Elenco Electronics Snap Circuits STEM, SCSTEM1 Instruction Manual And Recipe Book

Copyright © 2017 by Elenco®Electronics, Inc. All rights reserved. No part of this book shall be reproduced by 753136
any means; electronic, photocopying, or otherwise without written permission from the publisher.

U.S. Patents: 7,144,255; 7,273,377, & patents pending

Instruction Manual

Projects 1 - 93

Project 3

8-108

AGES

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-1-

1. Most circuit problems are due to incorrect assem­bly, always double-check that your circuit exactly
matches the drawing for it.

2. Be sure that parts with positive/negative markings
are positioned as per the drawing.

3. Be sure that all connections are securely snapped.

4. Try replacing the batteries.

Elenco®is not responsible for parts damaged due to
incorrect wiring.

Basic Troubleshooting

Note: If you suspect you have damaged parts, you can follow

the Advanced Troubleshooting procedure on page 11 to deter­mine which ones need replacing.

Basic Troubleshooting 1

Parts List 2

How to Use It 3

Assembling the Build-Your-Own Electromagnet 4

Guidelines for Use in Classrooms & Home School 4

About Your Snap Circuits

®

Parts 5-8

Introduction to Electricity 9

DOs and DON’Ts of Building Circuits 10

Advanced Troubleshooting 11

Project Listings 12

Projects 1 - 93 13 - 74

Test Your Knowledge 75

Other Snap Circuits

®

Projects 76

Block Layout Back Cover

Table of Contents

WARNING: Always check your wiring

before turning on a circuit. Never leave
a circuit unattended while the batteries
are installed. Never connect additional
batteries or any other power sources to
your circuits. Discard any cracked or
broken parts.

Adult Supervision: Because children’s

abilities vary so much, even with age
groups, adults should exercise discre­tion as to which experiments are suit­able and safe (the instructions should
enable supervising adults to establish

the experiment’s suitability for the
child). Make sure your child reads and
follows all of the relevant instructions
and safety procedures, and keeps them
at hand for reference.

This product is intended for use by
adults and children who have attained
sufficient maturity to read and follow
directions and warnings.

Never modify your parts, as doing so
may disable important safety features
in them, and could put your child at risk
of injury.

 Use only 1.5V AA type, alkaline batteries

(not included).
 Insert batteries with correct polarity.
 Non-rechargeable batteries should not

be recharged. Rechargeable batteries

should only be charged under adult su-

pervision, and should not be recharged

while in the product.
 Do not mix old and new batteries.

 Do not connect batteries or battery

holders in parallel.

 Do not mix alkaline, standard (carbon-

zinc), or rechargeable (nickel-cadmium)
batteries.



Remove batteries when they are used up.

 Do not short circuit the battery termi-

nals.

 Never throw batteries in a fire or attempt

to open its outer casing.

 Batteries are harmful if swallowed, so

keep away from small children.

Batteries:

!

WARNING: CHOKING HAZARD -

Small parts. Not for children under 3 years.

!

Conforms to all applicable U.S.

government requirements and

CAN ICES-3 (B)/NMB-3 (B).

!

WARNING: Moving parts. Do not touch the fan while it is spinning.

WARNING: SHOCK HAZARD - Never connect Snap

Circuits

®

to the electrical outlets in your home in any way!

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-2-

Important: If any parts are missing or damaged, DO NOT RETURN TO RETAILER. Call toll-free [phone] or e-mail us at: [e-mail].

Customer Service ● 150 Carpenter Ave. ● Wheeling, IL 60090 U.S.A.

