the theme i have chosen to do is security
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D&T: Electronics and Control Systems Unit A511: Introduction to designing and making Name: Candidate number: Centre Number: 16527. The theme I have chosen to do is security. - PowerPoint PPT PresentationTRANSCRIPT
D&T: Electronics and Control Systems
Unit A511: Introduction to designing and making
Name:
Candidate number:
Centre Number: 16527
The theme I have chosen to do is security
The reasoning for me choosing security as my theme is mainly because when ever I watch the news or read a newspaper I always seem to find one article about burley in their some where, also another main reason of more pressing on concern is that just last year the house over the road from where I live was burgled while they where inside it because they didn’t have an alarm
Security Baby bath temp alarm
Shed alarmProtect sheds in crowed area
stop them from dyingIn the bath because the water is hot
Heat senor
Alarm which goes of when temp gets to high
Buzzer that produces a load notice when either input goes off so people can tell that there's a shed being robbed
Pressure senor on a door mat or a some windows to detect changes in weight
Feeling secure
Fake cctv
Fake alarm boxes with LED on them which flash
Marketing Surveys
Areas of crime
Orangeis the area I have chosen to do
Area of crime are good marketing areas because people will more likely want to protect
Market research To be able to tell if it Is worth investing in the area
Flashing led to people can tell it’s your shed that’s being robbed
Motion senor connected to a flashing led which is connected to a speaker
Goldie locks circuit??
Investigation of user needs
Where: Usually people who live in a crowed area or some where in a
isolated area like this images
Why: people would want this because they would want to protect the things in there shed with out having to be out there guarding it thought out the day and night
How: this alarm would work in the dark because that is when they will most likely burgle you and be able to detect changes in heat such as when a burgle comes into a room
When: People who would usually want a shed alarm are people that go on holiday or that they live in a enclosed area which has had a lot of burglaries or perhaps they would set a their shed alarm when they go to sleep at night there afraid of being robbed in the night and not being able to hear it happening from their room
Question air• 1. Do you live in a area with a lot of houses and do you own a shed- why because if you live in a crowed area you might and
you don’t have a shed alarm you might be burgled because you’re a easy target?• 2.do you live in a area of crime-because my survey has sated that quite a few people have been burgled in the last few
months which would state that there Is a gap in market for these kinds of alarms.• 3. How valuable is the content of your shed-because the if the person doesn’t own very valuable items In there shed then
the buyer wont see the value of an alarm because they wont mind losing their items because they can properly claim it on insurance
• 4.Is the police force where you live good• 5.have there been robberies in your area lately –survey to found out if it’s worth selling in this area?• 6.would you buy a easy fit alarm-some people don’t like the complicated ones? • 7. would you buy this product if some one came around and fitted it for you-some people are more likely to buy it if they
don’t have to do any work? • 8. what would prefer? (Please circle your answer)A flashing LED with a siren just a flashing LED just a Led just a pressure plate or a pressure plate connected to a flashing LED
and a siren Just a pressure plate and a siren just a pressure pate and led or just a pure sure plate and a flashing led 9. Do you live a secluded area?- from investigation of user needs I an see that secluded areas are more likely to get burled10. How much would you pay for a alarm? (Please circle your answer)£10 £30 £50 or £100 or more
Question YES NO
1 7 3
2 5 5
3 4 people said quite valuable things where being kept in their shed
6 said not very valuable things where being kept in their shed
4 10
5 3 7
6 10 0
7 10
8 7 said a flashing led with a siren
9 6 4
10 7 people said up to £30
3 said more then the max listed
product cost Typical user/when where
function Technology used (input/ output
Manufacturing process used
NIKKAI EASY FIT CAR ALARM SYSTEM KIT + 2 REMOTE KEYFOBS
29.99 A typical user is anyone that ones a car it will most properly used by people that either leave there car in a car park a lot or some one that lives in the city
The functionOf this alarm is to go off when a amount of peruse is applied to the window or if it is broken
The technology used is a speakers and some led which are triggered by touch
Polostirsine plastics
Honeywell Pet Friendly Accenta Pro Burglar Alarm System
£151.00 A typical user is anyone that wants to product a large area of there house
The function of this alarm is that if one of motion sensors is triggered then it will go off flashing a led and making noise
The technology is a motion senor which is connected to a led and a speaker which goes of once triggered and stays on
ABS plastics
Yale wirefree Premium Alarm Kit HSA6400
£189.00 A typical user is properly any one that lives in a isolated area because that alarm can call the police as soon as it’s activated
The function of this alarm is to go of when one of it’s motion or heat sensors are triggerd this alarm can only be rest by a key code which is used in the key pad
The technology used works on motion and heat sensors placed around a house and as soon as they go off they call a number which is restated
ABS plastics
• Identifying the trend
• In slide 7 I showed you 3 eletrioncal alarm products all from amazon now in all these products their was a clear trend• That trend being that as the alarms got more and more specialised in what job they where doing the cost of buying the
device goes up we can quite clearly see this in slide 7 because the first alarm I shod you only costs around about £30.00, where as the last one I showed you costs around 189.00 in most stores.
