LASER GUARDIAN: Safe Guarding Spaces with Tech

1.CHAPTER

1.1 Introduction
Important monuments and places are valuable cultural and historical treasures that require robust
protection measures to ensure their preservation for future generations. These sites are vulnerable
to various threats, including vandalism, theft, and natural disasters. Therefore, implementing
effective security systems is crucial to safeguard these precious landmarks.

The Laser Guardian is highly accurate and reliable. The system is also highly customizable,
allowing users to adjust the sensitivity and detection range to suit their specific needs. The Laser
Guardian can be used in a variety of settings, including museums, banks, and private residences.
This system is used to protect valuable assets and prevent unauthorized access. The system uses
a laser beam to create an invisible barrier around the perimeter of the protected area. When the
laser beam is interrupted, the system triggers an alarm and alerts the security personnel.

One of the key advantages of the Laser Guardian is its ease of installation and use, The system
can be installed quickly and easily, with minimal disruption to the surrounding area. The Laser
Guardian is also highly energy-efficient, using very little power to operate.

Overall, the Laser Guardian is an ideal solution for anyone looking to protect their valuable
assets and prevent unauthorized access. With its advanced technology, customizable features,
and ease of use, the Laser Guardian is a reliable and cost-effective security solution.

1.2 Existing System:

• Access Control Systems: These systems regulate who can enter a secured area by
requiring a credential such as keycard, fob, or biometric identifier. Access control
systems can also track who enters and exits the area, providing valuable audit data.
• Security Cameras: Cameras can monitor activity in and around a secured area,
providing a visual deterrent to potential threats and recording evidence of any security

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breaches. Modern security cameras can be equipped with advanced features such as night
vision, motion detection, and facial recognition.
• Motion Detectors: These devices detect movement within a secured area and can trigger
an alarm or alert security personnel. Motion detectors can be used in conjunction with
other security systems, such as access control or security cameras, to provide an
additional layer of protection.
• Intrusion Detection Systems: These systems monitor a secured area for signs of
unauthorized entry, such as breaking a window or forcing open a door. Intrusion
detection systems can trigger alarm or alert security personnel, allowing them to respond
quickly to any security breaches.
• Environmental Monitoring Systems: These systems monitor environmental conditions
within a secured area, such as temperature, humidity, and air quality. Environmental
monitoring systems can detect anomalies that may indicate a security breach, such as a
sudden drop in temperature or an increase in humidity.
• Artificial Intelligence (AI) and Machine Learning (ML) Systems: AI and ML systems
can analyse data from various security systems to identify patterns and anomalies that
may indicate a security threat. For example, an AI system may detect that a person is
loitering in a secured area for an unusually long time, triggering an alert for securing
personnel.
Each of these existing systems has its advantages and limitations, and the choice of system
depends on factors such as cost, implementation complexity, accuracy, and suitability for the
intended application environment.

1.2 PROPOSED SYSTEM:

Proposed Solution:
The proposed Laser Guardian system works by utilizing a laser, an LDR (Light Dependent
Resistor), a resistor, a transistor, a buzzer, an LED and a switch to safeguard important
places or valuable items. The laser sensor continuously emits a beam of light that is
monitored by the LDR. When the laser beam is broken, the LDR's resistance changes,

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indicating an intrusion. This change in resistance is then used to trigger an alarm

mechanism, alerting security personnel or authorities of the intrusion.
The resistor is used to stabilize the circuit and ensure that the LDR's resistance changes are
accurately detected. The switch is used to turn the system on and off.
The laser beam provides a precise and consistent barrier, minimizing false alarms caused
by environmental factors. The system can be set up quickly and easily, without requiring
extensive modifications to the protected area, and is a cost-effective solution for
safeguarding important places or valuable things. Additionally, the system can be adapted
to various environments and applications, providing a versatile security solution.

