The document details a physics project on an automatic fire alarm system, acknowledging support from various individuals throughout the project. It outlines the objectives, theoretical background, components, working mechanism, observations, and conclusions regarding the fire alarm system's effectiveness. The project emphasizes the importance of fire alarm systems in ensuring life safety and property protection while also noting precautions for handling the circuit components.

1. PHYSICS PROJECT
FIRE ALARM
Made by:
NIKHIL DUGGAL
XII-A1

2. PAGE 1
ACKNOWLEDGEMENT
In the accomplishment of this project successfully, many
peoplehave best owned upon me their blessings and the heart
pledged support, this time I am utilizing to thank all the people
who have been concerned with project.
Primarily I would thank god for being able to completethis
project with success. Then I would like to thank my principal
Mrs. Jyoti Gupta and physics teacher Mr. Rajeev Agarwal,
whose valuable guidance has been the ones that helped me
patch this project and make it full proof success his
suggestions and his instructionshas served as the major
contributortowardsthe completion of the project.
Then I would like to thankmy parents and friends who have
helped me with their valuable suggestions and guidance has
been helpful in various phases of the completion of the
project.
Last but not the least I would like to thank my classmates
who have helped me a lot.
-NIKHIL DUGGAL
XII-A1 ____

3. PAGE 2
CERTIFICATE
Thisis to certifythat NIKHIL DUGGAL, a student of class
XII-A1has successfullycompletedtheresearch on the below
mentioned project under the guidance of MR. RAJEEV
AGARWAL( Subject Teacher ) during the year 2016-17 in
partialfulfilmentofphysicspractical examination conducted
by CBSE, New Delhi.
Signature of external examiner Signature of physics teacher
CONTENTS

4. PAGE 3
1. CERTIFICATE OF EXCELLENCE
2. ACKNOWLEDGEMENT
3. AIM OF PROJECT
4.INTRODUCTION
5. THEORY
6.APPARATUS REQUIRED
7. WORKING
8.OBSERVATION
9.CONCLUSION
10.PRECAUTIONS
11. BIBLIOGRAPHY

5. PAGE 4
INTRODUCTION
An automatic fire alarm system is designed to detect the unwanted presence of fire
by monitoring environmental changes associated with combustion. In general, a
fire alarm system is either classified as automatic, manually activated, or both.
Automatic fire alarm systems can be used to notify people to evacuate in the
event of a fire or other emergency, to summon emergency services, and to prepare
the structure and associated systems to control the spread of fire and smoke. Fire
alarm systems have become increasingly sophisticated and functionally more
capable and reliable in recent years. They are designed to fulfill two general
requirements: protection of property and assets and protection of life. As a result of
state and local codes, the life-safety aspect of fire protection has become a major
factor in the last two decades. There are a number of reasons for the substantial
increases in the life-safety form of fire protection during recent years, foremost of
which are
1. The proliferation of high-rise construction and the concern for life safety within
these buildings.
2. A growing awareness of the life-safety hazard in residential, institutional, and
educational occupancies.
3. Increased hazards caused by new building materials and furnishings that create
large amounts of toxic combustion products (i.e., plastics, synthetic fabrics, etc.).
4. Vast improvements in smoke detection and related technology made possible
through quantum advances in electronic technology.
5. The passing of the Americans with Disabilities Act (ADA), signed into law on
July 26, 1990, providing comprehensive civil rights protection for individuals with
disabilities. With an effective date of January 26, 1992, these requirements
included detailed accessibility standards for both new construction and Renovation
towards the goal of equal usability of buildings for everyone, regardless of
limitations of sight, hearing, and mobility. This had a significant impact on
fire alarm system signaling devices, power requirements, and device locations.

6. PAGE 5
THEORY
A fire alarm system has a number of devices working together
to detect and warn people through visual and audio appliances
when smoke, fire, carbon monoxide or other emergencies are
present. These alarms may be activated automatically
from smoke detectors and heat detectors or may also be
activated via manual fire alarm activation devices such as
manual call points or pull stations. Alarms can be either
motorized bells or wall mountable sounders or horns. They can
also be speaker strobes which sound an alarm, followed by a
voice evacuation message which warns people inside the
building not to use the elevators. Fire alarm sounders can be set
to certain frequencies and different tones including low,
medium and high, depending on the country and manufacturer
of the device.
WE WILL BE STUDYING A THERMISTOR BASED FIRE ALARM WHERE WE
WILL USE FIRE SWITCH TO CONTROL THE CIRCUIT.

7. PAGE 6
COMPONENTS OF
FIRE ALARM
CIRCUIT
1. Battery
2. PCB Board
3. Fire switch
4.Resistance330K
5. Resistance01K
6.PNP Transistor369
7. NPN Transistor548
8.Capacitor 0.04µF
9.Buzzer
10. Connecting wires
11. Solder

8. PAGE 7
CIRCUIT DIAGRAM

9. PAGE 8
CIRCUIT WORKING
[
All the components are soldered using soldering wire and are
fixed on PCB board.
Resistors of 330k and 0.1k are used to bias transistors so that
they work according to our requirement in the circuit and
control the flow of current I the desired way.
We have npn and pnp transistors to control the flow of current.
Capacitors store the energy and let the alarm sound for some
time after the fire switch turns off.
We have a buzzer that will sound as soon as a fire is detected by
the fire switch.
The main component of the whole circuit is the fire switch that
is responsible for its working.
FIRE SWITCH
It’s a device that works on the stimulus of temperature.
It consists of a bimetallic strips that are initially separated when
there is no fire that is the temperature is normal room
temperature. As soon as there is a fire the temperature goes up
and the strips comes closer to touch each other and complete
the circuit. This lead the current to flow in the circuit and the
buzzer sounds

10. PAGE 9
OBSERVATIONS
We have seen that initially there was no buzzer sound as none
of the fire was detected.
When we bring a match stick near the fire switch with a time
lag of 5-10 seconds the buzzer starts giving sound as the fire is
detected and the circuit is completed by the action of bimetallic
strip.
When we remove the burning match stick away from switch,
the buzzer continues to give the sound for some time due to
action of capacitor and time is required by switch to return to
room temperature.

11. PAGE 10
CONCLUSION
A fire alarm is a device that detects the presence of fire and
atmospheric changes relating to smoke. In some cases, a firm alarm
is a part of a complete security system, in addition to a burglary
protection system. The fire alarm operates to alert people to evacuate
a location in which a fire or smoke accumulation is present. When
functioning properly, a fire alarm will sound to notify people of an
immediate fire emergency. Fire alarms can be found in homes,
schools, churches and businesses, and function as the catalyst to
saving lives. For most fire alarms, when sounded, a beep, bell or horn
noise is made. This distinct sound exists to allow the notification to
be heard. The fire alarm constructed by this project work is reliable at
low cost.

12. PAGE 11
PRECAUTIONS
1. Components of the circuit should be handled carefully.
2. Care should be taken while soldering as it may burn the
skin.
3. Connecting wires should be insulated to prevent
disturbance.
4. Connections should be tight as it may break easily.
5. Soldering must be done carefully as it may burn the PCB
board.

13. PAGE 12
BIBLIOGRAPHY
1) NCERT textbook class 12
2) NCERT physics lab Manuel
3) INTERNET
4) www.yahoo.com
5) www.scribd.com
6) www.google.com
HELP FROM
INTERNET
INFORMATION
FROM LIBRARY
HELP FROM
TEACHERS