DESIGN AND CONSTRUCTION OF AN ELECTRONIC DIGITAL SECURITY ALARM SYSTEM FOR THE BURSARY OFFICE
ABSTRACT
The design and construction of a digital security system using Transistor-Transistor Logic
(TTL) and complementary Metal Oxide Semiconductor (CMDS) is presented. The
security system has five (5) sensors. The alarm will sound if sensor three is
ON and any other two sensor. i.e. one lower sensor and one higher sensor are
ON. Truth table gave a Boolean expression which minimized using a 5-variable
karnaugh map reduction techniques. Digital logic gates were used to realize the
circuit. The circuit is powered by a volt d. c supply, which is reduced to a 9
volt d. c. supply using an IC regulator. A bugger and a plastic casing were
also used. The system was mounted on a view board, which was tested and found
to be working.
CHAPTER ONE
1.0 INTRODUCTION
“Electronics” is
the word used in general conservation with little idea of the meaning of the
term of its importance electronics is
the branch of science and technology that deals with electric circuits
involving active electrical component such as vacuum tube (almost obsolete)
transistor, diodes and integrated circuit (more recent used). The nonlinear
behaviour of these components and their ability to control electron flow make
amplification of week signal possible, and is usually applied to information
and signal processing. Electronics is distinct from electrical and
electo-mechanical science and technology, which deals with the generation,
distribution, switching, storage and conversion of electrical energy to and
from other energy forms using wires, motors, generators, batteries, switches,
relays, transformers, resistors and others passive component. Today most
electronic devices uses semi-conductor component to perform electron control.
The study of semi-conductor devices and related technology is considered a
branch of solid-state physics, whereas the design and construction of
electronic circuit to solve problems come under electronic engineering.
Electronics is
an industry of great vigor and promise, and each step forward in its technology
will lead to further important application. These applications in turn will
result in new jobs in the design, construction and sales of new products.
An electronic component
is any entity in an electronic system used to affect the electrons or their
associated fields in a desired manner consistent with intended function of the
electronic system. Components are generally intended to be connected together,
usually by being soldered to a printed circuit board (PCB) to create an
electronic circuit with a particular function (for example an amplifier, radio
receiver or oscillator).
Components may be packaged singly
or in more complex groups are active (e.g. diodes, translator and thyristors)
or passive (e.g. resistor and capacitors).
Circuits
and components can be divided into two groups: analog and digital, the former
being gradually phased out by the letter. A particular device may consist of
circuitry that has one or the other or a combination of the two types.
The
word analogue is derived from the Greek (analogous) meaning proportional.
Analog describes the proportional relationship between a signal and a voltage
or current that represent signal. Most analog electronic appliances are
constructed from combinations of a few types of basic circuit. The number of
different analog circuit so far devised a huge, especially because a “circuit”
can be defined as anything from a single component to system containing
thousands of components. Analog circuits are sometimes called linear circuit
although many non-linear effects are used in analog circuit including vaccume
tubes and transistor amplifiers, operational amplifier and oscillator.
Digital
circuits are electric circuits based on a number of discrete voltage levels.
Digital circuits based on a number of discrete voltage levels. Digital circuits
are the most common physical representation of Boolean algebra, and are the
basis of all digital computers. To most engineers, the team “digital circuit”,
“digital system” and interchangeable in the context of digital circuit. Most
digital circuit uses a binary system with two voltage level labeled “0” and “1”
often logic “0” will be a lower voltage and referred to as “LOW” while logic
“1” is referred to as “HIGH”.
Computers, electronic clock and
programmable logic controllers (used to control industrial processed) are constructed
of digital circuit. Digital signal processors are another example (IEEE
Dictionary of Electrical and Electronics Terms, 1986).
Circuit
design is a creative activity that requires not only experience and skill but
infuction and success of achieving ones expectation at the end as well. An
intimate knowledge of the circuit properties of available components as well as
the ability of predicting the behaviour of circuit companies of interconnection
of these components.
