All About Electric Motors
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Lesson Focus
Electric Motors: their principles and everyday uses. Note: This lesson plan is designed for
classroom use only, with supervision by a teacher familiar with electrical and electronic
concepts.
Lesson Synopsis:
Students learn the basic principles of electric motors and explore everyday uses. They
build a working model of an electric motor for classroom use, using an inexpensive kit.
Then, they work as an "engineering" team to determine the changes they would need to
make to the motor to adapt it to power a hairdryer.
Age Levels
10-18.
Objectives
 Learn basic principles of electric motors.
 Apply theory to everyday uses of electric motors.
 Build a working model of an electric motor for classroom use.
Anticipated Learner Outcomes
As a result of this activity, students aged 10-14 should develop an understanding of:
 Principles of electric motors
 Principles of magnetism
 Principles of electric currents
Students should also apply theory to everyday uses of electric motors, and expand their
knowledge of motor design and operation.
Electric Motors: Introduction
The following are basic educational principles of electric motors:
 Magnets both attract and repel each other. Like poles repel, opposite poles attract.
 An electric current produces a magnetic field. The strength and direction of the
magnetic field varies according to the strength and direction of the electric current.
 Simply winding a wire that carries an electric current around an iron bar creates a
magnet that can be switched on and off. Also, the strength and direction of the
magnetic poles can easily be controlled by changing the strength and direction of
the electric current.
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Electric Motors: Introduction (continued)
Overview of Basic Motor Principles
‹ Principles of Magnetism
Magnetism is a force of nature that attracts and repels. Unlike gravity, which only attracts
and which affects all objects, only some types of materials can be magnetized so that they
exert magnetic force, and only some materials are affected by that force—mostly metals
like iron and nickel. When an object becomes magnetized and exerts magnetic force, it is
called a magnet. A magnet has a magnetic pole at each end, one called the north pole and
one called the south pole. Like poles repel, and opposite poles attract. That is, a north pole
attracts another magnet’s south pole but repels a north pole, and south attracts north but
repels south. The Earth is actually a giant magnet, which is why it has north and a south
magnetic poles, and why the south pole of a small magnet (such as the tip of the needle on
a magnetic compass) will always point north. The magnetic force around a magnet forms a
magnetic field. The field is made up of lines of force that run from the north pole to the
south pole. When opposite poles are brought together, their lines of force join, but when
like poles are brought together the lines of force push each other away.
‹ Electromagnets
Scientists long wondered if the attractive and repulsive forces of electricity and magnetism
were related. In 1820 Danish physicist Hans Christian Øersted discovered that a wire with
an electric current flowing through it produced a magnetic field. In fact, wrapping a wire
around an iron core and running a current through it produces a strong magnetic effect; this
is called an electromagnet. British scientist Michael Faraday then discovered that a wire
moving through a magnetic field developed a current running through it. This is called
induction.
‹ Applying Magnetic and Electric Principles Into Motor Design
These discoveries led to the invention of electric generators and electric motors. An electric
generator turns motion (which could be caused by a steam engine, by wind power, or
whatever) into electricity. An electric motor turns electricity back into motion. These two
machines are the basis of modern electric power.
Lesson Activities
Outline
I. Introductions
II. Overview of basic motor principles
A. Principles of magnetism
B. Electromagnets
C. Applying magnetic and electric principles into motor design.
III. Cooking up a motor
IV. Now you try it
V. Classroom instruction ideas
VI. Questions and answers
VII. Teacher feedback
Electric Motors
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Resources/Materials
 Teacher Resource Documents (attached)
 Inexpensive toy electric motor kit, available from Science First,
800-799-8301 or www.sciencefirst.com. See attached product
description.
 Resources not included in kit: sandpaper, cellophane tape,
scissors or wire cutting pliers, batteries, small screwdriver
Alignment to Curriculum Frameworks
See attached curriculum alignment sheet.
Internet Connections
 TryEngineering (www.tryengineering.org)
 IEEE Virtual Museum (www.ieee-virtual-museum.org)
 International Technology Education Association Standards for Technological Literacy
(www.iteawww.org/TAA/PDFs/ListingofSTLContentStandards.pdf)
 McREL Compendium of Standards and Benchmarks
(www.mcrel.org/standards-benchmarks)
A compilation of content standards for K-12 curriculum in both searchable and
browsable formats.
