Ia electronics lm grade 7 8 p-d

Table of Contents
LEARNING MATERIALS
ELECTRONICS

TLE-IA CONSUMER ELECTRONICS SERVICING Page 1
Table of Contents
I. INTRODUCTION 3
II. OBJECTIVES 4
III. PRE-ASSESSMENT 4
IV. LEARNING GOALS/TARGETS 5
V. COMMON COMPETENCIES
A. KNOW
Lesson 1. Occupational Health and Safety 6
Lesson 2. Introduction to Electricity 9
Lesson 3. Basic Structure of Matter 12
Lesson 4. Electric Charge 13
Lesson 5. The Valence Shell 15
Lesson 6. Electrical Current 17
Lesson 7. Voltage 19
Lesson 8. Resistance 20
B. PROCESS
Lesson 1. OHM’s Law 23
Lesson 2. Complete Circuit 29
Lesson 3. Types of Circuit 34
Lesson 4. Circuit Diagrams 36
Lesson 5. Resistor 44
Lesson 6. Other Electronic Components 51
Lesson 7. Basic Hand Tools and Equiment 54
C. REFLECT AND UNDERSTAND
Lesson 1/Activity 1: Resistor Color Coding 71
Lesson 2/Activity 2: Proper Use of Soldering Iron 81
Lesson 3/Activity 3: Desoldering 87
Lesson 4/Activity 4: How to Use and Read a Multimeter 88
Lesson 4/Activity 5: Use the Right Tool for the Job 96
D. TRANSFER
Performance 1/Assessment 1:
Construction of Series Circuit 99
Construction of Parallel Circuit 107
Soldering Technique Using Wire 114
Soldering Components on PCB 117
Astable Multivibrator Using Transistor 117
VI. SUMMARY 122
VII. GLOSSARY 122
VIII. REFERENCES 123

I. INTRODUCTION
Your Technology & Livelihood Education (TLE) subject has four areas:
Information and Communication Technoloy (ICT), Home Economics (HE), Agri-
Fishery Arts (AFA) and Industrial Arts (IA). Consumer Electronics is a course under
Industrial Arts.
Electronics is a branch of physics that deals with the behavior and controlled
flow of electrons.
Have you ever been curious about what is inside an FM radio box? Will you be
able to identify the components present inside that box? So many small components
inside that box.
The voltage commonly used in home appliances is 220V (It varies from country
to country). 220 V is applied between the terminals of the primary coil of
transformer. A transformer has the capability to change high voltage to low voltage
and vice versa. It converts 220 V into low level voltage.
If you explore inside a computer, you will find many rectangular shaped
objects which have many vertical pins along the edges. Known as Integrated Circuits
(IC), these chips consist of many electronic components.

Consumer Electronics Servicing is a full course that leads to the National
Certificate Level II (NCII).CES is designed to enhance your knowledge, skills, and
attitudes as a trainee/student on core competencies of electronics such as
assembly/disassembly of consumer electronic products and systems, maintainance
and repair of audio/video products, electronically-controlled domestic appliances and
cellular phones in accordance with industry standards. It also includes basic
competencies such as, being able to participate in workplace communication, work
in team environment, practice career professionalism and practice occupational
health and safety procedures. This module will mainly focus on, only common
competencies such as: basic hand tools and equipment; maintaining hand tools and
equipment; performing mensuration and calculation; preparing and interpreting
schematic diagrams; and occupational health and safety will be introduced.
Career Oppurtunities
Service technicians are electronic home entertainment equipment installers
and repairers; they can repairs a number of different products; among them are
televisions and radios, stereo components, video and audio disc players, video
cameras, video recorders and cellphones.

Smaller portable equipment and devices may be brought to repair shops for
service by customers. The workers here, called bench or shop technicians, have on
hand a wide variety of electronic tools and parts. Customers may request technicians
to make house calls when bigger, not so portable equipment breaks down. The
workers that typically make house calls are known as field technicians, and carry
with them a small set of tools and spare parts in order to make repairs on-site for the
customer. When field technicians run into a complicated jobs or problems, they may
return to the shop with the faulty part in order to identify the problem and finish the
repair there.
Growth in consumer electronics servicing as a career is expected to rise
steadily because repair is a lot cheaper than buying a new consumer product.
Furthermore, job opportunities are widely availlable both locally and abroad to those
who are knowledgeable and well experienced in this field.
II. OBJECTIVES
At the end of this module, you, as a learner, are expected to:
1. demonstrate understanding of the concepts and underlying principles of
process and delivery in using consumer electronics hand tools and
equipment while observing occupational and safety practices.
III. PRE-ASSESSMENT
Direction: Match the different hand tools in column A with their actual pictures in
column B. Write the letter on the blank provided before each number.
A B
____1.Soldering iron A.
____2.Desoldering tool B.
____3.Soldering stand C.
____4. Long nose pliers D.

____5.Mini- drill E.
____6.Paint brush F.
____7. Blade cutter G.
____8. Side-cutter H.
____9. Wire splicer I.
____10. Magnifying glass J.
K.
IV. LEARNING GOALS/TARGETS:
Now that you have an idea of the coverage of this module, set your learning
goal in terms of what you want to attain at the end of your lessons in Consumer
Electronics Servicing. Next, specify this in terms of the following:
Goal: ____________________________________________
Targets:
a. What I want to know: _________________________
b. What I want to be able to do: ___________________
c. What I want to understand: _____________________
d. What I want to produce or understand: _____________
Start writing your own learning goals/targets on your notebook based on the
stated objectives.

V. COMMON COMPETENCIES
A. KNOW
Lesson 1. Occupational Health and Safety (OHS)
After reading this section you will be able to do the
following:
 Define occupational health and safety.
 Value the importance of health and safety at work.
Occupational safety and health (OSH) is a cross-
disciplinary area concerned with protecting the safety, health and welfare of people
engaged in work or employment. The goals of occupational safety and health
programs include fostering a safe and healthy work environment. OSH may also
protect co-workers, family members, employers, customers, and many others who
might be affected by the workplace environment.
Occupational safety and health are important for moral, legal, and financial
reasons. Moral obligations involve the protection of employee's lives and health.
Legal reasons for OSH practices relate to the preventive, punitive, and
compensatory effects of laws that protect worker's safety and health. OSH can also
reduce employee injury and illness related costs, including medical care, sick leave
and disability benefit costs. OSH may involve interactions among many subject
areas, including occupational medicine, occupational hygiene, public health, safety
engineering, industrial engineering, chemistry, health physics, ergonomics, and
occupational health psychology.

WORKSHOP SAFETY RULES
In any activity involving skills, it is a standard procedure to always use the
right tool or equipment properly in a particular task. In spite of this reminder or
caution, some students abuse the use of some tools and still commit errors that may
cause accidents. Below are safety rules to be observed in the workplace.
1. Always listen carefully to the teacher and follow instructions.
2. Do not run in the workshop, you could ‘bump’ into another student and cause an
accident.
3. Know where the emergency stop buttons/power switches are positioned in the
workshop. If you see an accident at the other side of the workshop you can use the
emergency stop button/power switches to turn off all electrical power to machines.
4. Always wear an apron as it will protect your clothes and hold loose clothing.
5. Wear good strong shoes.
6. When attempting practical work all stools should be put away.
7. Bags should not be brought into a workshop as people can trip over them.
8. When learning how to use a tool/machine, listen very carefully to all the
instructions given by the teacher. Ask questions, especially if you do not fully
understand the given instruction.
9. Do not use a tool/machine if you have not been shown how to operate it safely by
the teacher.
10. Always be patient, never rush in the workshop.
11. Keep hands away from moving/rotating machinery.
12. Use hand tools carefully, keeping both hands behind the cutting edge.
13. Report any damage to tools, machines & equipment as this could cause an
accident.
Suggested Activities:
For additional localized information regarding Occupational Health and Safety
please download the NATIONAL PROFILE ON OCCUPATIONAL SAFETY AND
HEALTH (PHILIPPINES) from http://www.oshc.dole.gov.ph or by using this shortcut
link: http://cloud.eacomm.com/oshc2010/UserFiles/oshc2010/file/National-OSH-
Profile.pdf.
The teacher may require the students to visit the following interactive sites.

Safety Check
Safety Check is an online Occupational Health and Safety (OHS) test
designed for workers. Use this test to learn more about topics such as OHS
laws; manual handling; hazardous substances; noise; mechanical equipment;
and electricity.
Link:
http://203.147.178.216/safeworksa/EducationAndTraining/ActivitiesAndTests/
SafetyCheck/default.asp
Virtual Office
Working in the office environment may not be as safe as you think! A
test of safety knowledge designed for students and young workers, or workers
who may need reminding to be alert for hazards in the workplace.
Link:
http://www.safework.sa.gov.au/contentPages/EducationAndTraining/Activities
AndTests/VirtualOffice/vofficeframe.htm
10 Commandments of Workplace Safety
http://www.youtube.com/watch?v=08yxsNnzwnY&feature=related
Question:
What is occupational health and safety? Give its importance to a healthy working
environment.
Sample Scoring Criteria
Beginning
(1)
Developing
(2)
Approaching
Proficiency
(3)
Proficient
(5)
Organization Unclear flow of
ideas.
Some signs of
and/or abrupt
change of
ideas.
Some ideas
and sequence
may be
improved.
Sequence and
transition of
ideas was
effective.

Details Inappropriate
/off-topic
Too general. Contained
some
appropriate
details or
examples.
Convincingly
interpreted.
Sample Rating Scale:
Points earned Equivalent Percentage
10 100
9 97
8 93
7 90
6 86
5 83
4 79
3 76
2 72
1 69
0 65
Lesson 2. Introduction to Electricity
After reading this section you will be able to do the following:
 Define electricity and identify the origin of the term.
 Discuss how electricity can be observed in the world.
What is Electricity?
Electricity is a naturally occurring force that exists all around us. Humans
have been aware of this force for many centuries. Ancient man believed that
electricity was some form of magic because they did not understand it. Greek
philosophers noticed that when a piece of amber was rubbed with cloth, it would
attract pieces of straw. They recorded the first references to electrical effects, such
as static electricity and lightning, over 2,500 years ago.