Thus
the design is based on: first, the electrical description of the components
used in the circuit which is also called MODELING while the second which
relates to the mathematical description of interconnection of the model
components is called NETWORK THEORY.
The
electronic modeling and its theory to be described in this work is the security
alarm system of the bursary office. The components that will be used in this
work are mostly digital in nature.
1.1 REVIEW OF ALARM SYSTEM
Efforts have
been made to design various systems using different electronic components.
In 1981 (Ray
Marston) designed an alarm system (security), which was developed by Steve
Ramasahodeo tagged “Infrared (IR) intruder alarm” system. It was a maximum
useful range of about 10meters and from a basic of a domestic or commercial
security alarm system. The system comprises of two units namely: an infra-red transmitter
and an infra-red receiver with a relay output. The receiver unit contains
facilities for operating the relays in either the latch or non-latch mode and
for externally disabling the relays via concealed “by-pass” switches so that
authorized persons can pass through the beam without activating alarm. The
unique feature of this alarm system is the use of a dual-beam infra-red link.
The two beams must be broken simultaneously to operate the alarm. The stems
thus respond only to objects greater than the dual beam or setting on
transmitter or receive diodes. The basic transmitter signals are generated by
ICs and are wired as non-symmetrical stable multi-vibrator producing alternate
periods of IC and output is buffered by another IC. Similarly the two infra-red
detector diodes are connected in parallel and wired in series with a stable resistor.
The installation is such that both the transmitter and the receiver should be
pointing towards each other. J. spark (1997).
Designed a
bulger alarm. This circuit is basically composed of L.D.R. light depended
Resistor, Resistor of various transistor, buzzer, battery, thermistor.
When the bugler
walks in front L.D.R., the self holding relays pulls up and the relay contacts
can be used to operate a bell, buzzer or electronic siren or a bulb to give
visible warning instead.
The toggle
switch is used to switch the battery off, when the circuit is not being used
and also to reset the circuit. The variable is used to adjust the point at
which the relay pulls up. The 10 kilo ohms resistor connected to the base of
transistor T1 is not used now, to make the circuit sensitive.
Rory Holmes
(1981) also designed the “INFANT GUARD” alarm system to protect cabinet of
cupboard which contains valuable (delicate goods) from the accessibility of
young children hands. This system has as satisfactorily loud alarm sound to
prevent the children from meddling in the cupboard and to warn also the parents
in the house that somebody has opened the cupboard.
The circuit
consist of three Section; a light threshold detector, a latching circuit and a
gate antioscillator for the alarm. The light detector uses a photo transistor
which has a very low dark current that is effectively negligible. When any
light falls on the photo transistor , the current through it will increase and the
inputs to the ICs are now taken low. The alarm oscillator uses the well known
gate CMOS a stable configuration built around two ICs in which one input of
each gate is driven from the output of the inverter.
In 1984, Tooley
M and Whitefield designed an alarm called “ANTI – THEFT ALARM”, which provides
an available and visible warning to indicate that properties and goods kept are
being tampered with. The system consists of photo diodes, ICs, transistor, capacitors,
and resistors all of various values. The system illustrates the uses of basic
logic gate demonstrates techniques for driving light emitting diode (LED), and
shows how simple square wave oscillators can be constructed 5volts supply of up
to 500MA and suitable for with both anti-theft alarm and any of the subsequent
project.
In 1984, Lumky
G. E. desgined a “two timer alarm system” its circuit consist of three circuit
boards and a warning unit, the three circuits are: -
a. Alarm
comparator, to sense the intruder
b. Two-timers, to produce timing sequences
for external warning device. It also provides a tell-tale monitor to determine
whether or not the system has been activated during the owner’s absence.
c. An automatic reset is incorporated
within the design so that if the alarm is accidentally triggered, the process
is not repeated, but can be absorbed simply by removing the source of alarm.
The system makes use of
an NE 556 timer which has two 555 timers; this is to obtain two independent
adjustable periods of delays. Both periods are initiated simultaneously by
clamping the base of the transistor to its emitter, the intruder sensing
comparators. Defects change in the external network of the sensor whether they
are magnetically activated reed switches, pressure mats, micro switches or
active devices such as ultrasonic Doppler movement detectors.
