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CERTIFICATION

This it to certify that Osisiogu Ukachi Oluwaseun, a student of Nnamdi Azikiwe University,

Awka of the Faculty of Engineering and Department of Electronic and Computer Engineering

with registration number 2010364149 has successfully completed his SIWES programme with M

& M Electrical/Electronics and Telecommunications Company, Awka, Anambra State.

Students Signature Date

Industrial Based supervisors Signature and stamp Date


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DEDICATION

To my parents who have been a constant source of support and encouragement an epitome of

godly and loving parents.

To my siblings whose care and affection for me beats my understanding.

To every teacher who put every effort to see that they produce students who will one day become

better than themselves.

To every upcoming engineer who constantly works hard to help the world to be a better place.


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ACKNOWLEDGEMENTS

One of the major lessons I have come to learn in this life is that No man is an Island.

The completion of this industrial training was made possible because of some special persons

who have been helpful in my life.

They include

To my fellow IT students who have been very motivating to me. I am grateful to you all.

Also Engr. Abdul Malik, my industrial supervisor whose guidance has been of immense helps to

me.

The co-workers of M & M Electronics, I am also grateful.

I am also grateful to my Parents Prof. and Mrs. Osisiogu, my siblings and relatives who are

always understanding and still supportive to see that this program was concluded without much

stress.

Finally, to the Omni-potent God for His continuous supply of wisdom, understanding and

knowledge, and a whole lot more. I forever remain grateful to You.


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REPORT OVERVIEW

This purpose of this report is to inform the SIWES coordinator of Nnamdi Azikiwe University. It

is also meant to serve as proof that I actually did undergo the 6 months training required for a

student to do. In this report I will present all I know about the company, what I learnt in the

company, problems I encountered in the company and as well recommendations for Industrial

Trust Fund and the company of my place of attachment.


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Table of Contents

Certification 1

Dedication 2

Acknowledgements 3

Report Overview 4

Table of Contents 5

Chapter One: Introduction 7

1.1 Background of SIWES 7

1.2 The Objectives of SIWES 8

Chapter Two: Description of Establishment of Attachment 11

(M&M Electrical/Electronics and Telecommunications Company)

2.1 Location and Brief History 11

2.2 Objectives of M & M Electronics 11

2.3 Organisational Structure of M & M Electronics 12

2.4 Various Departments and their Functions 12

Chapter Three: Skills and Knowledge Acquired 14

3.1 Audio Amplifiers 14

3.1.1 Principles of Operation 15

3.1.2 How Sound Amplification Works 16

3.1.3 Maintenance and Troubleshooting 18

3.2 The Inverter system 20

3.2.1 Mode of operation 20

3.2.2 Design and Implementation 21


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CHAPTER ONE

1.1 BACKGROUND OF SIWES

SIWES was established by ITF in 1973 to solve the problem of lack of adequate practical skills

preparatory for employment in industries by Nigerian graduates of tertiary institutions.

The Scheme exposes students to industry based skills necessary for a smooth transition from the

classroom to the world of work. It affords students of tertiary institutions the opportunity of being

familiarized and exposed to the needed experience in handling machinery and equipment which

are usually not available in the educational institutions.

Participation in Industrial Training is a well-known educational strategy. Classroom studies are

integrated with learning through hands-on work experiences in a field related to the students

academic major and career goals. Successful internships foster an experiential learning process

that not only promotes career preparation but provides opportunities for learners to develop skills

necessary to become leaders in their chosen professions.

One of the primary goals of the SIWES is to help students integrate leadership development into

the experiential learning process. Students are expected to learn and develop basic non-profit

leadership skills through a mentoring relationship with innovative non-profit leaders.

By integrating leadership development activities into the Industrial Training experience, SIWES

hopes to encourage students to actively engage in non-profit management as a professional career


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objective. However, the effectiveness of the SIWES experience will have varying outcomes

based upon the individual student, the work assignment, and the supervisor/mentor requirements.