Parts List (Colors and styles may vary) Symbols and Numbers

Qty. ID Name Symbol Part # Qty. ID Name Symbol Part #

r 3

1-Snap Wire 6SC01

r 1

String 6SCM1S

r 6

2-Snap Wire 6SC02

r 1

Spare Motor Top 6SCM1T

r 3

3-Snap Wire 6SC03

r 1

Electromagnet 6SCM3

r 1

4-Snap Wire 6SC04

r 2

Iron Core Rod (46mm)

6SCM3C

r 1

5-Snap Wire 6SC05

r 1

Bag of Paper Clips 6SCM3P

r 1

6-Snap Wire 6SC06

r 1

Meter 6SCM5

r 1

Battery Holder - uses
3 1.5V type AA (not included)

6SCB3

r 1

Magnet 6SCMAG

r 1

Base Grid (11.0” x 7.7”)

6SCBG

r 1

Nut Snap 6SCNS

r 1

Compass 6SCCOM

r 1

Two Spring Socket 6SCPY1

r 1

White LED 6SCD6

r 1

Slide Switch 6SCS1

r 1

Copper Electrode with Snap

6SCECS

r 1

Press Switch 6SCS2

r 1

Zinc Electrode with Snap

6SCEZS

r 1

Relay 6SCS3

r 1

Iron Fillings 6SCIF

r 1

Switcher 6SCS6

r 1

Jumper Wire (Black) 6SCJ1

r 1

Reed Switch 6SCS9

r 1

Jumper Wire (Red) 6SCJ2

r 1

Coil 6SCWIRE1

r 3

Lamp 6SCL4

r 2

Grommet 662510

r 1

Motor 6SCM1

r 1

Thin Rod MWK01P5

r 1

Glow Fan Blade 6SCM1FG

You may order additional / replacement parts at our website:

www.snapcircuits.net

M1

S2

M5

M3

6

5

4

3

2

1

B3

L4

N

S

D6

S1

S3

S6

S9

?1

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-3-

How to Use SnapCircuits

®

Snap Circuits®uses building blocks with snaps
to build the different electrical and electronic
circuits in the projects. Each block has a func­tion: there are switch blocks, light blocks, bat­tery blocks, different length wire blocks, etc.
These blocks are different colors and have
numbers on them so that you can easily iden­tify them. The blocks you will be using are
shown as color symbols with level numbers
next to them, allowing you to easily snap them
together to form a circuit.

For Example:

This is the switch block which is green and has
the marking on it. The part symbols in this
booklet may not exactly match the appearance
of the actual parts, but will clearly identify them.

This is a wire block which is blue and comes
in different wire lengths.
This one has the number , , ,
or on it depending on the length of the wire
connection required.

There is also a 1-snap wire that is used as a
spacer or for interconnection between different
layers.

You need a power source to build each circuit.
This is labeled and requires three (3) 1.5V
“AA” batteries (not included).

When installing a battery, be sure the spring
is compressed straight back, and not bent up,
down, or to one side.

A large clear plastic base grid is included with
this kit to help keep the circuit blocks properly
spaced. You will see evenly spaced posts that
the different blocks snap into. The base has
rows labeled A-G and columns labeled 1-10.

Next to each part in every circuit drawing is a
small number in black. This tells you which
level the component is placed at. Place all
parts on level 1 first, then all of the parts on
level 2, then all of the parts on level 3, etc.

Some circuits use the jumper wires to make
unusual connections. Just clip them to the
metal snaps or as indicated.

Usually when the motor is used, the glow
fan will usually be placed on it. On top of the
motor shaft is a black plastic piece (the motor
top) with three little tabs. Lay the fan on the
black piece so the slots in its bottom “fall into
place” around the three tabs in the motor top.
If not placed properly, the fan will fall off when
the motor starts to spin.

S2

2

3

4

5

Note: While building the projects, be careful
not to accidentally make a direct connection
across the battery holder (a “short circuit”),
as this may damage and/or quickly drain the
batteries.

B3

M1

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How to Use SnapCircuits

®

Assembling the build-your-own electromagnet:

You need the coil, an iron core rod, a grommet, and the 2-spring socket
(?1).

Wrap the coil around one of the iron core rods, leaving about 3 inches
free at both ends. Place a grommet on the end of the rod to help keep
the coil wire from coming off it.

Check that some of the protective coating has been removed
at each end, leaving about half an inch of bare wire. If the coil
wire is broken (or later gets broken) then use sandpaper or
steel wool to scrape off the protective coating for about half an
inch at each end.

Connect the bare wire ends to the springs on the 2-spring
socket (the springs must connect to the wire where the varnish
has been removed, otherwise it won’t make electrical contact).

