest (garden, park, lake, etc.)
5. Outside the campus building
6. Desert

Actually, there are many other places that we can put this machine. For instance, if you are studying in a big university like Nottingham University, it might be tired for you to walk from your resident hall to your campus. By placing the machine somewhere in your route to the campus, you can easily purchase any drinks desired to quench your thirst whenever you feel thirsty or tired.

Beach is the most suitable place that we might think of putting this machine at because people will definitely buy some drinks or snacks after spending couple of hours playing beach volleyball, surfing or even swimming. It is convenient to have this machine close to the beach as people will easily go and buy the items wanted rather than place it far from the beach.

If we look at the Asian Middle East country, almost every part of the countries is covers with dessert. It is difficult to get electricity source directly from the mains. So, that is why this machine is perfect for them as the problem of having difficulties to get electricity source can be eliminate. Furthermore, Asian countries have no problem to receive enough sunlight as it situated at a portion of the world that able to receive enough sunlight every day.

Who can use this machine?

Almost everyone in this world can use this machine as this machine can be put anywhere as long as it receives sunlight.

http://shw.keytoe.fotopages.com/20350350/P6.html
Picture 6. Solar-powered vending machine at beach

http://shw.keytoe.fotopages.com/20350435/P7.html
Picture 7. Solar-powered vending machine at park

Outer casing

We decided that our solar-powered vending machine must use a weather proof body. Throughout a research, we found that an element called PVCU (Polyvinyl Chloride Un-plasticised) is fit for the machine as the element of the PVCU,
1. Not rot or biologically decompose
2. Resistant to weathering
3. Low maintenance requirements
4. Tough on impact
5. Retain its shape within normal climatic temperatures
6. Can be reshaped at very high temperature
7. Can be recycled
8. Cheap
9. Durable

Dimension and Weight

Height : 1.9m
Width : 1m
Depth : 1m

The dimension given above is reasonable for inserting these elements into it,
1. Selling product
2. Control unit (which controls the machine’s operation)
3. Coin/Notes validator and case
4. Output tray
5. Coin/Notes balance tray

The purpose of having it big is because to make sure that we are able to fit various selling products into one vending machine and also to store as many product as we could so that the responsible person does not has to frequently come to refill the product.

Weight : approximately 100kg (nett empty)
The purpose of making it heavy is because we want to make sure that this machine will not be easily remove by any unrelated person (i.e. thief, vandal).

Control Panel

Consists of these elements:
1) Weatherproof touch screen LCD panel

• Provide a user interface by displaying item/product price and receiving input from user when the product selection is made.
• We choose the weatherproof one as it can be used under various conditions/climate ( e.g: rain, hot temperature)

2) Coins validator

• Give option for user to pay with coins (eg: 5p,10p,20p,50,£1,£2)
• Balance return available

3) Notes validator

• Give option for user to pay with bank notes (eg: £5,£10,£20)
• Balance return available but in coins only.

4) Balance return slot

• Provide an output slot for balance return if any (in coins)

Advertising

We think of equipped the machine with advertising space. The way of advertising that we decided is by sticking the sticker on the machine’s body. Why we choose that is because it does not require any power from the machines but at the same time we able to gain some profits.

Security

We decided to include alarm system in the machine.

How does the alarm works?
The alarm include in the machine will produce a very loud sound if it receives a signal from control unit.

There are 2 possibilities that can contribute to alarm activation. First, we can put a very simple mechanical switch i.e. limit switch to the machine’s door.

What is limit switch?
Limit switch is a switch that provides the function of making and breaking electrical contacts.

The switch will give a signal to the control unit when it is in open circuit condition, hence the alarm will activate. This condition will happen if any inappropriate person tries to open the door (attempt to steal the money or products). We only can disable this system by inserting code lock via user interface (at the screen) which this can only be done by responsible person.

Another thing that has been put into our consideration is the movement of the machine. As the machine can be easily moved, we afraid that it might be taken by unrelated person. We suggest that simple mercury switch to be installed to the machine in order to avoid this thing happen.

What is mercury switch and how does it works?
Mercury switch is a switch where its configuration is similar to LED. It has 2 terminals with a transparent casing and mercury inside. Mercury switch will be in high position if mercury touches both terminals. The configuration is been shown in the Picture 8 below.

