Design And Construction Of A Fire Alarm System Using Light Dependent Resistor

This project is titled design and construction of an automatic fire alarm. Fire alarm is an electronics device that is stored in a building to detect the presence of fire accident. 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 classified as either automatically actuated, manually actuated, or both. Automatic fire alarm systems are intended to notify the building occupants to evacuate in the event of a fire or other emergency, report the event to an off-premises location in order to summon emergency services, and to prepare the structure and associated systems to control the spread of fire and smoke.

This fire alarm system composes of light dependent resistor (LDR) which works as a smoke sensor. Light dependent resistor is a type of resistor with high resistance in the presence of light and which reduces in its resistance when smoke passes through the surface.

The aim of this project is to design and construct a fire alarm for a building that will detect the presence of fire accident in a building.

TABLE OF CONTENTs

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRCT

TABLE OF CONTENT

CHAPTER ONE

• INTRODUCTION
• BACKGROUND OF THE PROJECT
• PROBLEM STATEMENT
• AIM/OBJECTIVE OF THE PROJECT
• SIGNIFICANCE OF THE PROJECT
• APPLICATION OF THE PROJECT
• LIMITATION OF THE PROJECT
• SCOPE OF THE PROJECT
• PROJECT ORGANISATION

CHAPTER TWO

LITERATURE REVIEW

2.0      LITERATURE REVIEW

2.1      REVIEW OF TYPES OF FIRE ALARM SYSTEM

2.2      REVIEW OF FIRE ALARM DESIGN

2.3      REVIEW OF FIRE ALARM PARTS

2.4      REVIEW OF FIRE ALARM INITIATING DEVICES

2.5      FIRE ALARM NOTIFICATION APPLIANCES

CHAPTER THREE

3.0      CONSTRUCTION METHODOLOGY

3.1      BLOCK DIAGRAM OF THE SYSTEM

3.2      SYSTEM OPERATION

3.3      CIRCUIT DIAGRAM

3.4      CIRCUIT COMPONENT LIST

3.5      CIRCUIT DESCRIPTION

3.6      POWER SUPPLY UNIT

3.7      LDR DESCRIPTION

3.8      DESCRIPTION OF MAJOR COMPONENTS USED

CHAPTER FOUR

4.1            RESULT ANALYSIS

4.1      CONSTRUCTION PROCEDURE AND TESTING

4.2      CASING AND PACKAGING

4.3      ASSEMBLING OF SECTIONS

4.4      TESTING OF SYSTEM OPERATION

4.5     INSTALLATION OF THE COMPLETED DESIGN

4.6      COST OF PRODUCTION

CHAPTER FIVE

• CONCLUSIONS
• RECOMMENDATION

5.3     REFERENCES

CHAPTER ONE

1.0                                                      INTRODUCTION

In modern society, it is impossible to imagine house or building without a fire accident detector. Modern houses require a continuous installation of fire detector. Not only industry, but also in the household. Take the case of a duplex that experience a fire accident without a detector that means everything in that building will get burnt even human beings. But in a case whereby fire alarm is installed that means everyone in that building will be alerted and also fire security bodies will also be informed for quick security action. The same thing can also happen to our offices and industries. In order to notify residence of any building in the presence of fire accident, a fire alarm system is used.

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 classified as either automatically actuated, manually actuated, or both. Automatic fire alarm systems are intended to notify the building occupants to evacuate in the event of a fire or other emergency, report the event to an off-premises location in order to summon emergency services, and to prepare the structure and associated systems to control the spread of fire and smoke.

1.1                                      BACKGROUND OF THE PROJECT

The very first fire alarm system was invented by Dr. William F. Channing and Moses Farmer in 1852, and their original design was two fire alarm boxes, each containing a telegraphic key with a handle attached. When someone detected a fire, they would crank the handle, which would then relay the details of the fire alarm box number to a central alarm station. The operator at the station would receive the message, which would then be forwarded to the fire department.

Francis Robbins Upton was the man responsible for designing the first electric fire alarm, but when he patented the design in 1890, the patenting office mistakenly recorded it as the “Portable Electric Tire Alarm”. Oh dear!

Although the design was largely unpopular at first and received little attention, it soon became apparent that the need for this device was growing.

The alarms of today

It wasn’t until the 21st century that modern day systems were introduced and with the introduction of the British Standards Specifications Alarm Systems are more and more vital to business and everyday life.

Here at Silver Group, we understand the individual needs of every client and with our BAFE (British Approvals for Fire Equipment) accreditation, it means that not only do we design, supply and install a system that’s based on the origins of the ‘very need’ for Fire alarms, but one that’s tailored to your particular needs.

The feeling of total security in both home and business can’t be measured in pounds and pence or dollars and cents. Knowing that if the worst happens and a fire breaks out, you, your family, your colleagues and the possessions inside the building are given the best advantage possible must surely rate high on your ‘must have’ list.