It is vital that each internship position description includes specific, written learning objectives to

ensure leadership skill development is incorporated. Participation in SIWES has become a

necessary pre-condition for the award of Diploma and Degree certificates in specific disciplines

in most institutions of higher learning in the country, in accordance with the education policy of

government.

Operators- The ITF, the coordinating agencies (NUC, NCCE, NBTE), employers of labour and

the institutions.

Funding - The Federal Government of Nigeria

Beneficiaries - Undergraduate students of the following: Agriculture, Engineering, technology,

Environmental, Science, Education, Medical Science, and pure and Applied Sciences.

Duration - Four months for Polytechnics and Colleges of Education, and six months for the

Universities.

1.2 THE OBJECTIVES OF SIWES

The following are some of the objectivesof SIWES:

1. SIWES will provide students the opportunity to test their interest in a particular career before

permanent commitments are made.

2. SIWES students will develop skills in the application of theory to practical work situations.

3. SIWES will provide students the opportunity to test their aptitude for a particular career before

permanent commitments are made.

4. SIWES students will develop skills and techniques directly applicable to their careers.

5. SIWES will aid students in adjusting from college to full-time employment.


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6. SIWES will provide students the opportunity to develop attitudes conducive to effective

interpersonal relationships.

7. SIWES will increase a student's sense of responsibility.

8. SIWES students will be prepared to enter into full-time employment in their area of

specialization upon graduation.

9. SIWES students will acquire good work habits.

10. SIWES students will develop employment records/references that will enhance employment

opportunities.

11. SIWES will provide students the opportunity to understand informal organizational

interrelationships.

12. SIWES will reduce student dropouts.

13. SIWES Students will be able to outline at least five specific goals with several staff members

by comparing performance with job duties and develop a draft plan with staff to accomplish

performance needs, supervision plan and rewards.

14. SIWES Students will be able to develop a draft agency or project budget and will be able to

identify methods of obtaining revenue to support the budget.

15. SIWES Students will be able to provide tools to use in prioritizing tasks of an assigned

project and create with staff a tentative schedule for completion based on these tasks.

16. SIWES Students will be able to develop a model policy that gives current front-line leaders

the permission and expectation to work with other staff on conflict resolution and explain how

this works to current front line leaders.

17. SIWES Students will be able to describe different skills leaders can use to

Foster commitment and collaboration with both internal and external constituents.


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The 6 months Students Industrial Work Experience Scheme (SIWES) which is a requirement for

the completion of my course of study, Electronic and Computer Engineering was done at M&M

Electrical/Electronics & Telecommunications Company. It has two departments. They are

experts in the field of sound systems and inverter designs. The Industrial Training was based on

working with the necessary tools used in an electronics workshop in order to design, build and

implement basic and complex electronic circuits needed for both home and enterprise users.

These things were being carried out in the company and some of them form part of my job

description.


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CHAPTER 2

2.0 DESCRIPTION OF ESTABLISHMENT OF ATTACHMENT

(M & M ELECTRICAL/ELECTRONICS & TELECOMMUNICATIONS COMPANY)

2.1 Location and Brief history of M & M ELECTRICAL/ELECTRONICS &

TELECOMMUNICATIONS COMPANY.

M & M is a young growing company which started its operation as a company register under

Corporate Affairs Commission on the 12th

of July, 2010. Ever since then company has been

growing.

She is well interested in seeing that she helps in her own way to solve the power supply problems

in the country by engaging in the design and building of inverters that could be used with solar

panels.

She has her head office at Awka in Anambra State at Odera Shopping Complex, Shop 67 & 68.

I had the privilege of working in this company which believes in the training of young minds.

2.2 Objectives of M & M Electrical/Electronics & Telecommunications Company.

The vision this company runs with is to see that young men and women are trained in order to

live a self-reliant and independent life i.e. to make a living on their own.

They are also committed to delivering excellent services to customers.

They are committed to delivering long lasting solutions to the power problems of the country.