BLOCK DIAGRAM:

Figure 1.1 LASER GUARDIAN: Safe Guarding Spaces with Tech

1. Laser Emitter:
The laser emitter is a device that emits a beam of light. In the Laser Guardian system, the
laser emitter is used to create a protective barrier that detects any intrusion.
2. LDR (Light Dependent Resistor):
The LDR is a type of resistor that changes its resistance based on the amount of light that

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it is exposed to. In the Laser Guardian system, the LDR is used to detect changes in the
laser beam's intensity, indicating an intrusion.
3. Switch:
The switch is used to turn the Laser Guardian system on and off.
4. LED (Light Emitting Diode):
The LED is used to provide visual feedback to the user, indicating that the system is turned
on and functioning properly.
5. BC547 Transistor:
The BC547 transistor is used to amplify the signal from the LDR, allowing it to trigger the
alarm mechanism.
6. Buzzer:
The buzzer is used to provide audible feedback to the user, alerting them of an intrusion.
7. Resistor:
The resistor is used to limit the current flowing through the circuit, preventing damage to
the other components.
8. Power Supply:
The power supply provides the necessary electrical power to the Laser Guardian system.

Together, these components work to create a reliable and effective security system that can
safeguard important places or valuable items.

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METHODOLOGY
For this project, there are many criteria that can be added and optimized in order to increase the
effectiveness of the system. The workflow of proposed system is shown below
1. The Laser emitter emits a beam of light that is detected by the LDR.
2. If the LDR detects a change in the laser beam’s intensity, indicating an intrusion, it sends
a signal to the BC547 transistor.
3. The BC547 transistor amplifies the signal from the LDR and sends it to the buzzer.
4. The buzzer sounds an alarm, alerting security personnel or authorities of the intrusion.
5. The LED provides visual feedback to the user, indicating that the system is functioning
properly.
Case I: When the Laser beam falls on the LDR, there is no disturbance, so there is no sound.

ON E C

LDR LED BC547 Buzzer

Transistor

OFF OFF B 0 No sound

Laser Resistor
Emitter

ON

Power
Supply

Case II: When the laser light is disturbed then there is a sound from the buzzer.

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2. CHAPTER

HARDWARE COMPONENTS
2.1 Laser
Introduction:
A laser is a device that emits light through a process called stimulated emission. The word
"laser" stands for "Light Amplification by Stimulated Emission of Radiation". Lasers are
characterized by their monochromaticity, coherence, and directionality. This means that
laser light is of a single wavelength (color), the waves are all in phase with each other
(coherent), and the light is emitted in a narrow beam.
Lasers consist of a gain medium that can be in the form of a gas, liquid, solid, or
semiconductor. The gain medium is excited by an external energy source, which causes the
atoms or molecules in the medium to emit photons. The photons are then amplified as they
pass through the gain medium, resulting in the emission of a coherent beam of light.
There are many different types of lasers, including gas lasers, solid-state lasers, dye lasers,
and semiconductor lasers. Gas lasers use a gas as the gain medium, while solid-state lasers
use a solid crystal or glass. Dye lasers use an organic dye as the gain medium, and
semiconductor lasers are made from semiconductor materials such as gallium arsenide.
Lasers have many different applications, including cutting and welding, material
processing, medical procedures, communication, and measurement. In the field of
measurement, lasers are used for distance measurement, speed measurement, and vibration
analysis.
Theory of Operation:
In the context of the Laser Guardian prototype, the laser emitter is used to emit a beam of
light that is detected by the LDR (Light Dependent Resistor). The LDR is a type of resistor
whose resistance changes with the intensity of light that falls on it. When the laser beam is
interrupted, the resistance of the LDR changes, which is detected by the BC547 transistor.
The transistor amplifies the signal from the LDR and sends it to the buzzer, which sounds
an alarm. The LED provides visual feedback to the user, indicating that the system is

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functioning properly. The switch can be used to turn the system on and off.
The laser emitter is typically a small device that emits a coherent beam of light. The beam
of light is typically in the visible spectrum, although some laser emitters can emit light in
the infrared or ultraviolet spectrum. The laser emitter is typically powered by a power
supply, which can be a battery or a DC power source. The laser emitter is typically
connected to the power supply through a resistor, which is used to limit the current flowing
through the laser emitter.