 National Science Education Standards (www.nsta.org/standards)
 Science First (Supplier of Toy Motor Kit) (www.sciencefirst.com)
Recommended Reading
 The Usborne Book of Batteries & Magnets (ISBN: 074602083X)
 DK Eyewitness Series: Electricity (ISBN: 0751361321)
 Janice VanCleave's Physics for Every Kid : 101 Easy Experiments in Motion, Heat,
Light, Machines, and Sound, by Janice VanCleave. John Wiley & Sons (ISBN:
0471525057)
Optional Writing Activity
 Identify examples of motors in use at your home or school. Write an essay (or
paragraph depending on age) about how the motor impacts the machine it is used
in. For example, an electric fan without a motor would have to be moved in some
other way to produce wind.
References
Ralph D. Painter, Douglas Gorham, and other volunteers from
Florida's West Coast USA Section of IEEE
URL: http://ewh.ieee.org/r3/floridawc
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Electric Motors
For Teachers:
Alignment to Curriculum Frameworks
Note: All lesson plans in this series are aligned to the National Science Education
Standards which were produced by the National Research Council and endorsed by the
National Science Teachers Association, and if applicable, to the International Technology
Education Association's Standards for Technological Literacy
‹National Science Education Standards Grades 5-8 (ages 10 - 14)
CONTENT STANDARD B: Physical Science
As a result of their activities, all students should develop an understanding of
 Motions and forces
 Transfer of energy
CONTENT STANDARD F: Science in Personal and Social Perspectives
As a result of activities, all students should develop understanding of
 Risks and benefits
 Science and technology in society
CONTENT STANDARD G: History and Nature of Science
As a result of activities, all students should develop understanding of
 History of science
‹National Science Education Standards Grades 9-12 (ages 14 - 18)
CONTENT STANDARD B: Physical Science
As a result of their activities, all students should develop understanding of
 Motions and forces
 Interactions of energy and matter
CONTENT STANDARD E: Science and Technology
As a result of activities, all students should develop
 Abilities of technological design
 Understandings about science and technology
CONTENT STANDARD G: History and Nature of Science
As a result of activities, all students should develop understanding of
 Historical perspectives
‹Standards for Technological Literacy - All Ages
Technology and Society
 Standard 7: Students will develop an understanding of the influence of
technology on history.
Design
 Standard 10: Students will develop an understanding of the role of
troubleshooting, research and development, invention and innovation, and
experimentation in problem solving.
The Designed World
 Standard 16: Students will develop an understanding of and be able to select
and use energy and power technologies.
Electric Motors
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Electric Motors
For Teachers:
Teacher Resources
Helpful Hints For Assembling The Motor Kit
 Winding the field coil is made much easier by taping the field poles to the mounting
bracket using cellophane tape before winding the field coil.
 Winding the armature is also made easier by taping the two armature pieces
together with cellophane tape. After taping the armature pole pieces together, the
shaft is inserted between the pole pieces. The position of the armature pole pieces
on the shaft is then adjusted by simply placing the armature on the bearing posts
and then sliding the armature pole pieces along the shaft until the pole pieces line
up with the field poles.
 The small plastic tubing that is used as a spacer between the armature coil and the
commutator can be cut to fit in the following manner. After the armature coil is
wound, temporarily slide the commutator onto the shaft. Place the armature on the
bearing posts, lining the armature poles up with the field poles. Slide the
commutator along the shaft so that the commutator lines up with the post that
supports the brushes. Cut a piece of tubing to fit the space between the armature
windings and the commutator. Slide the commutator off the shaft, place the tubing
on the shaft snugly against the armature coil. Replace the commutator on the
shaft, this time threading the lead wires from the armature coil into the
commutator.
 When the motor kits are purchased in bulk packages, the parts must be sorted to
make up individual motor kits. Much class time can be saved by pre-sorting the
parts into individual plastic sandwich bags.
Materials Not Included In The Kit
 Sandpaper. Any type of fine sandpaper or emery cloth will do.
 Cellophane tape. Not strictly required, but helpful for holding the field and
armature pole pieces together while winding the coils.
 Scissors or wire cutting pliers.
 Batteries. The battery clips provided are for AA size batteries. While a carefully
assembled motor will operate on a single AA battery that is new, using two AA
batteries in series to form a three-volt battery results in more reliable operation. In
fact, it is good to have a six-volt lantern battery on hand to "jump-start" finicky
motors
 Small screwdriver.