It was not until 1600 that a man named Dr. William Gilbert coined the term
“electrica,” a Latin word which describes the static charge that develops when certain
materials are rubbed against amber. This is probably the source of the word
“electricity." Electricity and magnetism are natural forces that are very closely related
to one another.
Watch this 5 minute video about electricity for additional information and
knowledge.
http://www.youtube.com/watch?v=WbNjrKtR0BY&feature=related
Review
1. Electricity is a naturally occurring force that exists all around us.
2. Electricity comes from “electrica,” a Latin word which describes the static
charge that develops when certain materials are rubbed against amber.
3. Electricity gives a wide variety of well-known effects, such as lightning & static
electricity.

Lesson 3. Basic Structure of Matter
 Give a basic definition of matter.
 Describe a molecule.
 Differentiate an element and a compound.
All matter such as solids, liquids, and gases, is composed of atoms.
Therefore, the atom is considered to be the basic building block of matter. Moreover,
atoms are almost always grouped together with other atoms to form what is called a
molecule. Only a few gases such as helium are composed of individual atoms as the
structural unit.
Atoms are extremely small and cannot be seen by our naked eyes.
Any material that is composed of only one type of atom is called a chemical
element, a basic element, or just an element. Any material that is composed of more
than one type of atom is called a compound.
Water is a compound made from the elements hydrogen and oxygen.
Activity 1. Fill-in the Missing Word.
Directions: Supply the necessary word or group of words that will make the sentence
complete.
1. Matter is composed of _________.
2. A group of atoms is called _________.
3. A material which composed of only one kind of atom is called _______.
4. _____________ is a material composed of more than one kind of atom.

Activity 2. Water Molecule
Directions: On an Oslo Paper draw the water molecule.
Review
1. Matter is composed of atoms.
2. A molecule is a group of atoms grouped together
3. An element is a material composed of only one kind of atom while a
compound is a material composed of more than one kind of atom.
Lesson 3. Basic Structure of an Atom
 Describe the basic structure of an atom.
 Explain what holds an atom together.
What is an atom composed of?
An atom is the smallest particle of any element that still retains the
characteristics of that element. However, atoms consist of even smaller particles.
Atoms consist of a nucleus that is surrounded by one or more negatively charged
particles called electrons. The nucleus is made up of positively charged particles
called protons and neutrons which are neutral. An atom is held together by forces of
attraction between the electrons and the protons. The neutrons help to hold the
protons together.
Hydrogen Atom
Niels Bohr was a Danish scientist who introduced the model of an atom in
1913. Bohr's model consists of a central nucleus surrounded by tiny particles
called electrons that are orbiting the nucleus in a cloud. In our pictures and

exercises, the electron appears to orbit in the same path around the nucleus much
like the planets orbit the Sun. The electrons, however do not really orbit in the same
path. The electrons actually change their orbit with each revolution.
Review
1. Atoms are composed of protons, neutrons, and electrons.
2. The forces of attraction between the electrons and the protons hold an atom
together.
Activity: The Hydrogen Atom
Directions: On an Oslo Paper draw the water molecule.
Lesson 4. Electric Charge
 Explain the differences between electrons and protons.
 Predict what happens when protons and electrons interact with other protons
or electrons.
Electrons are the smallest and lightest of the particles in
an atom. Electrons are in constant motion as they circle
around the nucleus of that atom. Electrons are said to have
a negative charge, which means that they seem to be
surrounded by an electrostatic field.

Protons are much larger and heavier than electrons.
Protons have a positive electrical charge. This positively
charged electrostatic field is exactly the same strength as
the electrostatic field in an electron, but it is opposite in
polarity. Notice that the negative electron (pictured at the
top left) and the positive proton (pictured at the right)
have the same number of force field lines in each of the
diagrams.
Like charges repel, unlike charges attract
Two electrons will tend to repel each other because both have negative
electrical charge. Two protons will also tend to repel each other because they both
have positive charge. On the other hand, electrons and protons will be attracted to
each other because they have unlike charges.
Repel
Repel
Attract
Another important fact about the electrical charges of protons and electrons
is that the farther away they are from each other, the less force their electric fields
have on each other. Similarly, the closer they are to each other, the more force they
will experience from each other due to this invisible force field called an electric field.
Activity: Repel or Attract
Direction: Based on your observation, write whether the following magnet instances
“repel” or “attract” each other.
INSTANCES
________1.
________2.
________3.
________4.

Review
1. Electrons have a negative electrostatic charge and protons have a positive
electrostatic charge.
2. A good way to remember what charge protons have is to remember
both proton and positive charge start with “P.”
3. Like charges repel, unlike charges attract, similar with magnets.
Lesson 5. The Valence Shell
 Define valence shell.
 Explain what free electrons are and why they are important.
What is the valence shell?
Notice that in the copper atom pictured below that the outside shell has only
one electron. This represents that the copper atom has one electron that is near the
outer portion of the atom. The outer shell of any atom is called the valence shell.
When the valence electron in any atom gains sufficient energy from some outside
force, it can break away from the parent atom and become what is called a free
electron.
Pictured here is an atom of copper, which is much more complex than either
an atom of hydrogen or helium.
Atoms with few electrons in their valence shell tend to have more free
electrons since these valence electrons are more loosely bound to the nucleus. In
some materials like copper, the electrons are so loosely held by the atom and so
close to the neighboring atoms that it is difficult to determine which electron belong
to which atom. Under these conditions, the valence or free electrons tend to drift
randomly from one atom to its neighboring atoms. Under normal conditions the
movement of the electrons is truly random, meaning they are moving in all directions
by the same amount. However, if some outside force acts upon the material, this
flow of electrons can be directed through materials and this flow is called electrical

current. Materials that have free electrons and allow electrical current to flow easily
are called conductors. The top three best conductors of electricity are Silver,
Copper and Gold. Many materials do not have any free electrons. Because of this
fact, they do not tend to share their electrons very easily and do not make good
conductors of electrical currents. These materials are called insulators, examples
are rubber, plastic and glass.

Crossword Puzzle
Direction: Complete the crossword by filling in a word that fits each clue.
Clues
Review
1. The valence shell is the outer shell of the atom.
2. Some materials have a free electron in their valence shell and this electron
can easily move from atom to atom.
3. The free electrons are responsible for electrical current.
4. Conductors are materials that allow the electrical current to flow easily.
5. Insulators are materials that do not allow the electrical current to flow easily.
Lesson 6. Electrical Current
 Define amperes.
 Identify the instrument that is used to measure amperage.
Electricity refers to the energy produced (usually to perform work) when
electrons are caused to flow directionally from atom to atom. This movement of
electrons between atoms is called electrical current.

Electricity can be very dangerous. It is important to know
how it behave in order to work with it safely. The flow of
electrons is measured in units called amperes.
An ammeter is an instrument used to indicate how many amps of current are
flowing in an electrical circuit.
Open Circuit
Closed Circuit

Review
1. Amperage is a term used to describe the number of electrons moving past a
fixed point in a conductor in one second.
2. Current is measured in units called amperes or amps
3. An Ammeter is used to measure amperage.
Lesson 7. Voltage
 Define electromotive force (EMF) and explain how it is measured.
 Explain why EMF is important to the flow of electrical current.
 List several examples of sources of electromotive force.
The force that causes the electrons to move in an electrical circuit is called
electromotive force (EMF). This force is called electromotive force, or EMF.
Sometimes it is convenient to think of EMF as electrical pressure. In other words, it is
the force that makes electrons move in a certain direction within a conductor.
But how do we create this “electrical pressure” to generate electron flow?
There are many sources of EMF. Some of the more common ones are batteries,
generators, and photovoltaic cells, just to name a few.
Batteries are constructed so there are too many electrons in one material and
not enough in another material. The electrons balance the electrostatic charge by
moving from the material with the excess electrons to the material with the shortage
of electrons. If these two unbalanced materials within the battery are connected
together with a conductor, electrical current will flow as the electron moves from the
negatively charged area to the positively charged area. When you use a battery, you
are allowing electrons to flow from one end of the battery through a conductor and
something like a light bulb to the other end of the battery. The battery will work until
there is a balance of electrons at both ends of the battery.
Caution: you should never connect a conductor to the
two ends of a battery without making the electrons pass
through something like a light bulb which slows the flow of
currents. If the electrons are allowed to flow too fast the
conductor will become very hot which may cause damage to
the battery.

To understand how voltage and amperage are related, it is sometimes useful
to make an analogy with water. Look at the picture here of water flowing in a garden
hose. Think of electricity flowing in a wire in the same way as the water flowing
through the hose. The voltage causing the electrical current to flow in the wire can be
considered the water pressure at the faucet, which causes the water to flow. If we
were to increase the pressure at the hydrant, more water would flow in the hose.
Similarly, if we increase electrical pressure or voltage, more electrons would flow in
the wire.
Without EMF, there will be no current. Also, we could say that the free
electrons of the atoms move in random directions unless they are pushed or pulled
in one direction by an outside force, which we call electromotive force, or EMF.
Review
1. Electromotive force causes the electrons to move in a particular direction.
2. EMF is measured in units called volts.
3. Some sources of EMF are batteries, generators and photovoltaic cell.
Lesson 8 Resistance
 Define resistance.
 Identify the unit of measurement of resistance.
 Discuss the similarities between resistance in a wire and the resistance in a
water hose.

