A laser based intruder alarm system as in this project work is a security system based on the use of laser beam. Laser is an Acronym for Light Amplification by Stimulated Emission of Radiation.
Laser beam in light operated project works are mostly used as means of putting things ‘ON’ remotely or used as trap which when obstructed results in a switching into action another operation. Burglar alarms widely use this kind of beam which is invisible to the naked eye. Ultrasound signals are also invisible but would be easily detected unlike the laser beam which becomes only visible when blocked by a plain background such as wall and so this could be used as an indicating pointer for many applications such as ammunition or target pointer for bombing aircraft or snipers.
Furthermore this project intends to use the laser system as a trap which when breached by a burglar, triggers and alarm as an alternating unit
1.1 PROBLEM DEFINATIONS
Detecting a burglar or intruder who is very smart at what he does best is a difficult task and as such to do it without an intruder knowledge is even more difficult. How to detect an intruder without his or her knowledge is the problem needing Engineering solutions.
1.2 AIM AND OBJECTIVES
The aim of this project work is to design and construct a laser based intruder alarm system with the following objectives.
a) To develop a laser gun using a GA as diode to generate continuous laser beam for sensing by a detector
b) To develop a receiving circuit based on LDR (light dependent resistor) to detect the laser beam
c) To develop a switching circuit to switch into action a specified load
d) To design a 555 timer based alarm system
e) To realize a suitable power supply system unit for the whole circuit
1.3 JUSTIFICATION OF THE PROJECT
The means by which our valuables are secured cannot be over emphasized as the saying security is very crucial to all
1.4LIMITATION OF THE STUDY
The limitation of this work is the non-availability ofelectric power to keep the system active and operational.
In terms of scope, this work is limited to security alternating system by design and construction in its basic form.
1.5 BLOCK DIAGRAM
The figure of fig 1.1 shows the block unit which make up the laser based intruder alarm system.