So, if mercury touches both terminals, it will give a signal to the control unit, thus alarm will be activated.

http://shw.keytoe.fotopages.com/20350436/P8.html
Picture 8. Construction of mercury switch

We also decided to include SMS (short messaging service) features into our system.

Why include the SMS features?

One of the reasons is to monitor the machine. Once control unit gives a signal to alarm, it also running a code that generates a SMS to notify the responsible person (i.e. technician) telling that alarm is activated, please take some actions.

The other reason is to notify the responsible person that the coin/notes is almost full and the selling products are running empty.

Below is a block diagram showing the overall overview of how the security system of the machine.
http://shw.keytoe.fotopages.com/20350438/Block-Diagram-1.html

Any emergency case happen

We are considering to put the telephone number of the responsible person at the body of the machine where people can easily found, if any emergency case happen i.e. coin is stuck or any other emergency cases that might arise.

Output tray

We choose to have an automated output tray mounted at our machine where it equipped with a diffuse optical sensor.

What is diffuse optical sensor?
Diffuse sensor is one of the optical sensors where both receiver and transmitter mounted at the same place. When the receiver receives a transmitted light produces by the transmitter, it means that there is no object inside the tray but when the receiver does not receives any transmitted light produced by the transmitter, it means that there is an object exist in the tray where it blocked the light from transmitted to the receiver.

The picture below shows the working principle of this sensor.
http://shw.keytoe.fotopages.com/20351953/diffuse-sensor.html

This machine uses robotic arm as for purpose of taking the desired product from the display panel to the output tray. Once the product has been put inside the output tray by the robotic arm, it will block the transmitted light produced by the transmitter to the receiver. When this condition occurs, the sensor will send a signal to the control unit and control unit will send a signal to the output tray door to open. Once the diffuse sensor receiver receives the transmitted light back (this is a condition where the customer has picked up their desired product), it will send another signal to the control unit. Hence, control unit will send a signal to the output tray door to close back.

The product that the machine will display

.
Solar powered vending machine is one of the most environmentally friendly products ever invented. One of the biggest benefits and organization may gain from using this machine to distribute its products, is the unbelievable amount of money that can be saved on electricity bill. Especially now, when the economy around the world is not at its best shape, we all try to save every penny we possibly can.

It does not require a plug or any cords as it operates on solar panels, which are charged during the day to use stored energy for the night time. This is another advantage – it may be placed absolutely anywhere as long as the sun light reaches the machine’s solar panels.
Choosing different locations for placing the machines does not require much attention, it’s the products that should be sold at those locations need to be thought about very carefully. Taking the beach as an example, still there are not as many vending machines as we would like to see on a sunny hot day in the UK or whole year around in Thailand. Products that may be sold there would include the product as showing below those are the products most necessary at the beach and are not always at the local stores if there are any.

Beach: sun block-first aid- goggles-cigarettes-gum-disposable camera-nuts –charcoal flame-shampoo- plastic cutlery
Desert: phone charger-phone card-read map-tissue-flash light-battery-biscuits- first aid
Garden: crisp- gum-disposable camera-tissue-biscuits-first aid-city map-plastic cutleries
http://www.jun-gifts.com/others/littlethingsjapanese/littlethingsjapanese.htm

Display Panel

Display panel is a place where all selling product will be displayed. We decided to make the display as wide as possible because we decided to make this machine able to sell various products in one machine. The tray of displaying the products will be placed slightly higher at the back and it goes lower to the front. This is because we thinking of the products will slide to the front itself (naturally - gravity force) once the most front product displayed has been taken out by the robotic arm as this can save the usage of electricity.

As we mentioned before, the responsible person will not have to come everyday just to inspect the machine's condition as we have included the SMS features into this machine's operation. In order to make it happen, we think of placing a sensor at each products tray at the display section. The most suitable place to mount the sensor is at the both sides of tray, and it would be better if it been placed a bit to the front because it will indicate that the products running empty.

Limit switch is the best sensor that we can think of at this moment because although it is cheap, but it able to function perfectly. This limit switch will give a signal to the control unit once it has not been touched by any products at the tray (this is a signal showing that the product is running empty). Then, the control unit will activate the logiccode application and hence, a SMS will be send to the responsible person as to notify him that the product is running empty and he needs to take some actions.