Resistance is a term that describes the forces that oppose the flow of electron
current in a conductor. This is measured in units called ohms. All materials naturally
contain some resistance to the flow of electron current.
If we use our water analogy to help picture resistance, think of a hose that is
partially plugged with sand. The sand will slow the flow of water in the hose. We can
say that the plugged hose has more resistance to water flow than does an
unplugged hose. The same is true with electricity. Materials with low resistance let
electricity flow easily. Materials with higher resistance require more voltage (EMF) to
make the electricity flow.
Is resistance good or bad?
Resistance can be both good and bad. If we are trying to transmit electricity
from one place to another through a conductor, resistance is undesirable in the
conductor. Resistance causes some electrical energy to get lost along the way.
However, it is resistance that allows us to use electricity for heat and light. The heat
that is generated from electric heaters or the light that we get from light bulbs is due
to resistance. In a light bulb, the electricity flowing through the filament, or the tiny
wires inside the bulb, causes them to glow white hot.
An important point to mention here is that the resistance is higher in smaller
wires. Therefore, if the voltage or EMF is high, too much current will flow through
small wires which will make them hot. In some cases, they could be hot enough to
cause a fire or even explode. Therefore, it is sometimes useful to add components
called resistors into an electrical circuit to restrict the flow of electricity and protect
the components in the circuit.

Review
1. Resistance is the opposition to electrical current.
2. Resistance is measured in units called ohms.
3. Resistance is sometimes desirable and sometimes undesirable.
Fill in the blanks. Write the word or group of words that will make the sentence true
and complete.
1. A naturally occurring force that exists all around us is called _________.
2. Greek philosophers noticed that when a piece of amber was rubbed with
cloth, it would __________ pieces of straw.
3. Latin word which describes the static charge that develops when certain
materials are rubbed against amber is called ___________.
4. The natural forces that are very closely related to one another is electricity
and ________.
5. Anything that has mass, weight and occupies space is called______.
6. A group of atoms bunched together is called ________.
7. A material composed of only one kind of atom is called _______.
8. A material composed of more than one kind of atom is called ________.
9. Composed of protons, neutrons, and electrons and is called ____.
10.The forces of ________ between the electrons and the protons hold an atom
together.
11.Protons have a ________ electrostatic charge.
12.Like charges repel, unlike charges _________
13.The outer shell of the atom is called________.
14.The electron that can easily move from atom to atom is called_______.
15.The free electrons are responsible for _________.
16.A term used to describe the number of electrons moving past a fixed point in a
conductor in one second is called________.
17.The actual flow of electrons is called _______.
18.This causes the electrons to flow and is called ______.
19.The opposition to electrical current is called _________.
20.Resistance is measured in units called _________.

B. PROCESS
Lesson 1. OHM’S Law – The relationship of Voltage, Current, and Resistance
After reading this section you will be able to:
1. Explain the relationship of voltage, current and resistance.
2. Identify the different units of measurement and their corresponding symbols.
3. Compute for voltage, current and resistance.
The continuous movement of free electrons through the conductors of a circuit
is called a current, and it is often referred to in terms of "flow," just like the flow of a
liquid through a hollow pipe.
The force motivating electrons to "flow" in a circuit is called voltage.
Free electrons tend to move through conductors with some degree of friction,
or opposition to motion. This opposition to motion is properly called resistance.
The amount of current in a circuit depends on the amount of voltage available
to motivate the electrons, and also the amount of resistance in the circuit to oppose
electron flow. Just like voltage, resistance is a quantity relative between two points.
For this reason, the quantities of voltage and resistance are often stated as being
"between" or "across" two points in a circuit.
Here are the standard units of measurement for electrical current, voltage,
and resistance:
The "symbol" given for each quantity is the standard alphabetical letter used
to represent that quantity in an algebraic equation. The "unit abbreviation" for each

quantity represents the alphabetical symbol used as a shorthand notation for its
particular unit of measurement. And, yes, that strange-looking "horseshoe" symbol is
the capital Greek letter Ω. Each unit of measurement is named after a famous
expert in electricity: The amp after the Frenchman Andre M. Ampere, the volt after
the Italian Alessandro Volta, and the ohm after the German Georg Simon Ohm.
The mathematical symbol for each quantity is meaningful. "R" stands for
resistance; “V" is for voltage while "I" is thought to have been meant to represent
"Intensity" (of electron flow), and the other symbol for voltage, "E," stands for
"Electromotive force."
In this algebraic expression, voltage (E) is equal to current (I) multiplied by
resistance (R). Using algebra techniques, we can manipulate this equation into two
variations, solving for I and for R, respectively:
Let's see how these equations might work to help us analyze simple circuits:
In the above circuit, there is only one source of voltage (the battery, on the
left) and only one source of resistance to current (the lamp, on the right). This makes
it very easy to apply Ohm's Law. If we know the values of any two of the three
quantities (voltage, current, and resistance) in this circuit, we can use Ohm's Law to
determine the third.

In this first example, we will calculate the amount of current (I)
in a circuit, given values of voltage (E) and resistance (R):
What is the amount of current (I) in this circuit?
In this second example, we will calculate the amount of resistance (R) in a
circuit, given values of voltage (E) and current (I):
What is the amount of resistance (R) offered by the lamp?

In the last example, we will calculate the amount of voltage supplied by a
battery, given values of current (I) and resistance (R):
What is the amount of voltage provided by the battery?
Ohm's Law is a very simple and useful tool for analyzing electric circuits. It is
used so often in the study of electricity and electronics that it needs to be committed
to memory by students. For those who are not yet comfortable with algebra, there's a
trick to remembering how to solve for any one quantity, given the other two. First,
arrange the letters E, I, and R in a triangle like this:
If you know E and I, and wish to determine R, just eliminate R from the picture
and see what's left:
If you know E and R, and wish to determine I, eliminate I and see what's left:

Lastly, if you know I and R, and wish to determine E, eliminate E and see
what's left:
Eventually, you'll have to be familiar with algebra to seriously study electricity
and electronics, but this tip can make your first calculations a little easier to
remember. If you are comfortable with algebra, all you need to do is commit E=IR to
memory and derive the other two formulae from that when you need them!
REVIEW:
 Voltage is measured in volts, symbolized by the letters "E" or "V".
 Current is measured in amps, symbolized by the letter "I".
 Resistance measured in ohms, symbolized by the letter "R".
 Ohm's Law: E = IR ; I = E/R ; R = E/I
Ohm’s Law
Directions: Using the Ohm’s Law, compute for the missing value:
1.
I=2A
E=36V R=?
ACTIVITY

2.
3.
I=2A
E= R=6Ω
I=?
E=25V R=5Ω

Lesson 2. Complete Circuit
 Explain how a circuit is formed.
 Identify the sources of electricity.
The electric circuit can be defined as a complete path where electricity flows
from a source to the load and back again to the source.
Parts of Electric Circuit:
 Source – The Source is where the electricity comes from. It is sometimes
called as “source of emf”, refers to a generator, a battery of cell or a
transmission power line. It is here where the current or electricity starts to flow. The
function of the source is to establish difference from a high (+) to low (-) potential
point. The potential difference makes the current to flow.
Batteries

Power Plant
 Path – The Path is all the parts of the circuit where the current
or electricity flows. It is the pathway of flowing electricity. The Path is made up of
conducting materials or “conductor”. These are materials that conduct electricity and
allow electricity to pass through.
Electrical Wires

Printed Circuit Board (PCB)
 Load – Load are devices that consumes electricity on its
operation. Examples are light bulbs, television set, electric fan, radios and many
others. They are also called current consuming devices.
Light Bulb Television

 Switch – The means of control allows us to control the entire circuit operation.
It enables us to regulate electricity. Means of control has the capability to connect or
disconnect the flow of electricity from the source to the load. It usually comes in
different forms, maybe a slide switch, push button switch, circuits breakers and
others. The means of control functions in two ways; on or off.
Switches
When we connect various components together with wires, we create an
electric circuit. The electrons must have a voltage source to create their movement
and, of course, they need a path in which to travel. This path must be complete from
the EMF source, through the other components and then back to the EMF source.
The voltage for any electric circuit can come from many different sources.
Some common examples are batteries, power plants, fuel cells.
Power Plant
Flash
Light
Battery
Car Battery Fuel Cell

When we plug an appliance into a wall outlet, voltage and current are
available to us. That voltage is actually created in a power plant somewhere else and
then delivered to your house by the power wires that are on poles or buried
underground.
As a matter of fact, since no current can flow unless there is a voltage source,
we also refer to these sources as current sources.
In addition to the voltage source, we need to have wires and other
components to build an electric circuit. Remember that copper wires are conductors
since they can easily conduct the flow of electrons.
We may also use resistors or other forms of loads to form a
complete circuit. If we do not include resistors in our circuit,
there may be too much current flowing to and from our voltage
source and we could damage the voltage source.

Complete Circuit
Directions: Draw a complete circuit.
Sample illustration.
Review
1. Source, Path, Load and Switch connected together form a circuit.
2. Power plants, photovoltaic cells and batteries are some examples of voltage
source
Lesson 3: Types of Circuits
1. Identify the different types of circuits.
There are three types of electric circuits – series, parallel and combination.
Series Circuit
We've already come across series circuits. In this type of circuit, the
components are arranged end to end and so the electric current flows through the

first component, then through the next component and so on, until it reaches the
battery again.
Here's a series circuit to remind you.
If there's a gap in a series circuit or maybe one of the components has
broken, the current can't flow and so, the whole circuit turns off.
Parallel Circuit
In parallel circuits, the components don't have to be end to end because the
circuit can have branches.
In a parallel circuit, the current splits as it reaches a branch so the current
flows around both branches.
If there's a gap or broken component in one of the branches of a parallel
circuit, the component(s) in other branches will carry on working.