The arrangement is such
that any attempt to short circuit or cut the external network wiring will
result in triggering the system. The compensators are used to substitute for an
open sensor; one for one all it does is to put one resistor in, when one has
been taken out of the circuit.
Paul Horowitz and Winfield
Hill, (1996) designed a synchronous (homodyne) detector. An interesting method
that combines dynamic range, accuracy and speed is synchronous detection called
“homodyne detection”. In this method the output is rectified by being inverted
during alternative half circles. This obviously requires a clean signal at the
same frequency as the signed detected, either supplied externally or
regenerated internally with a phase-locked loop. Synchronous detection works
well-up to frequencies of few megahertz, at least, the big disadvantages is the
need for a coherent reference signal. The circuit consist of ICs, capacitors
and resistors all of various values, it shows how a simple square wave can be
s\constructed using logic gates (stroke 1984).
1.2 TYPES OF ALARM
An alarm gives
an audible or visual warning about a problem or condition, alarms includes:
i. Burglar
alarm, designed to warn of burglaries; this is often a silent alarm.
ii. Alarm
clocks, can produce an alarm at a given time.
iii. Distributed control manufacturing system
or DCSs, found in nuclear power plants, refineries and chemical facilities also
generate alarms to direct the operators’ attention to an important event that
he or she needs to address.
iv. Alarms in an operation and maintenance (O
& M) monitoring system, which informs the bad working state of (a
particular part of) the system, under monitoring.
v. Safety alarms, is a gadget system that
monitors the sound or movement of a baby in his/her room enables the mother to
know precisely the movement and condition of the baby.
Common
public safety alarms include
ü Tornado
Sirens
ü Car
Alarm
ü Community
alarm or auto dealer alarm (medical alarms
ü Air
raid sirens
ü Personal
alarm
ü
Tocsins – a historical capability of causing fight –
or flight response in human (Walker, 1985)
CHAPTER TWO
2.0 THEORY OF COMPONENTS
2.1 INTRODUCTION
Logic is the
formal systematic study of the principle of valid inference and correct
reasoning. It was studies in several ancient civilizations including the Indian
subcontinent, China and Greece. Logic was established as a discipline by a
Greek philosopher Aristotle (322-348 BC) who gave it a fundamental place in
philosophy, although logical thinking and clear reasoning certainly existed as
far back as 2000BC. Development of logic was slow until the 17th
century. When men such as Francis Bacon, Gottfried Herbuiz and Rene Descartes
contributed their thoughts. The study of logic was part of the classical
trivium, which also include grammar and rhetoric. Logic was further extended by
Al-farabi who categories it into two separate groups (Idea and proofs),
(Wikipedia 2009).
In 1847, two
mathematicians, George Boole and Augustus de Morgan independently proposed
forms of algebra to represent logical expressions. Seven years later Boole
published the laws of thought, which was first practical way of expressing
logic in algebraic form. Boolean algebra, as it is now called, has only two
values Zero “0” and one “1” and thus is
ideal for computer logic applications.
Logic can be
applied to a very board spectrum of problems, and is used almost subconsciously
in a large variety of every situation. Applying the principle of logic to
problem analysis provide a powerful tool with which to solve the problems. In
the same way the use of logical circuits, which operates according to the
principles of logic provides an automated methods of solving problems. Such
circuits are found not only in computers but also in many other places like telephone
systems and household items such as central heating controls and automatic
washing machine controls. Electronic calculations and digitals instruments such
as the computer contain circuits which will perform arithmetic operations like
addition, subtractions, multiplication and division. In the Central Processing
Unit (CPU) of a computer, these arithmetic operations are carried out by the
arithmetic and logic unit (ALU). All digit circuits are built up using basic
building blocks called logic gates (devices) to perform logical operations in
computer (AND OR, and NOT functions) and all other more complex devices (gates)
are built up from these (NOR, NAND, EX-OR and EX – NOR).
