Lesson Plan
Course Title: Computer Maintenance
Session Title: Power Quality and Protection
Lesson Duration: 90 Minutes
Performance Objective:
Upon completion of this assignment, the student will be able to describe power problems
associated with the operation of computers and recommend solutions.
Specific Objectives:
• Describe and identify various external power problems related to the operation of
computers.
• Differentiate between catastrophic and degradation types of damage.
• Describe and identify surge suppression solutions for external power problems.
• Describe and identify uninterruptible power supply solutions for external power
problems.
Preparation
TEKS Correlations:
130.273(c) (4)
The student acquires an understanding of computer technologies. The student is expected to:
(A) explain the fundamentals of microprocessor theory;
(C) explain the theories of magnetism, electricity, and electronics as related to computer
technologies;
(D) explain proper troubleshooting techniques as related to computer hardware;
(I) explain computer system environmental requirements and related control devices.
130.273(c) (6)
The student applies the concepts and skills of the trade in simulated work situations. The
student is expected to:
(C) identify the operational features and proper terminology related to computer systems;
130.273(c) (8)
The student uses troubleshooting skills with hardware knowledge to solve client problems. The
student is expected to:
(A) understand the rationale behind error messages and symptoms of hardware failures;
Instructor/Trainer
References:
1. IDG Books Worldwide Inc., A+ Certification for Dummies, Chap. 8: Power.
Instructional Aids:
1. PowerPoint presentation: Power Quality and Protection.
IT: Computer Maintenance: Power Quality and Protection Plan
Copyright © Texas Education Agency, 2011. All rights reserved.
1
2.
3.
4.
5.
6.
7.
PowerPoint presentation: Power Quality and Protection – Handouts.
Power Quality and Protection Presentation Outline Organizer.
Power Quality and Protection Word Game.
Power Quality and Protection Word Game Key.
Power Quality and Protection Exam.
Power Quality and Protection Exam Key.
Materials Needed:
1. Copies of Power Quality and Protection Word Game for each student.
Equipment Needed:
1. A projection system to display the PowerPoint presentation [PC & monitor/projector, etc.]
Learner
1. Students should read the appropriate curriculum material for power quality and
protection [depending on the text/curriculum being used for this course]. This lesson can
be taught with only the PowerPoint presentation, and the equipment outlined above.
Introduction
MI
Introduction (LSI Quadrant I):
Most external power problems go unnoticed because they are usually small enough
that the computer’s power supply can deal with them. These problems can lead to
reliability problems in your computer and result in major damage. As a computer
technician you should be aware of the hazards of external power problems in a
computer, and know how to prevent some of these problems from materializing.
A power surge lasts for only a few thousandths of a second. Does anyone know
what changes to voltage can occur during those few thousands of a second?
A power surge can cause the voltage to increase to 1,000 volts or higher. These
high voltage spikes degrade the power supply. Multiple surges over time can
destroy it.
Outline
MI
Outline (LSI Quadrant II):
Instructor Notes:
Introduction: (PPT slides 1-4)
NOTE: Hand out the Power
Quality Organizer (1 per
student). Have students fill in
the blank areas during the
PowerPoint presentation.
Use a computer and
projector to display the PPT
slides & discuss each
topic/concept.
I.
Describe and identify various external
power problems related to the
operation of computers (slides 5-11).
II.
Differentiate between catastrophic
and degradation types of damage
(slide 12).
III.
Describe and identify surge
suppression solutions for external
IT: Computer Maintenance: Power Quality and Protection Plan
Copyright © Texas Education Agency, 2011. All rights reserved.
2
power problems (slides 13-17).
IV.
Describe and identify uninterruptible
power supply solutions for external
power problems (slides 18-20).
V.
The teacher gives a demonstration, of
surge suppressors and UPS.
NOTE: The teacher should hand out 1 copy of
the Power Quality Word Game to each student.
Students complete the Power Quality and
Protection word game.