• My explanation for this is that alarms that only serve one function are cheaper because they are easy to make where as alarms that have many functions and product something in more ways then one cost more because they are harder to manufacture and also to design
Examples of products
Product -Motion Sensor Alarm/ Home/ Garage/ Shed/ Extra Remote price- £7.40 This easy to install motion sensor alarm includes 2 remote control key-rings 5m range and wall mount. The main unit requires 4 x AA batteries (not supplied) or alternatively, a 6V adaptor can be used The remote units come supplied with 3 x AG13 button cell batteries This is an ideal burglar deterrent
• Fire angel CO-9D Digital Sealed for Life Carbon Monoxide Alarm Automatic self diagnostic check;7yr sealed for life Lithium battery;Loud 85dB alarm at 1 metre; Large Test & Silence button; Large multi-function digital screen and room thermometer.
• 7yr sealed for life Lithium battery• Loud 85dB alarm at 1 metre• Large Test & Silence button• Large multi-function digital screen and room thermometer.
• Friedland Response SL2 Wire free Multi User Keypad Controlled Burglar Alarm System
• Suitable for any home• Secure 868MHz technology• Comprehensive range of accessories• Tamper and jamming detection provides additional security and prevents interference from potential intruders• Energy saving solar siren
Helix mini personal alarm with rip cord operation, 100db, EACH
function This alarm’s job is to make a loud noise when the cord is pulled
User needs fulfilled People would buy this if they where going out at night
Martials used in construction polystyrene
Durability This alarm is designed to brake as soon as it is pulled so I don’t think it’s very durable
Sustainability This alarms casing would have been made out of a plastic
lifecycle The life cycle of this alarm is that I would break as soon as some ones pulled the cord
Energy use Two nine volt batteries
Design brief• I am going to design a device that will sense a burglar breaking into a shed• The inputs I am thinking for using for this circuit will be a -pressure mat to sense the burglar if comes any where near the door once the alarm is set - heat senor because if some how gets past the pressure mat and into the shed we want to be able to detect him before he can steel anything.
The outputs I plan to use for this circuit are a siren because if your asleep at the top of your house and your shed is at the bottom of your garden your not likely to hear any one breaking in. -flashing LED the reason behind a flashing led is because most people in my survey results said that they would feel that a flashing LED would attract more attention then just a bright red one.
The processes I plan to use to drive my circuit is a mosfet because that process has the largest electrical drive and the biggest gain out of those choose able giving me more accurate results making my product more efficient getting me better results
Creativity (slide 8)
Product Analysis• Analyse in detail 2 products related to your project (probably 2 different types of
burglar alarms, one fairly simple and one a little more complex.)• Use the table on the next slide to help you organise the information.
A simple system for the hotel room on holiday.
A more complex system for the home.
Creativity (slide 9)
Name and picture of product 1 Name and picture of product 2
Function
User need fulfilled
Materials used in construction
Durability of product
Sustainability (6Rs)
Life cycle
Energy use
Use 10 or 12 point text in this table
specification• The purpose of the my product is to be able to detect when some one is trying to breaking into your shed
while you sleep, a reason for this is that people that have a shed and want to keep it safe with out have to be out there guarding it.
• The product would be a alarm which would sound when the burglar enters your shed and then the alarm would detect the changes in heat and or the pressure detect changes is light when he/she opens the door once they have been detected a buzzer will sound on a latch and not turn of until the owner rests it.