Visual Basic

A software development tool used to interface hardware and software. We plan to use this software as the main controller of the machine to operate efficiently. Input devices such as sensors and limit switches will be interfaced with other controlling devices such as robotic arm and DC motor through this software. Visual Basic also will become the main platform for Logiccode GSM SMS ActiveX to operate in order to enable the SMS alert system.

Logiccode GSM SMS ActiveX

Used to read/delete SMS, send WAP Push and send text messages in English or Unicode supported languages using GSM modems/mobile phones connected to serial port by data cable, bluetooth or IR. This software works together with Visual Basic as it main platform, to send a SMS alert to responsible person (technician/supplier) when selling product is running out and during the emergency alarm is activated.






Below is the layout of the machine's front view that we might think it suitable to design it in such way.
http://shw.keytoe.fotopages.com/20351829/Front-view.html

http://s566.photobucket.com/albums/ss108/mustd3as/?action=view&current=A_edit-1.jpg

http://i566.photobucket.com/albums/ss108/mustd3as/B.jpg


During the day time i.e with sufficient sunlight, the vending machine will operate using the solar power. At the same time, the battery will be also recharged with the energy gained from the solar cell as well as powering the machine. When the sun goes down or when the available light is not sufficient to generate electrical energy, the machine will operate using the battery power which is stored before. Basically, the machine has 2 power sources that can be used alternately during the day and night. The battery should be able to supply power to operate the machine for at least 5 days consecutively without sufficient sunlight in worst-case-scenario.

The user interface (control panel) is activated all the time as the machine operates. It works just like other vending machine i.e displaying products’ price, providing items selection for users, accepting the payment and dispensing the items, but with the weatherproof features. The operation of product dispensing is controlled by the control unit which consists of microcontroller circuit, DC motors, sensors and robotic arms.

The machine is also equipped with product counter and a unique system to alert the responsible person (supplier) whenever the machine is almost empty or the money storage is almost full, so that he/she could refill the machine, reset the counter and clears the money. The system consists of a simple short-message-service (SMS) transmitter to automatically send an alert message to supplier when the stated conditions happen.

As for security features, the anti-theft system operate all the time in order to ensure the machine is always secured. If any attempt of vandalism or theft happens, security alarm will be activated to alert everyone nearby and at the same time an emergency message (SMS) will be sent to responsible persons (supplier/security) for further actions. The system consists of sensors such as mercury switches and limit switches to trigger the alarm due to aggressive vibrations and displacements. Once activated, the alarm only can be disabled by authorized person by keying in a secret code via the user interface.

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We have probably seen calculators that have solar cells, calculators that never need batteries, and in some cases don't even have an off button. As long as we have enough light, they seem to work forever. We may have seen larger solar panels on emergency road signs or call boxes, on buoys, even in parking lots to power lights.
Although these larger panels aren't as common as solar powered calculators, they're out there and not that hard to spot if you know where to look. There are solar cell arrays on satellites, where they are used to power the electrical systems.
On a bright, sunny day, the sun shines approximately 1,000 watts of energy per square meter of the planet's surface, and if we could collect all of that energy we could easily power our homes and offices for free.
T¬he solar cells that we see on calculators and satellites are photovoltaic cells or modules (modules are simply a group of cells electrically connected and packaged in one frame). Photovoltaic’s, as the word implies (photo = light, voltaic = electricity), convert sunlight directly into electricity. Once used almost exclusively in space, photovoltaic are used more and more in less exotic ways. They could even power your house.
Photovoltaic (PV) cells are made of special materials called semiconductors such as silicon, which is currently the most commonly used. Ba¬sically, when light strikes the cell, a certain portion of it is absorbed within the semiconductor material. This means that the energy of the absorbed light is transferred to the semiconductor. The energy knocks electrons loose, allowing them to flow freely. PV cells also all have one or more electric fields that act to force electrons freed by light absorption to flow in a certain direction. This flow of electrons i¬s a current, and by placing metal contacts on the top and bottom of the PV cell, we can draw that current off to use externally. For example, the current can power a calculator. This current, together with the cell's voltage (which is a result of its built-in electric field or fields), defines the power (or wattage) that the solar cell can produce.
That's the basic process, but there's really much more to it.