Series-Parallel Circuit
Also as combination circuit, many real life circuits are combination circuits.
See the sample figure used in Parallel Circuits. If we put a switch in each of the
branches of a parallel circuit, we can control each component separately.
This is how our homes are wired.
Review
There are three types of circuit, series circuit, parallel circuit and combination
circuit.
Lesson 4: Circuit Diagrams
 Explain what circuit diagrams are for.
 Identify what the symbols in the circuit diagrams stand for.
Circuit diagrams are a visual way of showing circuits. A circuit
diagram (also known as an electrical diagram, elementary diagram, or electronic
schematic diagram) is a simplified conventional graphical representation of
an electrical circuit. A pictorial circuit diagram uses simple images of components,
while a schematic diagram shows the components of the circuit as symbols; both
types show the connections between the devices. A Block diagram is a diagram of
a system, in which the principal parts or functions are represented by blocks
connected by lines that show the relationships of the blocks (Details of block diagram
will not be covered by this module).

Electricians and engineers draw circuit diagrams to help them design the
actual circuits. Here is an example circuit diagram
.
The important thing to note on this diagram is what everything stands for. You
see that there are straight lines that connect each of the symbols together. Those
lines represent a wire.
This is the Ammeter symbol.
This is the Voltmeter symbol.
This is the resistor symbol.
This is the switch symbol.
This is the battery symbol.
The important thing to remember about this symbol is that the long bar on top
represents the positive terminal on a battery while the short bar on the bottom
represents the negative terminal.

Below is the actual circuit made from the circuit diagram above. Pay close
attention to see how similar the diagram and how the real circuit looks.
---------
However, before you do, there are more symbols you will need to learn.
Other Electrical Symbols & Electronic Symbols
Symbol Component name Meaning/Function
Wire Symbols
Electrical Wire Conductor of electrical current

Connected Wires Connected crossing
Not Connected Wires Wires are not connected
Switch Symbols and Relay Symbols
SPST Toggle Switch Disconnects current when open
SPDT Toggle Switch
Selects between two
connections
Pushbutton Switch
(N.O)
Momentary switch - normally
open
Pushbutton Switch
(N.C)
Momentary switch - normally
closed
Ground Symbols
Earth Ground
Used for zero potential reference
and electrical shock protection.
Chassis Ground
Connected to the chassis of the
circuit
Digital / Common
Ground
Resistor Symbols
Resistor (IEEE)
Resistor reduces the current
flow.
Potentiometer (IEEE)
Adjustable resistor - has 3
terminals.
Variable Resistor /
Rheostat(IEEE)
Adjustable resistor - has 2
terminals.

Capacitor Symbols
Capacitor Capacitor is used to store
electric charge. It acts as short
circuit with AC and open circuit
with DC.Capacitor
Polarized Capacitor Electrolytic capacitor
Polarized Capacitor Electrolytic capacitor
Variable Capacitor Adjustable capacitance
Inductor / Coil Symbols
Inductor
Coil / solenoid that generates
magnetic field
Iron Core Inductor Includes iron
Variable Inductor
Power Supply Symbols
Voltage Source Generates constant voltage
AC Voltage Source AC voltage source
Generator
Electrical voltage is generated by
mechanical rotation of the
generator
Battery Cell Generates constant voltage

Battery Generates constant voltage
Meter Symbols
Voltmeter
Measures voltage. Has very high
resistance. Connected in
parallel.
Ammeter
Measures electric current. Has
near zero resistance. Connected
serially.
Ohmmeter Measures resistance
Wattmeter Measures electric power
Lamp / Light Bulb Symbols
Lamp / light bulb
Generates light when current
flows through
Lamp / light bulb
Lamp / light bulb
Diode / LED Symbols
Diode
Diode allows current flow in one
direction only (left to right).
Zener Diode
Allows current flow in one
direction, but also can flow in the
reverse direction when above
breakdown voltage
Light Emitting Diode
(LED)
LED emits light when current
flows through

Photodiode
Photodiode allows current flow
when exposed to light
Transistor Symbols
NPN Bipolar
Transistor
Allows current flow when high
potential at base (middle)
PNP Bipolar
Transistor
Allows current flow when low
potential at base (middle)
Miscellaneous Symbols
Motor Electric motor
Transformer
Changes AC voltage from high
to low or low to high.
Electric bell Rings when activated
Buzzer Produces buzzing sound
Fuse The fuse disconnects when
current is above the threshold.
Used to protect circuit from high
currents.Fuse
Loudspeaker
Converts electrical signal to
sound waves
Microphone
Converts sound waves to
electrical signal
Antenna Symbols
Antenna / aerial
Transmits & receives radio
waves

Antenna / aerial
Dipole Antenna Two wires simple antenna
Common Electronics Symbol
On an Oslo Paper, draw the following electronic components with their
corresponding symbols and give the meaning/function of each.
NAME SCHEMATIC
SYMBOL
MEANING/FUNCTION
Wire Symbols
Electrical Wire
Connected Wires
Not Connected
Wires
Switch
SPST Toggle Switch
SPDT Toggle Switch
Pushbutton Switch
(N.O)
Pushbutton Switch
(N.C.)
Ground Symbols
Earth Ground
Chassis Ground
Digital Common
Resistors
Fixed Resistor
Variable Resistor
Capacitors
Capacitor (Fixed)
Polarized Capacitor
Variable Capacitor
Inductor/Coils
Inductor
Iron Core Inductor
Variable Inductor

Power Supply
Voltage Source
AC Voltage Source
Battery Cell
Battery
Meter
Voltmeter
Ammeter
Ohmmeter
Lamp/Lights
Lamp/Light Bulb
Diodes
Diode
Zener Diode
Light Emitting Diode
Photodiode
Transistors
NPN
PNP
Miscellaneous
Fuse
Buzzer
Loudspeaker
Microphone
Lesson 5: Resistor
1. Define resistor.
2. Identify types of resistor.
Resistors ( R ), are the most fundamental and commonly used of all the
electronic components. There are many different types of resistors available, from
very small surface mount chip resistors up to large wirewound power resistors. The
principal job of a resistor within an electrical or electronic circuit is to "resist"
or to impede the flow of electrons.

A Typical Fixed Type Resistor
Resistors are "Passive Devices", that is, they contain no source of power or
amplification but only attenuate or reduce the voltage signal passing through them.
This attenuation results in electrical energy being lost in the form of heat as the
resistor resists the flow of electrons through it.
Most resistors produce a voltage drop across themselves when electrical
current flows through them because of Ohm's Law and different values of resistance
produce different values of current or voltage. Resistance is the opposition to the
flow of current. This can be very useful in electronic circuits by controlling or
reducing either the current flow or voltage produced across them.
In all Electrical and Electronic circuit diagrams and schematics, the most
commonly used symbol for a fixed value resistor is that of a "zig-zag" type line with
the value of its resistance given in Ohms, Ω. Resistors have fixed resistance values
from less than one ohm, ( <1Ω ) to well over tens of millions of ohms, ( >10MΩ ) in
value. Fixed resistors have only one single value of resistance, for
example 100Ω'sbut variable resistors (potentiometers) can provide an infinite
number of resistance values between zero and their maximum value.
Standard Fixed Type Resistor Symbols
The symbol used in schematic and electrical drawings for a Resistor can
either be a "zig-zag" type line or a rectangular box.
All modern fixed value resistors can be classified into four broad groups;
Carbon Composition Resistor - Made of carbon dust or graphite paste, low
wattage values
Film or Cermet Resistor - Made from conductive metal oxide paste, very
low wattage values
Wire-wound Resistor - Metallic bodies for heatsink mounting, very high
wattage ratings
Composition Type Resistors
Carbon Resistors are the most common type of Composition Resistors.
Carbon resistors are a cheap general purpose resistor used in electrical and
electronic circuits. Their resistive element is manufactured from a mixture of finely
ground carbon dust or graphite (similar to pencil lead) and a non-conducting ceramic
(clay) powder to bind it all together.

Carbon Resistor
The Carbon Composite Resistor is a low to medium type power resistor.
Power rating is from 0.25 or 1/4 of a Watt up to 5 Watts.
Carbon composite resistors are very cheap to make and are therefore
commonly used in electrical circuits. However, due to their manufacturing process
carbon type resistors have very large tolerances so for more precision and high
value resistances, film type resistors are used instead.
Film Type Resistors
The generic term "Film Resistor" consist of Metal Film, Carbon
Film and Metal Oxide Film resistor types, which are generally made by depositing
pure metals, such as nickel, or an oxide film, such as tin-oxide, onto an insulating
ceramic rod or substrate.
Film Resistor
Film type resistors also achieve a much higher maximum ohmic value
compared to other types and values in excess of 10MΩ (10 Million Ω´s) are
available.

Metal Film Resistors have much better temperature stability than their
carbon equivalents, lower noise and are generally better for high frequency or radio
frequency applications. Metal Oxide Resistors have better high surge current
capability with a much higher temperature rating than the equivalent metal film
resistors.
Metal Film Resistors are prefixed with a "MFR" notation (eg MFR100kΩ) and
a CF for Carbon Film types. Metal film resistors power rating is 0.05 (1/20th) of a
Watt up to 1/2 Watt. Generally speaking Film resistors are precision low power
components.
Wirewound Type Resistors
Another type of resistor, called a Wirewound Resistor, is made by winding a
thin metal alloy wire (Nichrome) or similar wire onto an insulating ceramic former in
the form of a spiral helix similar to the film resistor above. These types of resistors
are generally only available in very low ohmic high precision values
(from 0.01 to 100kΩ) due to the gauge of the wire and number of turns possible on
the former making them ideal for use in measuring circuits and Whetstone bridge
type applications.
They are also able to handle much higher electrical currents than other
resistors of the same ohmic value with power ratings in excess of 300 Watts. These
high power resistors are moulded or pressed into an aluminum heat sink body with
fins attached to increase their overall surface area to promote heat loss and cooling.
These types of resistors are called "Chassis Mounted Resistors". They are designed
to be physically mounted onto heatsinks or metal plates to further dissipate the
generated heat increasing their current carrying capabilities even further.

Wirewound Resistor
Wirewound resistor types are prefixed with a "WH" or "W" notation
(eg WH10Ω) and are available in the WH aluminium cladded package with power
ratings from 1W to 300W or more.
Variable Resistor
Variable resistors or potentiometers are used in many areas of electronics.
They are used for volume and gain controls as well as a variety of other applications.
Preset variable resistors or potentiometers are also used in circuits that need a small
adjustment to be made to set the circuit up after manufacture.