Suggestions For Teaching With The Motor Kits
The motor kits can be used in a wide variety of ways limited only by the combined
imaginations of the teacher and the students. The suggestions that follow are intended
only to stimulate your thinking. No one knows better than the teacher just how a
particular group of students will respond to a given learning opportunity. The use of the
motor kit can be as simple as having an assembled motor on the teacher’s desk to pique
the curiosity of students or it can involve follow-up activities such as research papers or
team efforts to improve the motor design. A list of experiments appears in of the
instruction sheet that comes with the motor kit.
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For Teachers:
Teacher Resources (continued)
The motor kits can be used as a classroom or laboratory exercise in electromagnetism for
high school students. One approach is to have students observe their instructor assemble
one motor kit. Each student is then given an instruction sheet and a motor kit to
assemble at home. A satisfactory grade is awarded to each student who demonstrates a
working motor to the instructor within a period of one week. Students are allowed to
receive help from parents, siblings or friends. The hands-on nature of the project ensures
that some learning will take place regardless of the amount of help the student receives.
The project is generally well received by parents. The activity can be expanded by asking
each student to write in his own words a description of how the motor works.
With practice, the motor kit can be assembled in about 40 minutes or less. Students,
however, are novices and will require much more time. If the teacher chooses to have
the students build the motor during a class period, then the project can be done in parts.
For instance, day one can include a brief explanation of the exercise and the assembly of
the field winding. Day two can be devoted to the winding of the armature. Day three can
then be the final assembly and test running of the completed motor.
Researching the history of the invention of the electric motor is a good follow-up
assignment for especially able students. An internet search turned up mentions of
Oersted, Faraday, Henry, Page, and Tesla. All of these men from Denmark, England,
America, and Hungary had a part in the invention and development of the electric motor.
However, one major final step in the development of the electric motor was entirely
accidental. During and industrial exposition in Vienna in 1873, an idle dynamo generator
was accidentally connected to an second dynamo generator that was already in operation.
The idle generator started and ran as a motor. The effect was recognized by Zenobe
Theopile Gramme, the designer of the dynamos in question.
Hans Christian Andersen and Hans Christian Oersted shared more than first and middle
names. Both men lived in Denmark in the first half of the nineteenth century and both
men became famous. Hans Christian Andersen earned fame as a writer of fairy tails such
as The Ugly Duckling and The Match Girl. Hans Christian Oersted, on the other hand,
became a distinguished scientist. While performing a laboratory demonstration for a
group of students, Oersted noticed that a nearby compass was affected by the flow of
electric current in the wires leading to his apparatus. Oersted published a paper
describing this interaction between electric current and magnetism in July of 1820.
Andersen was only fourteen when he first met Oersted. Gradually, Andersen and Oersted
became close friends. Andersen was eventually to write of Oersted, “ his house became
very early a home for me; his children, when they were small, I have played with, seen
them grow up and keep their love for me. In his home I have found my eldest and
unchanged friends.” Without revealing these facts to your students beforehand, challenge
your students to research and report on both men to see if any student can discover the
connection between these two famous men.
Electric Motors
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For Teachers:
Teacher Resources (continued)
Applications Of This Type Of Electric Motor
The toy motor kit is an example of a “universal” motor so called because it can be
operated on either direct current (DC) or alternating current (AC). This type of motor is
also referred to as a series motor because the armature winding is connected in series
with the field winding. The series motor does not have very good speed regulation since
the speed of the motor varies appreciably as the load is increased from no load to full
load. However, the series motor produces higher torque as the speed drops and can be
designed to operate at very high speeds. These properties allow the motor designer to
put a large amount of power into a relatively small package. Typical applications for the
series motor are listed below.
 Kitchen mixers
 Food processors
 Hand held power tools such as drills, circular and reciprocating saws, routers and
sanders.
 Automobile starter motors
 Electric hair dryers
 Rotary electric shavers
 Traction motors for diesel electric locomotives, electric trains, and subway trains
 Golf cart and electric car motors
 Electric wheelchair motors
 Robot motors
 Vacuum cleaners
Other types of electric motors exist, principally AC induction motors. However, practically
all electric motors depend on the forces of attraction and repulsion between
electromagnets that is demonstrated by the series motor.
Electric Motors
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Electric Motors
For Teachers:
Kit Description/Ordering Instructions
Science First Toy Motor Kit
Questions and Orders:
Call 800-799-8301 or visit www.sciencefirst.com.
• Build a real working motor for less than the price of a slice of pizza
• Also available in handy class-packs
• Our best-selling product for over 40 years
• For scout groups, science fairs and more
• Revised instructions with computer-generated assembly diagrams
All you need to build a working DC motor and learn its parts from the inside out!
