Design And Implimentation Of Solar/PC-Powered Appliances

ABSTRACT

This paper proposes the design and construction of fire alarm system which is controlled by microcontroller. Computer is used to indicate situations of the system composed of 4 modes of working state, regular working mode, short circuit mode, open circuit of wiring signal mode, and fire mode. Graphic output states are displayed on personal computer, PC, by using software delphi, interfacing with microcontroller. Input signal coming from the normally opened warning devices such as heat detector, smoke detector and master key is sent into a detectable instrument to separate the mode of working state. After that, output signal is dispatched to  microcontroller for analysis. This microcontroller can transfer data and display the situation of detector in 6 zone. Thus, the calculated all output data is exposed on PC. In case of fire mode, the data will be sent to PC and to bell simultaneously. Delay time of signal message can be changed directly and easily by PC. In addition, all information including mode of state, date and time are recorded to be database for further analysis that is benefit for the development of fire alarm system to possess both more efficiency and more accuracy. Comparing this controller with another conventional controller in the same specifications, the controller is used and installed easier because of working with no specific fire alarm devices, as well function of working mode and retardation are changed more comfortable because of program computer. Moreover, total price of this fire alarm system unit is significantly cheaper.

CHAPTER ONE

INTRODUCTION

Conventional fire alarm systems having hard wire layout and normally opened warning devices like heat detector and smoke detector in general specifications, have a good view in low price, but have a bad view in

1. Low efficiency to warn and to communicate to human
2. difficult of maintenance
3. hard expansion and transformation of working
4. no record and no database to develop in the future

This fire alarm system is designed and built to solve that problem. The connection between warning devices and personal computer are dealt with microcontroller.

1.1                                          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. The connection between warning devices and personal computer are dealt with microcontroller.

Fire Alarm System that would fulfill the following objectives:

• Indicate the room in which fire erupted
• Sound the alarm if fire occurs
•  False Alarm occurrence should be kept minimum
•  The system should be flexible enough to be easily modified in case if new rooms are added to the building
•  The system should also provide the flexibility to adjust the temperature and smoke sensitivity levels as per the operating environment
• The system should never be in any ambiguous state. Under normal conditions the system should indicate the state of the room as ‘NORMAL’ in order to avoid any confusion.

1.2                                         SIGNIFICANCE OF THE PROJECT

In any modern structure or building of the world, safety has the highest priority and therefore fire detection system is one of the basic components of the structure. Timely information of fire not only helps save lives but also makes it easier to put out fire.

1.3                                ADVANTAGES OF FIRE ALRM 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.

1.4                               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.