This document is a project report on a laser-based door security system using a siren generator. It describes the system's components, which include a UM3561 integrated circuit, transistors, resistors, capacitors, LEDs, and a battery. The circuit uses a laser beam and light dependent resistor (LDR) to detect intruders. When the laser beam is blocked, the LDR resistance changes and triggers the alarm circuit to sound a siren using the UM3561 IC. The report provides the circuit diagram, descriptions of major components, advantages and applications of the system. It concludes that home security technology continues to advance while security remains an important concern.

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A Mini Project Report on
LASER BASED DOOR SECURITY SYSTEM USING SIREN
GENERATOR
Submitted to
T JOHN INSTITUTE OF TECHNOLOGY
Bangalore.
Bachelor of Engineering
In
Electronics and Communication Engineering
By
Shahrukh Javed BEE141570
Syed Moula BEE141528
Session: 2016-2017
Date of submission 13th
Oct 2016
UNDER THE ESTEEMED GUIDANCE OF
PROF. BASAVANAGOUDA
DEPARTMENT OF ECE.
Department of Electronics and Communication Engineering
T JOHN INSTITUTE OF TECHNOLOGY
(Visvesvaraya Technological University)
(Approved by AICTE, Affiliated to VTU & Accredited by NAAC)
86/3, Gottigere, Bannerghatta Road, Bangalore - 560083

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PREFACE
This project provides complete information on the topic “LASER BASED
DOOR SECURITY SYSTEM USING SIREN GENERATOR” and
maximum efforts have been taken to make the project more comprehensive and
lucid to understand.
This project covers a variety of sub topics like basic information, its working,
day to day uses in life and different aspects of Laser Security Alarm System.
One may notice a perceptible change in written in an easy dialogue style
engaging the readers constantly and included with more informatics comments.
I assure you to go through this project thoroughly to know a bit more and facts
about Laser Security Alarm System.

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Declaration
I hereby declare that the project entitled “LASER BASED DOOR
SECURITY SYSTEM USING SIREN GENERATOR” submitted by us
to T. John Institute of Technology, Visvesvaraya Technological University
during the degree of Bachelor of Engineering in Electronics &
Communication Engineering is a record of bonafide project work carried
out by us under the guidance of Mr. Basavanagouda.
I further declare that the work reported in this mini project has not been
submitted & will not be submitted either in part or in full for award of any
degree in this institute.
SHAHRUKH JAVED
SYED MOULA

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Acknowledgement
The satisfaction that accompanies the successful completion of the
task would be put incomplete without the mention of the people who made
it possible, whose constant guidance and encouragement crown all the
efforts with success.
It is my greatest pleasure to thank Dr. Arun Vikas Singh Head of
Department of Electronics and Communication, T.John Institute of
Technology for providing us heart full encouragement support and
allowing us to work in such a resourceful lab of this esteemed institute &
thereby fulfilling one of my dreams.
I whole heartedly thank my project guide Mr. Basavanagouda (Asst.
Professor Electronics & Communication Department) for his consistent
guidance, expert academic and support throughout the project, without his
great concepts & inspiration it would have been impossible.
I’m very much thankful to Mr.Chethan for his help in the laboratory for
practical guidance during this project.
I thank my parents for their emotional and financial support which they
provided during this project.
We show gratitude to our Honourable Principal Dr. H.N Thippeswamy,
for having provided all the facilities and support.
I thank to all faculties who directly and indirectly helped us in the
completion of this projects.

