CHAPTER ONE
INTRODUCTION
1.1.         Background of the Study
The industrial Electronics has changed the whole field of Engineering and technology is occurring so rapidly, even in developing countries. It is so because newer technologies overcome older ones. After the industrial revolution the world shifted towards the information age with the development of computers during the1950's.
As such, mechantronics means the principle that combines the application of mechanical and electrical means has taken over the greater part of industrial electronics which is indispensable in modern technology.
In Nigeria, security which is one of the basic lookouts in any productive firm, has been on the decrease. Most industries have gone bankrupt because of their inability to meet up to the security standard required in a modern day setting. Equally, some homes and offices have lost important documents and properties due to easy access that criminals have. There is thus an urgent need for significant security measures to improve the standard of living of the people, enhance development and put to a stop the menace of insecurity. That is the reason as a student of Computer System Engineering the project named "Intruder Detector Alarm System with direction”, was embarked on.
1.2       General Description of the Project
This electronic system consists of four sensors made up of opto couplers realized with combination of Laser beam, from Laser diode coupled into a cadmium sulfide photocell (C.D.S photocell).
This component serves as an electronic eye, the output of opto couplers conditioned by a Schmitt trigger NAND gate control Logic (74 Ls 132) TTL chip. The output of the 132 chips is used to trigger one short delay which reset an astable multi-vibrator which generates the frequency that is used to drive the buzzer alarm. Each of the sensor output is fed to a BCD to decimal priority encoder whose output is decoded to a format that can be displayed using a seven-segment display (common anode).   The buzzer is interfaced through a single transistor static switch.