PASCO SF-8616, SF-8617 User Manual

Instruction Manual
and Experiment Guide
for the PASCO scientific
Model SF-8616 and 8617

COILS SET

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11/89

Copyright © November 1989 $15.00

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How to Use This Manual

The best way to learn to use the PASCO Basic Coils Set or
the PASCO Complete Coils Set (referred to collectively as
PASCO Coils Set) is to spend some time experimenting with
it. We’ve organized this manual to get you started as
quickly as possible. We strongly recommend that you read
the Introduction and Experiments sections first. These are

Introduction

The PASCO scientific SF-8616 Basic Coils Set and SF-8617
Complete Coils Set provide necessary parts to experimen­tally investigate relationships involved with electromagnet­ism and electromagnetic induction. Coupled with a galva­nometer, an accurate A.C. voltmeter, an A.C. ammeter, an
oscilloscope and an A.C. power supply, little else is needed
to carry out studies in this important area.

Additional equipment which is recommended includes small
but strong magnets such as the ones found in the PASCO
SE-8604 Bar Magnet Set, low constant springs, ring stands,
a magnetic compass and iron filings.

One can study basic electromagnetism. The direction of the
windings is shown on the top of each coil, allowing the
relationship between current direction and the direction of
the resulting magnetic field to be studied. See Figure 1.

followed by 4 experiments for your students to get started
on. The experiments are ready to send to the copy room.

The Appendix contains technical data on the construction
and operation of the coils.

between the magnet and coil is needed. The effect of
moving slow versus moving fast can be demonstrated.

Finally, changing the number of coils of wire and repeating
the process will complete an initial investigation. These
investigations are generally semi-quantitative, focusing on
relative sizes and directions. Another way to change the
magnetic field is to provide an alternating magnetic field
through the use of a second coil and an alternating current.
See Figure 3.

OUTIN

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compass

Figure 1

Using a coil from either
kit, it is easy to demon­strate that a moving coil
of wire near a magnet, or
a moving magnet near a
coil of wire will induce a
voltage, and therefore a
current. Simply move a
magnet into the coil as
shown in Figure 2, and a
galvanometer will show a
current flow.

Moving the magnet back out will yield a current in the
opposite direction. Reversing the magnet will reverse the
relative currents, also. Leaving the magnet at rest inside the
coil will produce no current. Thus, a change in relationship

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Galvanometer

Figure 2

Figure 3

The Coils Set provides multiple coils and cores to experi­ment with this principle. These investigations lead to the
basic relationships involved in transformers, and lead to
more advanced studies of self- and mutual-induction.

With the addition of
two magnets and small
springs, a classic
interaction of induced
current and electro­magnetic effects, plus
simple harmonic
motion, can be studied.
See Figure 4.

Figure 4

Suggested Experimental Approach

Demonstrate the basic principle of using the core and two
coils to make a transformer. Show coils, core(s), supplies,
loads, meters, etc. Have students develop areas of investiga­tion and then proceed to carry them out. "Research teams"
could investigate different factors and then combine their
results for a comprehensive look at transformers.

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Equipment Supplied

Your SF-8616 Basic Coils Set comes with the items shown in Figure 5a:

a. (1) SF-8609 200-turn Coil
b. (2) SF-8610 400-turn Coils
c. (1) SF-8611 800-turn Coil
d. (1) SF-8614 U-shaped Core
e. (1) Manual

Your SF-8617 Complete Coils Set comes with all of the items in the SF-8616 Basic Coils Set along with the following
additional items, as shown in Figure 5b:

f. (1) SF-8612 1600-turn Coil
g. (1) SF-8613 3200-turn Coil
h. (2) SF-8615 E-shaped Core

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a

Figure 5a

Figure 5b

b

b

c

f

g

d

PASCO
Manual

e

h

2

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Experiments

Nature of Magnetic Field from an Electro­magnet

The coils from your PASCO Coils Set can be used in
conjunction with a d.c. power supply or a battery to produce
constant magnetic fields. Three possible experiments are
shown below.

