• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10
  11. 11
    11
  12. 12
    12
  13. 13
    13
  14. 14
    14
  15. 15
    15
  16. 16
    16
  17. 17
    17
  18. 18
    18
  19. 19
    19
  20. 20
    20
  21. 21
    21
  22. 22
    22
  23. 23
    23
  24. 24
    24
  25. 25
    25
  26. 26
    26
  27. 27
    27
  28. 28
    28
  29. 29
    29
  30. 30
    30
  31. 31
    31
  32. 32
    32
  33. 33
    33
  34. 34
    34
  35. 35
    35
  36. 36
    36
  37. 37
    37
  38. 38
    38
  39. 39
    39
  40. 40
    40

An electronics firm wishes to introduce a range burglar alarms. This coursework contains the design and a prototype, which has been made for further development by the firm.

Extracts from this document...

Introduction

Electronics Coursework Problem An electronics firm wishes to introduce a range burglar alarms. This coursework contains the design and a prototype, which has been made for further development by the firm. Possible Projects Brief I have decided to design and make a prototype of a home burglar alarm. Research into Alarms - I have phoned companies, talked to staff at electrical shops, to find the following information. Analysis of commercial alarms From my research into commercial alarms I have found out the following... * All alarms have more than 1 input. * All alarms sound for a time after they have been triggered. * Most alarms sound for a variable time of between 2 minutes and 20 minutes. * All alarms have a sound output of at least 98dB. * All alarms have either a delay between being switched on and being armed or they can be remotely switched on and off from outside the premises. * The better alarms have a small delay between being triggered and the siren sounding. Research into Burglaries - To Catch a Thief The following research came for the television programme 'To Catch a Thief'. The presenters are ex-burglars, who have decided become good to help people prevent burglaries. First the ex-burglars find a house, burgle them (with the householders permission), and then the BBC pay for extra security to be fitted e.g. Burglar alarm, new locks, windows, and doors. Finally, the burglar is back for the last time to see whether or not he can get in. * A burglar will go for any kind of house. * Burglars go to upmarket places because the bigger the house, the bigger the 'whore'. * Burglars will go for 'posh' neighbourhoods o Three cars on the drive, shows his wealth * Secluded areas are more vulnerable because there is less chance of someone reporting a burglary. Burglars don't like public areas. ...read more.

Middle

resistor 62-0409 0.01 2 push switch 78-0100 0.20 1 key switch 79-0295 1.60 Total �1.92 PROCESS Double Delay Unit LARGE ORANGE 1 4098 i.c. 83-0426 0.25 1 16 pin chip socket 22-0160 0.06 1 1M? preset 67-0160 0.08 1 4M7? preset 0.20 1 33k? resistor 61-0409 0.01 1 47 ?F Cap. up to 24 s 11-0325 0.03 1 100 ?F Cap. up to 50s 11-0245 0.03 Total �0.66 PROCESS 4 INPUT OR GATE LARGE BLUE 1 4072BE i.c. 83-0316 0.20 1 14 pin chip socket 22-0155 0.05 Total �0.25 DRIVER Transducer Driver LARGE YELLOW 1 MPSA 13 Darlington 81-0142 0.04 1 33k? resistor 62-0409 0.01 Total �0.05 OUTPUT Sound 1 75 dB Buzzer 35-0035 �0.58 1 108 dB Miniature piezo siren 35-0272 �3.29 4 self adhesive p.c.b. pillars 33-2135 �0.09 Total �7.26 Plan 1 Plan 2 Diary 1 Task Est. time Tools and equipment needed. Time taken Problems encountered Use 2-D Design to produce layout of final circuit 20 min. Computer 2-D Design and final system diagram. 60 min. I didn't know how to use the double timer and had to ask my friends Print 2-D Design layout. 5 min. Computer 2 D Design printer 5 min. None Mill printed circuit board using CNC milling machine 15 min. Computer CNC milling machine and copper board. 60 min. I had to wait for the milling machine Drill p.c.b. 10 min. Mini drill. 20 min. None Clean p.c.b. with wet and dry paper 5 min. Wet and dry paper 5 min. None Produce parts list 10 min. Computer Microsoft Works and printer 40 min. I couldn't find where the correct values for the double delay unit. The database didn't seem to have the values I wanted. I couldn't find the correct components for the delayed arming part of the system Solder power connector components in place. 40 min. Soldering iron, stand, pliers, cutters. Heat mat and solder. 10 min. None Test the correct working of power connector. 50 min. Alpha building and testing manual and multi-meter. ...read more.

