Description
ABSTRACT
The main objective of this project was to ensure a proper security to car being parked in garage against theft or an intruder. The circuit uses three NE555 timers; one of the NE555 was wired as a monostable oscillator and remaining two were wired as tone generator and amplified to obtain a maximum audible sound. However, pin 2 of the first NE555 was used as sensor part .When pin 2 has contact with human body or hand it will activate the IC1 which will also bias transistor and this transistor was wired in a way that once it is powered it will close circuit thereby passing a negative supply voltage to tone generator circuit and outputted out through a loud speaker or buzzer.
This device functions as a major security device against car-theft as stated above. It is an electronic device that is connected to the battery of the car it is being installed in and gets activated when the car engine is switched off and the car stationed at a place. The device is not seen but, it has an indicator light which shows that the alarm has been activated. When the body of the car is touched by human hand, it sends a negative signal to the device which needs a negative pulse to get activated; it sends this negative from the human hand to the tone generator IC which triggers the alarm.
TABLE OF CONTENT
Title Page
Certification – – – – – – – – i
Dedication – – – – – – – – – ii
Acknowledgement – – – – – – – iii
Abstract – – – – – – – – – iv
Table of content – – – – – – – – v
CHAPTER ONE
1.1 Introduction
1.1 Background of the study
1.2 problem statement
1.3 Objective of the project
1.4 Purpose of the project
1.5 significance of the project
1.6 Application of the project
1.7 scope of the project
1.8 methodology
1.9 project organisation
CHAPTER TWO
2.1 LITERATURE REVIEW – – – – – – 5
2.2 door alarm System – – – – – – 5
2.3 Types of touch activated alarm System – – – – 5
2.4 The D.C. Power Supply Unit – – – – 6
2.5 The Touch Point Unit – – – – – – 7
2.6 The MonostableMultivibrator Unit – – – 8
2.7 The Transistor Switching Unit – – – – 9
2.8 The Load Power Control Unit – – – – 11
2.9 The Alarm Sounder Unit – – – – – 12
2.10 Component Review – – – – – – 13
2.10.1 Transformer – – – – – – – 14
2.10.2 Diode – – – — – – – – 16
2.10.3 Capacitor – – – — – – – 17
2.10.4 Resistor – – – – – – – – 21
2.10.5 Silicon Controlled Rectifier – – – – – 23
2.10.6 555Timer IC – – – – – – – 25
2.10.7 Transistor – – – – – – – 30
2.10.8 Switch – – – – – – – – 33
2.10.9 Piezo Buzzer – – – – – – – 33
CHAPTER THREE
3.1 RESEARCH / METHODOLOGY – – – – 35
3.2 Design Philosophy – – – – – – 35
3.3 Design Approach – – – – – – – 35
3.4 Design Procedure- – – – – – – 36
3.5 Circuit Principle of Operation – – – – 38
CHAPTER FOUR
4.1 DESIGN AND CONSTRUCTION – – – – 40
4.1.1 Selection of the Transformer – – – – 40
4.1.2 Selection of the Diodes – – – – – 40
4.1.3 Selection of the Capacitor – – – – – 41
4.2 Design of the Power Supply Unit – – – – 42
4.3 Design of the MonostableMultivibrator – – – 42
4.4 Design of the Switching Unit – – – – 43
4.5 Design of the Load Power Control Unit – – – 45
4.6 Design of the Alarm Sounder Unit – – – 45
4.7 Construction of the Project – – – – – 46
4.7.1 Construction of the Main Electronic Circuit – – 46
4.7.2 Construction of the Casing – – – – – 47
4.3 Testing and Result – – – – – – 47
4.4 Bill of Engineering Measurement and Evaluation – 48
4.4.1 Cost Analysis – – – – – – – 48
CHAPTER FIVE
5.1 Conclusion – – – – – – – – 50
5.2 Recommendation – – – – – – – 50
5.3 References – – – – – – – – 51
CHAPTER ONE
1.0 INTRODUCTION
The car door alarm system is an electronic system that gives an audible alarm when the car door knob it is connected to, is touched. If the door is the metal type then it will sound an alarm whenever any part of the door is touched. For the wooden door, the door alarm system is connected to the door handle, and hence, sounds an alarm only when the door handle is touched. The car door alarm system is represented by a block diagram below. It consists of a d. c. power supply unit, touch point, monostablemultivibrator unit, latching unit, electronic switching unit and the alarm sounder unit.
1.1 BACKGROUND OF THE PROJECT
The first car alarm was a primitive contraption that utilized a bell or horn connected to the drive shaft. It was created by an unnamed Nebraska inventor in June 20th, 1920. It utilizes the drive shaft to operate its own bell or horn signal when the car is properly moved. This is just a little talk on a car alarm but not a car touch intruder alarm which is a modern, more advanced, and more reliable type of car alarm.