GUIDELINESFORUSEINCLASSROOMSORHOMESCHOOLING:

This product is a tool for opening the exciting world of electronics, and its relationship to
magnetism. Following the Learn by Doing®concept, electronics & magnetism will be easy
for students to understand by using Snap Circuits®to build circuits as they learn about them.
This kit emphasizes the practical applications of electronics, without bogging down in math­ematics. This course is as much about science as about electronics & magnetism.

Why should students learn about electronics? Electronics plays an important and increasing
role in their everyday lives, and so some basic knowledge of it is good for all of them. Learn­ing about it teaches how to do scientific investigation, and the projects develop basic skills
needed in today's world.

This product is intended for ages 8 and up. The only prerequisite is basic reading skills.

It should take about 6 hours to do this entire book, or about 2 hours to read the Introduction
to Electricity (page 9) and do just the educational summary projects (shown on page 12).
Teachers should review the Project Listing (page 12) and decide what is best.

INSTRUCTOR PREPARATION/ORGANIZATION

● Determine what the learning environment will be. Will the students be learning independ­ently or in small groups? How much teacher instruction will there be for each section?
Will the students be reading the lesson as homework and then have limited teacher in­struction before performing the experiments? Decide when quizzes will be given and
how they will be organized.

● Allocate time within the session as needed for:

● Teacher instruction about the topics being covered during the session.

● Getting the Snap Circuits

®

components into the workspace.

● Teacher instruction about the specific projects to be performed during that ses­sion.

● Building and testing the circuits.

● Performing experiments (and teacher verification if desired).

● Dismantling the circuits and returning Snap Circuits

®

components to storage area.

● Reassembling the class for review.

● Make sure the students know their objectives for the day, how much time they will need

for cleanup, and where the materials are being stored.

● Students must understand that there are usually many ways of making the same circuit,
and that the instructor may not know all the answers. They are doing scientific investi­gation, and many circuit projects suggest variations to experiment with.

● Have students review the DO’s and DON’Ts of Building Circuits on page 10 at the begin­ning of each session.

Answers to quiz questions are at www.snapcircuits.net/scstem1

.

-4-

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About Your Snap Circuits

®

Parts

(Part designs are subject to change without notice).

The base grid is a plat-

form for mounting
parts and wires. It
functions like the
printed circuit boards
used in most elec-

tronic products, or

like how the walls are
used for mounting the electrical wiring in your
home.

BASEGRID

The blue snap wires

are wires used to con-

nect components.

They are used to trans-

port electricity and do not af-

fect circuit performance. They

come in different lengths to allow orderly

arrangement of connections on the base grid.

The red and black

jumper wires

make flexible con­nections for times
when using the snap wires
would be difficult. They also
are used to make connections off the base grid.

Wires transport electricity just like pipes are used
to transport water. The colorful plastic coating
protects them and prevents electricity from get­ting in or out.

The batteries (B3) produce an electrical

voltage

using a chemical reaction. This “voltage” can be
thought of as electrical pressure, pushing elec­tricity through a circuit just like a pump pushes
water through pipes. This voltage is much lower
and much safer than that used in your house
wiring. Using more batteries increases the “pres­sure”, therefore, more electricity flows.

The funny marking on the battery holder is the
standard battery symbol used in electrical wiring
diagrams. These wiring diagrams are called

schematics, and are used in everything from

house wiring to complex radios.

SNAP WIRES & JUMPER WIRES

BATTERY HOLDER

Battery Symbol

Battery Holder (B3)

Symbols

Slide &Press

Switches
(S1 & S2)

SWITCHES

The slide & press switches (S1 &S2) connect
(pressed or “ON”) or disconnect (not pressed or
“OFF”) the wires in a circuit. When ON they have
no effect on circuit performance. Switches turn
on electricity just like a faucet turns on water from
a pipe.

Reed Switch (S9)

The reed switch (S9) is an electrical switch that
can be controlled by a magnet. It has two metal
contacts close together. The magnetic field from
the magnet makes the contacts come together,
completing a circuit just like other switches do.

The switcher (S6) is a more complex switch used
to reverse the wires to a component or circuit. See
project 2 for an example of connections.

