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Skill Generator
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of the carbon resistor in the electronic product. You need to discuss and demonstrate how to
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idea on how to deal with this short circuit problem caused by underload and overload resistance
values.
Thought Build er
1.
Why is it important to determine the tolerance value of a carbon resistor?
2.
What do you think will happen to the electronic equipment if the resistor tolerance
value exceeds its maximum reading?
3.
What is the importance of the determining factors in reading the minimum and
maximum tolerance value of a carbon resistor?
Bright Light
Tolerance is the small allowable amount of variation of a specified resistance
measurement of an electronic component. The fourth color in the color code or the fifth
color in a five-band type of carbon resistor is the tolerance value specified. Gold, silver,
and no color are the three determining factors of tolerance value.
To determine the minimum tolerance reading, multiply the tolerance value percentage
to the coded value of the resistor and then subtract the product from the coded value.
To determine the maximum tolerance value, multiply the coded value of resistor to
its tolerance percentage value and add then add the product to the coded value as its
maximum tolerance reading.
332
Resistor Tolerance Value Using the Ohmmeter
Learning Outcomes
In this lesson, you will be able to answer this question: How can one measure the
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tolerance value of a resistor using the ohmmeter of the multitester?
Springboard
Watch the video clip on https://www.youtube.com/watch?v=wUgJgK2aTG0. Then
answer the following questions:
1.
Why is it important to select a range higher than the value of the resistor?
2.
Why is the value of the resistor not exactly the same as its coded value?
3.
What do you think is the importance of having knowledge about the tolerance value
of a resistor?
Focal Point
Having knowledge in using either the analog or digital multitester is an advantage to deal
with the consumer electronics servicing activity. In the previous lesson, you have learned
lesson that the multitester has three major functions. In this lesson, you will focus on one of its
major functions—reading the resistance using the ohmmeter of multitester.
How to Use the Ohmmeter of a Digital Multitester
1.
Turn on the digital multitester.
2.
Insert the probes into the correct connections.
3.
Select and set the switch to the correct measurement type and range for the measurement
to be made. Choose the maximum range above the component to be measured to prevent
the multitester from being overloaded. The range must be above the resistance value if you
are going to measure the resistance of the resistor; so, you need to set the range in the
R
4.
1K range which is above the R 100 range.
Enhance the range for the best reading. Enable all the leading digits to not read zero, so
the greatest number of significant digits can be read. Doing so yields the most accurate
reading.
5.
Once the reading is complete, place the probes into the voltage measurement sockets and
turn the range to maximum voltage to avoid damage in case it is connected to the range
when used again.
How to Use the Analog Multitester
1.
Place or insert the probes into the correct connections.
2.
Place the probes together to ensure that the pointer is adjusted to zero using the zero-ohm
adjust.
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Lesson 5
Select and set the switch to the correct measurement type and range for the measurement
to be made. Choose the maximum range above the anticipated measurement to prevent
overloading the multitester. The range must be above the resistance value if we are going
to measure the resistance of the resistor; so, you need to set the range in R
which is above the R
4.
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3.
1K range
100 range.
Enhance the range for the best reading. Enable all the leading digits to not read zero, so
the greatest number of significant digits can be read. Doing so will yield the most accurate
reading.
5.
Once the reading is complete, place the probes into the voltage measurement sockets and
turn the range to maximum voltage to avoid damage in case it is connected to the range
when used again.
Ohmmeter Reading
Note: Turn the Zero-Ohm Adjustment to the right or left in order to place it exactly at zero at
the right (with the + and – COM test leads shorted together to confirm that the pointer is
exactly adjusted to zero at the top ohm scale.
1 range.
10 range.
Multiply the scale reading by 1 000 if you used the R 1K range.
Multiply the scale reading by 10 000 if you used the R 10K range.
1.
Read the scale directly if you used the R
2.
Multiply the scale reading by 10 if you used the R
3.
4.
To determine the actual reading,
multiply the scale reading by the range
value. In this case (see figure 15.11), the
pointer is placed in 20 nonlinear scale
at R
1. You need to multiply the scale
reading to the range used to get the
actual reading.
Big Idea
Resistor tolerance value is
not exactly the same value in the
Scale Reading
ohmmeter reading because it depends
on the tolerance value of the resistor
Range Used
color code.
R
–
Fig. 15.11.
Actual Reading:
= Scale Reading
= 25
1
= 25 ohms
334
 Range Used
1
+
1K range, multiply the scale reading by the range value.
In this case (see figure 15.12), the pointer is placed in 500 nonlinear scale. Multiply the scale
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reading of 500 to the range used (1 000) to get the actual reading.
Scale Reading
Range Used
R
–
1
+
Fig. 15.12.
Actual Reading
= Scale Reading
= 500
Range Used
 1K
= 500K ohms
Skill Enhancer
Follow the given steps.
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2. Determine the coded value of each carbon resistor and supply the needed information on the
table.
3. You may use the digital or analog multimeter in measuring the resistance of a carbon resistor.
4. Identify the ohmic value of each resistor and write the results in the Measured Value column
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analog or digital multimeter.
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Difference Coded/Measured column.