For convenience variable resistors are made by having a fixed resistor with a
variable tapping point. As a result of this arrangement these devices are often called
potentiometers or "pots" for short. Here the potentiometer consisted of a length of
resistance wire with a tapping point that could be moved along the wire - the same
configuration as that used in these variable resistors.
As shown in the diagram below, a variable resistor consists of a track which
provides the resistance path. Two terminals of the device are connected to both the
ends of the track. The third terminal is connected to a wiper that decides the motion
of the track. The motion of the wiper through the track helps in increasing and
decreasing the resistance.
The track is usually made of a mixture of ceramic and metal or can be made
of carbon as well. As a resistive material is needed, carbon film type variable
resistors are mostly used. They find applications in radio receiver circuits, audio
amplifier circuits and TV receivers.
A track made in a straight path is called a slider. As the position of a slider
cannot be seen or confirmed according to the adjustment of resistance, a stopping
mechanism is usually included to prevent the hazards caused due to over rotation.
There are two major types:
1. Rotary: The most common form of variable resistor or potentiometer is a
rotary version. This version of potentiometer uses a rotary motion to move the
slider around a track that compromises most of a circle, with contacts at either
end of the track in the area where part of the circle is missing. This form is
widely used with knobs on a spindle for the actual control, and they are found
in many applications from providing adjustments on test equipment through to
being used for volume controls on domestic radios.

2. Slider: Slider controls are those variable resistors that slide in a linear
fashion, i.e. in a straight line. These controls take up more front panel space,
but are much easier to use under some circumstances. For example they are
widely used for audio mixers and lighting desks. The advantage of sliders is
that it is easier to control them quite precisely and compare the relative
positions of a number of sliders. It is also possible to control a number of
sliders together.
Review
1. A Resistor is an electronic component used to resist the flow of electrons.
2. There are many types of resistors, for fixed type; Carbon Composition, Film or
Cermet, and Wirewound. The variable types are rotary and slider.

Lesson 6: Other Electronic Components
1. Identify other electronic components and explain their basic function.
Capacitor
A device that consists essentially of two conducting surfaces separated by a
dielectric material like air, paper, mica, ceramic, glass, or Mylar. It makes it possible
to store electric energy. Electrons are detained within a capacitor. This, in effect, is
stored electricity. The component is designed intentionally to have a definite amount
of capacitance. This capacitance is a property that exists whenever insulating
material permits the storage of electricity. It is measured in Farad (F) micro Farad
(μF), nano Farad (nF), and picoFarad (pF).
Characteristics of Capacitor:
1. It can store electric charge even though the voltage source is already
disconnected.
2.It can discharge electrical voltages.
Fixed type capacitor
Electrolytic Tantalum Mica

Symbols of Capacitor
Diode
A diode is a two-terminal electronic component with asymmetric transfer
characteristic, with low (ideally zero) resistance to current flow in one direction, and
high (ideally infinite) resistance in the other. It is a semiconductor device.
The most common function of a diode is to allow an electric current to pass in
one direction (called the diode's forward direction), while blocking current in the
opposite direction (the reverse direction). Thus, the diode can be viewed as an
electronic version of a check valve. This unidirectional behavior is called rectification,
and is used to convert alternating current to direct current, these diodes are forms
of rectifiers.
Transistor
A semiconductor device used to amplify and switch electronic signals and
electrical power. It is composed of semiconductor material with at least three
terminals for connection to an external circuit.

Integrated Circuit (IC)
An integrated circuit, or IC, is small chip that can function as an amplifier,
oscillator, timer, microprocessor, or even computer memory. An IC is a small wafer,
usually made of silicon, that can hold anywhere from hundreds to millions of
transistors, resistors, and capacitors. These extremely small electronics can perform
calculations and store data.
Review
Capacitor is an electronic component used to charge and discharge electric
energy. Diode is an electronic component used to allow the current to pass in one
direction only. Transistor is used mainly for switching amplification purposes.
Integrated Circuits or ICs can function as an amplifier, oscillator, timer,
microprocessor or memory; and can hold hundreds to millions of transistors,
resistors and capacitors.

LESSON 7. BASIC HAND TOOLS & EQUIPMENT
After reading this section you will be able to:
1. Identify some basic tools and equipment and explain their uses.
2. Value the proper maintenance of hand tools and equipment.
Sic t
Assembling an electronic project and making it work is a good start in helping
one to learn troubleshooting methods as well as becoming familiar with your tools,
test equipments, electronic schematics and component color codes.
It's hard to produce a good project/product or service unless proper electronic
tools and knowledge of using them and observing safety precautions are adequate.
Some of the basic tools & equipment that should prove useful are listed below.
Electric Drill and Drill Bits
Electric drill and drill bits in the range of 1/8 inch to 1/2 inch will come in handy
when you need to drill holes on the printed circuit board (PCB) that has been etched.
Drilling of plastic or metal enclosure that houses the printed circuit board are
sometimes necessary.

Electric Drill
A suitable PCB Mini Hand Drill can be easily obtained from any electronic
shop.
Soldering Iron
In large and heavy metal work, welding is used in joining metals permanently.
In electronics work, soldering is used to join pigtails of components, transistor leads,
and IC pins among others. Soldering is the process of heating materials, and joints
to be soldered and applying solder on the heated joints to ensure permanent
connection.

Soldering Iron
A 30 Watt to 40 Watt soldering iron with tips of 1/8 inch to 1/2 inch can be
used for soldering of through hole components. Soldering of surface mount
components may require smaller tips depending on the sizes of the components.
Soldering iron normally will last a long time if it is taken care of properly by keeping
the tips clean and well tinned.
Basic Soldering Guide

What Is Soldering?
Soldering is a process in which two or more metal items are joined together
by melting and flowing a filler metal (solder) into the joint, the filler metal having a
lower melting point than the workpiece. Soldering differs from welding in that
soldering does not involve melting the work pieces. In soldering, the filler metal melts
at a higher temperature, but the workpiece metal does not melt.
Formerly nearly all solders contained lead, but environmental concerns have
increasingly dictated use of lead-free alloys for electronics and plumbing purposes.

Solder is a thin tube, usually rolled in spools, made of various metal alloys. Its
job is to hold the individual components together. The individual components and
their quantities can vary, but for computer electronics, you’re usually looking at a
60% tin and 40% lead. Lead-free solder is also available, though it has higher
melting temperatures and less “wettability,” meaning you may need a better
soldering iron to use it and removing it can be more tedious.
It is better to use lead free solder because it functions well
and is environmentally friendly.
A solder’s tube is filled with “flux,” a substance that gets rid of oxidation and
helps clean the surfaces involved in the fusing process. For electronic use, we want
rosin-core/rosin-flux solder. Acid-flux is used in plumbing and the acid can damage
the sensitive components on PCBs.

Wire Stripper
Wire stripper is used to strip off wire insulator from its conductor before it is
used to connect to another wire or soldered into the printed circuit board. Some wire
stripper or wire cutter has a measurement engraved on it to indicate the length that
can be stripped.
Long nose Pliers
A pair of 4-inch long nose pliers will come in handy when you need to hold
components that have short leads that need to be soldered onto the PCB but will be
too hot to handle with bare hands. It will also be useful to hold the component that
needs to be de-soldered from the board.

Side-Cutting Pliers
A pair of 4-inch side cutting pliers will come in handy when one needs to trim
off excess component leads on the printed circuit board. It can also be used to cut
wires into shorter length before being used.
Tweezers
Small tweezers are used to hold much smaller components especially when
doing soldering and de-soldering of surface mount components.

Allen Wrench set
Allen wrench set is sometimes used to unscrew or screw Allen type of
screws.
Philips Screwdrivers
Various sizes of Philips head screwdrivers will be handy as a lot of electronics
projects that use screws are Philips Head type.

Flat Head Screwdrivers
Flat head screwdrivers of various sizes are also necessary as many screws
commonly used are of this type.
Hammer
A small, light hammer will be useful when assembling projects that involve
casing.

Socket wrench sets
A socket wrench set includes nut drivers, hex drivers, and starters in assorted
sizes that will come in handy during the assembly work of electronics project.

Blade Cutter
A Blade Cutter will be useful when one need to cut PCB, wires or remove
some copper from the printed circuit board.
Equipment
Aside from hand tools, certain equipment are also needed for more accurate
and quality output. Three of the commonly used equipment are presented here for
you to be familiar with their uses and the proper way of maintaining them.
a. Oscilloscope. An oscilloscope (commonly abbreviated CRO, for
cathode ray oscilloscope, or simply scope) is a piece of electronic test
equipment that allows signal voltage to be viewed.

b. Signal generator. A device which produces simple waveforms.
Such devices contain an electronic oscillator, a circuit that is
capable of creating a repetitive waveform. These are typically used in
simple electronics repair and design where they are used to stimulate a
circuit under test
.
Oscilloscope and signal generator should be given regular
check-up for at least once a week by connecting them in the power
line. This will prevent their components from having moisture that might
cause trouble in their circuits.
c. Volt-OHM-Milliammeter (VOM). A handheld device that combines
three functions: as a voltmeter that measures both ac and dc voltages:
an ohmmeter that measures resistance: and milliammeter that
measures small amount of dc current. It is called Multitester (Multi-
tester) or Multimeter (Multi-tester). It can measure to a very high
degree of accuracy. They can be used to troubleshoot electrical
problems in a wide array of industrial and household devices such
as electronic equipment, motor controls, domestic appliances, power
supplies, and wiring systems. As safety precautions in the maintenance
of this instrument, the following should be observed:

General Rule for Analog:
 Always rest the function switch at 250Vac
if an off position is not available in the
instrument.
 For current and voltage measurement,
always set the function switch in the
correct setting which is a little higher than
the expected current or voltage present in
the circuit.
 Optimise the range for the best reading. If possible adjust it so that
the maximum deflection of the meter can be gained. In this way the
most accurate reading will be gained.
 When making measurements, Keep your fingers behind the finger
guards on the test probes.
 Place the instrument in a cool dry place, away from any magnetic
devices, and free from vibrations.