2.2: LDR (Light Dependent Resistor)

Introduction:
LDR (Light Dependent Resistor) as the name states is a special type of resistor that works
on the photoconductivity principle means that resistance changes according to the intensity
of light. Its resistance decreases with an increase in the intensity of light.
It is often used as a light sensor, light meter, Automatic street light, and in areas where we
need to have light sensitivity. LDR is also known as a Light Sensor. LDR are usually
available in 5mm, 8mm, 12mm, and 25mm dimensions.

How are LDRs Made?

The Light-dependent resistors made with photosensitive semiconductor materials like
Cadmium Sulphides (CdS), lead sulfide, lead selenide, indium antimonide, or cadmium
selenide and they are placed in a Zig-Zag shape.

Two metal contacts are placed on both ends of the Zig-Zag shape these metal contacts help

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in creating a connection with the LDRs.

Now, a transparent coating is applied on the top so that the zig-zag-shaped photosensitive
material gets protected and as the coating is transparent the LDR will be able to capture
light from the outer environment for its working.

LDR Working Principle:

It works on the principle of photoconductivity whenever the light falls on its
photoconductive material, it absorbs its energy and the electrons of that photoconductive
material in the valence band get excited and go to the conduction band and thus increasing
the conductivity as per the increase in light intensity.
Also, the energy in incident light should be greater than the bandgap gap energy so that the
electrons from the valence band got excited and go to the conduction band.
The LDR has the highest resistance in dark around 1012 Ohm and this resistance decreases
with the increase in Light.

LDR Applications

• The photoresistor is generally used in detecting the presence and intensity of light
• Used in automatic lights that switch on and off according to light
• Simple Smoke Detector Alarm, Clock with automatic light
• Optical circuit design
• Photo proximity switch
• Laser-based security systems
• Solar Street Lamps
• Camera light meters
• Clock radios
• Can be used in Dynamic Compressors, some compressors use LDR and LED
connected to the signal source to create changes in signal gain.

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Limitations:

• LDRs require a few milliseconds or more to respond fully to the changes in light
intensity, i.e. they require a few seconds to return to their normal resistance once the
light source is removed.

• The sensitivity of a Light-dependent resistor varies with the light wavelength. If the
wavelength is outside a certain range, it will not affect the resistance at all.

• Light-dependent resistors have lower sensitivity than photodiodes and

phototransistors.

2.3: LED (Light Emitting Diode)

Introduction
Light-emitting diode (LED) is a widely used standard source of light in electrical
equipment. It has a wide range of applications ranging from your mobile phone to large
advertising billboards. They mostly find applications in devices that show the time and
display different types of data.
A light-emitting diode (LED) is a semiconductor device that emits light when an electric
current flows through it. When current passes through an LED, the electrons recombine
with holes emitting light in the process. LEDs allow the current to flow in the forward
direction and blocks the current in the reverse direction.

Light-emitting diodes are heavily doped p-n junctions. Based on the semiconductor
material used and the amount of doping, an LED will emit colored light at a particular

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spectral wavelength when forward biased. As shown in the figure, an LED is encapsulated
with a transparent cover so that emitted light can come out.

LED Symbol

The LED symbol is the standard symbol for a diode, with the addition of two small arrow

denoting the emission of light.

How does an LED work?

When the diode is forward biased, the minority electrons are sent from p → n while the
minority holes are sent from n → p. At the junction boundary, the concentration of minority
carriers increases. The excess minority carriers at the junction recombine with the majority
charges carriers.

