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Transcript
SCRIPT FORM - TR 130 – (for a 5 minute show)Final Ver.
Producer: Jerome Ferro
Show Title: Do Try This
at Home.
Date: 09/29/2015
Time
Video
Audio
6:00
Bars
Tone
5:30
Slate
5:10
Countdown
5:00
Camera
With tone
Show Title super (key over opening
shot)
Lower 3rd super: host
. Good morning and welcome to "Do try
this at home".My name is Jerry Ferro and
today I am going to build a simple electric
motor known as a "Beakman's Motor" and
explain the theory of operation.
Have you ever played with magnets? If so,
you are well on your way to understanding
how simple electric motors work. Magnets
produce a magnetic field with a north pole
and a south pole. Like poles repel, opposite
poles attract. .
An electric motor uses these
attracting and repelling properties of
magnets to create motion. An electric
motor contains two types of magnets;
1. A permanent magnet

A magnet with a constant
magnetic field..
and
2. A temporary magnet or electromagnet

A magnet that needs electrical
current to create a magnetic
field..
In this project, I will use a permanent
magnet and a temporary magnet. The
temporary magnet can also be called an
electromagnet.
To make an electric motor, an
electromagnet is placed on an axle so it
can spin freely. It is then positioned
within the magnetic field of a permanent
magnet. When current is passed through
the electromagnet, the resulting
magnetic field interacts with the
permanent magnetic field to create
attracting and repelling forces. These
forces push the electromagnet, which
spins on its axle, and an electric motor is
born.
The method applied in this demonstration
uses Newton's first law of motion , which
states that, "an object in motion remains in
motion unless acted upon by an outside
force". This means that when the
electromagnet is spinning, it will continue to
coast through a rotation unless something
stops it. If current is always flowing through
the wire, the resulting pushes will oppose
each other, and the coil might bounce back
and forth, but it will not spin continuously.
However, if we can make the current flow
only half of the time, all the pushes are in
the same direction. This means the coil is
actively pushed one-half of each rotation
while current is flowing, and "coasts"
through the next half cycle while no current
is flowing, until it comes around and
receives the next push. This allows the
motor to spin continuously.
Key CG Materials
This project demonstrates what happens
when an electromagnet is placed in the path
of the magnetic field of a permenant
magnet.
Materials:
These specialty items can be purchased
from the Science Buddies Store:
Electric Motor and Generator kit (1). You
will need these items from the kit:



Magnet wire,
enamel-coated, approximately 50
inches [120 cm].
Sandpaper, fine-grit
Magnets (3)






Compass (1)
A dowel or other cylinder, 1/2
inch [1.3 cm] in diameter.
Ruler or measuring tape
Scissors
Battery, AA cell (2)
Tape electrical tape or masking
From one end of the magnetic wire,
measure about 1.6 inches (4 cm), and from
that point onward, wind about 30 inches of
magnetic wire around a cylinder . Cut the
magnetic wire with the scissors, leaving
about 1.6 inches (4 cm) free (uncoiled) at
the other end.
Key CG Figure1
The magnetic wire must be neatly and
evenly coiled. If it is not, the weight may not
be evenly distributed, making it difficult for
the electromagnetic coil to rotate in the final
motor setup. Try to ensure the loops are
touching each other, always parallel to one
another, as shown in Figure 1.
A coil is formed by winding magnetic
wire neatly around a cylinder. 1.6 inches of
wire is left free on each end to create the
axles.
Key CG Figure2
Carefully slide the loops of magnetic
wire off the cylinder. Your coil should look
circular or square, as shown in Figure 2.
In this graphic you can see two
examples of neatly coiled wire, each forming
an electromagnet.
The electromagnet is a coil.
Because all loops of wire are parallel,
each loop will get the same push.
Adding up all those pushes, or motions,
creates the nice spinning movement of a
motor.
Key CG Figure3
Keep the loops bunched together to
form a tight coil:
Thread each free end of the
magnetic wire through the loops of the coil
in the 3 o'clock and 9 o'clock positions, as
shown in Figure 3.
You should knot the magnetic wire to
help the coils stay tightly bunched.
The free ends of the magnetic wire
should form a straight imaginary line
through the coil (the imaginary line connects
the 3 o'clock and 9 o'clock positions and
runs further along the free ends). The free
ends will be the axle on which your
electromagnet turns.
Figure 3 is a drawing illustrating how the
coil and the axle that it spins on look when
formed.
The magnetic wire is protected with an
electrically insulating enamel coating. This
enamel coating needs to be removed from
both ends of the axles to create electrical
contact between the left and right axles
and their supports.
Key CG Figure4
Put up Figure 4 Please
The top part of this drawing shows how the
axles should be stripped: on the right axle,
only the top half of the coating should be
removed; on the left axle, all the coating
should be removed.
Why do we strip the wire this way?
Stripping the insulation allows electrical
contact so electrical current will flow.
Stripping off the top half of the insulating
material on the right axle will provide a
period of time when current can flow
through the coil to create a temporary
magnetic field and a period of time when
current cannot flow, so no temporary
magnetic field is created.
When the bare copper of the axle is
rotated downward, bare copper will be
touching the axle support, and current will
flow through the coil. As soon as current
flows through the coil, it becomes an
electromagnet, creating a temporary
magnetic field. The temporary magnetic field
will interact with the permanent magnetic
field and give the wire a push.
When the bare copper is rotated
upward, insulated copper will be touching
the axle support, and no current will flow
through the coil. There will not be a
temporary magnetic field. According to
Newton's first law of motion, the coil will
keep moving in the direction it already
traveling, because no force is stopping it.
As soon as the bare copper of the axle
is rotated down again, current will flow and
the coil will get a new push, making it
continue to rotate.
So far, I have discussed the electromagnet.
Now I will attach the coil to the base
constructed off camera so that current can
flow through the coil.
I insert each axle end into a loop of the
axle support. The motor might well start
running right away!
This motor needs some fine-tuning:
Adjust the axle supports so the axle is
horizontal.
Give the coil a few turns to make sure it
can spin freely and does not rub against the
magnet.
Turn your coil 180 degrees, as maybe
the uncoated side of the axle was facing up,
not touching the axle support. Contact of the
bare wire with the axle support will create an
electrical connection and allow current to
flow.
CAM
Key CG Credits
SOC (standard out cue)
Theme Music
Fade to Black
Fade out Music