6. Fill in the tolerance value of each coded and measured carbon resistor.
7. Tell if the resistor is within the tolerance value by answering the question “Is the resistor
within the tolerance value?” with either “Yes” or “No.”
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To get the actual reading on R
Resistor
No.
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8. Tell if the resistor is good or not by answering the last column.
Coded
Value
Measured
Value
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(Coded0HDVXUH
Tolerance
Value in
Ohmmeter
Are the
resistor’s
within the
tolerance
value?
Are the
resistor’s
good or
not good?
1
2
3
4
5
Thought Build er
1.
How are you going to read the ohmic value of a resistor using the analog multimeter?
2.
What will happen when you select the range lower than the value of the resistor to be
3.
Why is the tolerance value not exactly the amount of the resistor coded value?
measured?
336
Bright Light
Using the analog and digital multitesters in performing CES tasks or jobs differs only
on the display of the resistor about to be measured. The value of the resistor using the
ohmmeter of the multitester is not exactly the same because of the tolerance value of the
resistor. The tolerance value will be deducted or added to its coded value to determine its
minimum and maximum range reading. However, to determine if the resistor is good or not
based on an ohmmeter reading, the value must be exactly or in-between the minimum and
maximum reading value of the resistor.
337
gnicivreS
As a domestic appliance technician, your client is complaining that the resistor of her
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out that the resistor used as a replacement for the defective one is not good. Before you do the
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report the coded value of the resistor and its reading in ohmmeter. Then indicate the tolerance
value or the reason why the resistor was concluded as not good.
scinortcelE remusnoC
Skill Generator
Interpreting Technical Drawings and
16
Chapter
Observing Occupational Health and Safety
This chapter introduces technical drawings and occupational safety and health standards.
Lesson 1 is about the common components and symbols in electronics. Lesson 2, on the
other hand, introduces the schematic diagram, which will help deepen your understanding of
technical drawings and then develop your skills in them.
Lesson 3 focuses on the hazards and risks in electronic servicing. It identifies the different
hazards and risks in CES and enumerates ways on how to control them. Lesson 4 then
discusses the effects of these hazards and risks. Lastly, lesson 5 introduces the occupational
health and safety procedures that will keep you safe in the CES workplace.
Lesson 1
Planning for Tasks in Consumer Electronics Servicing
Learning Outcomes
In this lesson, you will be able to answer the following questions:
1.
What is an electronic diagram? Why is it important?
2.
How can an electronic component be described based on the electronic diagram?
3.
What are the things that must be considered in preparing the identified electronic
component of the electronic diagram?
4.
Why is it necessary to identify the proper electronic component or its equivalent value
for the given electronic diagram?
Springboard
Match the figure in column A to its corresponding symbol in column B. Write the
letter of your answer on the blank.
A
338
B
______1.
A.
______2.
B.
______3.
C.
______4.
D.
______5.
E.
What is the importance of a resistor? Where do you usually see it?
2.
What is the purpose of the speaker?
3.
What is the main function of a light emitting diode (LED)?
4.
What is the importance of a diode in an electronic product such as television, radio, and
5.
gnicivreS
computer?
What is the main role of a fuse in an electronic product?
Focal Point
An electronic component is the basic electronic element. It has a discrete form—a unique
characteristic inside the component—with two or more connecting leads or metallic pads. It
is to be connected to a PCB through soldering to create an electronic circuit with a particular
function. These functions include the following: amplifier, radio receiver, oscillator, wireless
and others. The most commonly used electronic components are as follows:
•
Resistor – The main function of this electronic component is to resist the flow of current
in the electronic circuit. It has a variety of resistance values with a unit of measurement in
ohms (:).
•
Capacitor – The main function of this electronic component is to store an electric charge.
There are several types of capacitor, with the most common being the ceramic disk and the
electrolytic. Its value or capacitance is measured in microfarads (μF).
•
Transistor – This is a device capable of amplification with a three-terminal device in which
a voltage applied to one of the terminals (called base) can control the current that flows
across the other two terminals (called collector and emitter, respectively).
•
Diode – This is a semiconductor device that allows current to pass through in one direction
only. Made of germanium or silicon, a diode has two terminals: the anode and the
cathode. Current will flow through the diode only when positive voltage is applied to the
anode and negative voltage is applied to the cathode. If these voltages are reversed, current
will not flow.
•
Transformer – This electronic component is classified as an inductor or a magnetic
component. There are several types of transformer such as the power transformer, input
and output transformers, interstage transformer, I-F transformer, auto-transformer, and
horizontal output transformer.
•
Switch – This component is used to either conduct (closed) or not (open). The most
common types of switch are the single pole double throw (SPDT) toggle switch, the single
pole single throw (SPST) toggle switch, and the push-button type switch. The SPST is the
simplest switch. It connects or disconnects one terminal from one another.
•
Integrated circuit – The integrated circuit (IC) is known as the “building block of modern
electronic devices” such as computers and cellular phones. It is a microchip electronic
circuit that can serve as an amplifier, oscillator, timer, counter, computer memory or
microprocessor.
•
Terminals and connectors – These electronic components are used to make electrical
connections in an electronic circuit.