1.2                                               PROBLEM STATEMENT

The Nigerian environment is considered to be hazards prone brought about by man-made and natural disasters due to its geographic circumstance which is exposed to catastrophic, floods droughts and fires. Based on the reports; devastations of these natural hazards and disasters including fires have increased in recent years. Our lifestyle of negligence and adapting to emerging technological solutions puts us at the risk of loss to fire and related occurrences as seen in markets, homes and other public places. The risk of fire occurrence is high especially during the dry season, Christmas and New Year celebration due to firecrackers. In the case where house fires are prevalent, it has effect to derail the economic growth, destroy social and physical capital including infrastructures, which resort to reallocation of ongoing programs to finance relief operations to fatalities and inhabitants and reconstruction efforts which diverts funds to social services. Fires are considered natural and man-made hazards. This technology aimed at putting an end to these problems by alerting the owner of house at the starting point of fire accident via alarm [5][6].

1.3                           OBJECTIVE OF THE PROJECT

The objective of this work is to construct a device that will detect the unwanted presence of fire by monitoring environmental changes associated with combustion.

1.4                                           PURPOSE OF THE PROJECT

Fire is one of the most costly causes of damage and loss of life in a facility. Fire alarm system supervises the facility for smoke and heat in the installed environment. The purpose of this work is to design a device that does such function.

1.5                                       SIGNIFICANCE OF THE PROJECT

The primary advantage of a home fire alarm system is increased reliability and the ability to place alarms and bells exactly where needed. However, the reason most people have them is that they wanted a burglar alarm system and the cost of adding fire alarm features to a residential burglary system is relatively small.

Another advantage is that they are the only way to obtain remote monitoring services. This becomes important in cases where family members may not be capable of escaping from a fire without assistance. For example, if you have an older or physically impaired person in your home and a fire started when no one was home to assist that person, alarms alone might not be enough to assure their safety.

A feature of most monitoring services is the ability to keep special information on the residence which comes up on the computer screen whenever an alarm is received from that home. Thus, if there is a disabled person in the home who needs special assistance this fact will be known to the operator and can be passed along to the fire department when they are called

1.6                                              SCOPE OF THE PROJECT

In this project, we will go over how to build a smoke sensor circuit with LDR sensor.

The smoke sensor we use is the LDR. This is a sensor that is not only sensitive to smoke, but also to flammable gas.

The circuit a potentiometer is used to adjust the sensitivity to smoke. By adjusting the potentiometer, you can change how sensitive it is to smoke, so it’s a form of calibrating it to adjust how much voltage it will put out in relation to the smoke it is exposed to.

The Output pin gives out the voltage reading, which is proportional to the amount of smoke that the sensor is exposed to. Again, a high voltage output means the sensor is exposed to a lot of smoke. A low or 0 voltage output means the sensor is exposed to either little or no smoke.

1.6                                         LIMITATION OF THE PROJECT

The amount of “smoke” present may be insufficient to alarm smoke detectors. Smoke detectors are designed to alarm at various levels of smoke density. If such density levels are not created by a developing fire at the location of detectors, the detectors will not go into alarm.

• Smoke detectors, even when working properly, have sensing limitations. Detectors that have photo-electronic sensing chambers tend to detect smoldering fires better than flaming fires, which have little visible smoke. Detectors that have ionizing-type sensing chambers tend to detect fast flaming fires better than smoldering fires. Because fires develop in different ways and are often unpredictable in their growth, neither type of detector is necessarily best and a given type of detector may not provide adequate warning of a fire.
• Smoke detectors are subject to false alarms and nuisance alarms. For example, a smoke detector located in or near a kitchen may go into nuisance alarm during normal operation of kitchen appliances.

In addition, dusty or steamy environments may cause a smoke detector to falsely alarm. If the location of a smoke detector causes an abundance of false alarms or nuisance alarms, do not disconnect the smoke detector; call a professional to analyze the situation and recommend a solution.

• Smoke detectors cannot be expected to provide adequate warning of fires caused by arson, children playing with matches (especially within bedrooms), smoking in bed, violent explosions (caused by escaping gas, improper storage of flammable materials, etc.
• System components will not work without electrical power. If system batteries are not serviced or

Replaced regularly, they may not provide battery backup when AC power fails.

• Environments with high air velocity or that are dusty or dirty require more frequent maintenance.

• In general, fire alarm systems and devices will not work without power and will not function properly unless they are maintained and tested regularly.
• The most common cause of an alarm system not functioning when fire occurs is inadequate maintenance.  As such, the alarm system should be tested weekly to make sure all sensors, transmitters, and notification devices are working properly.

1.7                                       APPLICATION OF THE PROJECT

There are a number of critical issues that are solved with fire alarm system.
When designing a fire alarm system, the most important issue is fast detection, notification, and evacuation.

Smoke Detectors are used in hallways, business offices, break rooms, and restrooms. They are also used in dusty areas like warehouses, attics, basements, or in shop environments.

1.8                                     PROJECT WORK ORGANISATION

The various stages involved in the development of this project have been properly put into five chapters to enhance comprehensive and concise reading. In this project thesis, the project is organized sequentially as follows:

Chapter one of this work is on the introduction to a fire alarm. In this chapter, the background, significance, objective limitation and problem of a fire alarm were discussed.

Chapter two is on literature review of a fire alarm. In this chapter, all the literature pertaining to this work was reviewed.

Chapter three is on design methodology. In this chapter all the method involved during the design and construction were discussed.

Chapter four is on testing analysis. All testing that result accurate functionality was analyzed.

Chapter five is on conclusion, recommendation and references.