Switcher (S6)

Its symbol & connections look like this:

Symbol

-5-

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About Your Snap Circuits

®

Parts

How does electricity turn the shaft in the motor?
The answer is magnetism. Electricity is closely
related to magnetism, and an electric current
flowing in a wire has a magnetic field similar to
that of a very, very tiny magnet. Inside the motor
is a coil of wire with many loops wrapped around
metal plates. This is called an electromagnet. If
a large electric current flows through the loops,
it will turn ordinary metal into a magnet. The
motor shell also has a magnet on it. When elec­tricity flows through the electromagnet, it repels
from the magnet on the motor shell and the shaft
spins. If the fan is on the motor shaft, then its
blades will create airflow.

The meter (M5) is an important measuring de­vice. You will use it to measure the voltage (elec­trical pressure) and current (how fast electricity
is flowing) in a circuit.

The electrical symbol for a meter is shown below.

The meter measures voltage when connected in
parallel to a circuit and measures the current
when connected in series in a circuit.

This meter has one voltage scale (5V) and two
current scales (1mA and 1A). These use the
same meter but with internal components that
scale the measurement into the desired range.
This will be explained more later. Note: Your M5
meter is a simple meter. Don’t expect it to be as
accurate as normal electronic test instruments.

The motor (M1) converts electricity into mechan-
ical motion. An electric current in the motor will
turn the shaft and the motor blades, and the fan
blade if it is on the motor. The electrical symbol
for a motor is also shown here.

METER

MOTOR

Meter Symbol

Magnet

Coil

Pointer

Contacts

Motor Symbol

Magnet

Electromagnet

Shaft

Power Contacts

Shell

Meter (M5)

Motor (M1)

Inside the meter there is a fixed magnet and a
moveable coil around it. As current flows through
the coil, it creates a magnetic field. The interac­tion of the two magnetic fields causes the coil
(connected to the pointer) to move (deflect).

Glow-in-the-dark Fan

-6-

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About Your Snap Circuits

®

Parts

A light bulb, such as in the 4.5V lamps (L4), con-
tains a special thin high-resistance wire. When a
lot of electricity flows through, this wire gets so
hot it glows bright. Voltages above the bulb’s rat­ing can burn out the wire.

The electrical symbol for a lamp is shown here,
though other symbols are also used in the industry.

LAMP

Lamp Symbol

The electromagnet (M3) is a large coil of wire,
which acts like a magnet when electricity flows
through it. Placing an iron bar inside increases
the magnetic effects. The electromagnet can
store electrical energy in a magnetic field.

The properties of the electromagnet will be ex­plained in the projects. Note that magnets can
erase magnetic media like computer disks.

The grommet will be used to hold the iron core
rod on the electromagnet.

ELECTROMAGNET

Electromagnet (M3)

Iron Core Rod

(usually placed in

electromagnet)

Electromagnet Sym-

bol with Rod Inside

Grommet

OTHER PARTS

The magnet is an ordinary magnet
like those in your home.

The compass is
a standard compass.
The red needle will
point toward the
strongest magnetic
field around it, usually
the north pole of the
earth.

The iron filings are tiny
fragments of iron in a
sealed case. They
will be used in
m a g ne t i s m
projects.

The copper and zinc elec-
trodes are just metals that
will be used for electro-chem­ical projects. They have
snaps attached for easy con­nection.

The nut-snap is an iron nut
mounted on a snap for special
projects.

The string will be used
in special projects. You
can use your own
string if you need more.

The thin rod is an iron
bar for special projects.

The Paper Clips will be
used for special proj­ects. You can use your
own if you need more,
but they must be metal.

The spare motor top is provided in
case you break the one on the
motor. Use a screwdriver to pry
the broken one off the motor,
then push the spare one on.

Electromagnet Sym-

bol without Rod

(a coil of wire)

Lamp (L4)

-7-

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About Your Snap Circuits

®

Parts

LED

White LED (D6)

The white LED(D6) is a light emitting diode, and
may be thought of as a special one-way light
bulb. In the “forward” direction, (indicated by the
“arrow” in the symbol) electricity flows if the volt­age exceeds a turn-on threshold brightness then
increases. A high current will burn out an LED,
so the current must be limited by other compo­nents in the circuit (Snap Circuits

®

LEDs have in­ternal resistors added, to protect them in case
you make wiring mistakes). LEDs block electricity
in the “reverse” direction.