They are committed to excellence and a model of a good servicing company

2.3 Organisational Structure of M & M Engineering Company.

M & M has an organizational structure which is expected to be like an arranged hierarchal

manner which starts from the director, manager of technical services and management,


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production manager and installation manager. It also should include clerical offices such as

secretary, cashier and cleaner. During my stay in M & M electronics I underwent my industrial

work experience scheme under the productions department.

Figure 1 below shows the representation of the company.

2.4 Various Departments and their Functions

1. Technical Services and Management: This department has the responsibility to make sure

that the equipment in the workshop is functional. They are also the department that repairs all the

faulty systems that a customer brings.

2. Training Department: One of the main visions of M&M Electronics is to train young men

and women who will gain skills to work in companies of relative fields and also be able to have

their own companies and be self-employed and in turn create jobs for other people. This

department is responsible to make sure that vision is fulfilled. They train students and they are

also responsible for the materials and tools that these students will use. Courese like basic

electronics, power inverter designs, micro-controller basics and audio amplifiers are taken

3. Production Department: This department ensures that all the jobs of production are being

carried out, they also regulate quality control. If a customer complains of a product they look into

it. They also make research so they can be able to provide state of the art services to improve the

companys worth. Products produces are solar inverters, power inverters, and audio amplifiers.

4. Installation Department: After the production made by the production department this

department is to ensure proper installation of equipment, it is possible that the equipment may not

have been produced by the company but they can be called upon to perform installation services

like solar power related devices, satellite dishes, inverter systems and audio systems.


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COMPANY ORGANISATIONAL CHART (Organogram)

M & M ELECTRICAL/ELECTRONICS& TELECOMMUNICATIONS

COMPANY

Director

Technical and Services

Management

Production

Manager

Installation

Manager

Training

Design and production of audio

system, automatic voltage

regulator, inverter and project

desi n

Repair and

Troubleshooting of

Electrical/Electronic

equipment

Installation of

wiring security

systems

Clerical

Officers

Secretary

Fig. 1: Organisational chart of M & M ELECTRICAL/ELECTRONICS & TELECOMMUNICATIONS COMPANY


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CHAPTER THREE

3.0 SKILLS AND KNOWLEDGE ACQUIRED

During the industrial attachment I was acquainted with a lot of things which includes

a.

Audio power amplifiers

b.

The inverter system

c.

Basic electronics

3.1 AUDIO POWER AMPLIFIERS

An audio amplifier is an electronic amplifier that amplifies low power audio signal (signals

composed primarily of frequencies between 20 20,000 Hz, the human range of hearing to a

level of suitable for driving loudspeakers and is the final stage in a typical audio playback chain.

The preceding stage in such a chain are low power audio amplifiers which perform tasks like pre-

amplification, equlisation, tone control, mixing/effects or audio sources like record player, CD

player and cassette players.

Most audio amplifiers require this low-level input to adhere to line levels. While the input signal

to an audio amplifier may measure only a few hundred microwatts, its output may be tens,

hundreds or thousands of watts.

Figure 2 (a)

Figure 2 (b)


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3.1.1 PRINCIPLES OF OPERATION

The audio amplifier works on the principle of magnetic amplification. The magnetic amplifier is

a static device with no moving parts. It has no wear out mechanism and has a good tolerance to

mechanical shock and vibration. It requires no warm up time. Multiple isolated signals may be

summed by additional control windings on the magnetic cores. The windings of a magnet

amplifier have a higher tolerance to momentary overloads then comparable solid state devices.

The magnetic amplifier is also used as a transducer in applications such as current measurement.

A magnet amplifier device may resemble a transformer but the operating principle is quite

different from a transformer essentially the magnetic saturation of the core, a nonlinear property

of a certain class of transformer cores. For controlled saturation characteristics, the magnetic

amplifier employs core materials that have been designed to have a specific B-H curve shape that

is highly rectangular in contrast to the slowly tapering B-H curve of slowly saturating core

materials that are often used in normal transformers. The typical magnetic amplifier consist of

two physically separate but similar transformer magnetic core, each of which has two windings

a control winding and an AC winding. A small DC current from a low impedance source is fed

into the series connected control windings. The AC windings may be connected either in series

or in parallel, the configurations resulting in different types of magnetic amplifiers. The amount

of control current fed into the control winding, sets the point in the AC winding wave form at

which either core will saturate. In saturation, the AC winding on the saturated core will go from a

high impedance state into a very low impedance state, i.e. current control at which voltage, the

magnetic amplifier switches on.