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scinortcelE remusnoC
Based on the exercise, discuss the following:
1.
The following are the types of electronic components.
1.
Passive electronic components are components that do not have direction (the flow of
electrons does not depend on whether it will flow in a right, left, or reverse direction in
a circuit). They are the electrical elements or electrical components. Examples of passive
electronic components are the resistors,
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Types of Electronic Components
capacitors, diodes, and inductors.
2.
Big Idea
Active electronic components are components
that have gain or direction. Examples of active
Electronic components are used
components are transistors, integrated circuits
to create electronic circuits and are
or ICs, and logic gates.
connected to the PCB through soldering.
Table 16.1 shows the common electronic components, their respective symbols and
meanings, and their actual images.
Table 16.1. Common Electronic Components
Component
Symbol
Image
Meaning of the Symbol and Its Function(s)
Reduces the current flow
Resistor
Adjustable resistor which has three terminals
Potentiometer
Variable resistor/
Adjustable resistor which has two terminals
rheostat
Preset resistor
Trimmer resistor
Changes resistance with light intensity change
Photo resistor
Changes resistance when temperature changes
Thermistor
Stores electric charge and acts as short circuit
Capacitor
340
with AC and open circuit with DC
Polarized
Symbol
Image
Meaning of the Symbol and Its Function(s)
Electrolytic capacitor
Adjustable capacitance
Variable capacitor
Coil / solenoid that generates magnetic field
Inductor
Includes iron
Iron core inductor
An inductor whose inductance can be adjusted
Variable inductor
Generates constant voltage
Battery
Generates light when current flows through
Lamp
Allows current flow in one direction only: left
Diode
(anode) to right (cathode).
Allows current flow in one direction, but can
Zener diode
also flow in the reverse direction when above
breakdown voltage
Variable capacitance diode
Varactor
A heavily doped p-n junction device in which
Tunnel diode
the electric current decreases as the voltage
increases
341
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capacitor
scinortcelE remusnoC
Component
Symbol
Image
Meaning of the Symbol and Its Function(s)
Emits light when current flows through
Light emitting
diode (LED)
Allows current flow when exposed to light
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Component
Photo diode
NPN transistor
PNP transistor
B
B
C
Allows current flow when high potential at
base (middle)
E
E
Allows current flow when low potential at base
(middle)
C
Changes AC voltage from high to low or low to
Transformer
high.
Produces buzzing sound
Buzzer
Protects circuit from high currents
Fuse
Converts electrical signal to sound waves
Speaker
Converts sound waves to electrical signal
Microphone
Operational
Amplifies input signal
amplifier
Used to generate precise frequency clock
Crystal oscillator
342
signal
Symbol
Image
Meaning of the Symbol and Its Function(s)
Transmits and receives radio waves
Two wires simple antenna
Dipole antenna
Used for zero potential reference and electrical
Earth ground
shock protection
Solder to close connection
Solder bridge
Disconnects current when open
SPST toggle switch
SPDT toggle
Selects between two connections
switch
Push button switch
Momentary switch – normally open
(N.O.)
Push button switch
Momentary switch – normally closed
(N.C.)
Conductor of electrical current
Electrical wire
Connected crossing
Connected wires
Not connected
Wires not connected
wires
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gnicivreS
Antenna/aerial
scinortcelE remusnoC
Component
Access http://www.electronic-symbols.com/graphics_files/periodic_table.pdf and then
do the following:
1.
Study the schematic diagram of electronic symbols.
2.
Analyze the schematic diagram of a 5V regulated power supply below.
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Skill Enhancer
9
230 ඞ
AC IN
T1
1
3
LM317T
0
230 V Pri
0-9 v Sec
2A
Transformer
3.
D1-D4
1N 4007
C1
47 0uF
50 V
C2
C3
0.01uF 0.01uF
Cer
Cer
+ 5V DC
OUT
Identify the different electronic components and the quantity that you need to prepare
for a 5V regulated power supply.
Thought Build er
1.
2.
In what way are the two types of electronic components different in their functions?
What is the importance of being knowledgeable on the symbols of electronic
components?
3.
Why is it necessary to be familiar with the different electronic components in dealing
with a job or task in CES?
Skill Generator
As an information and technology specialist, your boss asked you to make a
PowerPoint presentation that will be used in the training of newly-hired electronic
technicians of the company. Your boss wanted to have a presentation on the types of
the electronic components in which the symbol, actual image, and its function must be
indicated in the presentation. Before the training, you are required to submit it in a CD for
review. Your work will be evaluated based on content, creativity, and accuracy.
Bright Light
An electronic component is the basic electronic element with a discrete form with two
or more connecting leads or metallic pads, which are intended to be connected through
soldering technique in a printed circuit board to create an electronic circuit.
Typically, electronic components have two types: passive electronic components and
active components.
344
The Schematic Diagram
Learning Outcomes
1.
What are the things that must be considered in interpreting technical drawing?
2.
How do you interpret working plans and electronic diagrams?
gnicivreS
In this lesson, you will be able to answer the following questions:
Springboard
Figures 16.1 and 16.2 show the image of a dry cell battery as one of the most
common electronic components. Try to draw the same figures and then answer the
questions that follow.