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INTRODUCTION
Security is a prime concern in our day-today life. Everyone wants to be as much
secure as possible. Technology develops day by day in the world & crime also
improves their technology to perform their operation. So technology of security
should be modern with time to protect the crime works.
In this project to make a door security system we have used phototransistor operated
switch & laser light to cover a large area.
Door guard is a device that can senses intrusion, providing an indication of possible
disturbance, thus providing security to the commercial and residential people.
If some intruder tries to open the door of your house, this circuit sounds an alarm to
alert you against the attempted intrusion.
In case of commercial security, little door guard popularly known as guard alarm
which provides audible or visual alarm from the detecting object itself.
When any person or object crossover the laser line the security alarm will ring-on also
the focus light will "on" to focus the entrance of unauthorized person.
This circuit diagram of a little door guard based on national semiconductor
UM3561integrated circuit, siren generator and a laser beam.
The circuit uses readily available, low-cost components. For compactness, an alkaline
9v battery is used for powering the unit. Input dc supply is further regulated to a
steady dc voltage of 5v by 3-pin regulator IC7805. Assemble the unit in the box and
mount the same on the door.
Now mount a constant source of light i.e., laser beam exactly aligned with the unit.
We know laser light goes through long distance without scattering effect. It is also
visible only at source & incident point, otherwise invisible.
These two properties help us to build up a modern security system, which may name
as “Laser Based Door Security System Using Siren Generator".

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COMPONENTS USED
SR.NO. COMPONENT NAME SPECIFICATION QUANTITY
1. INTEGRATED CIRCIUT
UM3561
IC7805
1
1
2. TRANSISTOR
BC547
BC548
BC549
SL100
1
1
1
1
3. RESISTOR
100KΩ
10KΩ
220KΩ
1KΩ
330Ω
1
1
1
3
1
4. CAPACITOR 100uf
0.1uf
1
1
1
5. ZENER DIODE 3.1V
2
6. LED
RED
GREEN
1
1
7. BATTERY 9V
1
Table 1. List of the Components Used.

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MAJOR COMPONENTS DESCRIPTION.
1. UM3561 IC.
Fig.1 IC UM3561 & Transistor BC548
UM3561 is a low-cost, low-power CMOS LSI designed for use in alarm and toy applications.
Since the integrated circuit includes oscillator and selector circuits, a compact sound module
can be constructed with only a few additional components. The UM3561 contains a
programmed mask ROM to simulate siren sound.
Absolute Maximum Ratings:
DC Supply Voltage .......................................... -0.3V to +5.0V
Input Voltage Range ........................................ Vss -0.3V to Vdd +0.3V
Operating Ambient Temperature .................... -10 C to +60 C
Storage Temperature ....................................... -55 C to +125 C
Features:
• Four sounds can be selected.
• Typical 3V operating voltage.
• A magnetic speaker can be driven by connecting an NPN transistor.
• Power on reset.
• 8-pin DIP package form.

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Playing modes:
SEL-1 SEL-2 Sound effect
NC NC Police siren
Vdd NC Fire engine siren
Vss NC Ambulance siren
X Vdd Machine gun
NC: No connection.
X: Don’t care.
Pin configuration:
Fig. 2 IC UM3561 pin configuration.
Pin No. Symbol Description
1 SEL-2 Sound effect selection pin no. 2
2 Vss Negative power supply
3 OUTPUT Mono-tone output
4 NC Internal testing pin
5 Vdd Positive power supply
6 SEL-1 Sound effect selection pin no. 1
7 OSC-1 External oscillator terminal 1
8 OSC-2 External oscillator terminal 2

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2. LDR.
LDR means light dependent resistance also called a photoresistor or a cadmium
sulfide (CdS) cell is a light-controlled variable resistor.A photoresistor is made of a
high resistance semiconductor.
It is basically a photocell that works on the principle of photoconductivity.One of the
most commonly used symbol is shown in the figure below. The arrow indicates light
falling on it.
If LDR placed in darkness, the resistance of LDR increases and when light falls on it,
the resistance of LDR decreases and act as a conductor. Any LDR in the presence of
light and darkness changes its resistance is depends on the different types of LDR.
Fig 3. Light Dependent Resistor
TYPICAL CONSTRUCTION.
The snake like track shown above is the Cadmium Sulphide (CdS) film which also passes
through the sides. On the top and bottom metal film are connected to the terminal leads & the
sensitivity of a photo detector is the relationship between the light falling on the device and
the resulting output signal. Thus it is designed in such a way as to provide maximum possible
contact area with the two metal films, to provide free access to external light.