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Mixer

Console

Input Unit Amplifier Loudspeaker

A relatively small DC current on the control winding is able to control or switch large AC

currents on the AC windings. This results to current amplification.

3.1.2 HOW SOUND AMPLIFICATION WORKS.

In the amplification of sound, you need not just the audio amplifier but also the presence of the

audio speakers and the microphones in conjunction with an audio mixer. In order to give more

illustrations we will use the block diagram.

Figure 3.1: Block diagram of sound amplification

Here, the input unit can be a microphone depending on the mode of application. This device

converts sound to electrical signals. This signal is fed to the mixer console where the effects of

the sound can be modified and made better and then this signal is fed to an amplifier which may

be inside the mixer console or through the use of a power amplifier as discussed above. Then the

signal produced by the amplifier is then fed into the loudspeaker to drive it. When this is done

this signal is then converted form electrical signal to sound.

3.1.3 Maintenance and troubleshooting

In the maintenance of an audio speaker it normally requires that you observe the sound waveform

produced through the use of an oscilloscope especially when it is running at a maximum output.

A good example of this type of maintenance is the adjustment of the bias of the final amplifier

tubes in an amplifier. Using a sine wave test signal as input to the amplifier tubes in an amplifier,

the output tube bias may be adjusted is that the output signal has no crossover distortion.


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In any event where the audio power amplifier is not coming on, we troubleshoot to ascertain the

fault with a bit to fixing it. These are the things we were told to check.

When we plug it and the amplifier does not come on at all, we check for the fuse.

We check for the fuse in the external plug if it is bad, we replace it.

If it is not that we check the fuse in the amplifier.

We also have signs to check if it actually a power problem. For example if there is a

power surge when it is being plugged then we can infer that one of the components of the

power supply like the transformer or even the rectifier diode is damaged.

If we check the above and they are still alright, then we check the power transistors. This

is most likely to be the problem with almost all the panels we worked on. So when this

occurs we test for the damaged one and then replace it.

If the issues still persist we check for other components like the capacitors to make sure

they are connected to the printed circuit board (PCB)

We also check the relay which is used for switching

There are even times when most or all the components in a panel get burnt to much

voltage being initially supplied to it. In that case we have to design and construct a new

panel. This time around we can even produce a better one that will suit the conditions of

power supply in this country.

By the time we are sure that the solution is perfect we then test the equipment and make

sure it is working properly.

Some other issues may also come up. The ones listed above were amongst the common

ones I encountered in the workshop.


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3.2The Inverter System

The inverter system is an electronics device that converts direct current (DC) to alternating

current (AC); the converted AC can be at any required voltage and frequency with the use of

appropriate transformers, switching, and control circuits.

Solid-state inverters have no moving parts and are used in a wide range of applications, from

small switching power supplies in computers, to large electric utility high-voltage direct current

applications that transport bulk power. Inverters are commonly used to supply AC power from

DC sources such as solar panels or batteries. There are two main types of inverter. The output of

a modified sine wave inverter is similar to a square wave output except that the output goes to

zero volts for a time before switching positive or negative. It is simple and low cost and is

compatible with most electronic devices, except for sensitive or specialized equipment, for

example certain laser printers. A pure sine wave inverter produces a nearly perfect sine wave

output (


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lights and fans. This kind of inverter eventually reduces the life span of the appliances they

power. This is also the cheapest form of inverter.