The energy is released in the form of photons on recombination. In standard diodes, the
energy is released in the form of heat. But in light-emitting diodes, the energy is released in
the form of photons. We call this phenomenon electroluminescence. Electroluminescence is
an optical phenomenon, and electrical phenomenon where a material emits light in response
to an electric current passed through it. As the forward voltage increases, the intensity of
the light increases and reaches a maximum.

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Uses of LED

LEDs find applications in various fields, including optical communication, alarm and
security systems, remote-controlled operations, robotics, etc. It finds usage in many areas
because of its long-lasting capability, low power requirements, swift response time, and
fast switching capabilities. Below are a few standards LED uses:

• Used for TV back-lighting

• Used in displays

• Used in Automotives

• LEDs used in the dimming of lights

2.4: Transistor

Introduction:

What is a transistor?

A transistor is a miniature semiconductor that regulates or controls current or voltage flow

in addition amplifying and generating these electrical signals and acting as a switch/gate
for them. Typically, transistors consist of three layers, or terminals, of a semiconductor
material, each of which can carry a current.
When working as an amplifier, a transistor transforms a small input current into a bigger
output current. As a switch, it can be in one of two distinct states -- on or off -- to control
the flow of electronic signals through an electrical circuit or electronic device.
The BC547 transistor is typically connected to a circuit that is designed to control the flow
of electric current through the transistor. The circuit is typically designed to limit the
current flowing through the transistor, which helps to prevent damage to the transistor.

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A transistor's three-layer structure contains one of the following layers:

• an n-type semiconductor layer between two p-type layers in a positive-negative-

positive (PNP) configuration; or

• a p-type layer between two n-type layers in a negative-positive-negative (NPN)

configuration

How transistors work

A transistor can act as a switch or gate for electronic signals, opening and closing an
electronic gate many times per second. It ensures the circuit is on if the current is flowing
and switched off if it isn't. Transistors are used in complex switching circuits that
comprise all modern telecommunications systems. Circuits also offer very high switching
speeds, such as hundreds of gigahertz or more than 100 billion on-and-off cycles per
second.
Parts of a transistor

A transistor is like a set of two diodes with their cathodes or anodes tied together. It has

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three terminals that carry electrical current and help make a connection to external
circuits:

• the emitter, also known as the transistor's negative lead,

• the base, which is the terminal that activates the transistor, and

• the collector, which is the transistor's positive lead.

The emitter -- indicated by the letter E -- is moderately sized and heavily doped as its
primary function is to supply numerous majority carriers to support the flow of
electricity. It's called the emitter since it emits electrons.

The base -- indicated by the letter B -- is the center terminal between the emitter and the
collector. It is thin and lightly doped. Its main purpose is to pass the carriers from the
emitter to the collector.

The collector -- indicated by the letter C -- collects carriers sent by the emitter via the
base. It's moderately doped and larger than both the emitter and base.

There are three types of configurations, which are common base (CB), common collector
(CC) and common emitter (CE).

In common base (CB) configuration, the base terminal of the transistor is common
between input and output terminals.

In common collector (CC) configuration, the collector terminals are common between the
input and output terminals.

In common emitter (CE) configuration, the emitter terminal is common between the input
and the output terminals.

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Transistors are classified into two major types:

• Bipolar junction transistor (BJT)

• Field-effect transistor (FET)

A BJT is one of the most common types of transistors, and can be either NPN or PNP.
This means a BJT consists of three terminals: the emitter, the base and the collector. By
joining these three layers, a BJT can amplify an electrical signal or switch the current on
or off.

A field-effect transistor (FET) also has three terminals -- source, drain and gate -- which
are analogous to BJT's emitter, collector and base, respectively. In the FET, the n-type
and p-type silicon layers are arranged differently from those of the BJT. They are also
coated with layers of metal and oxide to create the metal-oxide semiconductor field effect
transistor (MOSFET).

Advantages of Transistor

• Lower cost and smaller in size.

• Smaller mechanical sensitivity.

• Low operating voltage.

• Extremely long life.

• No power consumption.

• Fast switching.