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Applications: Photoconductive cells are used in many different types of circuits and
applications.
Analog Applications Digital Applications
Camera Exposure Control. Automatic Headlight Dimmer.
Photocopy Machines - density of toner. Night Light Control.
Auto Slide Focus & Electronic Scales - dual cell. Oil Burner Flame Out.
Densitometer & Colorimetric Test Equipment. Street Light Control.
Automatic Gain Control – modulated light source. Absence / Presence (beam
breaker)
Automated Rear View Mirror. Position Sensor

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CIRCUIT DIAGRAM
Fig 4.circuit diagram-DOOR SECURITY
Working:
This circuit is based on LDR (Light Depended Resistor), a variable resistor in which
the resistance varies according to the light intensity falling on it. The LDR and resistor
form a potential divider network, which is the main part of our security alarm Circuit.
We have already discussed about how transistor acts as a switch. The voltage drop
across the LDR is used to drive the transistor switch. When the voltage drop is above
cut in voltage (0.6V), the transistor is turned ON. LDR has low resistance range, In
the presence of light the LDR has high resistance (M-ohms) and sense the light.
In our security alarm, a LASER light is allowed to fall on the LDR continuously (see
the project arrangement figure). Light from other sources should not be allowed to fall
on the LDR, so place the LDR in a box with a single hole to pass LASER.

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In this situation, the resistance offered by LDR is too low, since the LASER light is
continuously allowed to fall on the LDR surface. Thus the voltage drop across the
LDR is also low [V=IR (Ohm’s law)] which is insufficient to turn on the transistor, so
the transistor remains in OFF state.
When a person (eg: thief) makes a block to the continuous flow of LASER beam, then
the light falling on the LDR gets blocked or interrupted. Thus its resistance increases
to a high value in the order (M-ohms) range. While resistance increases the voltage
drop also increases, when this voltage drop exceeds the cut in voltage of the Silicon
NPN transistor (BC547), it will turn ON.
Then current from Vcc starts flowing to ground via the IC UM3561 to speaker and
transistor, which makes the sound, the musical tone from the security alarm gives the
indication of some security failures.
Thus in this circuit we built a laser security alarm which uses a laser light and a laser
light detector circuit, so when any person or object crossover the laser line the security
alarm will ring & its gets activated when someone crosses it.

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Advantages
1. To protect home and industry.
2. Easy to construct, parts of the circuit are easily available.
3. It reduced the man’s effort.
4. Accuracy of this circuit is more than accuracy of other circuits.
5. The cost of circuit is low.
6. They need very small power and voltage for its operation.
Disadvantages
1. Highly inaccurate with a response time of about tens or hundreds of
milliseconds.
2. Unnecessary disturbances may occur while using in the apartments.
3. It is difficult to work with this equipment if there are no sufficient
lightning conditions.
Application
1. Used for home security.
2. Used in the banks as a burglar alarm.
3. It can be used in jail to prevent prison break.
4. Used as automatic indicator.
5. It can be used in mines areas to indicate restricted place.
6. Helps to keep you tabs on kids & notifies you.

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CONCLUSION
Home security is rapidly growing field and there are new & improved burglar alarms
popping up every day.
With rapid advancement of technology this field is turning out to be an area full of
scope and new changes can be made to make it more efficient. It has years to come
because security is of prime importance to one and all.
I am proud to express my delight as the project I embarked upon is successfully
finished in such a short span. The project gave us more confidence that we will be
able to put in practice, whatever the theoretical knowledge we gained during the
course of study till now.
It really persuades us to do more and more perhaps in better way in future.
I take this opportunity to thank everyone who contributed directly or indirectly for
successful completion of project.

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