Silicon has some special chemical properties, especially in its crystalline form. An atom of sili¬con has 14 electrons, arranged in three different shells. The first two shells, those closest to the center, are completely full. The outer shell, however, is only half full, having only four electrons. A silicon atom will always look for ways to fill up its last shell (which would like to have eight electrons). To do this, it will share electrons with four of its neighbor silicon atoms. It's like every atom holds hands with its neighbors, except that in this case, each atom has four hands joined to four neighbors. That's what forms the crystalline structure, and that structure turns out to be important to this type of PV cell.

We've now described pure, crystalline silicon. Pure silicon is a poor conductor of electricity because none of its electrons are free to move about, as electrons are in good conductors such as copper. Instead, the electrons are all locked in the crystalline structure. The silicon in a solar cell is modified slightly so that it will work as a solar cell.
A solar cell has silicon with impurities, other atoms mixed in with the silicon atoms, changing the way things work a bit. We usually think of impurities as something undesirable, but in this case, the cell wouldn't work without them. These impurities are actually put there on purpose. Consider silicon with an atom of phosphorous here and there, maybe one for every million silicon atoms. Phosphorous has five electrons in its outer shell, not four. It still bonds with its silicon neighbor atoms, but in a sense, the phosphorous has one electron that doesn't have anyone to hold hands with. It doesn't form part of a bond, but there is a positive proton in the phosphorous nucleus holding it in place.

When energy is added to pure silicon, for example in the form of heat, it can cause a few electrons to break free of their bonds and leave their atoms. A hole is left behind in each case. These electrons then wander randomly around the crystalline lattice looking for another hole to fall into. These electrons are called free carriers, and can carry electrical current. There are so few of them in pure silicon, however, that they aren't very useful. Our impure silicon with phosphorous atoms mixed in is a different story. It turns out that it takes a lot less energy to knock loose one of our "extra" phosphorous electrons because they aren't tied up in a bond -- their neighbors aren't holding them back. As a result, most of these electrons do break free, and we have a lot more free carriers than we would have in pure silicon. The process of adding impurities on purpose is called doping, and when doped with phosphorous, the resulting silicon is called N-type ("n" for negative) because of the prevalence of free electrons. N-type doped silicon is a much better conductor than pure silicon is.

Actually, only part of our solar cell is N-type. The other part is doped with boron, which has only three electrons in its outer shell instead of four, to become P-type silicon. Instead of having free electrons, P-type silicon ("p" for positive) has free holes. Holes really are just the absence of electrons, so they carry the opposite (positive) charge. They move around just like electrons do.
The interesting part starts when the N-type silicon together with P-type silicon. Every PV cell has at least one electric field. Without an electric field, the cell wouldn't work, and this field forms when the N-type and P-type silicon are in contact. Suddenly, the free electrons in the N side, which have been looking all over for holes to fall into, see all the free holes on the P side, and there's a mad rush to fill them in.



Solar Cells are rugged, dependable devices for converting sunlight directly into electrical energy. They have no moving parts and a long working life. System maintenance costs are lower and reliability is much higher than for other power sources. They can be used on any scale, from powering a digital watch to running a multi-megawatt generator for a public utility. Because they are usually arranged in modular panels, it is possible to start with a small system and expand it as necessary without making the early panels obsolete. But because only small amounts of energy are converted by each cell, large-scale electrical requirements require large and costly arrays of PV cells. Thus, the main applications of PV cells have been to supply relatively low demands. Planners who may be considering long-term economics should also consider that selecting PV power helps to achieve a pollution-free environment.

About 1 kilowatt (kW) of radiant power falls on a square meter (sq m) of the earth's tropics at midday. If a solar panel has an efficiency of 10%, then each square meter of cell array will generate a peak of 100 W of electrical power. A typical 10-W panel, capable of keeping an automotive battery charged, measures 31 cm by 35 cm including the frame. The solar cell energy can be generate for the vending machine usually up to 8 hours after the sun drop.