• Better efficiency circuits can be developed.

• Used to develop a single integrated circuit.

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Limitations of Transistor:

• Transistors lack higher electron mobility.

• Transistors can be easily damaged when electrical and thermal events arise. For example,
electrostatic discharge in handling.

• Transistors are affected by cosmic rays and radiation.

2.5: Resistor

Introduction:

What is Resistor?

Resistor is defined as a passive electrical component with two terminals that are used for
either limiting or regulating the flow of electric current in electrical circuits. The main
purpose of resistor is to reduce the current flow and to lower the voltage in any particular
portion of the circuit. It is made of copper wires which are coiled around a ceramic rod
and the outer part of the resistor is coated with an insulating paint.

The SI unit of resistor is Ohm.

Types of Resistors

Resistors are available in different shapes and sizes. Common types that are available are
through-hole and surface mount. A resistor might be static, standard resistor, special, or a

pack of variable resistors. There are two basic types of resistors as follows:

➢ Linear resistors

The resistors whose values change with change in applied temperature and voltage are
known as linear resistors. There are two types of linear resistors:

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Fixed resistors: These resistors have a specific value and these values cannot be changed.
Following are the different types of fixed resistors:

• Carbon composition resistors

• Wire wound resistors

• Thin film resistors

• Thick film resistors

Variable resistors: These resistors do not have a specific value and the values can be changed
with the help of dial, knob, and screw. These resistors find applications in radio receivers for
controlling volume and tone. Following are the different types of variable resistors:

• Potentiometers

• Rheostats

• Trimmers

➢ Non-linear resistors

The resistor values change according to the temperature and voltage applied and is not dependent
on Ohm’s law. Following are the different types of non-linear resistors:

• Thermisters

• Varisters

• Photo resistors

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What is Colour Coding of Resistors?

Resistors may not display the value outside but their resistance can be calculated through their
colour pattern PTH (plated-through-hole) resistors use a colour-coding system (which really adds
some flair to circuits), and SMD (surface-mount-device)resistors have their own value-marking
system.

Following is a table with colour code of resistors:

Resistors in Series

Resistors are said to be in series when the current flowing through all the resistors is the same.
These resistors are connected from head to tail in series. The overall resistance of the circuit is
equal to the sum of individual resistance values.

Rtotal = R1 + R2 + R3 +……+Rn

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Resistors in Parallel
Resistors are said to be in parallel when the terminals of resistors are connected to the same two
nodes. Resistors in parallel share the same voltage at their terminals.
1 1 1 1 1
= R1 + R2 + R3 +……+ Rn
Rtotal

Applications of Resistor

• Wire wound resistors find applications where balanced current control, high sensitivity,
and accurate measurement are required like in shunt with ampere meter.
• Photoresistors find application in flame detectors, burglar alarms, in photographic
devices, etc.
• Resistors are used for controlling temperature and voltmeter.
• Resistors are used in digital multi-meter, amplifiers, telecommunication, and oscillators.
• They are also used in modulators, demodulators, and transmitters.

2.6: Power Supply

Introduction:
Power supply is a supply of electrical power. A device or system that supplies electrical or other
types of energy to an output load or group of loads is called a power supply unit or PSU.
A power supply may include a power distribution system as well as primary or secondary sources
of energy such as conversion of one form of electrical power to another desired form and voltage,
typically involving converting AC line voltage to a well-regulated lower-voltage DC for electronic
devices. Low voltage, low power DC power supply units are commonly integrated with the devices
they supply, such as computers and household electronics.
• Batteries.
• Chemical fuel cells and other forms of energy storage systems.
• Solar power.
• Generators or alternators.

