Design And Construction Of A Smoke Detector Alarm Using Photo Interupter And 555 Timer

ABSTRACT

This project is titled design and construction of a smoke detector alarm. Fire/smoke alarm is an electronics device that is installed in a building to detect the presence of fire accident. Smoke detector alarm system is designed to detect the unwanted presence of fire by monitoring environmental changes associated with combustion. Smoke detector 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 device constructed using a 555 timer circuit and a photo interrupter. The photo interrupter module is used as the smoke detector, while timer 555 is wired in astable configuration as an AF oscillator for sounding alarm via a loudspeaker.

TABLE OF CONTENTS

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

TABLE OF CONTENT

CHAPTER ONE

INTRODUCTION

AIM/OBJECTIVE OF THE PROJECT

SIGNIFICANCE OF THE PROJECT

SCOPE OF THE PROJECT

LIMITATION OF THE PROJECT

APPLICATION OF THE PROJECT

PARTS OF FIRE ALARM

PROJECT ORGANIZATION

CHAPTER TWO

LITERATURE REVIEW

2.0 LITERATURE REVIEW OF SMOKE ALARM

2.1 REVIEW OF SMOKE DETECTOR

2.2 REVIEW OF TYPES OF FIRE ALARM SYSTEM

2.3 REVIEW OF FIRE ALARM DESIGN

2.4 REVIEW OF FIRE ALARM PARTS

2.5 REVIEW OF FIRE ALARM INITIATING DEVICES

2.6 FIRE ALARM NOTIFICATION APPLIANCES

CHAPTER THREE

3.0 CONSTRUCTION METHODOLOGY

3.1 BLOCK DIAGRAM OF THE SYSTEM

3.2 CIRCUIT DIAGRAM OF THE SYSTEM

3.3 CIRCUIT OPERATION OF THE SYSTEM

3.4 CIRCUIT DESCRIPTION OF THE SYSTEM

3.5 LIST OF COMPONENTS USED

3.5 POWER SUPPLY UNIT CHAPTER FOUR

4.0 RESULT ANALYSIS

4.1 CONSTRUCTION PROCEDURE AND TESTING

4.2 ASSEMBLING OF SECTIONS

4.3 CONSTRUCTION OF THE CASING

4.4 TESTING

4.5 ECONOMICS OF THE PROJECT

4.6 PROJECT EVALUATION

4.7 COST ANALYSIS

CHAPTER FIVE

5.1 CONCLUSIONS

5.2 RECOMMENDATION

5.3 REFERENCES

CHAPTER ONE

1.0                                                               INTRODUCTION

1.1                                               BACKGROUND OF THE STUDY

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 every one 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 fire detector 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. Fire detector 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.

Commercial security detectors generates a signal to a fire alarm control panel as a part of a fire alarm system, where as household security detectors generally generates a buzzer sound from the detector itself. These detectors are kept in plastic enclosures and usually designed like a disk about 6 inches diameter and 1 inch in thickness, but size and shape can vary.

Smoke can be sensed either photoelectric or by ionization, smoke detectors may use either or both the methods. Smoke detectors are used in an industrial, residential and large commercial buildings are powered with a battery back up. The range of domestic smoke detectors are from individual powered battery units to various interlinked powered units with battery backup.

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 using 555 timer ic and a photo interrupter . The photo interrupter module is used as the smoke detector, while timer 555 is wired in astable configuration as an AF oscillator for sounding alarm via a loudspeaker.

1.2                                            STATEMENT OF PROBLEM

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.

1.3                                    OBJECTIVE OF THE PROJECT

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 using 555 timer ic and a photo interrupter . The photo interrupter module is used as the smoke detector, while timer 555 is wired in astable configuration as an AF oscillator for sounding alarm via a loudspeaker.

1.4                                  SIGNIFICANCE OF FIRE ALARM SYSTEM

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

1.5                                                                SCOPE OF THE WORK

This work is constructed using a 555 timer circuit and a photo interrupter . The photo interrupter module is used as the smoke detector, while timer 555 is wired in stable configuration as an AF oscillator for sounding alarm via a loudspeaker.

In the absence of any smoke, the gap of photo interrupter module is clear and the light from LED falls on the photo-transistor through the slot. As a result, the collector of photo-transistor is pulled towards ground. This causes reset pin 4 of IC 555 to go low. Accordingly, the timer is reset and hence the alarm does not sound.

When smoke is present in the gap of the photo interrupter module, the light beam from LED to the photo-transistor is obstructed. As a result, the photo-transistor stops conducting and pin4 (reset) of IC 555 goes high to activate the alarm.

1.6                                   APPLICATIONS OF THE PROJECT

Smoke detectors are suggested for a common use as they give the maximum level of protection. These devices can be used in leakage routes to offer sufficient early warning to let the clearing of residents.

There are two kinds of smoke detectors namely ionization and optical that are familiar as well general purpose detectors and they are accessible in both analogue addressable and conventional.

Ionization smoke detectors are highly sensitive to burn quickly and flaming fires that generate small smoke particles. These detectors are used widely for workshop printings, paint stores, paper mills and also used for general purpose

Optical smoke detectors are apt for detecting slow burning, fires smoldering which generate large smoke particles. These detectors are used in bedrooms, electrical switch rooms and escape corridors and also used for general purpose.

1.7                                             PARTS OF FIRE ALARM

Fire alarm composed of the following parts:

Primary Power supply: Commonly the non-switched 240 Volt Alternating Current source supplied from a commercial power utility. In non-residential applications, a branch circuit is dedicated to the fire alarm system and its constituents. “Dedicated branch circuits” should not be confused with “Individual branch circuits” which supply energy to a single appliance.

Secondary (backup) Power supplies: This component, commonly consisting of sealed lead-acid storage batteries or other emergency sources including generators, is used to supply energy in the event of a primary power failure.

Initiating Devices: This component acts as an input to the fire alarm control unit and are either manually or automatically actuated. Examples would be devices pull stations, heat detectors, or smoke detectors. Heat and smoke detectors have different categories of both kinds.

1.8 PROJECT WORK ORGANIZATION

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 smoke detector using photo interrupter and 555 timers. In this chapter, the background, significance, objective limitation and problem of smoke detector using photo interrupter and 555 timers were discussed.

Chapter two is on literature review of a smoke detector using photo interrupter and 555 timers. 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.