Laser Security System Project Report

Table of Contents

1. Introduction

2. Purpose of the System

3. Components Used

1. Laser
2. Light Dependent Resistor (LDR)
3. Buzzer
4. Transistor BC547
5. 9V Battery
6. 10k Ohm resistor

4. Working Principle of the System

5. Block Diagram of the System

6. Circuit Design

7. Conclusion

8. Future Scope
1. Introduction :

In today's world, the need for security has become paramount. There are
numerous ways to enhance safety, and technology plays a critical role in
this regard. One such advancement is the Laser Security System, which
provides an innovative way to protect properties and sensitive areas. The
laser security system uses light beams, typically lasers, to detect any
intrusion or unauthorized movement within a defined area. The system is
designed to be sensitive, reliable, and cost-effective, making it suitable for
home security, industrial applications, and even military use. This report
will discuss the purpose, components, working principles, and design of a
laser security system.

2. Purpose of the System :

The primary purpose of the laser security system is to detect any
unauthorized access or intrusion within a secured area. The system
operates using a laser beam that creates an invisible barrier around the
perimeter of the area being protected. When an object (e.g., a person)
crosses this beam, it disrupts the laser, triggering an alarm. The system
provides a quick and reliable response to any breach, ensuring that the
security personnel or the owner can take immediate action.

The laser security system can be used in various settings, such as:

 Home Security: Protecting homes from burglary or unauthorized

access.
 Industrial Applications: Securing factory or warehouse areas
where high-value goods are stored.
 Military or Governmental Installations: Providing security for
sensitive areas, such as defense establishments or research labs.
 Exhibitions or Museums: Protecting valuable artifacts or
exhibitions from theft.

The system aims to provide both preventative and reactive security

measures with minimal maintenance.
3. Components Used :
The laser security system consists of several key components, each
playing a vital role in ensuring its functionality. These components include
the laser, Light Dependent Resistor (LDR), buzzer, transistor BC547, 9V
battery, and a 10K Ohm Resistor. Below is a brief explanation of each of
these components:

Laser

The laser is the primary component used to create the invisible light beam
for detection. In the context of the laser security system, a simple laser
pointer or laser diode can be used. When the system is activated, the laser
emits a continuous beam of light across the protected area. The laser
beam is designed to be narrow and direct, making it ideal for creating a
security perimeter.

Light Dependent Resistor (LDR)

The LDR is a type of resistor whose resistance varies depending on the

amount of light falling on it. In the laser security system, the LDR is used to
detect the presence of the laser beam. Under normal conditions, when the
laser beam is uninterrupted, the LDR detects a specific light intensity.
However, if the beam is interrupted by an object crossing the path, the
amount of light falling on the LDR changes, triggering the system’s
response.
 LDR Symbolic representation

Buzzer

The buzzer serves as an alerting mechanism when the security system is

triggered. Once the LDR detects a disruption in the laser beam, it sends a
signal to activate the buzzer. The buzzer then produces a loud sound,
indicating an intrusion or breach in the protected area. Buzzers come in
various types, such as piezoelectric or electromagnetic, and in this system,
a simple piezoelectric buzzer is used due to its reliability and low cost.

Transistor BC547

The BC547 is a general-purpose NPN transistor used in the circuit as a

switch. The transistor amplifies or controls the electrical signal from the
LDR to trigger the buzzer. When the laser beam is interrupted and the
LDR detects the change in light, the transistor amplifies this signal and
closes the circuit, activating the buzzer. The BC547 is chosen because of
its reliability and efficiency in switching operations.

9V Battery

The 9V battery provides the necessary power to operate the laser, LDR,
buzzer, and transistor. A 9V battery is commonly used in low-power
electronic systems like the laser security system because it is compact
and capable of supplying consistent voltage to the components. The
battery ensures that the system runs autonomously for a reasonable
period without requiring an external power supply.