This car touch sensitive alarm project consist of three NE555 timer IC, the first NE555 was wired as monostable multi-vibrator and the remaining two were wired as tone generator. When the sensor is touch or has contact with human hand perhaps body, IC1 is triggered at its pin 2 and output pin 3 goes high for a time period previously set by the values of R4 (10M) and Q1 (transistor) was bias via R3 and this transistor is in such a way that once it was biased it will supply a negative voltage to tone generator thereby making two NE555 timer which was know as (tone generator) to oscillate to make a bell sound through the buzzer. The tone generators are configured as an astable multi-vibrator whose oscillation frequency can be varied with the help of PR1 and PR2. By adjusting the values of PR1 and PR2, modifications on the tone are possible.
The reset button is used to set or open circuit the system back to its initial stage. The system is powered with 12V power supply voltage.
The first chapter of this project is narrating on the introduction, the concept of the system and also the aims and objective. Chapter two is all about literature review. Chapter three talks about specification and operation of system component. Chapter four is operation of system. Chapter five is about construction, testing and packaging. Chapter six is conclusion, observation, recommendation and References.
1.2 PROBLEM STATEMENT
The need for having a constant home protection has always been there. But in the recent times, considering a dramatic rise in petty crimes like robbery and theft, the need has been more strongly felt to have a fool proof protection of the belongings and the family members. Homesecurity has come a long way in the last few decades. It was in the hands of a guard who manually provided surveillance during nights in the earlier days, but it was not fool proof as it was only normal for him to have momentary lapse of concentration. This device brought solution to this need. It ensures adequate protection against intruders.
1.3 OBJECTIVE OF THE PROJECT
The main aim and objective of the design and construction this project is to create a comfort in the minds of vehicle owners or users when their vehicles are parked or stationed anywhere without much fear of car-theft.
1.4 PURPOSE OF THE PROJECT
The car touch alarm system circuit was designed to the sound on alarm when the touch point is touched by a human being making contact with the earth.
1.5 APPLICATION OF THE DEVICE
The car touch system finds application in the following arrears;
- It can be used as a bugler alarm.
- It can be used as an intruder alarm.
- It can be modify for use as a tap door bell
1.6 SCOPE OF THE PROJECT
This system designed to detect intrusion – unauthorized entry – into a car or other area such as a home or school. Security alarms are used in residential, commercial, industrial, and military properties for protection against burglary (theft) or property damage, as well as personal protection against intruders. This Touch Alarm Circuit is constructed by using timer IC 555 and few easily available components. This circuit will give alert sound when someone touches the car door knob, It is suitable for simple security applications. To implement this circuit your door knob must be a conducting material.
1.7 METHODOLOGY
To achieve the aim and objectives of this work, the following are the steps involved:
- Study of the previous work on the project so as to improve it efficiency.
- Draw a block diagram.
- Test for continuity of components and devices,
- Design of the device was carried out.
- Studying of various component used in circuit.
- Construction of the circuit was carried out. The construction of this project includes the placing of components on Vero boards, soldering and connection of components,
- Finally, the whole device was cased and final test was carried out.
1.8 PROJECT ORGANISATION
The work is organized as follows: chapter one discuses the introductory part of the work, chapter two presents the literature review of the study, chapter three describes the methods applied, chapter four discusses the results of the work, chapter five summarizes the research outcomes and the recommendations.
CHAPTER FIVE
5.0 CONCLUSION AND RECOMMENDATION
5.1 CONCLUSION
The aim of the project has been the design and construction of a door alarm system. The door alarm system gives an audible alarm when the door handle to which it is connected to is touched. The necessary specification was taken and the design was made according to this specification. The module was then constructed and tested. It operated as required. It suffices me to say that the aim as stated above has been achieved. However, a lot of difficulties were encountered in the process of realizing the project work, one of which is due to first timer syndrome but with advices from my supervisor and colleagues, most of it was conquered. Furthermore, the project work has enabled me to gain experience in electronic circuit designing and construction. Also, it has enabled me to understand properly how the different circuit element works.
5.2 RECOMMENDATION
In realization of the project work, a lot of observations were made; this observation is what I am putting down as my recommendation:
- Such project work should be given to student on time to avoid rush and unnecessary pressure.
ii. This killer initiative also, whoever wishes to embark on this project, should improve on it. Such improvement can be by adding entry and exit delay time for the door alarm to sound to enable the installer leaves or enter the house after setting the alarm.