2. Modified sine wave inverter: Modified sine wave is more like the square wave which

possesses less harmonic distortion compared to square wave. The harsh corners from the square

wave were eliminated to transform it to a modified sine wave. This type of inverter is the most

seen in todays market. Although it is less harmful to devices compared to the square wave, it

still heats up the coil in filer due to large amount of harmonic distortion and dissipates power.

3. Pure sine wave inverter: Unlike square wave and modified sine wave, pure sine wave

inverters maintain the best quality due to the least number of harmonic distortions present in it.

Usually sine wave inverter is the more expensive of the two.

The advantage it has over the others is that it allows us to use all AC appliances and reduces the

humming noise of inductive loads like fans. The figure below shows the output of a pure sine

wave form.

Before we go into the design of an inverter we must first understand the basics.

So I will start with a block diagram

Figure 3.2: Waveforms of Square, modified and pure sine wave inverters.


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3.2.1 Mode of operation

The power inverter I learnt during my IT operated in the following way:

The DC voltage from a battery is fed to an oscillator which produces signals that may be pure

sine wave, modulated sine wave or square sine wave. These signals can then be amplified by an

amplifier circuit which then increases the strength of the signal in question. It should be noted

that the amplifier section is not compulsory. The switching circuit is made up of transistors

especially Metallic Oxide Semiconductor Transistors (MOSFETS) and is connected in such a

way that the output of the oscillator switches them on and off at the frequency of the oscillator.

Oscillator

Circuit

Amplifier

Circuit

Switching

CircuitTransformer AC Output

AC Mains Change

Over CircuitOutput

Socket

Battery

Charger

BatterySensing

Unit

Fig. 3.3: Detailed block diagram of inverter


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The transformer steps up the resultant AC from the switching circuit to a value that can drive the

required load.

The change over circuit enables the battery to connect to the oscillator which in turn feeds the

amplifier. The amplifier feeds the switching circuit while the switching circuit feeds this signal

produced to the transformer to get the required AC voltage output for the inverter. The AC from

the mains supply is also connected to the changeover circuit so that it will feed the output socket

when there is power from the public AC mains. When there is supply from the AC mains, the

oscillator circuit will be switched off to switch off the inverter. The AC main also feeds the

battery charger through the changeover circuit in order to charge the battery. The sensing unit

senses a number of conditions like low battery, full battery and overload.

3.2.2 Design & Implementation of Inverter System

In the implementation of the above mentioned design, we are going to be looking at the

following components.

a. The required power transformer

b.

The regulator circuit

c.

The Oscillator circuit

d.

The signal amplification circuit

e.

The switching circuit

f.

The battery charger

g.

The charge controller


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3.2.2.1 THE POWER TRANSFORMER

In order to obtain the required specification needed to construct we are going to perform some

calculations.

Using the formula:

Where P = perimeter of bobbin

V = voltage

T = number of turns

Applying this formula we can therefore calculate the transformer windings for both secondary

and primary windings.

During my industrial training we were faced with the task of producing a 5KVA inverter, with

primary winding voltage of 48V, secondary winding voltage of 220V and the inverting voltage

to be 290V.

The perimeter of the transformer bobbin was given as 27cm2

For the primary voltage we have that V = 48V, therefore the number of turns needed is given as

For the secondary voltage winding at 220V


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Therefore,

For the inverting voltage winding at 290V

It should also be noted that in getting the correct wire gauge to be used for the inverter we must

know the current that will pass through the coil and use an approved chart to get the appropriate

wire gauge to use.

3.2.2.2THE REGULATOR CIRCUIT

The regulator gives the oscillator its reference voltage and determines the amount of power that

drives the system. The amplitude of the oscillator or timer is determined by the voltage output of

the oscillator and the current of the regulator determines the stability of the oscillator. The zener

diode D1 determines the regulating voltage ranging from zero to the maximum applied voltage

since to clips and clamps the base voltage of the transistor Q1.

The transistor Q1 determines the regulator output current and the maximum applicable voltage

the regulator can regulate whiles the resistor R1 gives a feedback between the input and

regulating reference voltage.


