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I think my finished project should:
- Have several outputs
- Have easy battery access
- Have an On / Off switch
- Have out of the way leads that are well secured
- Be able to be produced within 40hrs
- Be made out of materials which are available at my school, and materials which are easy to clean and are strong
- Not exceed £10
- At most require a 9v battery to operate
-
Be completed before 17th March 2007
- Advertise quite a well known brand
- Be stimulating
I will now arrange these in order of importance:
My project should:
-
Be completed before 17th March 2007
- Be made out of materials which are available at my school, and materials which are easy to clean and are strong
- Be able to be produced within 40hrs
- Not exceed £10
- Have several outputs
- Be stimulating
- Have an on / off switch
- Have out of the way leads which are well secured
- Have easy battery access
- At most require a 9v battery to operate
- Advertise a well known brand
To begin with I experimented with different ideas
but I soon decided to focus on advertising
confectionary, in particular Toblerone
On the next 5 pages I will show 5 different circuits which I may use in my finished project.
The five circuits I will show are the:
- 555 monostable
- 555 astable
- chaser circuit
- monostable and astable joined
- and an example of a PIC circuit
Explanation -in the above circuit when the switch is pressed the chip will allow current to go out through the output. This will activate the transistor which will allow current to go through the bulb. The bulb will stay on for a period of this then go off. The amount of time the bulb stays on for is dependant on the size of the capacitor and the size of the variable resistor. Once the bulb goes out, the circuit can only be reset by repressing the switch.
Application: This could be used in my project to activate my outputs for a set time example it could light up a series of LED’s that are around a Ford sign.
Explanation- The above circuit uses the 555 timer chip just like the monostable circuit. However the way in which the circuit has been connected gives a different result as an output. When switch 1 is closed it activates the output and the four L.E.D.s will light and pulse for a frequency by the resistors and capacitor. By opening the switch they LED’s will go out
Application- This circuit could pulse LED’s round a brand sign to draw a persons attention to it. The switch could be replaced by an LDR with a potential divider which enables the circuit to come on at night so the LED’s can be seen clearly.
Explanation - In the above circuit the astable pulses a signal as its output. This then activates the 4017 chip which acts as a counter; each time a new current enters it switches off an L.E.D. and lights a new one. Now the rate at which the 555 pulses is set up its resistors. Now depending on the speed of 555, the speed in which the L.E.D.’s light is determined. The result with many L.E.D.’s attached is a chaser circuit i.e. the L.E.D.’s “follow” each other
Application – The above circuit could be used in my circuit to enable a series of LED’s to “chase” each other possibly to highlight an advertisement.
Explanation - The Monostable above acts as a timer, and the time is set via the potential difference of the variable resistor and the capacitor C1. This sends an output to the astable which pulses. Its frequency is set by R2, VR2 and C2. Should the resistance drop in variable resistor, VR1 the only the top LED will be lit and it will be constant. The resistance must be increase in VR1 and the switch pressed for the circuit to operate normally, i.e. the Monostable time for a period and control the astable to pulse.
Application- This could be used in my project to pulse LED’s for a certain time then switch off. It could be activated by a switch in a mat and light up a sign for half a minute.
As a PIC circuit cannot be transferred into Microsoft Word I shall recreate one using a normal flow diagram.
This PIC circuit is quite simple and works like this; if the switch isn’t pressed then the PIC will basically wait for it to be pressed. When it is pressed 2 LED’s will switch on and will stay on for 2 seconds then will switch off and 2 more will turn on. After 2 seconds the circuit will reset
My finished circuit is going to be a chaser circuit, i.e. an astable circuit combined with a 4017 chip. There is a formula for calculating the rate at which the astable chip pulses the 4017 and it is:
I am now going to calculate the
value of R2; my variable resistor.
1 = 1.44 / (0.001 + 2R2) x 100
0.1 + 20R2 =1.44
20R2 = 1.43
R2= 0.0715MΩ
My finished project will require several different types of circuits linked together. Below are the system diagrams of some circuits which I could join together.
This combination allows my circuit to pulse a series of LED’s for a set time before stopping. This can only be reset by pressing the switch.
The above systems diagram shows a Chaser circuit which lights LED’s in order one after the other while the switch is on. This is likely the circuit I will use in my project.
The above circuit uses a PIC which allows me to have a lot more control over the outputs than in the previous circuits. I can program the functions using computer software which allows many more possibilities for the outputs.
Ten weeks worth of periods (40) have been allocated for the development and construction of my circuit. I have planned this work in the flow diagram below.
Six school weeks worth of periods (24) have been allocated for preparation and building of the materials part of my project.
After completing my advertisement I am now going to evaluate it. Below a photograph of the front of my advertisement.
As you can see my finished project is advertising Toblerone, and the frame of the project is made from redwood, with an acrylic front, with 9 LED’s.
Below is a photo of the back of my project.
The back of my project houses all the electronic aspects of my project, the PCB, switch, and all the wiring to the components. The wiring has been tidied up with insulation tape as well as metal wire clips. The PCB was compressed to the smallest size I could make within the time, so I would have sufficient room for the wires to be tidied away, as well as room for the LED’s and the switch.
Originally I planned out a specification for my project; I am going to evaluate my finished project against this to see how well I planned my project.
Have several outputs
Originally I planned for my project to have several different types of outputs, which my finished project doesn’t have, its only outputs are LEDs. I felt that LEDs were the only suitable output available to me, since components such as a buzzer wouldn’t have been suitable for this advertisement.