Application
MI
Guided Practice (LSI Quadrant III):
1. Teacher shows and demonstrates the surge suppressor.
2. Teacher shows and demonstrates the UPS.
3. Have students, rotating from student to student, discuss the various aspects of
the surge suppressor and the UPS.
MI
Independent Practice (LSI Quadrant III):
1. Students work independently to complete the word game exercise for Power
Quality and Protection.
Summary
MI
Review (LSI Quadrants I and IV):
1. Ask students summary questions.
a. What is the major difference between a brownout and a blackout? [during a
brownout there is a drop in the power line voltage; during a blackout the
power fails completely]
b. What is the primary component of a surge suppressor? [A metal oxide
Varistor (MOV)]
c. What are the two types of uninterruptible power supplies (UPS)? [Standby
UPS and In-line UPS]
2. Revisit the major power problems a technician encounters and the solutions to
these problems.
Evaluation
MI
Informal Assessment (LSI Quadrant III):
1. The teacher will monitor student progress during independent practice and
IT: Computer Maintenance: Power Quality and Protection Plan
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provide independent re-teach/redirection as needed.
MI
Formal Assessment (LSI Quadrant III, IV):
1. Administer the Power Quality and Protection Exam.
Extension
MI
Extension/Enrichment (LSI Quadrant IV):
Students that have mastered the lab assignments can peer-tutor students [one-onone] that are having difficulty with the disassembly or assembly of the PC.
IT: Computer Maintenance: Power Quality and Protection Plan
Copyright © Texas Education Agency, 2011. All rights reserved.
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Icon
MI
Verbal/
Linguistic
Logical/
Mathematical
Visual/Spatial
Musical/
Rhythmic
Bodily/
Kinesthetic
Intrapersonal
Interpersonal
Naturalist
Existentialist
Teaching Strategies
Personal Development
Strategies
Lecture, discussion, journal
writing, cooperative learning,
word origins
Reading, highlighting, outlining,
teaching others, reciting information
Problem-solving, number
games, critical thinking,
classifying and organizing,
Socratic questioning
Mind-mapping, reflective
time, graphic organizers,
color-coding systems,
drawings, designs, video,
DVD, charts, maps
Use music, compose songs
or raps, use musical
language or metaphors
Organizing material logically, explaining
things sequentially, finding patterns,
developing systems, outlining, charting,
graphing, analyzing information
Developing graphic organizers, mindmapping, charting, graphing, organizing
with color, mental imagery (drawing in
the mind’s eye)
Use manipulatives, hand
signals, pantomime, real life
situations, puzzles and board
games, activities, roleplaying, action problems
Reflective teaching,
interviews, reflective listening,
KWL charts
Cooperative learning, roleplaying, group brainstorming,
cross-cultural interactions
Natural objects as
manipulatives and as a
background for learning
Socratic questions, real life
situations, global
problems/questions
Creating rhythms out of words, creating
rhythms with instruments, playing an
instrument, putting words to existing
songs
Moving while learning, pacing while
reciting, acting out scripts of material,
designing games, moving fingers under
words while reading
Reflecting on personal meaning of
information, studying in quiet settings,
imagining experiments, visualizing
information, journaling
Studying in a group, discussing
information, using flash cards with
others, teaching others
Connecting with nature, forming study
groups with like-minded people
Considering the personal relationship to
the larger context
IT: Computer Maintenance: Power Quality and Protection Plan
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Power Quality & Protection PowerPoint Outline
Objectives
•
•
•
Identify and describe the various types of external power problems.
Differentiate between catastrophic and degradation types of damage.
Identify and describe various protective measures against power problems.
I. External Power Problems
A. Some common external power problems: _________________________,
________________, _____________________, ____________________________,
___________________________.
B. All of these (except the ____________________) go unnoticed by the computer.
C. These common power problems can lead to ____________________ problems
with the computer.
D. When plugged directly into a wall outlet, over time these can result in
___________ damage to a computer.
Type of Power
Description
Problem
• Consists of small variations in the ________________ of the
power line.