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Block Diagram:

Battery Power Supply:

A battery is a type of linear power supply that offers benefits that traditional line operated power
supplies lack: mobility, portability and reliability. A battery consists of multiple electrochemical
cells connected to provide the voltage desired. Fig: 3.3.4 shows Hi-Watt 9V battery

Hi-Watt 9V Battery
The most commonly used dry-cell battery is the carbon-zinc dry cell battery. Drycell batteries are
made by stacking a carbon plate, a layer of electrolyte paste, and a zinc plate alternately until the
desired total voltage is achieved.
When the battery is charging, the lead sulfate is converted back to lead and lead dioxide A nickel
cadmium battery has become more popular in recent years. This battery cell is completely sealed
and rechargeable. The electrolyte is not involved in the electrode reaction, making the voltage
constant over the span of the batteries long service life. During the charging process, nickel oxide
is oxidized to its higher oxidation state and cadmium oxide is reduced. The nickel-cadmium
batteries have many benefits. They have a long service life, high current availabilities, constant
voltage, and the ability to be recharged. Fig: 3.3.5 shows pencil battery of 1.5V.

Pencil Battery of 1.5V

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2.7 Buzzer

Introduction:

Buzzer meaning electronic component that generates sound through the transmission of
electrical signals. Its primary function is to provide an audible alert or notification and
typically operates within a voltage range of 5V to 12V. There are various types of these
modules that differ in their sound generation mechanisms, operating principles, and
applications.

How it Works?

Here's how a typical buzzer works:

1. Power Source: The buzzer requires a power source to operate, typically a direct
current (DC) supply.

2. Electromagnetic Coil: Inside the buzzer, there is an electromagnetic coil. When

electricity is supplied, the coil becomes magnetized.

3. Metal Diaphragm: Adjacent to the coil, there's a metal diaphragm. This

diaphragm is usually made from a ferromagnetic material, which means it's
attracted to magnets.

4. Operation Mechanism: When the current flows through the coil, it creates a
magnetic field. This magnetic field causes the metal diaphragm to be attracted
towards the coil, moving away from its original position.

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5. Sound Production: As the diaphragm moves, it compresses and rarefies the air in
front of it, creating sound waves. The rapid movement back and forth of the
diaphragm produces the buzzing sound we hear.

6. Oscillation: In some buzzers, particularly piezoelectric types, the electric current

causes the piezoelectric material (usually a ceramic disc) to bend back and forth.
This bending motion creates the sound. The frequency of the current determines
the frequency of the sound, and thus its pitch.

7. Volume Control: The volume of the sound can often be controlled by the amount
of current supplied to the buzzer. Higher currents produce a louder sound.

Buzzer Types

1. Passive Buzzer: This type of module generates sound through the vibration of a
rotating magnetic field within a coil. It requires an external driver circuit and does
not produce sound directly.

2. Active Buzzer: They have an integrated driver circuit and can operate directly
with a sound signal. They are often more user-friendly due to the built-in driver
circuit.

3. Piezo Buzzer: They produce sound by applying voltage changes to a piezoelectric

crystal. They are widely used due to their small size and low power consumption.

4. Electromechanical Buzzer: They produce sound using the magnetic field of an

electromagnet instead of the vibration of a coil. They can produce larger and more
powerful sounds.

5. Sirens: Sirens are a specialized type of it used in emergency or fire alarm

systems. They can generate very high sound levels and are powerful enough to be
heard from a distance.

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These types are selected based on diverse application requirements, with sound level, power
consumption, size, and other factors serving as crucial criteria that influence the buzzer type
chosen.

Buzzer Application Areas

1. Alarm Systems: They can be utilized to provide audible alarms in burglar alarm
systems or fire alarm systems.

2. Clock and Timer Alarms: A clock or timer project created with Arduino
or Raspberry Pi can incorporate it to sound an alarm at a specific time.

3. Music and Melody Playback: Their sounds can be utilized for simple music and
melody playback projects, with the ability to program specific notes or music.

4. Automation and Control Systems: They can be integrated into automation

projects or to indicate when specific events occur. For instance, they can be
utilized to provide an audible alert when a door is opened.