–
+
Fig. 16.1.
Fig. 16.2.
1.
What did you feel while you were trying to draw the image of a dry cell battery in a
2.
Which among the two figures is easier to draw? Why?
3.
What do you think is the importance of having symbols for electronic components
different form?
in CES?
Focal Point
A diagram is a simplified drawing showing the appearance, structure, or workings of
something—in the case of CES, an electronic component or electronic circuit. It can serve as
a framework of the task that needs to be done by an electronic technician. Diagrams are used
by engineers, technicians, and servicemen in CES to make the electronic components in an
electronic circuit easy to identify. Using symbols makes tasks in CES easier and more accurate
as an electronic technician simply reads the symbols specified. Pictorial drawings—or the
actual images of the electronic components that can be found in the electronic diagram—make
the electronic circuit easy to understand, although it is very difficult to draw pictorial diagrams
of electronic systems with a complicated circuitry. Hence, electronic circuit connections are
greatly simplified with the use of electronic symbols.
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scinortcelE remusnoC
Lesson 2
There are four types of diagram used in CES: schematic, block, pictorial, and wiring.
1.
A schematic diagram is a graphical representation that shows the electrical construction of
a system or circuit.
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Four Types of Diagram
D1-D4
1N 4007
LM7812
1
230 V
AC Supply
+
Tx
IN OUT 3
COM
2
1 000uF
25V
+12V
+
1uF
Tx = Primary 230V,Secondary 12V,1A
Stepdown Transformer
Fig. 16.3. Schematic diagram of regulated power supply
2.
A block diagram represents the relationships and functions of a system. Stages or blocks of
an entire circuitry are drawn in boxes, accompanied by lines and arrows showing the flow
of current or signals.
Power
5HFWL¿HUV
Filter
Circuit
Regulator
Fig. 16.4. Block diagram of a regulated power supply
3.
A pictorial diagram shows the true appearance of components in a circuit and how these
are interconnected with one another.
Fig. 16.5. Pictorial diagram of regulated power supply (0–30V/0-1.5A–Preassembled)
346
A wiring (connection) diagram is a diagram that shows the connection of an installation or
its component devices or parts. It shows closely the actual location of each component in a
circuit, including the control circuit and the power circuit.
V
R2
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R1
A
A
R3
Big Idea
6x
TIP2955
R4
R5
Diagrams are used in
CES to simplify the work of the
R6
technician and make it easy
and accurate.
A 830.88mA
R7
V124
V
47.000u 4700
4.03V
A
A
A
07115m 856 13mA
LM7812C
10o
V
Rload
12.0V
Fig.16.6. Wiring diagram of a regulated power supply
Skill Enhancer
Analyze the schematic diagram of a mobile phone charger below. Then do the tasks
that follow.
1.
Identify the different electronic components in the diagram.
2.
Indicate the quantity of each electronic component.
347
scinortcelE remusnoC
4.
Answer the following based on your answers in Skill Enhancer.
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Thought Build er
1.
Why is it important to know how to read the different kinds of diagram in CES?
2.
Which among the four types of diagram do you prefer to use? Why?
3.
Do you think it is possible for a CES technician to do a task or job without a diagram?
Justify your answer.
Skill Generator
As a mobile phone technician, you have been requested by a client to create a
schematic diagram of a mobile phone This schematic diagram must give the client an idea
on the electronic components that can be found in a mobile phone. Make sure that you
include a legend that will describe or identify each component.
Bright Light
Diagrams are used by engineers, technicians, and servicemen in CES to make the
electronic components in an electronic circuit easy to identify. The following are the types
of diagram: schematic, block, pictorial, and wiring.
348
Hazards and Risks in Electronics Servicing
Learning Outcomes
How can one identify health hazards and occupational risks in CES?
2.
What are the different health hazards and risks found in a CES workplace?
3.
How do you control the hazards and risks in the workplace in CES?
gnicivreS
In this lesson, you will be able to answer the following questions:
1.
Springboard
Watch the video on https://www.youtube.com/watch?v=PZmNZi8bon8. Then
answer the following:
1.
What are the forms of agent (the classification of hazards) that caused the risk?
2.
Differentiate hazard from risk.
3.
How can one manage the risks?
Focal Point
It is important to understand the hazards and risks in CES in order to ensure the safety,
health, and welfare of people engaged in this kind of work. Being familiar with hazards and
risks will lessen the problems that might be encountered while doing tasks or jobs.
Hazards and Risks
Hazards and risks can be found everywhere. A hazard
is a possible source of potential damage while a risk refers
to the probability or likelihood of causing harm or adverse
Big Idea
effects on something or someone. An example of an
adverse effect on someone is a health problem caused by
a biological agent such as bacteria or virus. An example of
an adverse effect on something is damage caused to a 110V
electronic equipment that short-circuited (the risk) because it
was plugged in a 220V convenience outlet (the hazard).
Identifying the hazards
and risks in the workplace can
prevent health problems and
damage to the property of the
technician in the workplace.
