1. D&T: Electronics and Control Systems Unit A511: Introduction to Designing Name: Connor Brookfield Candidate number: Centre Number: 16527

2. SECURITY BY Connor Brookfield

3. Creativity I have chosen security because there is a need for a rape alarm as 1-in-5 women collage age or older get raped.

4. Investigation of users needs To solve the problem of rape or reduce the risk of rape they user needs a rape alarm. This girl could feel safer if she had a rape alarm or if it had a street light to make it brighter If she had a rape alarm someone would be alerted. These are all articles From the internet and news papers

6. Survey and Reasons For Questions 1)Are you a:man, woman, young girl?- I want to find out gender as a woman or young girl will be typical user. 2)2) If you’re a man or woman do you have a daughter?-If daughter goes out parents might buy her one so she is safer. 3) If you’re a woman do you and/or daughter go out at night?- Might not use product if they don’t go out at night. 4) Do you feel safe going out at night?- If they don’t feel safe then they will be more likely to buy the product. 5) Are you aware of the danger of going out at night?- If they are not aware of danger but got told they might buy one. 6) Would you feel safe going out at night if you had a attack/rape alarm?-If they had one they could feel safer knowing they have a rape/attack alarm. 7) how much would you be willing to pay: under£10,£10,£10+(circle answer0?-Might not want to pay much so find out who much they willing to pay so decide what materials to use. 8) Would you go for a new cheaper brand or more expensive trusted brand?- Might not buy it as from new brand. 9) What would you prefer: Press a button? A sensor that detects when someone comes within a metre for more than 30 seconds?-To see how complex they want it to be. 10) if you wouldn’t buy it for yourself would you buy it or recommend it for/to someone?- They might buy one for someone else or get one and recommend it. YES NO 1)man-3 woman-5 young girl-2 2)4 6 3)7 3 4)5 5 5)4 6 6)8 2 7)Under£10-3 £10-5 £10+- 2 8)7-new brand 3- trusted brand 9)9 press button 1- sensor 10)Buy for self- 8 recommend -2

7. Summary of the questionaire From the answers on my questionnaire I come to the conclusion that I should make a rape alarm because 7/10 people said they go out at night and out of that 7, 5 people said they don’t feel safe. Also I can conclude that I need to put a push button switch in it as 9/10 people said they want to push a button. Next to enthuses the point of there is a gap in the market for a rape alarm because 7/10 people said they would buy a new brand rather than go with a trusted brand which shows they want a new product. I can also extract from the questionaire result that 50% of the 10 asked would pay around£10 for the product. Finally when asked do you know the dangers of going out at night? 6/10 people said they were not aware.

8. Picture of filled out questionarie

9. Creativity productcostTypical user when/where used functionTechnology used (input/ output) Manufacturi ng process used 140 decibel mini personal attack alarm. £6.39When someone is alone in dark or going out in dark. Press a button and siren goes off. Push to make switch and then a buzzer sounds. Injection mould and PCB working then assembly. Remote car alarm. £22.39Someone who owns a car. When the motion sensor picks up movement in or around car led flashes. Motion sensor and then led flashes. PCB soldered then plastic case injection moulded then assembly. Honeywell pet friendly acenta£151.00 Someone who owns a house. Alarm goes of when sensor picks up movement. Movement sensor and then when senses movement an alarm goes off Injection mould for plastic casing then PCB working then assembly Trend: the trend is that as the price goes up the more inputs & outputs it has or more features.

10. Creativity I am going to make a rape alarm as there is a problem of girls being raped and no one can hear until the woman tells someone. In my circuit I will need a siren or something that makes a loud sound. I could use a circuit similar to a burglar alarm, however it will be simpler as a burglar alarm uses movement sensors where as I will use a button(push to make switch). I have chosen to make a rape alarm because while researching i found numerous newspaper articles about women or girls getting raped; one of these articles is shown earlier in the presentation. Design Brief

11. Product analysis MINI PERSONAL ATTACK RAPE PANIC ALARM 91dB LOUD KEYRING SIZE SWT 120DB Keyring Personal Attack / Rape Alarm FunctionTo prevent/deter rapist or attackers. To deter someone from attacking or raping you. User need fulfilledYes it makes a loud noise when triggerd.(90db siren) The users needs are fulfilled as makes a loud noise when triggerd.(120db) Materials used in construction Pcb&Components, injection mould casing. Pvc casing and the pcb and components. Durability of productThe product is fairly durable as it has a hard plastic case. The case will make it durable as its plastic. sustainabilityThe product is sustainable because it can be reused by replacing the battery. The product is not sustainable because it cannot be recycled. Energy use9 volt battery.9 Volt battery. Life cycleLife cycle is: brought, used, no longer needed, thrown away Life cycle: bought,used, not needed anymorer, thown in the bin