COM

Relay:

Coil - connection to coil
Coil - connection to coil
NC - normally closed contact
NO - normally open contact
COM - common

See project 69 for an example of proper connections.

Coil

Coil

NO

NC

The relay (S3) is an electronic switch with contacts
that can be closed or opened. It contains a coil that
generates a magnetic field when current flows
through it. The magnetic field attracts an iron arma­ture, which switches the contacts. See project 69 for
further explanation.

RELAY

Relay (S3)

Two Spring Socket

Two Spring
Socket (?1)

The two-spring socket (?1) just has two
springs, and won’t do anything by itself. In this
set it is used to make the build-your-own electro­magnet, as per page 5. It can also be used by
advanced users to connect other electronic com­ponents to Snap Circuits

®

for creating your own

circuits.

LED Symbol

Relay Symbol

-8-

The symbols for the parts shown in
this section are used by engineers in
drawings of their circuits, called
schematics. Wires connecting com­ponents are shown as lines, with a
dot indicating a connection between
lines that cross. Here are schematics
of some of the circuits you will build:

SCHEMATICS

Project 14 Schematic:

Project 27 Schematic:

Project 43 Schematic:

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-9-

Introduction to Electricity

What is electricity? Nobody really knows. We only know how to produce it, under­stand its properties, and how to control it. Electricity is the movement of sub-atomic
charged particles (called electrons) through a material due to electrical pressure
across the material, such as from a battery.

Power sources, such as batteries, push electricity through a circuit, like a pump
pushes water through pipes. Wires carry electricity, like pipes carry water. Devices
like LEDs, motors, and speakers use the energy in electricity to do things. Switches
and transistors control the flow of electricity like valves and faucets control water.
Resistors limit the flow of electricity.

The electrical pressure exerted by a battery or other power source is called volt-
age and is measured in volts (V). Notice the “+” and “–” signs on the battery; these
indicate which direction the battery will “pump” the electricity.

The electric current is a measure of how fast electricity is flowing in a wire, just
as the water current describes how fast water is flowing in a pipe. It is expressed
in amperes (A) or milliamps (mA, 1/1000 of an ampere).

The “power” of electricity is a measure of how fast energy is moving through a
wire. It is a combination of the voltage and current (Power = Voltage x Current). It
is expressed in watts (W).

The resistance of a component or circuit represents how much it resists the elec­trical pressure (voltage) and limits the flow of electric current. The relationship is
Voltage = Current x Resistance. When the resistance increases, less current flows.
Resistance is measured in ohms (W), or kilo ohms (kW, 1000 ohms).

Nearly all of the electricity used in our world is produced at enormous generators
driven by steam or water pressure. Wires are used to efficiently transport this en­ergy to homes and businesses where it is used. Motors convert the electricity back
into mechanical form to drive machinery and appliances. The most important as­pect of electricity in our society is that it allows energy to be easily transported
over distances.

Note that “distances” includes not just large distances but also tiny distances. Try
to imagine a plumbing structure of the same complexity as the circuitry inside a
portable radio - it would have to be large because we can’t make water pipes so
small. Electricity allows complex designs to be made very small.

There are two ways of arranging parts in a circuit, in series or
in parallel. Here are examples:

Placing components in series increases the resistance; highest
value dominates. Placing components in parallel decreases the
resistance; lowest value dominates.

The parts within these series and parallel sub-circuits may be
arranged in different ways without changing what the circuit
does. Large circuits are made of combinations of smaller series
and parallel circuits.

Series Circuit

Parallel Circuit

SC_STEM1_manual_PRINT.qxp_Layout 1 7/13/17 4:41 PM Page 10

DO’s and DON’Ts of Building Circuits

After building the circuits given in this booklet, you may wish to experi­ment on your own. Use the projects in this booklet as a guide, as many
important design concepts are introduced throughout them. Every circuit
will include a power source (the batteries), a resistance (which might be
a lamp, motor, electromagnet, etc.), and wiring paths between them and
back.