• Reasons for heat sensor- there effective at detecting people because vey one gives of heat so we can see if thee in a room quite easily
• Reason for pressure mats- they have to enter the shed some where so if place presser mats where there more likely to enter so that way where more likely to find them and stop them bugling into peoples homes.
• Reason for latch- every one other alarm has one, also the reason for having a latch • The device would have to be small enough to be transportable with ease the circuit board would properly
be either in the shape of a rectangle or in the shape of a square Depending on the way we arrange it
Time delay after battery isswitched on
Possible inputs
Combineinputs
Delay after INPUT
PROCESS Delay before OUTPUT
OUTPUT Combined outputs
Zero seconds Motion sensor
Pressure and heat seniors
Zero seconds
Transistor
Zero seconds
Buzzer-siren
Siren and LED
3 seconds Tempsensors
Heat senor and light senor
3 seconds
Darlington pair
3 seconds
LED Siren and flashing LED
4 seconds
Pressure mat
Heat and dark senor
4 seconds
Mosfet 4 seconds
Flashing LED
5seconds
Dark senor Humidity and light
5 seconds
Transistor and a comparator
5 seconds
6 seconds Lightsenor
Humidity and dark
6 seconds
Thyristor 6 seconds
7 seconds Humidity senor
Motion and light
7 seconds
7 seconds
8seconds
Motion and dark
8 seconds
8 second
Red is what I have chosen to do
Design (slides 12 and 13)
Slide 10 – Ideas for the circuit• Include 3/4 circuits that could solve the problem:
– Picture of each circuit – from internet, hand drawn and scanned in or from circuit wizard.– Brief description of the circuit saying what does in terms of what it senses and how it
controls its outputs.– How well it could it solve the problem?– Choose one circuit and give your reasons for choosing it.
Slide 11 – Development of the chosen circuit• Build your chosen circuit in circuit wizard
– Show annotated screen shots of the circuit being developed – component values being changed to fine tune the way it works (especially in terms of timing delays etc.)
– Show annotated screen shots of the circuit being tested to show that it will work and that it will solve the problem.
– Include a video of it working using “Blueberry FlashBack Recorder for top marks.
• It is important that the screen shots and video show it working so that it is clear that it solves the problem.
The development of my circuit• This my starting circuit as you can see it Uses two separate circuits that both require Separate turning on at different points at Different times then also do not have a On/off switch so once there on there stuck onThis was costly and infective because I found That you do not have to use two separate Circuits to so hold 2 inputs so I came up withThis
Second stage of development• For the second stage wecombined the two inputs into one circuit using a logic gate so we didn’t have to build to separate circuitsWe also add a Latching On/off switch so people can turn the circuit on and off
How ever there were problems with this circuit because it required both inputs to be on at the same time before it sounded the alarm which was a problem if the burglar didn’t trigger both of them imputes so I came up With this.
Third stage of developmentFor this stage of development we switched to or gate in stead of an and gate so that if one of the inputs is triggered with outthe other the alarm will still sound we also upgraded to a more powerful driver so that the inputs would be able to detect more sensitive changes in there environment and react quicker to them.
I felt that the circuit was almost complete but Then look at my spider diagram of security and What makes people feel safe(slide 2) and I found that the alarm may benefit from a flashing light of some kind
Fourth stage of development• For this stage we added a lamp to thecircuit so that once the buzzer was triggered the lamp would go of alertingpeople that this shed is being robbed and not there's. But I felt that this was the wrong kind of lamp because it wasn’t flashing it alsowasn’t bright enough.