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Lesson 3
Table 16.2 shows the different classifications of hazards and sources.
Table 16. 2.
Classifications of Hazards
Type
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Source
Biological
Bacteria, viruses, insects, plants, birds, animals, humans, and others
Chemical
Depends on the physical, chemical and toxic properties of the
chemical; an example is lead, which is a highly toxic chemical
commonly present in the soldering PCB and the glass panel in
computer monitors (cathode-ray tube).
Ergonomic
Repetitive movements, improper set up of the workstation, and others
Physical
Radiation, magnetic fields, pressure extremes (high pressure or
vacuum), noise, and others
Psychosocial
Stress, violence (threatening behavior, verbal or written threats,
harassment, verbal abuse, and physical attacks)
Safety
Slipping/tripping hazards, inappropriate machine guarding, equipment
malfunctions, or breakdowns
Risk Assessment-Prioritizing the Risk
Risk assessment is a process of identifying the potential hazards and analyzing what could
happen if a hazard occurs (https://www.ready.gov/risk-assessment). Table 16.3 shows risk
assessment in terms of the likelihood and severity of harm.
Table 16.3.
Risk Assessment in Terms of Likelihood and Severity of Harm
Severity of Harm
Likelihood of Harm
Slight Harm
Moderate Harm
Extreme Harm
Very unlikely
Very low risk
Very low risk
High risk
Unlikely
Very low risk
Medium risk
Very high risk
Likely
Low risk
High risk
Very high risk
Very likely
Low risk
Very high risk
Very high risk
To understand the table 16.3, refer to table 16.4 which shows a descriptive interpretation
of the previous table.
Table 16.4
Descriptive Interpretation of Table 16.3
Descriptive Interpretation
I.
Description
Likelihood of Occurrence (Probability) of Harm
A. Very likely
Experienced at least once every six months by the worker.
B. Likely
Experienced once every five years by the worker.
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Experienced once in a lifetime by the worker.
D. Very unlikely
Experienced in < 1% chance in a lifetime of the worker.
II.
Severity (Consequence) of Harm
A. Slightly harmful
Minor conditions such as superficial injuries; minor cuts and
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bruises; eye irritation from dust; nuisance and irritation;
ill-health leading to temporary discomfort
B. Harmful
Conditions like lacerations, burns, concussion, serious
sprains, minor fractures, deafness, dermatitis, asthma,
work-related upper limb disorders, ill-health
C. Extremely harmful
Major conditions such as amputations, major fractures,
poisonings, multiple injuries, fatal injuries, occupational
cancer, other severely life-shortening diseases, acute fatal
diseases
II.
Risk Level
A. Very low
Risk is considered acceptable. No further action needed, but
ensure that controls are maintained.
B. Low
Consideration to lower the risks to a tolerable or acceptable
level, but additional risk reduction measures are necessary.
Risk reduction measures should be implemented within a
defined time period. Arrangement is needed to ensure that
controls are maintained.
C. Medium
Consideration to lower the risk to tolerable or acceptable,
but additional risk reduction measures are necessary. Risk
reduction measures should be implemented within a defined
time period. Arrangement is needed to ensure that controls
are maintained.
D. High
Risk reduction measures should be considered and then
implemented urgently within a definite time period.
Suspending or restricting the activity or implementing interim
risk control measures must also be considered until the risk
reduction measures are set in place. Allocation of substantial
resources is necessary for additional control measures.
Arrangements should be made to ensure that controls are
maintained, particularly if the risk levels are associated with
extremely harmful consequences.
E.
Very high
Risks are unacceptable. Extensive improvements in risk
control measures are necessary to reduce the risk to a
tolerable or acceptable level. The work activity should be
stopped until risk controls are implemented that reduce the
risk so that it is no longer very high. If risk reduction is not
possible, the work should remain prohibited.
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C. Unlikely
To identify the hazards in the workplace, inspection must be done for appropriate action
to be taken based on its findings.
The following is a sample of risk assessment report in the workplace.
Workplace Inspection Report
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Workplace Inspection
Location: ___________________
Department/Areas Covered : ________________
Date of Inspection: __________
Item
Hazards
(Location)
Observed
Convenience Convenience
outlet in the
outlet is
electronic
burned
Time of Inspection : ________________
Repeat
Item Yes/
Priority
Recommended
Responsible
Action
Person
No
Yes
A
Action Taken
Date
Replace a new
Juan Dela
Replacement
3 January
one
Cruz-School
of
2016
Electrician
convenience
shop
outlet
Analysis and Comments:
The teacher in-charge has reported the condition immediately but the school electrician did not do the repair
immediately due to other immediate tasks that required attention.
Priority Codes:
A – Do immediately.
B – Do within three days.
C – Do within two weeks.
D – Others
Controlling Hazards and Risk in the Workplace
Controlling the hazards and risks in the workplace requires an assessment to evaluate and
then prioritize them accordingly. It is a very important task to prevent damage to equipment
and properties or harm to the workers in CES.
Controlling the hazards in the workplace can be done through the following measures:
1.