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3.2.2.3 The Oscillator circuit

During my industrial training we used the SG3524 integrated circuit (IC). This was used to

generate a modified sine wave. The figure below shows the IC pin-out

Fig 3.4: The regulator circuit

Fig 3.5: The pin out of SG3524


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After the amplification is done this signal is then fed into the switching circuit. This circuit is

made up of MOSFETs of which the gates are all connected together and the signal from the

oscillator is fed in.

Also the drain of all the MOSFETs are all connected together and then connected to the

transformer, while the source are also connected together and then connected to ground.

The frequency of the oscillation produced by the oscillator switches, these transistors on and off

at that same frequency thereby generating the AC signal which then fed to the transformer, the

transformer steps up this AC signal to the required voltage which can now be fed to the load.

Fig 3.7: A schematic diagram for a MOSFET switching circuit.


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3.2.2.6 Operation and Description

When grid power is on, the transformer T1 is energized which triggers all the switches to ON

mode. At this mode the loads automatically connects to the grid power and DC supply to the

regulator is cut off to stop the inverters from operating.

When the grid power goes OFF the switches are released and the load automatically connects

itself to the inverter and at the same time power is released to the regulator circuit which causes

the inverter circuit to start operation. No capacitor is used to filter or smoothing the rectified

power from the bridge diode because the introduction of a capacitor to a relays power supply

increases the tendency for a delay in switching the relays to either ON or OFF mode.

3.2.2.7 Charging System

The charging system for this system is in a hybrid mode (internal and external) meaning that at

time the mains or the grid power is available the internal charging system would partially

recharge the battery when its voltage is below 12.5. An external source like the Solar Cells or the

Wind turbine can also be connected to replace the internal charger when the system is being used

at a place where grid power is not available. The internal charging circuit uses a transformer less

battery charging system instead of the normal transformer type because the transformers

produces great amount of heat when the batteries are highly discharged which sometimes

eventually causes it to burn.

3.2.2.7 Battery Charger

When 220 volts AC is connected in series to a capacitor making the AC tire which passes

through the capacitor to make behave like a pulse which created when the capacitor charges and


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discharge. Since power cannot pass through the charger but only store electrical power. The

output from the capacitor is series to the rectifier, changes the power to D.C ripples near zero

hertz making it conductive for battery charging. The diode only used power stored in the

capacitor. This procedure continues until capacitor charges to full charge or the mains are

disconnected.

3.2.2.8 Charge Controller

The charge controller is a circuit tuned to either close or open circuit for charging the battery

when it is low and cut charging when the battery is fully charged.

The minimum voltage is set to 9V and the maximum is left to the digression of the installer since

ever battery has a different charging voltage.

Fig 3.9: A schematic diagram of the battery charger


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3.2.3 Maintenance & Troubleshooting

During the course of my industrial training we did not only produce the power inverters we also

did some maintenance and some trouble shooting. Also due to the fact that we are core

manufacturers, customers always come to us in order to repair the faulty components.

One of the major problems we faced in the workshop was the overheating of transformers. To

tackle that issue we always had to trace the fault by recoiling the power transformer, sometimes

the transformer had a bridge inside it or the transformer gets burnt when any of these happened

we recoiled the transformer.

Another problem we faced also was when the MOSFETs started to overheat once the inverter

was turned on so we just had to trace the fault to the connection of these MOSFETs to their drain,

source and gates that were connected once the wrong connection was rectified it would work

perfectly.

Fig 3.10: A schematic diagram of a charge controller


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Lastly, when the other circuits involved in the inverter circuit seems to be faulty, problems may

come from damaged transistors, damaged relay, and any other damaged circuit. The needed

action to take was simply the replacement of such component and then test for its functionality.

3.2.4 Precautionary measures

During my industrial training I was made to understand some precautions that were needed to be

taken. They are

1.

Do not overload the inverter system so as to avoid blowing up the inverter system.

2.

Ensure that the polarity of the inverter system is not reversed or bridged or else a hazard

may occur.

3.

Make sure that the battery being used is an original so that it can serve you for longer

hours.