Conclusion

Test - burglars climbing the stairs. The pressure pad circuit worked with 100% accuracy. However it was possible to ascend the stairs and step over the pressure pad. Burglars would probably climb stairs one at a time. Therefore this system should work every time. Test - burglars entering the front door. The pressure pad circuit worked with 100% accuracy. However it was possible to leave the house without triggering the alarm. It must sound an alarm that can be heard 50m away. I triggered the alarm and tested how far away that it could be heard. With the door open I could hear it 75metres away. With the door closed I could hear it 55metres away. Test - the timer The timer ran for between 3 minutes 10 seconds and 3 minutes 40 seconds. The average time was 3 minutes 35 seconds. Although this was below the specification it was not seriously below specification and the discrepancy was probably due to the low tolerance capacitors used. Test - the 20-second entry timer I adjusted the preset on the first part of the double delay unit and arrived at an average time of exactly 20 seconds. Resetting the alarm Pressing the reset button stopped the alarm 100% of the time. Test - the quiet audible signal. The standard buzzer could be heard 15 meters away. My system therefore meets the specification in almost all ways and meets the specification in all-important ways. To improve my system I would do more research into timers and find one that could time for longer. The 555 timer can time up to several hours and this would seem to be what I need but it is difficult to make it edge triggered. Use of Industrial practices I used a lot of CAD/ CAM when making my project. I used croc clips to produce a virtual circuit and used 2D Design to design the layout. I used a CNC milling machine to cut my circuit board and could use the file to produce many identical circuits. I could never have designed such a complex circuit without the CAD/CAM equipment. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Systems and Control section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Systems and Control essays

  1. electonics specification

    It is 1750mm in length x 200mm width x 22mm height the website www.diy.com is for the shop B & Q therefore can be bought at the shop instead of online. -Have wood glue from www.diy.com it has no part number but is called 'B&Q general purpose wood glue BQ05 50ml' costing £1.98.

  2. Wailing Alarm Siren

    It makes use of two 555 timer ICs used as astable multivibrators. The frequency is controlled by the pin 5 of the IC. The first IC (left) is wired to work around 1Hz. The 47uF capacitor is charged and discharged periodically and the voltage across it gradually increases and decreases periodically.

  1. Design and Technology Project Design an Advertisement

    You will notice that each Secondary Colour on the Colour Wheel is bounded by two primaries. These are the components that one would mix to get that Secondary Colour. There are three secondary colours; green, orange, and violet. Secondary colours are the hues between the primary hues on the colour wheel.

  2. Bicycle Alarm Project

    This is triggered by movement in any direction from any other position. Unlike a mercury tilt switch the vibration switch can be left in any position. 2. The theft of the accessories could be done in many ways. The method I intend to use is aluminium foil on the lamps connected to the alarm by a contactor.

  1. Review of Electronics Systems in Society

    Television Television was first introduced around 1930 and has made a huge impact on society, providing news coverage and entertainment. Originally television was only in greyscale but in 1940 the first colour transmission was made and colour televisions were gradually introduced.

  2. Getting On Line Without a Computer or Internet Access at Home

    Computers are usually available during normal hours of library operation. Each library has its own hours. Some libraries are open only during the day, while others have evening hours. Some are only open during the week, while others are open on weekends.

  1. The paper discusses the issues associated with the risks assessed between the organizations bidding ...

    The contract between Shang-wa and Lester Electronics has lasted for the last 35 years being renewed annually and has served the growth and finances of both organizations well. Because of this continual relationship between these two organizations, both CEOs have become friends as well as business partners.

  2. Water level sensor

    Sensitivity: Sensitivity is known as the gradient of the graph: Change in voltage / Change in the depth of the water (3.49-2.34)/(800-200)=1.92�10-3v/ml Response time: My sensor was different to other sensors; the response time was real quick in the sensor.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work