CONSTRUCTION OF LIGHT SENSITIVE ALARM SYSTEM
TABLE OF CONTENTS
Title page Certification Dedication Acknowledgement Abstract Table of contents CHAPTER ONE Introduction Aims and objective Purpose of the study Scope of the study Limitation of the study Significance of the project
CHAPTER TWO Literature review History of light – electric bulb CHAPTER THREE Construction procedures Materials used in the project Selection of appropriate tools and equipment Safety precautions Assembly CHAPTER FOUR Sequence of operation Capacitor Resistor Transistors CHAPTER FIVE Summary Recommendation Conclusion
CHAPTER ONE1.1 INTRODUCTION
The light-sensitive alarm is an electronic circuit that detects a sudden shadow falling on the light sensor and sounds the bleeper. When this happens, the circuit will respond to gradual changes in brightness to avoid false alarms. The beeper sounds for only a short time to prevent the battery from running flat. Normal light can be used. The circuit will work best if a beam of light is made to fall on the light sensor. Breaking this beam will then cause the bleeper to sound. The light sensor is a light-dependent resistor (LDR); this has a low resistance in bright light and high resistance in dim light. The light sensitivity of the circuit can be adjusted by varying the 100kiloohms (K) preset. The length of bleep can be varied from 0.5 to 10 seconds using 1 milliohm (M) preset. using the 7555 low power timer ensures that the circuit draws a very little current of about 0.5 milli-Amps except for the short time when the bleeper is sounding, this uses 7 milli-Amps. If the circuit is switched on continuously, an alkaline 9V battery should last for about a month.1.2 AIMS AND OBJECTIVESThe project is actually designed to promote a high level of security in workshops, industries, and homes. It enhances a recorded indication of visitors and summons staff or personnel to fulfill a service as in domestic and industrial use.1.3 PURPOSE OF THE STUDYThe purpose of this study is to provide maximum security around the world.1.4 SCOPE OF THE STUDYThis project “light-sensitive alarm” is design mainly to alert the user by a bleeper when the circuit detects a sudden shadow falling on the light sensor the bleeper duration can be controlled by varying the I ohms – preset resistor.1.5 LIMITATION OF THE STUDYThe limitations of this study are the bleeper sound for only a short time to prevent the battery from running flat. If there is any little mistake during soldering, there will not work well. Also by met being able to purchase some components and their exact value couple with transportation problems has also gone a long way to reduce the efficiency of this project.1.6 SIGNIFICANCE OF THE PROJECTThis project helps to provide security in offices, hotels, homes, etc. it also promotes and encourages researches involving in security research projects..