Design And Construction Of A Multiperpose Security System With Alarm And Display

OBJECTIVE OF THE PROJECT

Alarms are frequently used for detecting the presence of an intruder. These include signaling the presence of unwanted moisture or liquids, presence or absence of light, the removal of a small object, the unwanted opening of a door, power outage, and presence of an unwanted signal in an electronic gadgets etc.

Most electronics alarms are either activated when a circuit is opened or short circuited.

However, the aim or objective of the project is to build a multi-purpose alarm system   with situation indicators from inexpensive and local electronics components that will detect burglar operations, shadow and fire incidence and give the consequent warning signal or indication in order to alert house occupants for appropriate safety actions.

PROJECT LAYOUT

The project report or thesis has been arranged and organized in such a away that as followed all the steps and procedures taken to ensure the success of this project.

Chapter one deals with the introduction of the project, where the objective of the project. The background information and what the project is all about were clearly stated.

Chapter two deals with the literature review in which the origin, concept, nature and review of the method used in designing the project were discussed.

Chapter three, however deals with the detection and the switching of the project it actually concerned about the sensor units – fire, shadow and the burglary sensors,

Chapter four contains the design analysis, component value calculations and general description of all the components and IC units used in this design are treated in details. Complete circuit realization from block diagram is discussed and treated here.

Chapter five, however deals with the methodology of the design and construction of the project. It was here that all the steps involved in realization, analysis, design, selecting component values, choosing a suitable circuit and obtaining project topic and specification are succinctly stated.

Chapter six has to do with construction proper of the designed circuits making use of the various electronic workshop tools and equally the testing analysis, packaging and assembling.

Chapter seven dealt with conclusion, recommendation and references.

BACKGROUND INFORMATION

The project is dominated by ICs. These include 555 timer, encoders, decoders, comparators, bitable multivibrators or flip flops IC units or chips. Hence the project can be termed a digital system.

Digital logic can be divided into combinational and sequential. Combination circuits are those in which the output state depends only on the present input states in some predetermined manner. Combinational circuits can be constructed with logic gates alone. But in sequential logic circuits, the output state depends both on the input states and on the previous history i.e. the knowledge of the past inputs or what actually took place on the previous or preceding states. Sequential circuits can be constructed from logic gates and some form of memory device, the flip flops. Sequential logic circuits may be either synchronous or asynchronous. The synchronous sequential circuits are built to operate at a clocked rate whereas asynchronous ones are without clocking.

From these facts, it can be deduced that the system (project) is a sequential logic system sense it is constructed from logic gates and a memory device, the flip flop. The units in this system are however clocked together so that they operate in synchronism with a pulse train of a certain period, regarded as the system clock. Hence the present output state of the alarm system depends both on the present input state and on the past input states. This is made possible by the memory device, flip flop.