Elimination and substitution – This can be done by removing or eliminating the hazard
or replacing it with a less hazardous one (substitution). When replacing materials, it is
important to consider as well the implications and potential risks of the new material. For
example, one can use cable wires with lower lead content instead of using cable wires
with higher lead content.
2.
Engineering controls – This refers to designing or modifying the physical environment
of the workplace to reduce exposure to hazards and risks. The physical environment is
the totality of the outside elements or the physical makeup that influences the workers.
The physical environment includes the room, its size, location, ventilation, lighting, and
materials as well as the arrangement of electrical tools cabinets, the electrical room, and
the provisions for orderliness, cleanliness, and sanitation. Moreover, engineering control
refers to the use of safer, more convenient, and more efficient tools and equipment, if
possible. For example, instead of using an electrical knife for wire splicing, a technician
may use a wire stripper instead.
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Administrative controls – These refer to changes in work procedures such as written safety
policies, rules, supervision, schedules, and training. The goal of such changes is to reduce
the duration, frequency, and severity of exposure to hazardous chemicals or situations.
4.
Personal protective equipment – Personal protective equipment (PPE) are equipment
goggles. In wearing PPE, the technician must consider the task he or she is performing so
that he or she can choose the appropriate PPE to use or wear. The technician must also
make sure that the PPE are in good condition; otherwise, he or she will still be exposed to
hazards or risks.
Skill Enhancer
Visit the computer laboratory in your school. Identify the hazards and risks in the room.
Fill in the table.
Workplace Hazard
Example of Hazard
Example of Harm Caused
Thought Build er
1.
Write a reflective essay on the importance of eliminating or control of CES-related
hazards and risks. Your essay must be informative yet concise, sensible, organized, and
free from grammatical errors.
2.
Form a group with three to five members. Compose a jingle that promotes awareness
on how to control hazards and risks in a CES workplace. Your jingle must be accurate,
informative, relevant, and creative.
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worn or used to ensure the safety of the individual. Examples of PPE are aprons and safety
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3.
As head of the Occupational Safety and Health Standard Department of an electronics
company, you were asked by the CEO to conduct a risk assessment of the CES laboratory.
The results of your assessment will be used to craft the health and safety precautions
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Skill Generator
handbook of the company. Thus, it must be informative, accurate, clear, organized, and
complete.
Bright Light
Hazards and risk are everywhere. A hazard is a possible source of potential damage
while a risk refers to the likelihood of causing harm or adverse effects on someone or
something. Hazards can be biological, chemical, ergonomic, physical, psychosocial, or
safety. To ensure the safety of workers in a CES workplace, it is imperative that these risks
and hazards are eliminated.
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Learning Outcomes
Why is it necessary to identify health hazards and occupational risks in CES?
2.
What are the effects of the health hazards and occupational risks in CES?
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In this lesson, you will be able to answer the following questions:
1.
Springboard
Form a group with three to five members. Together with your group mates,
rearrange the following group of jumbled letters.
SERVDAE
LEHTAH
TECFEF
1.
What is an adverse health effect?
2.
Try to think of a hazard in school. What adverse health effect can it cause?
3.
How can you or school officials prevent the adverse health effect of the hazard you
have identified in school?
Focal Point
As you have learned in the previous lesson, a risk refers to the likelihood of causing harm
or adverse effect on something or someone. Specifically, risks can cause adverse health effects
on someone, in this case, a person performing CES-related tasks in the workplace. An adverse
health effect refers to any change in body function or the structures of cells that can lead to
disease or health problems. Examples of adverse health effects include the following:
•
injured body
•
diseases
•
change in the way the body functions, grows, or develops
•
effects on fetus development (teratogenic effects, fetotoxic effects)
•
effects on children, grandchildren, and others (inheritable genetic effects)
•
decrease in life span
•
change in mental condition resulting from stress, exposure to solvent, and others
•
effects on the ability to handle additional stress
Adverse health effects may be acute if the injury or harm occurs immediately due to
contact with the hazardous agent (e.g., splash of a solder getting onto the hand of a technician).
They may be chronic (delayed); for example the effects of being exposed to the fumes of a
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Lesson 4
manifest.
Additionally, adverse health effects may be reversible or irreversible—an injury may heal
completely (reversible) even as an untreatable disease (irreversible) is also a possibility. Table
16.5 shows the effects of certain hazards in CES.
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toxic gas may not be noticeable right away as it may take a few minutes before those effects
Table 16.5.
Effects of Some CES Hazards
Workplace Hazard
Example of Hazard
Surface mounting device
Thing
Example of Harm Caused
Cadmium poisoning
(SMD) chip resistors
Brominated flame retardants
Substance
Increased risk of cancer to
the digestive and lymph
systems
PVC computer housing
Material
Dioxins and furans, which
are persistent organic
pollutants
Source of Energy
Electricity
Shock, elevated blood sugar
Condition
Open wire circuit
Electrocution
Process
Wire splicing
Bruise
Practice
Soldering
Dizziness, lead poisoning
Table 16.6 shows an example of risk assessment in CES.
Table 16.6
Sample Risk Assessment
Task
Hazard
Risk
The technician is working alone.
Cannot call attention or help if needed.
The technician can inhale the
Dizziness, lead poisoning
gas fume of lead.