Assembly involves winding your own armature and field coil; building the commutator
with two snap-together pieces; installing brushes into the holes in the base; and slipping
one battery into battery clips. This isn’t a watered-down geegaw with a few measly parts
that you’ll handle once and then discard. This clever kit has been used for over 40 years
to teach crucial concepts to children aged 10 and up. Our customers include Del Brown at
Burley Junior High, Burley, ID, who has known used this kit since our early days. Kit
includes: coil of copper wire; plastic base with holes for parts; field poles; armature core;
brushes; all fasteners; and detailed, illustrated assembly instructions with 8 experiments.
You need 1 AA battery.
An Accent exclusive! We can’t take credit - this idea came from a professor at Case
Western Reserve. Our teacher-friendly Toy Motor bulk packs contain enough parts for 30
or 48 students (plus spares). We keep costs low by including only half the instructions,
allowing 2 students to share.
Pricing:
(Note: Check current pricing at Science First's website: www.sciencefirst.com)
Code
10-135
10-136
10-137
10-138
Name Size
Toy Motor Kit
Toy Motor Kit
Toy Motor Kit
Toy Motor Kit
Material Price
Each: $4.95
12 pack: $55.00
Bulk Pack 36: $789.95
Bulk Pack 48: $139.95
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Electric Motors
Student Resource
Introduction to Electric Motors
Basic Educational Principles of Electric Motors
 Magnets both attract and repel each other. Like poles repel, opposite poles attract.
 An electric current produces a magnetic field. The strength and direction of the
magnetic field varies according to the strength and direction of the electric current.
 Simply winding a wire that carries an electric current around an iron bar creates a
magnet that can be switched on and off. Also, the strength and direction of the
magnetic poles can easily be controlled by changing the strength and direction of
the electric current.
‹ Principles of Magnetism
Magnetism is a force of nature that attracts and repels. Unlike gravity, which only attracts
and which affects all objects, only some types of materials can be magnetized so that they
exert magnetic force, and only some materials are affected by that force—mostly metals
like iron and nickel. When an object becomes magnetized and exerts magnetic force, it is
called a magnet. A magnet has a magnetic pole at each end, one called the north pole
and one called the south pole. Like poles repel, and opposite poles attract. That is, a north
pole attracts another magnet’s south pole but repels a north pole, and south attracts
north but repels south. The Earth is actually a giant magnet, which is why it has north and
a south magnetic poles, and why the south pole of a small magnet (such as the tip of the
needle on a magnetic compass) will always point north. The magnetic force around a
magnet forms a magnetic field. The field is made up of lines of force that run from the
north pole to the south pole. When opposite poles are brought together, their lines of
force join, but when like poles are brought together the lines of force push each other
away.
‹ Electromagnets
Scientists long wondered if the attractive and repulsive forces of electricity and magnetism
were related. In 1820 Danish physicist Hans Christian Øersted discovered that a wire with
an electric current flowing through it produced a magnetic field. In fact, wrapping a wire
around an iron core and running a current through it produces a strong magnetic effect;
this is called an electromagnet. British scientist Michael Faraday then discovered that a
wire moving through a magnetic field developed a current running through it. This is
called induction.
‹ Applying Magnetic and Electric Principles Into Motor Design
These discoveries led to the invention of electric generators and electric motors. An
electric generator turns motion (which could be caused by a steam engine, by wind
power, or whatever) into electricity. An electric motor turns electricity back into motion.
These two machines are the basis of modern electric power.
Electric Motors
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Page 9 of 11
How Electric Motors Work
by Marshall Brain
Electric motors are everywhere! In your house, almost every mechanical movement that you see around you is
caused by an AC (alternating current) or DC (direct current) electric motor.
By understanding how a motor works you can learn a lot about magnets, electromagnets and electricity in general. In
this article, you will learn what makes electric motors tick.
Inside an Electric Motor
Let's start by looking at the overall plan of a simple two-pole DC electric motor. A simple motor has six parts, as
shown in the diagram below:
Armature or rotor
Commutator
Brushes
Axle
Field magnet
DC power supply of some sort
An electric motor is all about magnets and magnetism: A motor uses magnets to create motion. If you have ever
played with magnets you know about the fundamental law of all magnets: Opposites attract and likes repel. So if you
have two bar magnets with their ends marked "north" and "south," then the north end of one magnet will attract the
south end of the other. On the other hand, the north end of one magnet will repel the north end of the other (and
similarly, south will repel south). Inside an electric motor, these attracting and repelling forces create rotational
motion.
