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D&T: Electronics and Control Systems. By Edward Doust. Candidate number: Centre Number: 16527. Theme choice I have chosen security as my theme.
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D&T: Electronics and Control Systems By Edward Doust Candidate number: Centre Number: 16527
Theme choice I have chosen security as my theme. The reason why I have chosen security alarms as my theme is because burglary has gone up in resent years due to people not having burglary alarms, poverty and people are getting attack more because they have more valuable objects on them. Also they are being raped because they have no alarm on them to say that they are being raped. The yellow is showing what I have chosen to do for my security alarm.
Conclusion • The reason that I have chosen a mat alarm Is that if you have it outside the front or back door the burglar will step on it and the alarm will go of even before he gets into the house. Also you could have it at the bottom of your stairs so if someone does get in and you have valuables upstairs then he would be deterred before e get a look at the valuables and runs away with nothing.
Users Needs • the users needs is an alarm to send a warning to the burglars and may deter them from burgling the building. Here are some examples to show the rise In burglary's in the UK • ‘Britain was hit by Three burglaries every two minutes last year as the number of break-ins soared.’ Says The Sun Here is some evidence of someone being robbed on holiday: • ‘‘The occupants were away on holiday and returned to find a downstairs window had been tampered with.’’ says BBC news and also ‘’An Essex couple whose house has been burgled for the third time in two years.’’ these quotes show that people are being burgled because they don’t have any security alarms. • You are most likely to be burgled if you are in an isolated place because no one can see you. When your on holiday because no one is at home so there isn’t a threat of you seeing them and if you can’t see you shed because its behind trees or its down the end off the garden. The reason for this is because you cant see the shed you wont now if your shed is being bracken into. This picture shows that the shed is easy to get access too. To hopefully prevent this from happening the owner should put an alarm on the fence or on the shed so if the owner couldn’t see the shed they then would Know if someone is climbing over the fence or braking into there shed. This picture show that there is no alarm to stop the bugler from bracketing in the house. To hopefully prevent this from happening the owner should fit a security alarm in or on the house.
Evidence of someone being burgled on holiday or at when out of the house • Here is some evidence of people being burgled whilst on holiday or out the house. ‘‘The occupants were away on holiday and returned to find a downstairs window had been tampered with.’’ says BBC news and also they say another one which is, ‘’An Essex couple whose house has been burgled for the third time in two years.’’
Conclusion • From these evidence I have found out that everyone ca get burgled no matter how rich, poor or how famous you are, you can still get burgled. This shows that even celebrities don’t have burglar alarms because the think that they won’t get burgled.
The Design Brief • I have found out that more people are getting burgled every year and every 3 minuets someone is getting there house broken into around the world. Its more likely if you haven't got an alarm in your house, you are going to got burgled . • I am going to make a product that will alert the owner of the house is being Brocken into. • what you need to do next. • I need to design my circuit in circuit wizard to see if it works first. Then I need to find these, an siren so the owner of the house can hear it going off, a battery to make the circuit have power, a switch to turn on the circuit, a small LED to tell you its on, a push to make button so to make the alarm go of, a latch so when the burglar steps on the mat the alarm stays on and a reset button so you can reset the alarm without turning it of.
My Questionnaire The red means that that is the most popular. • Have you ever been burgled? • Do you want a security devise? • How much would you pay for one? • What size would you like it? • Would you like it to have a flashing LED light ? • Would you like it to be sustainable? • Would you like it to be portable? • Roughly how many burglary's does your village have every year? • Do you want it disguisable? • Do you want it to have a power indicator?
Trend • The more expensive the product the better quality the casing and the design, however the cheaper products the less time has been spent on it and has bad quality casing. Conclusion • in conclusion I have deduced that my circuit will be around the middle of the table, it will not be expensive but will have decent and well designed components and materials. I will be doing this because 70% of the people I asked said they would pay between £5-£10, this is not cheap but not ridiculously expensive either.
System Diagram • The ones in yellow mean that they are the ones I’m using in my circuit.
In this circuit it senses pressure with a pressure mat and latches on with a Thyristor. This circuit could solve the problem very well as it has a latch so the buzzer will keep going till the circuit is reset or turned off. Ideas for the circuit In this circuit it sensors pressure with a pressure mat but doesn’t latch on because it doesn’t have a Thyristor. This circuit couldn’t solve the problem as it doesn’t have a latch so when the burglar steps on it he would only hear it when he stands on it.
chosen circuit I have chosen this circuit to be my circuit and to develop it. I have chosen this circuit to make and develop because it has a latch on it.
I this circuit I have added a reset button by the buzzer. Circuit development In this circuit I have added an AND gate and a dark sensor in so I can put more than one input in it and will work only in the dark only. In this circuit I have added a LED to the power so I now when the circuit is on
Testing my final and chosen circuit. Conclusion This circuit will solve the problem as most burglaries happen at night and this circuit will work at night.
Development of PCB In this PCB I have changed the pad sizes and hole size. I have done this because it won’t waste materials. So it is more sustainable. In this PCB I have changed the battery and switches connectors. In this PCB I have made it smaller so you can carry it around easier.
Tools and Equipment Printed circuit board PCB Drill Soldering Iron Bubble etch tank Wire cutters Solder Wire stripers
Manufacturing process This is my PCB board before all the components are on. Now I’m adding a little bit of solder to help the wire to stick to the off board components. This is me soldering the wires to the off board components on to the Board Next I’m shrink fitting the component so it stops water from damaging the component and helps keep the wires together. This Is my board after soldering on the resistors and the And.
After I then added a switch to make the circuit turn on, a push button switch, to reset the circuit when it goes off and a LDR sensor to activate the pressure mat. I then added a siren to deter the burglar if they step on the pressure mat, a LED to tell you that it’s on and a battery connecter to attach the battery.
Making the pressure mat Next I cut 3 squares of cardboard into the correct size. I then started to cut out 2 squares of foil to the size of the square cardboards. First I got some cardboard, foil and scissors. Then I cut the middle out of the cardboard so then the two bits of foil will then touch each other. I then taped the 3 squares of cardboard together with masking tape and taped the wires to each piece of foil. Next I glued the two squares of foil to the cardboard.
Mistakes that I made I made a mistake by soldering in the wrong off board component on the wrong hole. To solve the mistake I got the solder off with some copper filament by heating up the solder and placing the copper filament on the solder so it gets rid of the solder and pulled it out the off board component. I made a mistake by soldering two wires of a component together. To solve this I got some copper filament and heated the solder up and got the solder of and did the soldering again. I made a mistake by soldering in the chip socket I the wrong way. I know this because on one side there is a small dip which should face the top of the board. But even though it’s the wrong way round it still works but usually the dip faces the top of the circuit board.
Evidence of my final circuit working Drag the mouse over the picture, then press play underneath it. Checklist First when the circuit is turned on a green light power indicator should turn on. Then when you press on the pressure mat, when the LDR detects light, the alarm will not go off. When the LDR detects darkness and you press on the pressure mat the alarm will go off and will continue to sound even when it subsequently detects light. To stop the alarm you then press the blue.
Improvements of my circuit • To improve my circuit in the future I could make the alarm go off in the day and night rather than just at night because even though most burglary's happen at night some still happen during the day. Also if you are away on holiday then if your house is being burgled then the alarm could got off and scare the burglar of. • Also I could make the pressure mat have a setting to have a curtain weight to set the alarm of if the owner had a pet or if something fell on the pressure mat when it’s turned on. • I could make the circuit have flashing lights around the house if the owner of the house is death or hasn’t got very good hearing. Then they would no if someone is breaking in there house when they are in the house.