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CHAPTER FOUR

4.0 Basic Electronics

a.

Delay Circuit using Operational Amplifiers

b.

Power Supply Circuit.

c.

Crossover circuit for Audio Speaker

4.1 Construction of a delay circuit using operational amplifiers

The circuit uses RC circuit in combination with an Op-Amp Comparator to accomplish the delay

characteristic of a timer. In the above diagram a voltage is applied across the R3-C1 combination.

The input for the Op-Amp is tapped at the point where R3 and C1 meet. This is the point where

the positive terminal of the capacitor gradually charges to the value of the power supply. As the

capacitor C1 reaches the Op-Amp's reference voltage, the Op-Amp's output pin turns from High

to Low, allowing current to flow through the transistor, Q1, current enters the base of the

transistor and flows to the collector which acts as a switch to turn the relay on. When the relay is

on, current then passes through the LED (causing the LED to glow). The time delay can be

Fig 4.1: A delay circuit with the use of an OP-Amp.


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controlled by changing the values or R3 or C1 or by adjusting the value of the R1 and R2. For a

new timer cycle to occur, you must discharge capacitor, C1.

4.2 Regulated Power Supply Circuit

During my industrial training I also learnt how to build a power supply circuit.

First I had to understand the basics using a block diagram

From the diagram we can infer that the AC voltage is fed into a transformer which steps it

down to a value defined by the voltage specifications of the transformer. The output of the

transformer is then fed into a rectifier.

The rectifier converts the AC to DC. There are three kinds of rectification which are the half

wave reactivation, full wave rectification (with the use of two diodes) and also the full wave

rectification with use of four diodes. The one that I constructed was full rectification with four

diodes. The output from the rectifier is then being fed to the filter circuit in order to reduce the

ripple effect.

The filter circuit is of 3 types we can just connect the capacitor in parallel to the rectifier or use

the pi and T method but this time we use an inductor.

AC Mains FilterRectifierTransformer Regulated

DC output

Fig 4.2: A detailed block diagram of a power supply circuit


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Fig 4.4: A schematic diagram of a single rail regulated power supply circuit

Finally the output from the filter circuit is then fed into the regulator which can be an IC or

through the use of a zener diode. It should also be noted that we can also provide a variable

regulated power supply or a constant regulated power supply.

Also the power supply can be a single rail power supply (can only give an output of one polarity)

or a dual rail power supply (can give an output of both polarities).

It is important to note that in constructing a dual power rail we must use a center tapped

transformer.

4.3 Crossover circuit

For certain loudspeakers that has both a woofer (bass) and a tweeter a crossover circuit is being

used because the balance that the speaker gives depends on the amount of frequency the sound

produces.

Fig 4.3: A schematic diagram of a dual rail regulated power supply circuit


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CHAPTER FIVE

5.0 SUMMARY, RECOMMENDATIONS AND CONCLUSIONS

5.1 PROBLEMS ENCOUNTERD DURING THE PROGRAM

I enjoyed my industrial training at M & M Electrical/Electronics And Telecommunications

Company but I was not left without challenges.

1. No allowance

During my training I was not given any allowance to help with the expenses that I had to

take during the course of my training like the transportation, feeding and then the purchase

of some needed equipment for work.

2.

Distractions

During the course of training the colleague of my industrial supervisor had many friends

who came around. Sometimes they would chat for a long time and this distracted us the

trainees. They would even ask us to go get something for them in the midst of our

learning. This did not help us to learn very well.

3.

Inefficient transfer of knowledge

I did learn a few things but I believe I would have learnt more if we did not just only rely

on on the job training because we were not even given much jobs to do. Sometimes the

industrial based supervisor did not have enough time to teach us some things. So there was

transfer of knowledge but it was not so satisfactory.

4.

Lack of seriousness


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Some of my colleagues were not even so serious. Some would come in late and then some

would not even come at all. So whenever they were not around I was told to do things that

were not even related to my field of study.