The technician is exposed to
Soldering of PCB
Electrocution or shock
electricity.
The technician is exposed to
Too much exposure can cause cancer
different chemicals present
and poisoning
in the different electronic
components to be soldered in
the PCB.
In table 16.6, the nature of the work that needs to be accomplished in CES was analyzed.
The hazard and risk associated with each task were identified, duly giving considerations
to the nature of the work and the condition, time, and process involved in accomplishing
the task. The chemical composition of the materials and components to be soldered by the
technician was also considered.
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Go to a CES workplace in your community and observe the technician(s) at work. Then
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make a table similar to table 16.6.
Thought Build er
1.
Why is it important to identify the hazards and risks in a CES workplace?
2.
What is the advantage of having knowledge on the adverse health effects caused by
risks in performing CES-related tasks?
3.
What are some of the adverse health effects caused by risks in a CES workplace?
Skill Generator
As the operations manager of an electronics company, you have been asked by the
CEO to make a poster promoting the importance of identifying hazards and risks in the
workplace. The poster will be placed in prominent areas in the workplace. The poster must
be informative, creative, and relevant.
Bright Light
Adverse health effects refer to any change in body function or the structures of cells
that can lead to disease or health problems. These affects can be acute (immediate) or
chronic (delayed). They can also be reversible or irreversible.
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Skill Enhancer
Observing Occupational Health and Safety Practices
Learning Outcomes
In this lesson, you will be able to answer the following questions:
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Lesson 5
1.
Why is it important to observe occupational health and safety practices in CES?
2.
What does one need to consider when preparing a checklist of occupational health and
safety practices in CES?
Springboard
Study the quote below. Then answer the questions that follow.
“Prevention is better than cure.”
1.
What is your understanding of the quote in relation to what you have learned so far
in this course?
2.
Why is it important to consider preventive measures in CES?
3.
How is the quote applicable in CES?
Focal Point
Preventive maintenance must always be done to hand tools and test instruments in CES
to ensure that they will always be in perfect working condition for a longer period of time.
Preventive maintenance is simply maintenance—systematic care and protection—regularly
performed on a tool or piece of equipment to lessen the likelihood of it failing. It is performed
while the tool or equipment is still working to ensure that it does not break down unexpectedly.
It also prevents hazards and risks such as short-circuits and sudden machine failure.
Performing Basic Maintenance
Preventive maintenance requires planned and scheduled inspection of tools and
equipment to determine if cleaning, application of lubricants, repair, replacement, or other
courses of action must be implemented.
The following are the common maintenance tasks that need to be done to keep CES tools
and equipment in perfect working condition for a long time.
1.
Lubricating – This is normally done by applying lubricant to connected or tied parts—bolts,
nuts, bearings, and others—of hand tools. A lubricant is an organic substance used to
reduce friction between surfaces.
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Oiling – This can be done to make electronic tools and equipment such as electric drill
improve their moving parts. Careful consideration must be observed in applying a drop of
oil into mechanisms; that is, the oil must be placed only where it should be placed.
3.
Insulating – This is usually done for cables, transformers, and electrical machines through
insulation resistance testing. This procedure helps reduce repairs and replacement of
In performing preventive maintenance of hand tools and equipment, it is important to
make a maintenance schedule. Below is a sample equipment maintenance schedule.
EQUIPMENT MAINTENANCE SCHEDULE
Equipment Type
Analog oscilloscope
Equipment Code
CES-01
Location
Practical Work Area
Schedule for the Month of December 2018
Activities
Every
Manpower
Daily
Other
Every
Weekly
Day
Clean the
Electronic
unit
technician
Return to
Electronic
the proper
technician
15th
Monthly
Remarks
Day
Very Satisfactory

Very Satisfactory

location
Check
Electronic
power cable
technician
Check test
Electronic
probe
technician
Check
Electronic
functions/
technician
Very Satisfactory

Very Satisfactory

Very Satisfactory

buttons
Special Instructions: If there are any missing, damaged, or faulty parts, report them
immediately.
Trainer: Jonathan N. Carrasco
Housekeeping
Aside from the maintenance schedule of hand tools
and equipment, it is also important to have a housekeeping
schedule of the work area in order to maintain its cleanliness
and orderliness. Regular housekeeping also helps keep the
work area free from slip and trip hazards
On the next page is an example of housekeeping
Big Idea
Preventive maintenance
is the systematic care and
protection of tools and
equipment which must be done
periodically.
schedule in CES.
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equipment.
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2.
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Housekeeping Schedule
Industry
Consumer Electronics Servicing
Area/Section
Practical Work Area
Person in Charge
Juan Dela Cruz
Schedule for the Month of December 2018
ACTIVITIES
Person
Every
Responsible
Other
Return the
Trainer,
soldering
trainee
Daily
Day
Every
Weekly
15th
Day
Monthly
irons/
materials
Remarks
Very

Satisfactory
are in their
proper
places.
Clean
Trainer,
the work
trainee
stations.
Check
Trainer,
extension
trainee
Very
Satisfactory

Satisfactory

cables.