5. Education and Learning Projects: They are exceptional components for

individuals seeking to learn fundamental electronics and coding concepts. They
can aid students in comprehending topics such as basic music theory and
frequency control.

2.8: Switch

Introduction

A switch is an electrical component that can disconnect or connect the conducting path in
an electrical circuit, interrupting the electric current or diverting it from one conductor to
another. The most common type of switch is an electromechanical device consisting of one or

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more sets of movable electrical contacts connected to external circuits. When a pair of contacts is
touching current can pass between them, while when the contacts are separated no current can
flow.

Switches are made in many different configurations; they may have multiple sets of contacts
controlled by the same knob or actuator, and the contacts may operate simultaneously,
sequentially, or alternately. A switch may be operated manually, for example, a light switch or a
keyboard button, or may function as a sensing element to sense the position of a machine part,
liquid level, pressure, or temperature, such as a thermostat. Many specialized forms exist, such as
the toggle switch, rotary switch, mercury switch, push-button switch, reversing switch, relay,
and circuit breaker. A common use is control of lighting, where multiple switches may be wired
into one circuit to allow convenient control of light fixtures. Switches in high-powered circuits
must have special construction to prevent destructive arcing when they are opened.

2.9: Breadboard

Introduction:

A breadboard (sometimes called protoboard) is essentially the foundation to construct and

prototype electronics. A breadboard allows for easy and quick creation of temporary electronic
circuits or to carry out experiments with circuit design. Breadboards enable developers to easily
connect components or wires thanks to the rows and columns of internally connected spring clips
underneath the perforated plastic enclosure. The grid is made up of perfectly aligned spring clip
holes that are 0.1″ apart in both the X and Y dimensions.

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A breadboard can be divided into two segments, which are called the bus strip and the terminal
strip.
The bus strip consists of two long lines of spring clips running across the board, these lines can
be used to provide supply voltage (VCC) and ground (GND) to the circuit. Typically, the supply
voltage line is marked in red and the ground line is marked in blue (or black on some boards).
All spring clips along each line are internally connected, making both supply voltage and ground
signals conveniently accessible from any part of the breadboard.
What Is VCC?
VCC is the supply voltage that the microcontroller system uses. The LaunchPad can run properly
when a supply voltage of 1.8–3.6 V is available. In most cases, the VCC of our MSP430-based
projects will be ~3 V. We will use this terminology and referencing this supply voltage
throughout the book.
What Is Ground?
All electrical current in a system needs to flow back to ground. In a typical microcontroller
project, all components flow back to Ground, which is why this is usually referred to as
“common ground.” At GND, this is usually a 0-V reading. We will touch on VCC and GND
throughout the book, so don’t worry if this sounds foreign!
The terminal strip is the main area that can be used to populate the various circuit components. It
is usually separated into two sides by a notch that runs along the middle of the board. Each side
has many lines that are made up of five internally connected spring clip holes. The five spring
clips on each line of the terminal strip are connected internally, allowing for component
connections.

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Connecting Wires/ Jumper Wires

Connecting Wires

Introduction:

A connecting wire allows travels the electric current from one point to another point without
resistivity. Resistance of connecting wire should always be near zero. Copper wires have low
resistance and are therefore suitable for low resistance.

Wire as defined by "Compton’s Encyclopaedia" is a strand of metal in the form of a flexible

thread or slender rod. This is the most common form of conductors for power transmission,
smaller electrical signals, or as resistors. Insulated wires are most often used in electronic
circuits. The insulation provides electrical insulation and mechanical and chemical protection.

Different Types of Connecting Wires

Wires are either solid or stranded. Most wires are round, occasionally square or rectangular
conductors are used, such as integrated circuit external leads. Metals usually used in making
wires are aluminium, alloy and copper. Insulation is made up of rubber or non-conductive
materials and can come in different sizes and colours.

• Solid Wires
These wires are single solid wires with rubber insulation. Usually used in connecting
circuits or wiring connections in a protoboard.