5.2 Recommendations

SIWES is a very important programme in the life of any student especially for those who would

want to practice engineering. SIWES has gone a long way to bridge the gap between what is

done in the university and what is done in the industry.

5.2.1 For the Industrial Task Fund and SIWES

I strongly recommend that ITF should keep visiting the students on a regular basis i.e. at least 3

times in the space of the 6 months of the training so that these who are not serious will be more

dedicated to their place of work.

I also want to recommend that ITF should always liaise with many companies to ensure that IT

students do not have a hard time finding a place of attachment.

I also want to recommend that in order for ITF to fulfill its objectives in the career of students

they should always ensure that companies with the facilities to train engineering students should

be willing to accept a larger number of students than they are doing now. This will go a long way

to minimize the search many students undergo before they find a place for attachment.


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5.2.2 FOR THE COMPANY

I actually learned some useful things during my stay in M & M Electronics. During my stay I

observed a few things and I want to recommend the following.

1.

One of the things the company lack is a good marketer. There are lot of

persons in Anambra State and probably other states who may need the services you

provide but they need someone to encourage or push them to buy it. A good marketer with

good skills can make you get more jobs and more money so that you can even pay the

trainees that come to the company to work. One of the challenges I faced during my

training was lack of allowances during my stay there. So doing this can be of good help in

future.

2.

The environment where the company is hidden. You provide good

services yet you are not well known in Awka. I will advise that you either get another

place or you make banners or posters that will advertise your products and attract much

more customers. One of the challenges I also faced as regards the venue was the fact that

it was not conducive enough for learning because of the level of noise and some other

distractions.

3.

The customer relationship was not so wonderful, I am actually trying to

say that the way some customers get disappointed because of a delayed job or a job not

well done that causes them to come back again over a short period of time can continue to

degenerate customer relationship. So I recommend that they treat customers well so that in

the long run they would not lose many other customers.


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4.

In the world of business collecting loans to improve ones business is not

that bad. I know you have a lot of things in mind but then you need more packaging and

packaging is going to cost money. You have the capacity to become one of the leading

electronic schools in Awka but you have not provided room for that. So I recommend that

you get loans or apply for programs that can fetch such loans in order to get more money.

One of the challenges I faced was that most of the learning I did was always on the job

training. It was only a few times we sat down and learnt a few things. This did not cause

efficient transfer of knowledge. So I recommend that a training school be set up so that the

trainees can benefit well and even be willing to pay.

5.3 Conclusion

In conclusion this industrial training has afforded me the basic practical and theoretical

knowledge that I may not have gotten from the lecture room. It also gave me the opportunity to

have a feel of what it would be like after graduation when I start working. It has also helped me

to have knowledge of the electronics industry.

5.3.1 Benefits I got after the SIWES program

More Confidence

During my training I developed confidence in constructing any electronic circuit, because I was

told to do that a lot. I can even solder better than I used to.

With that to I can be able to analyse most electronic circuits.


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Knowledge

During my SIWES program I was used to seeing many things on electronics especially the

components used in making a circuit. I have an in depth knowledge of audio systems and how

they operate and also the inverter system.

Working Ethics

During this program I was learnt how to handle customers, and also involved myself into many

jobs that had to do with teamwork.

Exposure

I was exposed to many things like how to solder in a special way, how to respond to faulty

equipment and also how to respond to customers anytime.

Networking

During my industrial attachment I made new friends in my field of study, people I can be able to

look up to and also seek their help any time I have challenges whether it is during ny stay here or

beyond.

5.4 Suggestions to the improvement of Scheme

In order to make this scheme more interesting awareness needs to be made corporate bodies on

how industrial attachment students should be treated. Any company that can train students that

has not yet started accepting students can collaborate with ITF and see the best way they can start

taking industrial attachment students.


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SIWES supervisors should be visiting us more often than they are doing so that we can be

encouraged to be very serious with this programme.

SIWES should increase the pay and also pay the first half at the beginning of the training and

then pay the remaining at the end of the training so that those who may encounter financial

problems can be able to cope.

it report sample

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