Parts of an electric motor
In the above diagram, you can see two magnets in the motor: The armature (or rotor) is an electromagnet, while the
field magnet is a permanent magnet (the field magnet could be an electromagnet as well, but in most small motors it
isn't in order to save power).
Toy Motor
The motor being dissected here is a simple electric motor that you would typically find in a toy:
You can see that this is a small motor, about as big around as a dime. From the outside you can see the steel can
that forms the body of the motor, an axle, a nylon end cap and two battery leads. If you hook the battery leads of the
motor up to a flashlight battery, the axle will spin. If you reverse the leads, it will spin in the opposite direction. Here
are two other views of the same motor. (Note the two slots in the side of the steel can in the second shot -- their
purpose will become more evident in a moment.)
The nylon end cap is held in place by two tabs that are part of the steel can. By bending the tabs back, you can free
the end cap and remove it. Inside the end cap are the motor's brushes. These brushes transfer power from the
battery to the commutator as the motor spins:
More Motor Parts
The axle holds the armature and the commutator. The armature is a set of electromagnets, in this case three. The
armature in this motor is a set of thin metal plates stacked together, with thin copper wire coiled around each of the
three poles of the armature. The two ends of each wire (one wire for each pole) are soldered onto a terminal, and
then each of the three terminals is wired to one plate of the commutator. The figures below make it easy to see the
armature, terminals and commutator:
The final piece of any DC electric motor is the field magnet. The field magnet in this motor is formed by the can itself
plus two curved permanent magnets:
One end of each magnet rests against a slot cut into the can, and then the retaining clip presses against the other
ends of both magnets.
Electromagnets and Motors
To understand how an electric motor works, the key is to understand how the electromagnet works. (See How
Electromagnets Work for complete details.)
An electromagnet is the basis of an electric motor. You can understand how things work in the motor by imagining the
following scenario. Say that you created a simple electromagnet by wrapping 100 loops of wire around a nail and
connecting it to a battery. The nail would become a magnet and have a north and south pole while the battery is
connected.
Now say that you take your nail electromagnet, run an axle through the middle of it and suspend it in the middle of a
horseshoe magnet as shown in the figure below. If you were to attach a battery to the electromagnet so that the north
end of the nail appeared as shown, the basic law of magnetism tells you what would happen: The north end of the
electromagnet would be repelled from the north end of the horseshoe magnet and attracted to the south end of the
horseshoe magnet. The south end of the electromagnet would be repelled in a similar way. The nail would move
about half a turn and then stop in the position shown.
Electromagnet in a horseshoe magnet
You can see that this half-turn of motion is simply due to the way magnets naturally attract and repel one another.
The key to an electric motor is to then go one step further so that, at the moment that this half-turn of motion
completes, the field of the electromagnet flips. The flip causes the electromagnet to complete another half-turn of
motion. You flip the magnetic field just by changing the direction of the electrons flowing in the wire (you do that by
flipping the battery over). If the field of the electromagnet were flipped at precisely the right moment at the end of
each half-turn of motion, the electric motor would spin freely.
Armature, Commutator and Brushes
Consider the image on the previous page. The armature takes the place of the nail in
an electric motor. The armature is an electromagnet made by coiling thin wire around
two or more poles of a metal core.
The armature has an axle, and the commutator is attached to the axle. In the diagram
to the right, you can see three different views of the same armature: front, side and
end-on. In the end-on view, the winding is eliminated to make the commutator more
obvious. You can see that the commutator is simply a pair of plates attached to the
axle. These plates provide the two connections for the coil of the electromagnet.
The "flipping the electric field" part of an electric motor is accomplished by two parts:
the commutator and the brushes.
The diagram at the right shows how the commutator and brushes work together to let
current flow to the electromagnet, and also to flip the direction that the electrons are
flowing at just the right moment. The contacts of the commutator are attached to the
axle of the electromagnet, so they spin with the magnet. The brushes are just two
pieces of springy metal or carbon that make contact with the contacts of the
commutator.
Armature
Putting It All Together
When you put all of these parts together, what you have is a complete electric motor:
Brushes and
commutator
Armature
In this figure, the armature winding has been left out so that it is easier to see the commutator in action. The key thing
to notice is that as the armature passes through the horizontal position, the poles of the electromagnet flip. Because
of the flip, the north pole of the electromagnet is always above the axle so it can repel the field magnet's north pole
and attract the field magnet's south pole.