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Have you decided what type of solar cell that we want to use, the operating voltage, the weight, the power that it produce, the dimension
Which you might think it suitable for our machine

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Solar Design.
The capacity of energy’s that been expected for the vending machine around 120W to operate the machine smooth and without any problem accure. Our group make a research and we found that the mechanism that suitable for the vending machine is the product that distribute by BP.
These are the detail:
Performance
_
Rated power 125W
Module efficiency 12.4%
Nominal voltage 12V
Warranty 90% power output over 12 years
80% power output over 25 years
Free from defects in materials and workmanship for 5 years

Configuration

BP 3125S Clear Universal frame with LoPro junction box and polarized
Multicontact (MC) connectors
BP 3125U Clear Universal frame and robust junction box

Qualification Test Parameters

Temperature cycling range -40ºC to +85ºC for 200 cycles
Damp heat test 85ºC and 85% relative humidity for 1000h
Front & rear static load test (eg: wind) 2400 Pa
Front load test (eg: snow) 5400 Pa
Hailstone impact test 25mm hail at 23m/s from 1m distance
Quality and Safety
_
• Manufactured in ISO 9001 and ISO 14003 certified factories
• Conforms to European Community Directive 89/33/EEC, 73/23/EEC, 93/68/EEC
• Certified to IEC 61215
Module power measurements calibrated to World Radiometric Reference through ESTI
(European Solar Test Installation at Ispra, Italy)
Framed modules certified by TÜV Rheinland as Safety Class II (IEC 60364) equipment
for use in systems up to 1000 VDC
Framed modules listed by Underwriter’s Laboratories for electrical and fire safety
(Class C fire rating)
Approval by Factory Mutual Research in NEC Class 1, Division 2, Groups C & D hazardous
These graph prove that the efficiency of this solar cell.


Typical Electrical Characteristics : BP 3125

Maximum Power (Pmax) :125W
Warranted minimum power :119W
Voltage at Pmax (Vmp) :17.6V
Current at Pmax (Imp) :7.1A
Short circuit current (Isc): 7.54A
Open circuit voltage (Voc) : 22.1V
Temperature coefficient of Isc : (0.065±0.015)%/K
Temperature coefficient of Voc: -(80±10)mV/K
Temperature coefficient of Pmax : -(0.5±0.05)%/K
NOCT (Air 20ºC; Sun 0.8kW/m2; wind speed 1m/s): 47±2ºC
Maximum series fuse rating : 15A (BP 3125S) / 20A (BP 3125U)
Maximum system voltage :1000V (IEC 61215 rating)

1000V (TÜV Rheinland rating)

Mechanical Characteristics BP 3125
Dimensions (mm) :1510 x 674 x 50
(Overall tolerances +/-3mm)
Weight (kg) :12.0
Frame :Clear anodised aluminium alloy type 6063T6. Silver Universal frame.
Solar cells :36 cells (157mm x 157mm) configured geometrically for a 4 x 9 matrix connected in series.
Junction box : (BP 3125U) IP54 junction box with 6 terminal screw connection block, accepts PG13.5, M20, 13mm conduit, or cable fittings accepting 6 –12mm diameter cable. Terminals

accept 2.5 – 10mm2 (8 to 14 AWG) wire.

Output cables (BP 3125S) :RHW AWG# 12 (4mm2) cable with polarized weatherproof DC rated Multicontact (MC) connectors; asymmetrical lengths 900mm (-) and 800mm (+).
Diodes : IntegraBusTM technology includes for every 18 cells a Schottky by-pass diode integrated into the printed circuit board bus.
Construction : Front: High transmission 3mm tempered glass. ; Rear: White tedlar; Encapsulant: EVA.
This are the product that I have been search that suitable for our product

KEY COST DRIVERS

Determining battery usage, number of batteries needed.

Determine total load per day

Elements Load ( AC or DC Watts) Hours used per day Watt hours per day
Refrigerator 50 18 900
Control panel 20 10 200
Dispenser 30 8 240
Alarm system 10 24 240
Lights 20 12 480

Total load 2060 Wh

Determine the number of days of storage (backup) required.
Maximum required storage = 5 days

Watt hours storage required = 2060 x 5

= 10300

Determine depth of discharge (DOD) of the battery. 80% should be considered the maximum for deep cycle batteries.

DOD = 10300 / 0.8
= 20600

Include operating temperature for battery.
Let average temperature = 50°F, then multiplier = 1.19

DOD after include operating temperature = 20600 x 1.19

= 24514

Determine battery capacity. Let consider using 200Ah battery with 12V DC.

Battery capacity = 200 x 12

= 2400 Wh

Determine number of battery needed.