Line Noise
• Plug your PC into its _______ circuit.
• Sharing an extension cord with an _______________ will cause
major problems. This causes your power supply to burn out and
any line noise passes through to the ________________ or
________ ________ .
IT: Computer Maintenance: Power Quality and Protection Plan
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• A power spike or over-voltage happens when disturbances like
distant __________________ ______________ , or other
Power surges
anomalies in the electrical supply grid, create a voltage spike
that ___________ down the line and to your wall plugs.
• The surge lasts for only a few __________________ of a second,
but can cause the voltage to increase to __________ volts or
higher.
• High voltage spikes _____________ the power supply. Multiple
surges over time can ___________ it.
• Also known as __________________________, is the opposite
of a power surge and happens when a sudden ________ occurs
Brownouts
in the power line voltage.
• It doesn’t normally last too long. Usually the power level
________ below normal levels for a time and then ___________
to normal.
• They are extremely common during periods of heavy _______
on the electrical system (_____ afternoons/______ mornings).
• The reduced voltage level causes many devices to run
____________ than normal or _______________ in other ways.
• Occur when the power __________ completely.
• Problems caused are usually more frustrating than
Blackouts
_______________.
• NOTE: The _________________ of power surrounding a
blackout can, however, _________ your system.
• If you are in the middle of something that is not _________, or
_________________ a hard drive when a blackout occurs you
will have problems.
• More often the damage __________ when the power
___________ suddenly, usually in the form of a huge spike.
IT: Computer Maintenance: Power Quality and Protection Plan
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• This spike delivers __________ volts or more if it were to hit a
home or office directly.
Lightning
• A strike even in your ______________ can result in a very high
voltage spike.
strikes
• A lightning strike has been known to completely
________________ or ______________________ everything
plugged in: computers, copiers, fax machines, telephones, and
more.
II. Protecting Against Power Problems
A. Two types of damage can be done to the PC by electrical forces:
1. Catastrophic: When the device is _______________ all at once in a
______________ event.
2. Degradation: When a device is _______________ over a
_____________ of instances and begins to __________ or has
______________________ problems.
III. Surge Suppressor
A. Most users plug their computers into a power strip or surge
____________________.
B. The primary component of a surge suppressor is a ________ _________
___________ (MOV).
C. The MOV protects the computer by __________ the hit from voltage spikes.
D. The problem with MOV is that one big __________ or an ____________________
of small surges over time can knock it out.
IT: Computer Maintenance: Power Quality and Protection Plan
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E. Some surge suppressors have a ____________ to indicate that the MOV is still all
right.
F. A surge suppressor reduces power problems by ____________________ spikes
and surges and by smoothing out _________ ___________ (called line
conditioning)
G. Not all surge suppressors include line _____________________ .
H. Consider two main features when choosing a surge suppressor:
I. _____________ voltage: The voltage at which the suppressor begins to protect
the computer.
J. Clamping speed: The time __________ before the protection begins, or how much
time elapses between detection and protection.
K. Energy absorption: Surge suppressors are rated in ______________, which
measures their capability to ______________ energy
L. The higher the rating, the ______________ the protection:
M. ______ Joules is basic protection – _______ Joules is good protection – ______
Joules is superior protection
N. Line conditioning: Line conditioning capability is measured in
___________________.
O. The more decibels of noise reduction, the ______________ the line conditioning.
P. Protection indicators: An LED indicates you are __________________
Q. If the LED is out, get a ________ suppressor
IT: Computer Maintenance: Power Quality and Protection Plan
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R. Levels of protection: Surge suppressors have three levels of protection that
indicate the maximum number of ___________ the suppressor allows to pass
through to anything plugged into it. The standard ratings are: ______ (Good) –
______ (Better) – ______ (Best)
S. Line ____________________ filter the power stream to ___________________
line noise.
T. Because they are usually ______________, few PC users use a _____________ line
conditioner.