12. Design

13. Specification The purpose of the proposed product is to make someone feel safe in the dark. This is because people can get raped or attacked in the dark. The product should make a loud noise when the button is pressed, because peole want help if they get raped. The product will sense the pressure when the button is pushed because a push button switch will be the trigger for the circuit. The output will be need to make a loud noise( a siren for example) beacause if someone gets raped it is normally a sucluded area so they will need to alert people far away. The power supply will be a 9volt battery as its easy to replace and portable. The circuit will run on 9volts because you need at least 9volts to power a siren. My product will not have an on/off switch because it will always be on standby. It will have a power indicator because it will alaways be on standby so a power indicator will save the user testing it. The circuit will be designed on circuit wizard because its a good programme to design circuits on. Manufacturing: it will be designed on circuit wizard converted to a PCB then cut using Computer Edging Process and finally components are solderd in. I will test it on circuit wizard and oncer its made this is because i then have proof it works

14. Systems diagram InputProcess and LogicOutput Movement sensorThyristorBuzzer Push to BreakTransistorSiren Push to MakeMosfetLed Dark sensor/ light sensorAnd/NandFlashing Led noise monitorOr/Nor Nor invertor I have given alternate input, process, logic gates and outputs but have highlighted the components I will use in my circuit.

15. Circuit design 1 When the switch(sw1) is closed and the push to make switch is pressed the circuit is triggerd and makes a shrill note to try scare of the attacker. Also the thyristor acts as a latching switch so the circuit will stay on until it is reset or turned off. Personal attack alarm Block diagram Input the input is the PTM which will be you pressing the button. Process The process will be the thyristor latching on and driving the circuit. Output The output will be the buzzer producing the shrill note.

16. Circuit design2 When the PTM switch is pressed the transistor drives the circuit and the buzzer produces a loud noise. The LED is the power indicator so you know if its working or not. Block diagram Input The input is the PTM switch which is you pressing the button. Process The transistor is then activated and drives the power to the buzzer. Output The output is the buzzer making a loud noise.

17. Circuit design 3 When it is turned on the two monostables make a wailing sound. This is because they are on 2 different frequencys. The speaker then amplifies the sound of the wailing this could scare away the attacker. Block diagram Input The input is the person turning on the circuit. Process The process is the two monotstables making a wailing sound because of the 2 different frequencys. Output The output is the speaker amplifying the waling sound.

18. Circuit design 4 The inputs are PTM switch and PTB switch Ihave put both in because this could represent a button trigger or a pull cord trigger to the circuit. I put the output as a buzzer because they produce a noise which could scare away an attacker. Block diagram Input The input is a push to make switch and push to break. Process The process is a nor gate to combine the 2 inputs and a transistor. Output The output is a buzzer because they produce a loud sound.

19. My chosen circuit I am going to use circuit 2 because it simply and easy to make in school. I have not used circuit 3 because it could be mistaken for a police car and i could of used circuits 1 and 4 as they would fulfill the purpose aswell.

20. Development of circuit 1) 2)

21. Developing circuit 2 This is my final circuit, I have chosen to turn into a PCB.

22. Video of working circuit(click)

23. First stage of conversion to pcb This is when I first converted it to a pcb. The green wires mean it is only 89% routed. So i decided to move the compionents around to see if it would fully route, although before i did anyhing i turned on automatic rounting which stops the tracks become diagonal. I deleted the copper fill because if not the etching process I will use will be unsucessful.

24. Second stage I have now re arranged the components so that they are routed correctly and so it will function properly. Now it works properly i will move the so i can make the circuit smaller and neater by doing this i will be saving money as i will need a smaller PCB and i will use less resources.

25. Third stage This is the view of the circuit now i have made it neater and made it smaller as you can see i have not used half of the pcb.

26. Fourth stage Now I have re-routed the circuit I have added the off board components to test if it will work in reality. What my circuit does The toggle switch is to turn it on and off, then you use the red(ptm) or gray(ptb) button switch to trigger the circuit, it will stay on until reset by turning it off with the toggle switch.