Fifth stage of development• For this circuit we changed the Lamp for a led so that it would shine Brighter and so we could choose theBulbs colour as well
We also added a A-stable to the Circuit so that the led flashes on And of frequently
Adding the a-stable led to some strange problems with the circuit where as soon as I turned the circuit on the out puts turned on and wouldn’t turn off even when all the inputs where off. Possibly because of the variable resistors charge
6th stage of development• For this stage of development I decided to change the LED from a normal LED to a flashing LED because first of all my
question air results show that more people want flashing led then a normal led because of the fact that in my survey results most people said that they would prefer a flashing LED then a non flashing LED which was just bright I also removed the a stable as it was no longer needed and was just making the circuit larger
Slide 21 continued
At first when I tested this circuit I couldn’t under stand why it wasn’t working the problem was that why I turned my all my inputs of the buzzer and flashing led where still going at first my reaction was that their was something wrong with the mosfet and that I should change the circuit
7 stage problem inconunterd
When I changed the circuit to combat the problem with what I thought was the mosfet I simply just took out the mosfet and put in a comparator and a transistor instead because they have a similar amount electrical drive
At first I was happy with my circuit but when I came to putting it into a pcb I found that my circuit was to complex and was also just not routing properly so I went back and look at the old circuit with the mosfet and I still couldn’t find what was causing the problem so I asked a few people who where doing the same circuit as me and I found that my variable resistor was at the wrong percentage witch was causing the problem so once ide fixed that I went back to my old circuit and came up with this
This is my final working circuit
Testing circuit What's suppose to happen
Un expected problems
How to fix unexpected problems
Turning the circuit on When you slide the sptp switch to on if a green light comes on then the circuit is working
If green light is not coming on then circuit is broken
In a case such as this the most likely problem is that you have wired up the green LED wrong
Input one the thermistor
Once you wave your hand over the thermistor if the buzzer and the flashing led both turn on then it’s working
If once you wave your hand over the thermistor the buzzer and the led don’t go off then some thing is wrong in the circuit
In this case it’s going to be one of two things, one you wired it up wrong or two your variable resistor has the wrong percept
Input two the pressure mat
If you step on the pressure mat and insure that the buzzer has sounded and that the led is flashing then you can be sure it’s working
If nothing happens when you step on it then you can be sure it’s not working
In this case make sure you have weird up the pressure mat if that doesn’t work then make sure the pressure mat isn't damaged
Testing output one the buzzer
Once you have testes both inputs you have to insure the outputs are working basically use one of your inputs and then wait for the buzzer to sound
If the buzzer does not sound then there is something wrong with you buzzer
To fix your buzzer you first have to check if the wiring is done properly if so then insure to see if your buzzer is damaged
Testing out put two the led
Once you have testes both inputs you have to insure the outputs are working basically use one of your inputs and then wait for the Led to start flashing red
If this doesn’t happen then something is wrong with your circuit
To fix this problem you have to first check the wiring and if the wiring is fine check that you haven't damaged your led when soiling it in place
PCB development stage one
This was my circuit when I first turned it into a PCBAs you can see their a still a few faults with the circuit such as the 3 blue lines on the board
Blue line
PCB development stage 2
In this version of my pcb I decided to focus on getting rid of the blue lines in the pcb circuit board in doing this I had to make the circuit board a bit larger this is something I should change later
PCB development stage 3, 4 and 5
In these stages of development I decided to move the components around on my circuit board to reduce the size of the board when it’s made cutting it’s cost
Stage 3
Stage 4
Stage 5
PCB development the completed pcb and the bill of materials
This is my working pcb in video form you have to double click the black box for it to play
Process description Equipment required
Safety issues Tips for success
Design pcb and mask Circuit wizard Ensure that you are not at the computer for to long with out taking breaks other wise it could damage your eyes
Don’t over complicate your circuit
Cur board to size Band saw Band saws are sharp ensure that your hands are away from the saw when you are using it, Also when using saw insure that clothing is away from the saw to avoid it getting caught
Insure that your are happy with your measurements before you start cutting
Expose mask and photo pcb to uv light
Uv light, photo pcb, mask of your circuit
Cover up uv light or cover up open skin on your body when using it
Expose it for longer then five minutes
Develop exposed pcb Development fluid Wear gloves and goggles and cover up skin because liquid is corrosive
Don’t pour to much fluid on or you'll melt the board
Etch pcb bubble etch tank#Etching fluid
Don’t spill the fluid on your skin because it’s corrosive
Only use the amount of fluid you need don’t waste materials by over using
Drill holes Drill, Drill press (optional)
Insure hands are away from the drill when using the drill other wise it will go through your hands
Make sure your drilling the correct area
Solider chip sockets Soldering ironLogic gates, mosfet
Insure that your hands are far away from the soldering iron when using it because you could burn your self otherwise
Solider resistors Soldering ironresistors
Insure that your hands are far away from the soldering iron when using it because you could burn your self otherwise
Bend the resistors in place so that they fit through the holes once their through the hold bend them a bit so they cant fall out.Make sure it’s the right band resistors
Solider inputs Soldering ironThermistor, pressure mat
Insure that your hands are far away from the soldering iron when using it because you could burn your self otherwise
Make sure their soldiered in the correct place
Solider outputs Soldering ironFlashing ledBuzzer
Insure that your hands are far away from the soldering iron when using it because you could burn your self otherwise
Make sure their soldiered in the correct place
Solider of board components
Soldering ironBattery snapOn switch
Insure that your hands are far away from the soldering iron when using it because you could burn your self otherwise
Make sure their soldiered in the correct place
Shrink wrap connections between of board components and wires
Heat gunHeat shrink tubing
Don’t shoot your self with the heat gun
Add chip to sockets
Tools used in the making of the alarm
• Soldering iron• Solider• Solider braid• Felix wire• Masking tape• Craft kinfe
Manufacture of off board components
• Led and thermistors, • For the led I first had to collect red and black wiring and then i tint the ends wires of the flexi wire so it
would attach to the led easier I would then solider the wires to the led you have to be careful with this though as the wires must go on the right prong of the led red wire goes on the rounded side black on the flat, A problem I in counted though was that I put the black wire on the round side, this was easily fixed by desoilding the join and putting it in the correct place.