U. They prefer to purchase this capability in other devices, such as a __________
____________.
V. In the event of an electrical ________ or ___________ strike, power can surge up
the _________________ lines as well as the power lines.
W. When installing a surge protector, be sure it has ___________ line protection.
IV. UPS
A. An _____________________________ power supply (UPS) provides a
___________ power stream to the computer.
B. Under normal conditions, it’s a surge protector that can also handle
_________________ conditions.
C. When the power ______ below a certain level or is ________________
completely, the UPS kicks in and provides ____________ for a certain number of
minutes, or even hours in some cases.
IT: Computer Maintenance: Power Quality and Protection Plan
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D. All UPS units have two sets of circuits: ___________________ circuit - is a surge
___________________.
E. The other side is the _______________ and DC to AC _________________.
F. The batteries store a _____ charge that must be converted to _____ (because
that’s what the PC expects).
G. Two types of UPS units are available: ______________ UPS: Operates normally
from its ___ side.
H. When the power _______, it switches over to its _____________ backup side.
I. In-line UPS: Operates normally from its _____ or battery backup side.
J. The AC side is only used in the event of a _________ with the ____________powered circuits.
K. UPS units are often _____________ with a standby power supply (SPS), or battery
backup, which only supplies power when ________ is available and has no power
_____________ abilities.
L. Never plug a laser printer or monitor into a conventional PC _______. These
devices are not critical to the operation of the PC and __________ tremendous
amounts of power at startup.
IT: Computer Maintenance: Power Quality and Protection Plan
Copyright © Texas Education Agency, 2011. All rights reserved.
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Power Quality and Protection
Word Game
Student Name: ___________________________
Date: ____________
Find and circle the words from the Power Quality and Protection Lesson hidden in the puzzle
below. The words may be horizontal, vertical, diagonal, backward, or forward.
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1. BLACKOUTS
2. BROWNOUTS
3. CLAMPING SPEED
4. CLAMPING VOLTAGE
5. DECIBELS
6. ENERGY ABSORPTION
7. INLINE UPS
8. JOULES
9. LINE NOISE
10. MOV
11. POWER SURGES
12. SPIKES
13. STANDBY UPS
14. SURGE SUPPRESSOR
IT: Computer Maintenance: Power Quality and Protection Plan
Copyright © Texas Education Agency, 2011. All rights reserved.
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Power Quality and Protection
Word Game Key
Student Name: ___________________________
Date: ____________
Find and circle the words from the Power Quality and Protection Lesson hidden in the puzzle
below. The words may be horizontal, vertical, diagonal, backward, or forward.
T
B
Q
P
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1. BLACKOUTS
2. BROWNOUTS
3. CLAMPING SPEED
4. CLAMPING VOLTAGE
5. DECIBELS
6. ENERGY ABSORPTION
7. INLINE UPS
8. JOULES
9. LINE NOISE
10. MOV
11. POWER SURGES
12. SPIKES
13. STANDBY UPS
14. SURGE SUPPRESSOR
IT: Computer Maintenance: Power Quality and Protection Plan
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POWER QUALITY AND PROTECTION EXAM
Student Name: __________________________
Date: __________
1. Which of the following devices can supply backup power to a PC when the electricity
fails and provides for line conditioning as well?
A.
B.
C.
D.
SPS
UPS
Line conditioner
Surge suppressor
2. When are you subjecting your computer to the greatest risk of external power
problems?
A. When you plug your computer directly into the wall socket
B. When you plug your computer directly into a line conditioner
C. When you plug your computer directly into a surge suppressor
D. When you plug your computer directly into an uninterruptible power supply
3. Which of the following terms describes over-voltage in a power line?
A. Blackout
B. Brownout
C. Line Noise
D. Power surge
4. Which of the following terms describes power failing completely?
A.
B.
C.
D.