27. Annotated final pcb design Push to make swith Toggle switch Push to break switch Or gate buzzer 9 volt battery 2N5060 thryistor 10k resistor 1k resistor

28. Development of the PCB

29. Test plan for pcb design FeatureExpected resultActual resultDoes it solve the problem Siren make loud noise? Siren will soundSiren soundsYes Press the Ptm switch The circuit is triggered The circuit triggersYes Press the PTB switch The circuit will trigger The circuit is triggered Yes ThyristorStay on until circuit is reset Stays on until the circuit is reset Yes Turn on circuitCircuit should be ready to use Circuit is ready to use Yes ResetWont reset until circuit is turned off Didn’t reset until circuit turned off Yes

30. Video of pcb working(click)

31. Bill of materials

32. Planning the manufacture process Description of ProcessTools/Materials requiredTips for success Design PCB and create maskCircuit wizardMake sure you use right size tracks. Cut board to sizeBand sawCheck your pads, tracks, holes and measurements are the right size before cutting. Expose Mask and photoPCB to UV-PhotoPCB -UV light - Mask of my circuit Make sure that you don’t expose the pcb for to little or to long time. Develop exposed PCB Etch PCB Drill holes in solder padsDrillPoke small hole in middle for accurasy Add resistorsSoldering iron The resistor itself solder The soldering iron will be hot so don’t burn yourself. Add transistors/thyristorsSoldering iron The thryristor itself solder The soldering iron will be hot so don’t burn yourself. Add Chip socketSoldering iron The chip socket itself solder The soldering iron will be hot so don’t burn yourself. Add off board componentsSoldering iron The battery, siren, switches itself solder The soldering iron will be hot so don’t burn yourself. Add chip to socketSoldering iron The chip itself solder The soldering iron will be hot so don’t burn yourself. Also earth yourself before you touch the chip so you don’t blow it.

33. Tools Soldering iron – A heat source used for soldering, its electrically powered. Also it has a copper tip for efficient heat transfer. Components – these are sometimes very complex but can be really simple aswell. They can be a switch which can trigger the circuit.(EG) Push button switch triggering a siren to go off. Copper braid- the copper braid was helpful because it was easy to clean up some of the solder around the joints. Also it was helpful because on my chip socket i soldered over two joints. ` Heat gun- to shrink wrap the components on my circuit.

34. Problems encountered while in maufacture. One of my problems was that I had soldered my chip socket in the wrong way-it was easily fixed though as I just put the logic chip in”upside down” as such.(picture below) Also I soldered in the wrong resistor so I used a copper braid to clean some of the solder away so I could take it out of my circuit.(picture below)

35. Problems encountered while in manufacture continued In addition I also put in a push to make switch where there was meant to be a push to break switch. This is because i picked up the wrong

36. Final working circuit working video.

37. Evaluation Description of ProcessWhat went wellProblems encountered/changes made Action taken to deal with problem Add resistors I soldered the right value resistor into the write place. I soldered one resistor in that was the wrong value I removed it and put the write one in. Add switches I used put the switch in the write place. I put a push to make where there is meant to be a push to break Removed the PTM and put in the PTB Add thyristors I soldered it in the write place. none Add Chip socket I didn’t double join any pins that were meant to be double joined. I put the chip socket in upside down I had to place the chip in the socket upside down to. Add off board components I used a siren and wired it up correctly, E.g got the positive and negative write. none Add chip to socket I put it in fine and earthed myself to make sure i didnt “blow” it. Because i had placed the chip socket in upside down i had to put it in upside down.

38. Evaluation(narrative) In my coursework I produced a personal attack alarm which I successfully manufactered and it works. However I did encounter many problem in the making of the circuit itself and the powerpoint. Firstly I found it difficult to found it difficult to find evidence that there was a need for the product. Following this I also found it diffcult to find pictures of a place where someone could be attacked. Next my second problem that I encountered was that I had to develop a circuit and I used an or gate but it wouldn’t have worked in reality because I had used to push to make switches so one could have been a push button representation but I didn’t know what the other coukd be so I changed it to a push to break switch which was representing a pull chord. That was the only problems I had with the powerpoint I next ncounterted problems while making the circuit. In addition to the powerpoint problems I had problems while in manfucature of the circuit. The first problem was that I soldered in my chip socket upside down which isn’t a major problem because you can solve it easily- just put the chip in upside down aswell. Secondly i think i could have improved my circuit by making my soldering neater. So to help this i used the copper braid to remove some of the solder aweay from the joints. By doing this it makes the joint smaller and also makes it look neater than what it was like before. Also i think i could have improved the quality of my circuit if i had taken my time in the manufacture process because i rushed it at point and didn’t check that what i was doing; for example i soldered in the wrong resistor and that was due to me not checking.