You must be careful not to create “short circuits” (very low-resis-

tance paths across the batteries, see examples below) as this will dam­age components and/or quickly drain your batteries. ELENCO®is not

responsible for parts damaged due to incorrect wiring.

Here are some important guidelines:

ALWAYS

USE EYE PROTECTION WHEN EXPERIMENTING ON YOUR
OWN.

ALWAYS include at least one component that will limit the current

through a circuit, such as a lamp, motor, or electromagnet.

ALWAYS use the meter and switches in conjunction with other com-

ponents that will limit the current through them. Failure to
do so will create a short circuit and/or damage those parts.

ALWAYS disconnect your batteries immediately and check your

wiring if something appears to be getting hot.

ALWAYS check your wiring before turning on a circuit.

NEVER connect to an electrical outlet in your home in any way.

NEVER leave a circuit unattended when it is turned on.

NEVER touch the motor when it is spinning at high speed.

For all of the projects given in this book, the parts may be arranged in
different ways without changing the circuit. For example, the order of
parts connected in series or in parallel does not matter — what matters
is how combinations of these sub-circuits are arranged together.

Examples of SHORTCIRCUITS - NEVERDOTHESE!!!

You are encouraged to tell us about new programs and circuits you create.
If they are unique, we will post them with your name and state on our web­site at: www.snapcircuits.net/learning_center/kids_creation.
Send your suggestions to ELENCO

®

: [e-mail].

ELENCO®provides a circuit designer so that you can make your own Snap
Circuits®drawings. This Microsoft®Word document can be downloaded
from: www.snapcircuits.net/learning_center/kids_creation or through
the www.snapcircuits.net website.

WARNING: SHOCK HAZARD - Never connect your Snaptric-

ity®set to the electrical outlets in your home in any way!

Placing a 3-snap wire directly across
the batteries is a SHORT CIRCUIT.

This is also a
SHORT CIRCUIT.

When the switch (S6)
is turned on, this large
circuit has a SHORT
CIRCUIT path (as
shown by the arrows).
The short circuit pre­vents any other por­tions of the circuit from
ever working.

NEVER

DO!

!

!

NEVER

DO!

!

NEVER

DO!

!

NEVER

DO!

Warning to Snap Circuits®owners: Do not connect addi-

tional voltage sources from other sets, or you may damage
your parts. Contact ELENCO

®

if you have questions or need

guidance.

!

-10-

SC_STEM1_manual_PRINT.qxp_Layout 1 7/13/17 4:41 PM Page 11

-11-

Advanced Troubleshooting

(Adult supervision recommended)

ELENCO®is not responsible for parts dam­aged due to incorrect wiring.

If you suspect you have damaged parts,
you can follow this procedure to systemat­ically determine which ones need replac­ing:

1. White LED(D6), 4.5V lamps (L4), motor

(M1), and battery holder(B3):

Place bat­teries in holder. Place each 4.5V lamp di­rectly across the battery holder, it should
light. Place the white LED directly across
the battery holder (LED + to battery +), it
should light. Do the same with the motor, it
should spin. If none work then replace your
batteries and repeat, if still bad then the bat­tery holder is damaged.
If the Motor (M1) does not balance the fan
evenly: Inspect the black plastic piece at
the top of the motor shaft, it should have 3
prongs. If missing or broken, replace it with
the spare that is included with this kit (a bro­ken one can be removed with a screw­driver). If the motor is fine, then inspect the
fan.

3.

Jumper wires: Use this mini-circuit to test

each jumper wire, the lamp should light.

4.

Snap wires: Use the mini-circuit below to

test each of the snap wires, one at a time.
The lamp should light.

5.

Two-spring socket (?1) and coil (the
build-your-own electromagnet): use the

mini-circuit in test step 4 but replace the 4­snap wire with ?1, with the coil connected
between its springs; the lamp should light. If
the lamp does not light be sure the protec­tive coating has been removed from the
ends of the coil wire where it attaches to the
springs; if necessary use sandpaper or steel
wool to scrape off the protective coating at
each end.