Have easy battery access
I made sure to stick to this specification as for any electronic device changing the battery should be simple, since unnecessarily complicated methods are could result in the person replacing them to cause damage. So my battery is simply and securely fixed to the back of the product and is easy to remove.
Have an on/ off switch
My finished project has kept to this as well since it is ridiculous to expect the battery to have to be removed in order to cut the power to the circuitry.
Secured and tidied leads
Untidy or lose leads can catch on things and damage the components, so I made sure that my leads are suitably tidied away, which also makes the electronics look more attractive.
Produced within 40 hours
My finished project had to take under 40 hours to complete since we had the deadline of 17th March to complete the project for and it was essential that we stuck to it. I kept to this deadline although I didn’t have that much time left since I tended to get held up in certain areas of the manufacturing.
Be made out of easily available, strong and easy to clean materials.
All the materials my project was made out of were readily available in my school. They are all also strong, the only problem I have noticed that in the workshop the wood tends to dirty easily but I think that is just down to that nature of the environment, otherwise I feel it wouldn’t pick up marks too easily, so it shouldn’t be too difficult to clean. The acrylic is very easily cleaned, just requiring a quick wipe.
Not exceed £10
I am aware budgeting was important to this project which is why I made sure to stick to my original amount of less than ten pounds. Later on I have detailed information on my expenses.
At most require a 9v battery to operate
All the components made available to me were able to be operated by a 9v battery so I didn’t have to worry about this. A 9v battery was a good choice I thought because it has sufficient voltage to power all the components I required, and it is also a relatively cheap form of battery, and readily available.
Advertise a well known brand
Since I am advertising Toblerone I feel I have done this to a sufficient level since they are a well known chocolate producer.
Finished project should be stimulating
I feel I have stuck to this specification, since my finished project has 9 LEDs in a chaser circuit as well as a bright yellow acrylic background.
If I were to make this project again there are several things I would change.
I feel that my project is too plain; I would prefer it to have been more ambitious with a large use of different textures and colours. I would also like to have given it some practical use as well, such as a desktop tidy complete with a clock rather than a plain advertisement.
Although I feel that my cables have been tidied away sufficiently if I had the time I would have redone it, having the cables more compacted together so they would take it less room and at the same time looking better.
Also I would change the actual advertisement I use, instead of using a Toblerone carton I would actually make the advertisement myself, which would allow it to be more suited to my project. This would give me more control over the use of textures and colours, allowing me to make the advertisement more stimulating.
If I were make another electronic product I may consider making a child’s game since I would enjoy the challenge of making it entertaining. Possibly I could use a PIC which would have allowed my outputs to de controlled in some great detail by the inputs.
In regards to my finished project itself I am quite happy. I think it is aesthetically pleasing and it does advertise the product well.
However possibly my use of space wasn’t the best, I would like to have used more LEDs on a larger area so they would be more of the key feature of the advertisement. Also I am not too happy with the carton of Toblerone; I feel it isn’t quite right for my project; however I am still pleased with the final outcome.
I particularly like the yellow acrylic since it helps my LED’s to stand out in bright environments as well as matching my advertisement. I also like the triangular shape I chose for my project since it also matches the brand I chose to advertise, as well as keeping my project compact.
As for the electronic part of my project I am happy with the functioning of my circuit and components as they all appear to be working ok. However I still feel that the wiring isn’t as neat as it could be, but I did spent quite long organising and tidying the wires, and it was the best I feel I could have done in the time I had.
In my specification I planned that my project should be no more than £10. I am now going to calculate how much my finished project cost.
Electronics
Toggle Switch 75p
Terminal blocks 10p
Battery Snaps 4p
100μF Capacitor 6p
4 Resistors 4x 1p
4017 Chip 40p
555 Chip 18p
Variable Resistor 14p
PCB 120p
9x LED’s 9x 8p
Heat shrink 70p
Cable Clips 4p
Subtotal 437p
Materials
10mm thick MDF 300mm2 60p
Redwood 700mm 110p
Acrylic 150p
Subtotal 320p
Misc.
Solder, Cables, PCB spacers, Screws, etc 55p
Subtotal 55p
Total 812p
My final total was £8:12 which is under the £10 I allocated.
There are several scales of production when manufacturing.
One off production – This is when only one product is made at the time. Usually takes some time and the costs are usually quite high.
Batch production- When a series of the same products are made together in small or large quantities; once made the same workforce may produce another series of products.
Mass production- This is when the product is to be produced in large numbers for several weeks or months at a time. A relatively large workforce works on an assembly line, where different groups of workers are responsible for each part of the product.
If I were to batch produce 100 of my product I would use vacuum forming to create the main body of my product. This is done by first creating a mould of my product, which is then vacuum formed: forcing heated plastic to cover the mould by creating a vacuum. The mould itself can be removed and used over and over again. The moulded plastic can then have the electronics and materials built onto it.
The environment
As with all forms of manufacturing, there is some pollution to the environment from the creation of my project; i.e. scrap materials such as wires, wood, plastic. Also at some stage my project is ultimately going to be binned which again pollutes the environment.
Also the use of machines to create my project would have used up electricity which ultimately pollutes the environment.
If I were to mass produce this product, or any other there are several things I could do to help reduce pollution on the environment.
- Reduce the amount of raw materials used to a minimum.
- Use as much biodegradable materials as possible.
- Reuse as much materials as possible.
- Reduce the amount of electricity used in the creation of my project to a minimum.
- Make sure no material in my project is potentially toxic, which later will seep into the environment when in a landfill site.
- Make my project rechargeable battery friendly.