A Logic gate is
an electronic circuit which makes logic decisions. It has one output and one
more inputs. The output signal appears only for certain combination of input
signals. Logic gates are the basic building blocks from which most of the
digital systems are built up. They implement the hardware logic function based
on the logic algebra developed by George Boole (Theraja and Theraja, 2000).
Logic gate is
the basic elementary circuit which implements desired logical operations of 0
and 1 states either alone or combination with others. It is a combination of
electronic components that takes one or more logical level inputs and produces
a signal logical level output (Umar, 2013).
These gates are
available today in the form of various IC families. The most popular families
are: transistor – transistor logic (TTL), emitter – coupled logic (ECL), metal
– oxide – semiconductor (MOS) and complementary metal – oxide – semiconductor
(MOS).
In computing
systems, the number symbol 0 and 1 represent two possible states of a circuit,
a CLOSED switch, a HIGH voltage, a PLUS sign and a TRUE statement.
Consequently, a 0 represents: an
OFF circuit, an OPEN switch, a LOW Voltage, a MINUS sign, and a FALSE statement.
2.2 CONSTRUCTIONS OF GATE
Logic gate
called DIGITAL LOGIC CIRCUIT can be constructed from semi-conductor materials
and they include: Diodes, transistor and resistor. These materials are
connected in such a way that the circuit output is the result of a basic logic operation
(AND, OR, NOT, NOR, NAND, EX – OR, EX – NOR) performed on the inputs. The
following points are important to understand when constructing gates.
1. Electronic
gates require a power supply.
2. Gate inputs are driven by voltage
having two nominal values, examples 0 volts represents Logic 0 and 5volts
represent Logic 1.
3. The output of gates provides two
nominal values of voltage only (Wikipedia, 1997).
2.3 TYPES OF GATE
There are seven basic
types of gate which are:
OR, AND, NOT, NOR, NAND, EX-OR,
EX-NOR
“OR” GATE
The OR gate performs the logical sum
(addition) operation and it has more than a single input but a single output.
The electronic symbol for a two-input OR gate is shown in fig. 2.1 (a) and its
equivalent switching circuit in fig. 2.1 (b), the two inputs have been marked
as A and B and the output as X.
Logical
operation
From the truth below;
The OR gate has an output of 1 when
either A or B or both are 1. In other words, it is any-or-all gate because an
output occurs when any or all the input are present. As seen in fig. 2.1 (b),
the lamp will light up (logical 1) when either switch A or B or both are closed.
Obviously, the output would be 0 if
and only if both inputs are 0. In terms of the switching conditions, it means
that the lamp would be OFF (Logical 0) only when both switches A and B are OFF.
The OR gate represent
the Boolean equation A + B=X
The above logical
operation of OR gate can be summarized with the help of the truth table.
A truth table may be define as a
table, which gives the output state of all possible input combination.REQUEST FOR PROJECT MATERIAL
Good Day Sir/Ma,
WARNINGS!
PLEASE make
sure your project topic or related topic is found on this website and
that you have preview the abstract or chapter one before making payment.
Thanks for your interest in the research
topic. The complete research work will cost you N2000 and we will send
the material to you within 24hours after confirming your payment.
Make the payment of N2000 into any of the account
number below and we will send the complete material to you within
24hours after confirming your payment.
Account Name: Agada Leonard E
Account No: 2070537235
Bank: UBA
Or
Account Name: Agada Leonard E
Account No: 3049262877
Bank: First Bank
Or
Account Name: Agada Leonard
Account No: 0081241151
Bank: Diamond Bank
After payment, send the following information to us through this email
address: enemsly@gmail.com
Topic paid for:
Amount Paid:
Date of Payment:
Teller No or Transaction ID:
Name of Depositor:
Depositor Phone Number:
Email address:
NOTE: The material will be forwarded to the email address you provided
within 24hrs after confirmation of the payment.
Thanks.
Agada Leonard E.
For: Enems Project.
For more information visit our contact page @ CONTACT US
No comments:
Post a Comment