Hand Tools Classification
There are four different types of hand tools according to their uses:
 Cutting Tools:These are used to cut a physical object into pieces. For
example: side cutting pliers and blade cutters.
 Gripping Tools: These tools are used for gripping objects by using leverage.
For example: long nose pliers and twizzers.
 Striking Tools: The striking tools are the most widely used tools. Chiseling,
punching and riveting can be done properly using striking tools. Hand-held striking
tools have been used in a variety of disciplines as leverage devices providing a
striking force to complete endless variety of tasks. For example: hammers &
chisels
 Driving Tools: These are designed in such a way that insertion, tightening,
loosening, removing screws, bolts, nails or other pointed objects or hard-to-turn
items are done by applying torque. For example: screwdrivers, nut drivers and
wrenches.
 Struck or Hammered Tools: These tools are used for forcing a bolt, pin, or
rivet in or out of a hole. For example: punches, nail sets, chisels
.
Maintenance Tips of Electronic Tools
Good quality tools can last a lifetime if they are taken care of properly. Ensure
that the tools are used only for their intended purposes, keep them lubricated with a
light film of oil to inhibit rust, keep the tools clean and sharp, keep the soldering tips
clean and well tinned and ensure that proper use of the tools are always adhered to
by following the instructions in the proper use of tools.
Common Faults in Using Hand Tools
Pliers:
 Do not increase the handle length of the
pliers to more leverage. Use a larger pair of
pliers or bolt cutters if necessary.
 Do not substitute pliers for a wrench when
turning bolts and nuts. Pliers cannot grip
these items properly and might cause a slip and cause an accident.

 Never use pliers as a hammer on the handle. Such abuse is likely
to result in cracks or breaks.
 Cut hardened wire only with pliers designed for that purpose.
 Always cut the wire in right angle. Never rock from side to side or
bend wire back and forth against the cutting edges.
Screwdrivers:
 Never use screw drivers as a pry bar, chisel, and punch stirrer or
scraper.
 Never use screwdrivers with broken or worn-out handles.
Screwdrivers of these kinds should have tags to indicate that it is
defective.
 Never use pliers on a screwdriver for extra leverage. Only use
wrench or screwdrivers specially designed for the purpose.
Utility Knives/ Blades:
 Do not use dull blades because they require more force, thus, they
are more likely to slip. Replace the blades when they start to “tear”
instead of cut.
 Never leave a knife unattended with the blade exposed.
 Don’t bend or apply side loads to blades by using them to open
cans or loosen tight cover of containers. Blades are brittle and can
snap easily.

Inventory of Tools
1. Take hold of the tools found in your shop/house and acquaint yourself with
their parts. Try to identify the name and the use of each while being extra
careful not to damage the tools nor hurt yourself.
2. Categorize some available tools in your shop according to:
Cutting Tools
Gripping
Tools
Striking Tools Driving Tools
Additional Activities:
 The teacher may bring his/her class to an electronic shop and let the students
observe how the skilled electronic technician uses different kinds of tools.
 View a video about how skilled electronic technician uses different kind of
tools. (The teacher may show this video entitled Collin’s Lab:Electronic Tools
at http://www.youtube.com/watch?v=Kv7Y8nAOoFE ).
Review:
1. Some basic hand tools with the corresponding uses are: Electric drill is
used to drill holes on PCB; Soldering iron is used to join metals and solder electronic
components on PCB; Wire stripper is used to strip off wire insulators; Long nose
pliers are used to hold small components; Side cutting pliers are used to cut wires
and trim off excess component leads; and Screwdrivers are used to drive or remove
screw. Some measuring equipments with their uses are: Oscilloscope allows signal
voltage to be viewed; Signal generator produces simple waveforms; and Multitester
(VOM) can measure voltage, resistance and small amount of current. Tools can be
categorized to Cutting, Gripping, Striking and Driving.
2. Well maintained tools and equipment are important so that they are readily
available and function properly

IDENTIFICATION. Identify the following tools/equipment based on the cited uses.
1. Used to join metals and solder components.
2. Used to strip insulators.
3. Used to hold small components.
4. Used to drill holes on PCB.
5. Used to cut wires.
6. Used to drive screw.
7. Used to cut unnecessary copper on PCB.
8. Used to measure voltage, resistance and current.
9. Produces simple waveforms.
10. Used to view signal.
ESSAY. Write the importance of well maintained tools and equipment.
Beginning
(1)
Developing
(2)
Approaching
Proficiency
(3)
Proficient
(5)
Organization No idea or
unclear flow of
ideas.
Some signs of
and/or abrupt
change of
ideas.
Some ideas
and sequence
may be
improved.
Sequence and
transition of
ideas was
effective.
Details Inappropriate
/off-topic
Too general. Contained
some
appropriate
details or
examples.
Convincingly
interpreted.
Sample Rating Scale:
Points earned Equivalent Percentage
10 100
9 97

8 93
7 90
6 86
5 83
4 79
3 76
2 72
1 69
0 65
C. REFLECT AND UNDERSTAND
Lesson1/Activity1: Resistor Color Coding
We learned in the previous lesson that there are many different types
of Resistors available and that they can be used in electronic circuits to control the
flow of current or voltage in many different ways. But in order to do this, the actual
resistor needs to have some form of "resistive" or "resistance" value. Resistors are
available in a range of different resistance values from fractions of an Ohm ( Ω ) to
millions of Ohms.
Obviously, it would be impractical to have available resistors of every possible
value for example, 1Ω,2Ω, 3Ω, 4Ω etc, because literally hundreds of thousands, if not
millions of different resistors would need to exist to cover all the possible values.
Instead, resistors are manufactured in what are called "preferred values" with their
resistance value printed onto their body in colored ink.
4 Colored Bands

The resistance value, tolerance, and wattage rating are generally printed onto
the body of the resistor as numbers or letters when the resistors body is big enough
to read the print, such as large power resistors. But when the resistor is small such
as a 1/4W carbon or film type, these specifications must be shown in some other
manner as the print would be too small to read.
So to overcome this, small resistors use colored painted bands to indicate
both their value with the physical size of the resistor indicating its wattage rating.
These colored painted bands produce a system of identification generally known as
Resistors Color Code.
A resistors color code markings are always read one band at a time starting
from the left to the right, with the larger width tolerance band oriented to the right
side indicating its tolerance. By matching the color of the first band with its
associated number in the digit column of the color chart below the first digit is
identified and this represents the first digit of the resistance value. Again, by
matching the color of the second band with its associated number in the digit column
of the color chart we get the second digit of the resistance value and so on as
illustrated below:

The Standard Resistor Color Code Chart.

The Resistor Color Code Table (Four Bands).
Color Digit
(Leftmost
band for
first
significant
digit)
Digit
(Stands
for
second
significant
digit)
Multiplier
(Represents
the multiplier
or number of
zeros after the
two digits)
Tolerance
Black 0 0 1
Brown 1 1
10
(0)
± 1%
Red 2 2
100
(00)
± 2%
Orange 3 3
1,000
(000)
Yellow 4 4 10,000 (0000)
Green 5 5
100,000
(00000)
± 0.5%
Blue 6 6
1,000,000
(000000)
± 0.25%

Violet 7 7
10,000,000
(0000000)
± 0.1%
Grey 8 8
White 9 9
Gold
0.1
(Decimal point
is after the first
significant
digit)
± 5%
Silver
0.01
(Decimal point
is before the
first significant
digit)
± 10%
None ± 20%
Calculating Resistor Values
It is important to understand the Resistor Color Code system and
understand how to apply it in order to get the correct value of the resistor. The "left-
hand" or the most significant colored band is the band which is nearest to a
connecting lead with the color coded bands being read from left-to-right as follows;
Digit, Digit, Multiplier = Color, Color x 10 color
in Ohm's (Ω's)
For example, a resistor has the following colored markings;
Yellow Violet Red = 4 7 2 = 4 7 x 102
= 4700Ω or 4k7.
The fourth and fifth bands are used to determine the percentage tolerance of
the resistor. Resistor tolerance is a measure of the resistors variation from the
specified resistive value and is a consequence of the manufacturing process and is
expressed as a percentage of its "nominal" or preferred value.
Most of the four band resistors have tolerances of 5%, 10% and 20%. The
color code used to denote the tolerance rating of a resistor is given as;
Brown = 1%, Red = 2%, Gold = 5%, Silver = 10 %

If resistor has no fourth tolerance band then the default tolerance would
be at 20%.
Examples:
1. The value of a resistor is 10 Ohms with a tolerance of 5%. Let us find out
from the 4 Bands Resistor Color Chart what would be the color bands of the resistor.
black black
brown gold
1 0 - 5 %
Reading: 10 ohms
The colors that you have located in the table should match the digit and
multiplier in the first example. Continue checking with other examples.
2. The value of the resistor is 100 ohms with a tolerance of 10%.
black brown
brown silver
1 0 0 10 %
Reading: 100 ohms
3. In this example, the value of the resistor is 2000 0hms. Three
zeroes
Represent a thousand which can be substitute for abbreviation with
Letter K. Thus the value of the resistor will appear as 2 K ohms.
black red
red
2 0 00

Reading: 2,000 ohms or 2K
4. In example 4, the third color band is gold, multiply the first two
digits by 0.1. Therefore, the resistance would be 4.7 ohms.
violet gold
yellow
4 7 0.1
Reading: 4.7 ohms
5. In example 5, the third color is silver so the decimal multiplier is
.01.The decimal point is placed before the first digit. The reading will be .22
ohms.
red silver
red
2 2 .01
Reading: .22 ohms
It is sometimes easier to remember the resistor color code by using
mnemonics or phrases that have a separate word in the phrase to represent each
of the Ten + Two colors in the code. However, these sayings are often very crude
but never the less effective for remembering the resistor colors. Here are just a few
of the more "cleaner" versions but many more exist:
Black Brown Red Orange Yellow Green Blue Violet Gray
Bad Boys Ring Our Young Girls But Vicky Goes Without
Bad Boys Ring Our Young Girls But Vicky Gives Willingly-- Get Some Now
(This one is only slightly better because it includes the tolerance bands of
Gold, Silver, and None).