Check
Trainer,
ventilation
trainee
(electric

fan, air
Satisfactory
condition,
exhaust fan).
Skill Enhancer
Form a group with three to five members. Together with your group mates, watch the
video on https://www.youtube.com/watch?v=k3zfiTpyEnk. Then create your own group
infomercial on how to conduct preventive maintenance of hand tools and test instruments
in CES.
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After the housekeeping schedule is finalized, it is important to fill out a housekeeping
inspection checklist to determine the following:
1.
The hand tools and equipment in CES are in good working condition and stored
2.
The work area is clean and in order.
3.
The ventilation and electrical installations are safe.
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properly
Below is an example of housekeeping inspection checklist.
HOUSEKEEPING INSPECTION CHECKLIST
Industry
Consumer Electronics Servicing
Area/Section
Practical Area
Person in Charge
Juan Dela Cruz
YES
NO
INSPECTION ITEMS
9
Are the soldering irons/materials in their proper places?
9
Are the workstations clean?
9
Were the extension cables checked?
9
Were the ventilations (electric fan, air condition, exhaust fan) checked?
Remarks: The practical area is satisfactorily maintained.
Inspected by: Pedro D. Guevarra
Date: 6 December 2018
Equipment Maintenance Inspections Checklist
Furthermore, part of the maintenance procedure is having and accomplishing an
equipment maintenance inspections checklist as shown on the example below. It can also be
done to hand tools in CES.
EQUIPMENT MAINTENANCE INSPECTION CHECKLIST
Equipment Type
:
Property Code/Number
:
CES-01
Location
:
Practical work area
Trainer in Charge
:
Juan Dela Cruz
YES
Analog oscilloscope
NO
INSPECTION ITEMS
9
Is the oscilloscope clean?
9
Was the oscilloscope returned to its proper place?
9
Was the power cable checked?
9
Was the test probe checked?
9
Were the functions/buttons checked?
Remarks: The analog oscilloscope is functional and in good condition.
Inspected by: Pedro D. Guevarra
Date: 6 December 2018
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The Housekeeping Checklist
Another part of preventive maintenance is the tag-out index in which a particular hand
tool or equipment will be marked according to its condition. This procedure ensures that
all tools and equipment are properly accounted for and that the condition of each has been
monitored.
Below is an example of tag-out index card.
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The Tag-out Index
TAG-OUT INDEX CARD
DESCRIPTION
LOG
DATE
TYPE
SERIAL
ISSUED
(Danger/Caution)
2018–001
June 2018
Out of order/No Power
Analog oscilloscope
2018–004
June 2018
Broken Test Probes
Analog multimeter
(System Components, Test
Reference, etc.)
The Breakdown/Repair Report
The breakdown or repair report is another important part of the maintenance procedure.
The person who inspected the tools and equipment must make this report, part of which must
include the findings and recommendations of the person who did the inspection.
BREAKDOWN / REPAIR REPORT
Property ID Number
CES-01
Property Name
Analog oscilloscope
Location
Practical Area
Findings
Recommendation
No power, busted fuse
Change fuse
Inspected by:
Reported to:
Pedro D. Guevarra
Juan Dela Cruz
Date:
Date:
6 January 2018
6 January 2018
Subsequent Action Taken:
Recommendation:
Inspection of the equipment
Change fuse
By:
Reported to:
Technician
Juan Dela Cruz
Date:
Date:
7 January 2018
7 January 2018
Waste Segregation Checklist
In the CES industry, it is important to have a waste segregation list in order to determine if
the electronic waste can be recycled, reused, or disposed of.
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Qualification
Consumer Electronics Servicing NC-II
Area/Section
Practical Work Area
Person in Charge
Jonathan N. Carrasco
General/ Accumulated Wastes
Waste Segregation Method
Recycle
Reuse
Dispose
1. Broken cleaning brushes
2. Paper



3. Defective electronic components

4. Broken PCB

5. Used wires/cables
6. Used rags


7. Used ferric chloride


Thought Build er
1.
Why is it necessary to conduct preventive maintenance of hand tools and test
instruments in CES?
2.
How is preventive maintenance conducted?
3.
What are the things to consider in maintaining hand tools and test instruments in CES?
Skill Generator
As the electronics inspection officer of a company, your department is required
to submit the equipment maintenance schedule, housekeeping schedule, equipment
maintenance inspection checklist, housekeeping inspection checklist, tag-out index
card, breakdown/repair report, and waste segregation list. These reports should be clear,
organized, accurate, and complete.
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WASTE SEGREGATION LIST
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Below is a sample of waste segregation list in CES training.
Preventive maintenance is the systematic care and protection of tools and equipment.
It should be done regularly to ensure that tools and equipment are in perfect working
condition for a long period of time.
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Bright Light
Lubricating, oiling, and insulating are the common maintenance tasks that must be
done to CES tools and equipment. The equipment maintenance schedule, housekeeping
schedule, equipment maintenance inspection checklist, housekeeping inspection checklist,
tag-out index card, breakdown/repair report, and waste segregation list are also important in
CES to ensure a efficiency, productivity, cleanliness, and safety.
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