If you ever have the chance to take apart a small electric motor, you will find that it contains the same pieces
described above: two small permanent magnets, a commutator, two brushes, and an electromagnet made by winding
wire around a piece of metal. Almost always, however, the rotor will have three poles rather than the two poles as
shown in this article. There are two good reasons for a motor to have three poles:
It causes the motor to have better dynamics. In a two-pole motor, if the electromagnet is at the balance
point, perfectly horizontal between the two poles of the field magnet when the motor starts, you can imagine the
armature getting "stuck" there. That never happens in a three-pole motor.
Each time the commutator hits the point where it flips the field in a two-pole motor, the commutator shorts
out the battery (directly connects the positive and negative terminals) for a moment. This shorting wastes energy and
drains the battery needlessly. A three-pole motor solves this problem as well.
It is possible to have any number of poles, depending on the size of the motor and the specific application it is being
used in.
Motors Everywhere!
Look around your house and you will find that it is filled with electric motors. Here's an interesting experiment for you
to try: Walk through your house and count all the motors you find. Starting in the kitchen, there are motors in:
The fan over the stove and in the microwave oven
The dispose-all under the sink
The blender
The can opener
The refrigerator - Two or three in fact: one for the compressor, one for the fan inside the refrigerator, as well
as one in the icemaker
The mixer
The tape player in the answering machine
Probably even the clock on the oven
In the utility room, there is an electric motor in:
The washer
The dryer
The electric screwdriver
The vacuum cleaner and the Dustbuster mini-vac
The electric saw
The electric drill
The furnace blower
Even in the bathroom, there's a motor in:
The fan
The electric toothbrush
The hair dryer
The electric razor
Your car is loaded with electric motors:
Power windows (a motor in each window)
Power seats (up to seven motors per seat)
Fans for the heater and the radiator
Windshield wipers
The starter motor
Electric radio antennas
Plus, there are motors in all sorts of other places:
Several in the VCR
Several in a CD player or tape deck
Many in a computer (each disk drive has two or three, plus there's a fan or two)
Most toys that move have at least one motor (including Tickle-me-Elmo for its vibrations)
Electric clocks
The garage door opener
Aquarium pumps
In walking around my house, I counted over 50 electric motors hidden in all sorts of devices. Everything that moves
uses an electric motor to accomplish its movement.
Helpful Hints For Assembling The Motor Kit
•
Winding the field coil is made much easier by taping the field poles to the
mounting bracket using cellophane tape before winding the field coil.
•
Winding the armature is also made easier by taping the two armature pieces
together with cellophane tape. After taping the armature pole pieces
together, the shaft is inserted between the pole pieces. The position of the
armature pole pieces on the shaft is then adjusted by simply placing the
armature on the bearing posts and then sliding the armature pole pieces
along the shaft until the pole pieces line up with the field poles.
•
The small plastic tubing that is used as a spacer between the armature coil
and the commutator can be cut to fit in the following manner. After the
armature coil is wound, temporarily slide the commutator onto the shaft.
Place the armature on the bearing posts, lining the armature poles up with
the field poles. Slide the commutator along the shaft so that the commutator
lines up with the post that supports the brushes. Cut a piece of tubing to fit
the space between the armature windings and the commutator. Slide the
commutator off the shaft, place the tubing on the shaft snugly against the
armature coil. Replace the commutator on the shaft, this time threading the
lead wires from the armature coil into the commutator.
Electric Motors
Student Worksheet:
You are the Engineer!
‹ Instructions
Assemble the motor kit provided to you.
‹ The Challenge
You are part of an engineering team given the challenge of taking the motor you have
assembled and improving it so that it would safely power a hairdryer. As a team,
brainstorm on the current design, and come up with three changes you would recommend
make to the motor. Bear in mind that hairdryers are often used near water, or wet hair.
Step One:
Questions:
1. Were there any materials you changed in your new motor design? If so, explain why
you recommended these different materials.
2. Were there any new parts you added to your new motor design? If so, explain why
you recommended these additions.
3. Did you change the scale -- or size -- of your motor? If so, explain why you
recommended the change in scale.
4. Do you think the changes you recommended as a team would result in a more
expensive motor? How would it impact the cost of a hair dryer?
Step Two:
Present your team's new design to the class, and discuss what you learned by going
through the process of improving or adapting an existing product.
Electric Motors
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