Number of battery = 24514 / 2400

= 10.214
= 10 units (rounded)

Battery chosen:
AGM type model HGL 200-12
200Ah 12V output
Weight : 69.30kg
Price: £279.95

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The references

Solar powered vending machine
(these are some websites that I found that might be useful for our project)
- http://www.springwise.com/eco_sustainability/solar_powered_vending_machines/
- http://www.greenertrends.com/2008/07/14/solar-powered-vending-machines/
- http://www.solarpowerrocks.com/solar-technology/solar-powered-vending-machines/
- http://www.solarvending.com/
- http://www.homegreenelectricity.com/?tid=we027&gclid=CPX1j6rYrZkCFQulQwodAEWjJw

These are a few more websites about vending machine usage around the world:
-http://www.japan-guide.com/e/e2010.html
-http://www.photomann.com/japan/machines/
-http://en.wikipedia.org/wiki/Vending_machine

below are the URL of other solar powered products
http://www.aria.co.uk/Products/Gadgets/Life+style/UVee+Universal+Solar+Battery+Charger+(Pink)+?productId=30824
http://www.dixons.co.uk/martprd/store/dix_page.jsp?BV_SessionID=@@@@1343874277.1238110843@@@@&BV_EngineID=cccfadegldkkfhdcflgceggdhhmdfho.0&chain=Dixons&int=hp-greenshop&channel=WEB&page=GenericEditorial&genericeditorial=Greenshop-home

these are URL of how solar cell works (how it works itself and how it works on cars)
http://www.howstuffworks.com/solar-cell.htm
http://auto.howstuffworks.com/solar-cars.htm

Information about battery used with solar cell:
http://www.brightgreenenergy.co.uk/solar_batteries_agm_and_gel.asp
http://en.wikipedia.org/wiki/VRLA

these are websites that show power consumption / power usage in the world which I think might be useful to include in our feasibility studies report
http://enterprise.amd.com/Downloads/svrpwrusecompletefinal.pdf
http://en.wikipedia.org/wiki/World_energy_resources_and_consumption
http://www.absenergyresearch.com/energy-market-research-reports/electricity-market-research-reports
http://www.absenergyresearch.com/energy-market-research-reports/electricity-market-research-reports/generation/global-database-operational-power-generation-plant/global-database-operation-power-plants
http://www.absenergyresearch.com/cmsfiles/reports/Database-Power-Plants-2008.pdf
http://www.absenergyresearch.com/energy-market-research-reports/electricity-market-research-reports/generation/reports/hydro-power-large-small
http://www.absenergyresearch.com/cmsfiles/reports/Hydro-Power-Report-Ed-2-2009.pdf
http://www.planete-energies.com/content/nuclear-energy/production-consumption.html

About battery sizing estimation:
http://www.brightgreenenergy.co.uk/battery_sizing.asp

Information about cost estimation for designing the machine:
-http://www.brightgreenenergy.co.uk/solar_array_cost_estimation.asp?

Information on architecture of the machine
http://en.wikipedia.org/wiki/PVC
http://www.flitwickglass.co.uk/Technical.htm
http://www.redkite-glass.co.uk/pvcu.htm

Electricity price in UK
http://www.southern-electric.co.uk/ForYourHome/OurPrices.aspx

Vending machines with robotic arms
http://www.intelligentvending.co.uk/softdrinksselfmanagement.htm

Weatherproof touchscreen
http://www.armagard.co.uk/products/ip65/waterproof-touchscreen.html
http://www.vartechsystems.com/products/All-Weather-Displays/
http://www.morecomputers.com/extra.asp?pn=42LM5WPTC
http://www.slashgear.com/garmin-nuvi-510-weatherproof-touchscreen-gps-2420279/
http://www.alibaba.com/product-gs/211136476/touch_screen_6mm_Dust_proof_Waterproof_19_for_LCD_monitor.html

The Output Tray
http://www.ipf-electronic.de/data/eopti1000.pdf?PHPSESSID=8a233769c2b5c0e89e0b10d6ed536b6e
http://forms.baumerelectric.net/shared_data/forms_internet/baumer/255/2097_en_FHDK_04_low.pdf

Vending machines with robotic arms
http://www.intelligentvending.co.uk/softdrinksselfmanagement.htm

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