• With the thermistor I had to do exactly the same thing as with the Led but I didn’t need to worry about the positive and negatives wire place meant so I used a grey Flexi wire instead
Manufacture of off board components
• Push button switches, pressure mats sptd toggle switches• For making the pressure mat I first had to collect a set amount of card, I then had to messes a square out onto the card
twice then with the 3rd one we had to message out another square but this time I had to cut out a small whole in the middle of that square to act as the connecter in the pressure mat
• With the push button switch I took some Félix wire striped both ends of the wire place tinited the end I was going to solider the push button to, I then would take the wire but it through the loop whole in the push button switch, and then I wold bend the end of the wire so it count fall out whilst I solider it in. I then solider the other end of the wire to the board by putting them in bending the wire and soldering
On board components• Resisters and variable resisters• How I soldered the resisters 1st I would insure the resister was of the correct strength by checking that I had the correct
colour bands on the front of the resister.• When soldering the resister I would put it into the board and bend the wire back so that the resistor was unable to fall out
of the board I would then solider the resistor in place using the soldiering iron I would then cut the resister wires that remaned after soiling the component into place
Bending resistor wires
All resistors in place
What the board looks like with all resistors soldered in place
On board components• Battery snap/chip socket• With the chip socket I had to make sure that I had the correct size chip for the board by counting how many legs the chip
socket had, Once I had the right chip socket I would put it in the board and bend the wires a small bit just so it wouldn’t fall out unless I jogged it, then when soldering I would take the soldiering iron and run a peace of solider along the joint very quickly, My reasoning behind this was because the circuit board allows solider to run between the chip socket legs because otherwise it would make the component very hard to solider in with out connecting the joins and blowing the circuit later
• With the battery snap Simply tinted the ends of the wire and put them into the board and twisted them round through a whole for better support and then solider them into place
Evaluation (slide 19)
Testing your circuit• Show a step by step plan that can be used to test your finished circuit. Write
it as if it were for a person who does not know how it is supposed to work.• Tick of each step to show that the circuit works.• Provide a video showing it working so that it is clear that it solves the
problem. Use Blueberry Flashback Recorder).
Evaluation• Describe what went well and what did not go so well in the manufacture of
your circuit– Consider the development of the circuit and the development of the PCB– Consider the actual building of the circuit
• Could it have been made differently? – alternatives?• Could it have been made better? – how?• Compare what you did to the steps of your plan• See table on next slide as a suggestion.
Evaluation (slide 20)
Evaluation (continued)
Description of Process What went well Problems encountered/changes made
Action taken to deal with problem
Design PCB and create mask
Cut board to size
Expose Mask and photoPCB to UV
Develop exposed PCB
Etch PCB
Drill holes in solder pads
Add resistors
Add capacitors
Add transistors/thyristors
Add Chip socket
Add off board components
Add chip to socket
Copy the planning table and edit as required.Comments only need to be brief.
Evaluation (slide 21)
Improvements• In addition to describing how the circuit could have been manufactured
better;• Describe how the circuit could be improved to function better to solve the
problem more effectively.– Different inputs– More inputs– Different control of the outputs– Different outputs