Figure 8b

•

compass

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Figure 6

In Figure 6, a d.c. power supply is connected to the coil. A
nearby magnetic compass is used to show the presence of a
magnetic field and its direction. By noting the direction of
the windings on the coil (See Figure 7), students can develop
the rule for current direction and the resulting magnetic field
direction. This experimental setup can be quantified, leading
to a determination of how much current, through how many
turns, is needed to produce a magnetic field equal to the
earth’s field. Specifics of the experimental design are left to
the teacher and student.

1600

Figure 7

ALTERNATIVE: Small magnetic compasses can be used to
probe around the coil to show its magnetic field.

Figure 9 shows a current carrying coil with a magnetic field
inside. The cross-piece from the U-shaped Core is shown
inserted in the coil, although the same experiment can be
performed without the core. The strength of the electromag­net thus produced could be tested in a number of ways,
including the use of the PASCO SF-8606 Digital Gauss/
Tesla Meter. Note that the dramatic increase in magnetic
field strength with the addition of a core can be clearly
demonstrated.

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In Figure 8a and 8b, a coil is shown with its magnetic axis
parallel to the table. A piece of cardboard is mounted so that
it can be inserted into the center of the coil and extend
beyond it on all sides. Iron filings are then sprinkled on the
cardboard around the end of the current carrying coil. The
magnetic field pattern can be quickly demonstrated.

Figure 8a

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Figure 9

Solenoid

If the cross piece from the U-shaped Core is inserted into a
coil, but not centered, it will be pulled into the coil when the
alternating current is turned on. This demonstrates the basic
action of a solenoid. In experiments with the 400-turn coil, a
voltage of 8-10 volts A.C. was successful in demonstrating
this principle. See Figure 10.

Iron Core

Figure 10

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Electromagnetic Induction

Use a small, relatively strong bar magnet to demonstrate
electromagnetic induction. It is only necessary to move the
magnet up and down in the center of the coil. If the coil is
attached to a galvanometer, the relative size of the induced
current and the direction can be noted. See Figure 11.

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showed a drop-off to an output voltage of less than 20%
from the input voltage when the two 400-turn coils were
used in this manner.

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Galvanometer

Figure 11

A second way of showing the effect is to connect the coil to
an oscilloscope. See Figure 12

Figure 12

NOTE: A galvanometer shows the current
produced, which should be proportional to the size
of the induced voltage. Due to mechanical damp­ing, galvanometers do not rise to the maximum
value, but give useful semi-quantitative measure­ments of the maximum currents. An oscilloscope
shows the size of the induced voltage directly, and
gives a more instantaneous value.

Figure 14

To improve the mutual induction, an iron core can be
introduced. See Figure 15. Using the cross piece from the
U-shaped core, the induced voltage increased to almost 50%
of the primary voltage under the same conditions as above.

Iron Core

Figure 15

Primary Secondary

Numerous modifications of the cores which are provided can
be investigated. In each case, the ratio of secondary voltage
to primary voltage is noted. The variables in this situation
thus become: Primary Number of Turns, Secondary Number
of Turns, Existence of a Core, Shape of the Core, Primary
Voltage, Primary Current, Secondary Voltage and Secondary
Current. Students can be led on directed studies, or given
the materials to develop their own experiments. Some
possibilities are shown in Figure 16 below.

The set-up below gives a method of “automatically” show­ing the induced voltage. A light spring which gives a nice
simple harmonic motion with the attached magnet is needed.
Note that the method of attaching the magnet is via a
machine nut which is hooked to the spring and held by the
magnetic field of the magnet. See Figure 13.

Figure 13

TRANSFORMERS

Leading directly to the study of transformers, the setup in
Figure 14 allows students to see how induction can proceed
by passing magnetic field between the two coils. Using air
as the medium between the two coils, PASCO’s experiments

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Without Cross Bar

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With Cross Bar

Figure 16

Primary Secondary 1 Secondary 2

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