10K Ohm Resistor

The 10K Ohm resistor is an essential component in the circuit. It is used

to limit the current flowing through the LDR and the base of the transistor
BC547. Without this resistor, the transistor might receive excessive current,
which could damage the component. The 10K ohm resistor ensures that
the LDR operates within safe limits and helps maintain the stability of the
circuit. It is placed in series with the LDR to adjust the current flow to an
optimal level.

.
10K Ohm Resistor

4. Working Principle of the System :

The working of the laser security system can be explained as a sequence
of events:

1. Laser Beam Emission: The laser emits a continuous beam of light

across a specific area, forming a barrier or line of protection. This laser
beam remains uninterrupted under normal circumstances.

2. Light Detection: The LDR, placed opposite the laser, continuously

monitors the intensity of light falling on it. Under normal conditions, when
the laser beam is intact, the LDR detects a stable amount of light.

3. Interruption Detection: When an object (e.g., a person) crosses the

laser beam, the intensity of light falling on the LDR decreases or changes.
The LDR detects this change in light intensity.
4.Signal Processing: The change in light intensity causes the LDR to
alter its resistance. This change is sent to the base of the BC547
transistor. The transistor acts as a switch, amplifying the signal.

5.Buzzer Activation: The amplified signal is used to complete the circuit,

activating the buzzer. The buzzer sounds an alarm to alert the user of a
potential intrusion.

6.Power Supply: Throughout the process, the 9V battery provides power

to all components in the system, ensuring continuous operation until
manually turned off.

The system provides real-time feedback and alerts, making it highly

effective in detecting and responding to intrusions.

5. Block Diagram of the System :

The block diagram illustrates the major components and their

interconnections within the laser security system. Each component works
in tandem to create a secure environment. Below is a simple block
diagram of the system

6. Circuit Design :
The circuit design of the laser security system is relatively simple yet
effective. Below is the general layout of the circuit:

1. Laser Module: Positioned to emit the laser beam across the area to
be protected.
2. LDR: Positioned opposite the laser to detect the beam.
 3. BC547 Transistor: Acts as a switch to control the buzzer.
4. Buzzer: Positioned to provide an audible alert when the laser beam
is interrupted.
5. 9V Battery: Supplies power to the entire circuit.
6. 10K Ohm Resistor: Limits the current flowing through the LDR and
transistor.

Steps for circuit connections:

 Connect the positive terminal of the 9V battery to the laser

module and the collector of the BC547 transistor.
 Connect the emitter of the BC547 to the buzzer.
 The base of the transistor is connected to the LDR through the
10K Ohm resistor to control the switching operation.
 Finally, the negative terminal of the 9V battery completes the
circuit.

The entire circuit can be built on a breadboard or PCB (Printed Circuit

Board) for permanent installation.

7. Conclusion :
The laser security system is an innovative and cost-effective solution to
enhance security in various applications. By using the basic components
of a laser, LDR, buzzer, transistor, 10K ohm resistor, and a 9V battery, this
system provides a reliable mechanism for detecting intrusions. The system
operates autonomously, providing real-time alerts and ensuring quick
responses to potential threats. The use of lasers and light sensors makes
it a non-invasive method of security, suitable for both public and private
spaces.

In conclusion, the laser security system is a practical example of how

simple electronics can be utilized to improve safety and security. Its
simplicity, efficiency, and ease of implementation make it a viable choice
for various security applications.

8. Future Scope :
While the current laser security system works efficiently for basic
applications, there are several improvements and expansions that can be
made in the future. Some areas for improvement include:
 1. Wireless Communication: Adding a wireless feature to send alerts
to mobile phones or remote control systems.
2. Multiple Laser Sensors: Using multiple laser beams to cover larger
areas or create a more complex grid of security.
3. Integration with CCTV: Combining the laser security system with
CCTV cameras to create a more comprehensive security solution.
4. Solar Power: Implementing solar panels to make the system more
energy-efficient and reduce the dependence on batteries.

These improvements will increase the reliability, functionality, and scope of

the laser security system in real-world applications.

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B.Tech., CSE C

CSD 2102 Project report