Design And Construction Of A Fire Alarm System Using Photo Diode

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. A 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 Thermister based commercial Flame sensors have a drawback because, the alarm sounds only when the Thermister turns hot by the nearby flame. That means, the alarm sounds only after the room is full of fire. But this circuit overrides that drawback. It uses a Photodiode as Fire sensor. It sounds the alarm even if the flame is far away. Interestingly, the spark of the first fire burst can activates the alarm. It can be installed in Home, Commercial shops etc. It is battery operated and in the standby state the current consumption is as low as 5mA. So Simple, Efficient, and Low cost.

1.3 AIM AND OBJECTIVE OF THE PROJECT
The main aim of this work is to construct a device that will detect the unwanted presence of fire by monitoring environmental changes associated with combustion. The objectives are:
i. To evaluate the operation of fire alarm by using photodiode as the smoke sensor
ii. To detect the presence of fire outbreak via alarm
iii. To protect live and property

1.3 HYPOTHESIS/RESEARCH QUESTION
Hypothesis
Hi: There is a significant relationship between photodiode and smoke
Ho: There is no significant relationship between photodiode and smoke
Research Question
i. What is a fire alarm used for?
ii. Is a fire alarm the same as a smoke detector?
iii. What is the working principle of fire alarm system?
iv. How is photodiode used in smoke detectors?
v. Which sensor is used in fire alarm?
vi. Which diode is used in alarm circuit?

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
This study will help the reader to understand the importance of fire alarm in a building and to know how fire alarm can be used to protect lives and properties.
With this study, the reader shall be able to learn the application and operation of a photodiode used in the circuit.

1.6 SCOPE AND LIMITATION OF THE PROJECT
The scope of this study covers the used of photodiode as the smoke sensor in a circuit. This sensor is not only sensitive to smoke, but also it detects object movement.
The system uses a 9v-battery, as a result of that it tends to stop working whenever the battery discharges.

1.7 DEFINITION OF TERMS
Fire: Fire is the rapid oxidation of a material in the exothermic chemical process of combustion, releasing heat, light, and various reaction products
Fire accident: this is an accident caused by fire which can result in serious injury and damage to personal property.
Photodiode: A photodiode is a semiconductor p-n junction device that converts light into an electrical current