Additional Information:
Some resistors, particularly metal film types, are marked with a number or
letter code to indicate the value and tolerance instead of the color code.
3K3J
Value: 3,300 ohms + 5% or 3.3K, + 5%
The letter K represents both the multiplier and the location of the decimal point
in the number of the resistor.
Multipliers Value Represented
R 1
K 1000
M 1000000
The tolerance is given by the last letter.
Tolerance Value Represented
F 1 %
G 2 %
J 5 %
K 10 %
M 20 %
Assessment 1: Resistor Color Coding
Multiple Choice: Choose the letter of the best answer (Ask the students to show
their computation).
1. What is the value of a resistor with a Blue-Black-Orange-Gold Color Code?
A. 600 Ohms ± 5% B. 6K Ohms±5% C.60K Ohms±5% D. 600K Ohms ±5%
2. What is the value of a resistor with a Red-Violet-Brown-Silver Color Code?
A. 27 Ohms±10% B. 270 Ohms±10% C. 2.7K Ohms±10% D. 27K Ohms±10%

3. What is the value of a resistor with a Yellow-Yellow-Yellow-Gold Color Code?
A. 440 Ohms±5% B. 4.4K Ohms±5% C. 44K Ohms±5% D. 440K Ohms±5%
4. What is the value of a resistor with a Green-Blue-Black-Silver Color Code?
A. 56 Ohms±10% B. 560 Ohms±10% C. 5.6K Ohms±10% D. 56K Ohms±10%
5. What is the color of representing 20% tolerance?
A. Black B. Silver C. Gold D. No Color
Additional Activity/Assessment:
Resistor Tabulation
Materials:
10 pieces - Carbon resistors, 1 watt, assorted values
1 pc - Resistor Tabulation form
Procedures:
1. Arrange the resistors on a piece of styrofor.
2. Identify the colors of the resistors one by one and record them in the resistor tabulation
form.
3. Compute for the resistance value of each resistor by following the color coding scheme.
4. Write the value of the resistance in the tabulation form.

Sample Resistor Tabulation Form
(Photocopy this or simply copy on your notebook)
# 1st
COLOR
BAND
2nd
COLOR
BAND
3RD
COLOR
BAND
TOLERANCE COMPUTED
VALUE
1
2
3
4
5
6
7
8
9
10
Performance Test
Learner’s Name: Date:
Competency: Test Attempt
1st
2nd
3rd
Directions:
CALL THE TEACHER
and ask him
/ her to assess your
performance in the following
critical task using the performance
OVERALL EVALUATION
LEVEL
ACHIEVED
PERFORMANCE LEVEL

criteria below.
You will be rated based on the
overall evaluation on the right side.
4 - Can perform this skill without
supervision and with initiative and
adaptability to problem situations.
3 - Can perform this skill satisfactorily
without assistance or supervision.
2 - Can perform this skill satisfactorily but
requires some assistance and/or
supervision.
1 - Can perform parts of this skill
satisfactorily, but requires considerable
assistance and/or supervision.
The teacher will affix his/her initial on the level
achieved.
PERFORMANCE STANDARDS
For acceptable achievement, all items should receive
a "Yes" response.
Yes No N/A
1. Can recite the colors of the color coding chart in order without
looking at the chart.
2. Can identify the first color of the carbon resistor.
3. Can interpret equivalent numerical value of each color in the
chart
4. Can calculate the color coded value of the resistor.
5. Can give the over-all value of the resistor after calculation.
Lesson 2/Activity 2: Proper Use of Soldering Iron
Many who’ve never used a soldering iron are afraid
of damaging the equipment, but more important is the
danger to yourself! Soldering irons get really hot. Be sure
to wear safety glasses, keep loose clothing and hair out of
the way, and be careful with your fingers. Better still, use
protective gloves. Solder can contain lead, so be sure to
wash your hands thoroughly after handling it. It is also really
important to work in a well-ventilated area because the
fumes from the rosin can cause damage to your lungs when
inhaled.

A. Cleaning and Tinning the Tip
In order to conduct heat properly, your soldering iron needs to be free of any
old solder. After being exposed to air, it oxidizes and thus insulates against heat. We
want heat to conduct so that we can apply everything quickly and efficiently. A dirty
tip means that you’ll have to hold the iron on longer and risk heat damage to the
component or PCB. Keep a wet sponge handy, and after the soldering iron is fully
heated, softly scrape it against the sponge to remove old solder. The tip should be
clean and shiny, or at least very close to it.
Tinning protects the tip and allows heat to conduct better via the presence of
new solder. On the hot iron, carefully apply a small amount of fresh solder and coat
the tip. It should still be shiny if you’ve done it right. As soon as you tin the tip, start
soldering your components together. After a few joints, clean and re-tin again before
putting your iron away into storage. This will really help increase the longevity of your
tool.

Joining Parts on PCB
Hold the iron in your dominant hand and a long piece of solder in your other
hand. When soldering two components together, you want to touch the area where
they join with the soldering iron. Hold it there for about a second, then slide the
solder underneath the tip of the iron, sandwiching it to the PCB (refer to above
image, cursor points to solder). Hold it for another second or two, feeding in how
much solder you need. This amount will vary depending on the project, application,
and diameter of the solder, so check your instructions and study the pictures to get a
good idea of the end result.

Now, this is really important. Pull away the solder first, and continue holding
the iron for another second. This allows the solder to continue to melt and pool,
forming a good joint. Then, you can remove the iron. The total process shouldn’t take
more than 5 seconds, and usually you are aiming for 3-4.
Wait a few seconds and don’t disturb the solder. It cools very quickly, but
moving or blowing on the joint will cause it to deteriorate. A bad solder connection
will look really oxidized, overly dull, and grainy. It also sort of looks like a ball of
solder formed on the area. A good connection should be smooth and uniform and its
sides will be concave. It won’t look like a raised ball, it’ll look flat.
Soldering Wires
• Remove the insulator of the wire you want to connect together.

 Cross the twisted ends of the wires to be soldered.
• Starting at the cross section, twist the wires together around themselves.
• Twist the stands of wire to be soldered so that it becomes one and it will be
easy to solder.
 Solder the wires together
Remember
• Clean the tip of the soldering iron gun regularly.
• Tin the tip of soldering iron.
• Maintain the pointed tip of soldering iron and reshape it, if necessary.
• Apply right amount of solder on the preheated metallic surface and not directly
to the tip of the soldering iron.
• Let the melted solder flow freely around the joint surface.
• Solder the joint as quick as possible to avoid extreme heat on the
components.
• Reheat the cold soldered joint.
• Use a soldering stand to avoid the tip to get in contact with combustible
materials or your skin.
• Hold the excess terminal lead while cutting to prevent being hit by flying
• Cut excess terminal wires.

Additional Activity
Directions: Using an actual soldering iron and soldering gun compare the
features and characteristics of the two soldering tools.
Based on the results of the previous activity, which do you prefer to use? Why?
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
_____________________

87
Lesson 3/Activity3. Desoldering
When removing a connection or undoing a mistake, you can often resolder
over the original and add a touch of new solder. If you want to take the extra step
and do it right, you can remove the old solder completely and start with a fresh work
area. There are two tools you can use for this, a vacuum-based “solder sucker,” or a
solder wick.
A solder sucker is essentially a tiny hand-held syringe-like pump. It creates and uses
vacuum pressure to suck solder off of whatever it’s on. It’s a great tool to have and
works well.
Removing component components in PCB using a desoldering pump
1. Set the pump by pushing the spring- loaded plunger down until it
locks.
2. Apply both the pump nozzle and the tip of your soldering iron to
the joint.
3. Wait a second or two for the solder to melt.
4. Then press the button on the pump to release the plunger and
suck the molten solder into the tool.
5. Repeat if necessary to remove as much solder as possible.
6. The pump will need emptying occasionally by unscrewing the
nozzle.
After removing most of the solder from the joint(s), you may be
able to remove the wire or component lead straight away
allowing a few seconds for it to cool. If the joint does not come
apart easily, apply your soldering iron to melt the remaining
traces of solder at the same time as while pulling the joint apart,
taking care to avoid burning yourself.

88
Lesson 4ctivity 4/A. How To Use and Read a Multimeter
Using a multimeter is quite bit difficult for the first time especially the analog
type one unlike the digital which is more convenient to use for beginners.
Every multimeter has its own user manual when you purchase it. A
Multimeter is used to measure voltages AC or DC, currents and resistance,
continuity and electronics components.
PARTS OF A MULTIMETER
Sanwa YX-360TR/Sanwa-YX361TR
1.) Zero Position Adjuster 7.) Measuring Terminal +
2.) Indicatot Pointer 8.) Measurin Terminal - COM
3.) Indicator Scale 9.) Series Terminal Capacitor OUTPUT

89
4.) Continuity Indicating 10.) Panel
LED ( CONTINUITY ) 11.) Rear Case
5.) Range Selector Switch knob
6.) 0-ohms adjusting knob
/0- centering meter
(NULL meter) adjusting knob
EXPLANATION ABOUT THE SCALE
1.) Resistance (OHMS) scale
2.) DCV, A scale and ACV scale
(10V or more)
3.) 0-centerig (NULL) +/- DCV scale
4.) ACV 2.5 (AC 2.5V) exclusive scale
5.) Transistor DC amplification factor
(hFE) scale
6.) 1.5 baterry test (BATT 1.5V)
7.) OHMS range terminal to terminal current
(Li) scale)
8.) OHMS range terminal to terminal voltage
(LV) scale
9.) Decibel (dB) scale
10.) Continuity Indicating LED
11.0 Mirror: To obtain most accurate readings,
the mirror is deviced to make operator eyes, the indicator pointer, and the indicator
pointer reflexed to the mirror put together in line.