Blackout
Brownout
Line Noise
Power surge
5. Which of the following terms describes under-voltage in a power line?
A. Blackout
B. Brownout
C. Line Noise
D. Power surge
6. Which of the following terms describes a device being destroyed all at once in a
single event?
A. Disaster
B. Compromised
C. Degradation
D. Catastrophic
IT: Computer Maintenance: Power Quality and Protection Plan
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7. Which of the following terms describes a condition of a device that is damaged over
a period of instances and begins to fail or has intermittent problems?
A. Disaster
B. Compromised
C. Degradation
D. Catastrophic
8. Which of the following terms describes the voltage at which the suppressor begins to
protect the computer?
A.
B.
C.
D.
Conditioned voltage
Suppressed voltage
Beginning voltage
Clamping voltage
9. Which of the following terms describes the time lapse before the surge protection
begins, or how much time elapses between detection and protection?
A.
B.
C.
D.
Conditioned speed
Suppressed speed
Clamping speed
Beginning speed
10. Which of the following is the primary component of a surge suppressor?
A.
B.
C.
D.
Metal Oxide Varistor
Clamping voltage
Clamping speed
Line conditioner
11. If your computer shares an extension cord with an appliance, which of the following
will soon cause some major problems?
A. Brownouts
B. Line noise
C. Power surges
D. Clamping voltage
12. Which of the following external power problems are more frustrating than
damaging?
A.
B.
C.
D.
Line noise
Brownouts
Blackouts
Power surge
IT: Computer Maintenance: Power Quality and Protection Plan
Copyright © Texas Education Agency, 2011. All rights reserved.
15
Student Name: __________________________
Date: __________
POWER QUALITY AND PROTECTION – KEY
1. Which of the following devices can supply backup power to a PC when the electricity
fails and provides for line conditioning as well?
A.
B.
C.
D.
SPS
UPS
Line conditioner
Surge suppressor
2. When are you subjecting your computer to the greatest risk of external power
problems?
A. When you plug your computer directly into the wall socket
B. When you plug your computer directly into a line conditioner
C. When you plug your computer directly into a surge suppressor
D. When you plug your computer directly into an uninterruptible power supply
3. Which of the following terms describes over-voltage in a power line?
A.
B.
C.
D.
Blackout
Brownout
Line Noise
Power surge
4. Which of the following terms describes power failing completely?
A.
B.
C.
D.
Blackout
Brownout
Line Noise
Power surge
5. Which of the following terms describes under-voltage in a power line?
A.
B.
C.
D.
Blackout
Brownout
Line Noise
Power surge
6. Which of the following terms describes a device being destroyed all at once in a
single event?
A.
B.
C.
D.
Disaster
Compromised
Degradation
Catastrophic
IT: Computer Maintenance: Power Quality and Protection Plan
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7. Which of the following terms describes a condition of a device that is damaged over
a period of instances and begins to fail or has intermittent problems?
A.
B.
C.
D.
Disaster
Compromised
Degradation
Catastrophic
8. Which of the following terms describes the voltage at which the suppressor begins to
protect the computer?
A.
B.
C.
D.
Conditioned voltage
Suppressed voltage
Beginning voltage
Clamping voltage
9. Which of the following terms describes the time lapse before the surge protection
begins, or how much time elapses between detection and protection?
A.
B.
C.
D.
Conditioned speed
Suppressed speed
Clamping speed
Beginning speed
10. Which of the following is the primary component of a surge suppressor?
A.
B.
C.
D.
Metal Oxide Varistor
Clamping voltage
Clamping speed
Line conditioner
11. If your computer shares an extension cord with an appliance, which of the following
will soon cause some major problems?
A.
B.
C.
D.
Brownouts
Line noise
Power surges
Clamping voltage
12. Which of the following external power problems are more frustrating than
damaging?
A.
B.
C.
D.
Line noise
Brownouts
Blackouts
Power surge
IT: Computer Maintenance: Power Quality and Protection Plan
Copyright © Texas Education Agency, 2011. All rights reserved.
17