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• Stranded Wires
Is a group of wires used as a single wire. Due to their high flexibility, stranded wires are
the most commonly used conductors. There is no sharp distinction between stranded wire
and cable wires. Stranded constructions vary in the size, number and configuration of the
individual strands. All stranded designation systems relate to the total cross-sectional area
of the conductor. The cross-sectional area of metal determines the electrical resistance
and current carrying capacity of the conductor and is important for the proper size
selection for a specific application.

Jumper Wires

Jumper wires typically come in three versions: male-to-male, male-to-female and female-
to-female. The difference between each is in the end point of the wire. Male ends have a
pin protruding and can plug into things, while female ends do not and are used to plug
things into. Male-to-male jumper wires are the most common and what you likely will
use most often. When connecting two ports on a breadboard, a male-to-male wire is what
you’ll need.

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RESULTS AND ANALYSIS

The Laser Guardian prototype is a system that uses an LDR to detect the presence of a laser beam.
The LDR is connected to a BC547 transistor, which is used to amplify the signal from the LDR.
The amplified signal is then sent to a buzzer, which gives an alert when the LDR detects the
presence of the laser beam. The Laser Guardian prototype is able to detect the laser beam even in
the presence of dim light, thanks to the use of an LDR. This makes the system well-suited for use
in environments where the light level may vary, such as outdoors.

The Laser Guardian prototype is a simple and effective system that is able to detect the presence
of a laser beam, even in the presence of dim light. The use of an LDR allows the system to be
highly sensitive, while the use of a buzzer as an alert mechanism makes the system easy to use.
However, there are some potential areas for improvement in the Laser Guardian prototype. For
example, the use of a more sophisticated amplification circuit could improve the sensitivity of the
LDR, allowing the system to detect the laser beam at even lower light levels. Additionally, the use
of a more sophisticated alert mechanism, such as a flashing light or an audible alarm, could make
the system more noticeable and easier to use.

Another potential area for improvement is the integration of the Laser Guardian prototype with
other components, such as a microcontroller or a display. This would allow the system to be more
versatile and flexible, and could enable a wider range of applications.

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CONCLUSION

In conclusion, the Laser Guardian prototype is a simple and effective system that is able to detect
the presence of a laser beam, even in the presence of dim light. The use of an LDR and a BC547
transistor allows the system to be highly sensitive, while the use of a buzzer as an alert mechanism
makes the system easy to use.

While the Laser Guardian prototype is already a functional and useful system, there are several
potential areas for improvement. For example, the use of a more sophisticated amplification circuit
could improve the sensitivity of the LDR, allowing the system to detect the laser beam at even
lower light levels. Additionally, the integration of the Laser Guardian prototype with other
components, such as a microcontroller or a display, could enable a wider range of applications and
make the system more versatile and flexible.

Overall, the Laser Guardian prototype is a simple and effective system that is able to detect the
presence of a laser beam, even in the presence of dim light. With some minor improvements, the
system could be made even more sensitive and user-friendly, making it well-suited for a variety of
applications.

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REFERENCES

[1] https://youtu.be/LeXdsz6Jm58?si=nKXKa9s3onlyf-Rv
[2] https://www.britannica.com/technology/laser
[3]https://www.electronicsforu.com/technology-trends/learn-electronics/ldr-light-dependent-
resistorsbasics#
[4] https://byjus.com/jee/transistor/
[5] https://www.techtarget.com/whatis/definition/transistor
[6] https://eepower.com/resistor-guide/resistor-fundamentals/what-is-a-resistor/#
[7]https://en.wikipedia.org/wiki/Resistor#
[8] https://en.wikipedia.org/wiki/Buzzer
[9] https://en.wikipedia.org/wiki/Switch
[10] https://en.wikipedia.org/wiki/Breadboard
[11] https://steemit.com/science/@zararina/connecting-wires-and-its-history
[12] https://blog.sparkfuneducation.com/what-is-jumper-wire

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