90
How to Measure Resistance
Multimeter with selector set to "Ohms". This meter only has a single Ohms
range. Set the multimeter to Ohms or Resistance (turn meter on if it has a separate
power switch). Understand that resistance and continuity are opposites. When there
is little resistance there is a great deal of continuity. Conversely, when there is a
great deal of resistance, there is little continuity. With this in mind, when we measure
resistance we can make assumptions about continuity based on the resistance
values measured. Observe the meter indication. If the test leads are not in contact
with anything, the needle or pointer of an analog meter will be resting at the left most
position. This represents an infinite amount of resistance, or an "open circuit"; it is
also safe to say there is the no continuity, or path between the black and red probes.
Careful inspection of the dial should reveal the OHM scale. It is usually the top-most
scale and has values that are highest on the left of the dial (a sideways "8" for
infinity) and gradually reduce to 0 on the right. This is opposite of the other scales;
they have the lowest values on the left and increase going right.
Connect the black test lead to the jack marked "Common" or "-"
Connect the red test lead to the jack marked with the Omega (Ohm symbol)
or letter "R" near it.
Set the range (if provided) to R x 100.
Hold the probes at the end of the test leads together. The meter pointer
should move fully to the right. Locate the "Zero Adjust" knob and rotate so that the
meter indicates "0" (or as close to "0" as possible). Note that this position is the
"short circuit" or "zero ohms" indication for this R x 1 range of this meter. Always
remember to "zero" the meter immediately after changing resistance ranges.
Replace batteries if needed. If unable to obtain a zero ohm indication, this
may mean the batteries are weak and should be replaced. Retry the zeroing step
above again with fresh batteries.
When measuring the resistance of something like a light bulb, locate the two
electrical contact points of the bulb. These will be the threaded base and the center
of the bottom of the base. Have a helper hold the bulb by the glass only. Press the
black probe against the threaded base and the red probe against the center tab on
the bottom of the base. Watch the needle move from resting at the left and move
quickly to 0 on the right.
Change the range of the meter to R x 1. Zero the meter again for this range.
Repeat the step above. Observe how the meter did not go as far to the right as
before. The scale of resistance has been changed so that each number on the R
scale can be read directly. In the previous step, each number represented a value
that was 100 times greater. Thus, 150 really was 15,000 before. Now, 150 is just
150. Had the R x 10 scale been selected, 150 would have been 1,500. The scale
selected is very important for accurate measurements. With this understanding,
study the R scale. It is not linear like the other scales. Values at the left side are
harder to accurately read than those on the right. Trying to read 5 ohms on the meter

91
while in the R x 100 range would look like 0. It would be much easier at the R x 1
scale instead. This is why when testing resistance, adjust the range so that the
readings may be taken from the middle rather than the extreme left or right sides.
Test resistance between hands. Set the meter to the highest R x value
possible. Zero the meter. Loosely hold a probe in each hand and read the meter.
Squeeze both probes tightly. Notice the resistance is reduced. Let go of the probes
and wet your hands. Hold the probes again. Notice that the resistance is lower still.
For these reasons, it is very important that the probes not touch anything other than
the device under test. A device that has burned out will not show "open" on the
meter when testing if your fingers provide an alternate path around the device, like
when they are touching the probes. Testing round cartridge type and older style
glass automotive fuses will indicate low values of resistance if the fuse is lying on a
metal surface when under test. The meter indicates the resistance of the metal
surface that the fuse is resting upon (providing an alternate path between the red
and black probe around the fuse) instead of trying to determine resistance through
the fuse. Every fuse, good or bad, will indicate "good".
How to Measure Voltage
Measuring Alternating Current (AC)
Please be extra careful in doing this, 220 volts might be
expected. The higher the voltage the higher the risk of electric
shock. Do this with the supervision of your teacher
otherwise skip this hands-on activity.
Set the meter for the highest range provided for AC Volts. Many times, the
voltage to be measured has a value that is unknown. For this reason, the highest
range possible is selected so that the meter circuitry and movement will not be
damaged by voltage greater than expected. If the meter were set to the 50 volt range
and a common electrical outlet were to be tested, the 220 volts present could
irreparably damage the meter. Start high, and work downward to the lowest range
that can be safely displayed.
Insert the black probe in the "COM" or "-" jack.
Insert the red probe in the "V" or "+" jack.
Locate the Voltage scales. There may be several Volt scales with different
maximum values. The range chosen the selector knob determines which voltage
scale to read. The maximum value scale should coincide with selector knob ranges.
The voltage scales, unlike the Ohm scales, are linear. The scale is accurate
anywhere along its length. It will of course be much easier accurately reading 24
volts on a 50 volt scale than on a 250 volt scale, where it might look like it is
anywhere between 20 and 30 volts.

92
Test a common electrical outlet. Please be extra careful in
doing this, 220 volts should be expected. The higher the
voltage the higher the risk of electric shock. Do this with
the supervision of your teacher. Press the black probe
into one of the straight slots. It should be possible to let go
of the black probe, as the contacts behind the face of the
outlet should grip the probe, much like it does when a plug
is inserted. Insert the red probe into the other straight slot.
The meter should indicate a voltage very close to 210 or
230 volts. The range of the meter is important to obtain
accurate measurements. This could be deadly. Whenever possible, try to connect at
least one probe in such a way that it will not be required to hold both while making
tests. Some meters have accessories that include alligator clips or other types of
clamps that will assist doing this. Minimizing your contact with electrical circuits
drastically reduces the chances of sustaining burns or injury.
Measuring Direct Current
We will be using a 1.5 battery.
Introduction
Voltmeters measure the voltage difference between two points touched by their
leads.
Material:
A commercial voltmeter
a 1.5 volt cell such as a AA, C or D cell.
(or any kind of functional 1.5 battery)
To Do and Notice
Measure the voltage across one, “1.5 volt battery”.

93
Measuring the voltage across a battery.
Details
What voltage does the battery claim to be? (1.5 volts)
Set the meter scale to measure direct current DC voltage use the first scale larger
than 1.5 volts. Perhaps 2, 5, 10 or 20 volts.
Hook up a bulb to a battery, measure the voltage across the bulb by touching the two
leads of the meter to the two leads of the bulb.
A meter is used to measure the voltage across a bulb.

94
A closeup of the meter measuring voltage.
Voltage
Your answer is probably not 1.5 Volts but it should be close. The voltage
across older batteries will be lower.
If it isn’t see “troubleshooting” below.
Additional Activity
Measure the voltage across combinations of 2 batteries.
Each battery by itself will produce an increase in voltage of about 1.5 volts between
its negative end and its positive end.
Batteries in series.
Try batteries: in series, with the positive end of one touching the negative end
of the other; in opposition, with the positive end of one touching the positive end of
another; and in parallel, with both positives and negatives joined.

95
Batteries in parallel
Optional. Measure other cells such as C and D cells, notice that they produce
the same voltage difference between their ends as do AA cells.
Troubleshooting
If the meter needle “goes the wrong way” then reverse the two meter leads,
the red lead should go to the positive end of the cell&emdash; the end with the bump
on it&emdash; while the black lead should go to the negative end. (And, of course,
the black lead should go to the COM, or common, connection on the meter and the
red lead to the V, or voltage, connection.
If your answer is not between 1.4 and 1.7 volts then you are probably reading
the wrong set numbers, ask your teacher for help.
If they you get an answer far from 1.5 volts then try another battery Test the
battery first on another meter to make sure it gives the correct voltage. If the voltage
is still way off, try another meter
.
If your meter does not work swap connector leads with someone whose meter
does work. Were your leads bad or was it the meter?
What you have just done is called troubleshooting, in particular this is
troubleshooting by substitution, and is one of the most useful skills an electronics
technician can possess
Lesson 4/Activity 5 – Use the Right Tool for the Job
Directions: Given are the set of activity and the corresponding picture. Perform
them using the appropriate tools and materials. Your performance will be graded
using the following criteria:

96
Activity Images of the Activity
1. Tighten and loosen screws of
different head slots using different
types of screw drivers.
2. Cut different sizes of wires using
side cutting and long nose pliers.
3. Practice removing insulators
using side cutting and long nose
pliers.
4. Use a wire stripper to remove
wire insulators of different sizes of
wires (solid/stranded).

97
5. Using long nose pliers practice
making terminal loops.
6. Solder two pieces of electrical
wire.
• Never tease your classmates while working.
• Use the right tools for a specific task.
• Do not use tools with a broken insulator in the handle to
avoid accident.
• Work with your heart and always focus on your work.
• Always think that you are working with a live wire. Be
extra careful.
Additional Activity:
Directions: Answer the following questions.
• How did you find the activities?
___________________________________________________________________
___________________________________________________________________
__________.
• What particular activity did you enjoy the most? Why?
___________________________________________________________________
___________________________________________________________________
___________.

98
• Which activity did you find difficult? Why?
___________________________________________________________________
___________________________________________________________________
___________.
• What activity can you now confidently do? Why?
___________________________________________________________________
___________________________________________________________________
___________.
D. TRANSFER
Performance1/Assessment1 – CONSTRUCTION OF SERIES CIRCUIT
Your performance or product will be judged based on the following criteria:
 Functionality
 Quality
 Method
 Speed
Criteria 5 points 3 points 1 point
Functionality The circuit
wasfunctional
The circuit was
functional but
intermittent.
The circuit was not
functioning.
Quality Connections were
properly secured,
output was
presentable
Connections were
properly secured,
output was not
presentable.
Connections were
not properly
secured, output
was not
presentable.

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