Switcher (S6): Build this mini-circuit. With the

switch in the middle position the motor (M1)
should be off; in the top position the motor
should spin counter-clockwise, and in the
bottom position the motor should spin clock­wise. Do not touch the motor while it is spin­ning.

6.

Slide switch (S1), press switch (S2), &
reed switch (S9): Build project 85. When

you press the switch, the white LED should
light. Replace the press switch with the slide
switch to test it. Replace the slide switch
with the reed switch, and hold a magnet
next to the switch to turn on the LED.

7.

Meter (M5): Build project 85, but replace

the 3-snap wire with the meter.

a. Set the meter to the 5V scale and push

the press switch. The meter should
read at least 2.5V.

b. Set the meter to the 1mA scale and

push the switch. The reading should be
over maximum.

c. Set the meter to the 1A scale and push

the switch. The meter should show a
small current.

8.

Electromagnet (M3): Build project 47 and

place the iron core rod in the electromagnet.
When you press the switch (S2), the rod in
the electromagnet should act like a magnet.

9.

Iron filings: Sometimes the filings may

stick to the case, making it appear cloudy.
Move a magnet (the one in this kit or a
stronger one in your home) across the case
to clean them off.

10.

Relay (S3): Build project 69. Turn on the

slide switch (S1); the lamp (L4) should be
on. Push the press switch (S2) to turn off
the lamp and turn on the white LED (D6).

ELENCO

®

150 Carpenter Avenue

Wheeling, IL 60090 U.S.A.

Phone: [phone]

Fax: [phone]

e-mail: [e-mail]

Website: www.elenco.com

You may order additional / replace-

ment parts at:

www.snapcircuits.net

SC_STEM1_manual_PRINT.qxp_Layout 1 7/13/17 4:41 PM Page 12

Project # Description Page # Project # Description Page # Project # Description Page #

Project Listings (circuits with gold project numbers are the educational summary projects mentioned on page 4)

Fun Start

1 Lots of Lights 13
2 Flying Saucer 13
3 Electronic Playground 14

Fundamentals

4 Static Electricity 15
5 Light the Way (Lamp circuit) 17

6 Lights Bulbs of the Future 18

(LED circuit)
7 Ohm’s Law (Find lamp resistance) 18
8 Switches (4 types of switches) 19

9 Fuse 20

10 Materials Tester 21
(Conductors and insulators)
11 Make Your own Parts 22
(Resistance of water & pencils)
12 Motor Resistance 23
13 Electromagnet Resistance 23

Series & Parallel Circuits

14 Series Circuit (Lamps in series) 24
15 Series Circuit - Voltage 25

16 Parallel circuit (Lamps in parallel) 26

17 Parallel Circuit - Voltage 27
18 Parallel Swapping 28
19 Series Swapping 29
20 Batteries in Series 29
21 Lamp at Different Voltages 30
22 Motor at Different Voltages 31
23 LED at Different Voltages 31

24 Voltage Shifter 31

(Voltages in a series circuit)
25 Double Voltage Shifter 32

26 Double Switching Ammeter 33

(Currents in a series circuit)
27 Current Divider 34
(Currents in parallel circuits)
28 3 Currents 35
(Currents in parallel circuits)
29 AND Circuit 35

(AND gate with switches)

30 OR Circuit 36
(OR gate with switches)

Lamps &Motors

31 Light Bulb 36
(Incandescent light bulbs)
32 Light Bulb with Meter 37
33 2 Direction motor 38

(Reversing motor spin)

34 3-Speed Motor 39
(Adjusting motor speed with lamps)
35 3-Speed Motor - Voltage 40
36 3-Speed Motor with Fan 41
37 4-Speed Motor 42
38 Back EMF

(Motor characteristics) 42

39 Big Load 43
(Load effect on battery voltage)
40 Big Load - Voltage 44
41 Holding Down 45

(Overloading batteries)

42 Propellor and Fan (Motor direction) 46
43 Motor & Lights 47
44 Slow Motor & Lights 47

Magnetism &Electromagnetism

45 Compass 46

46 Magnetic Fields 47

47 Electronic Magnet 48
48 Electromagnet Magnetic Field 49
49 Electromagnet Tower 50

(Suspending iron rod in air)

50 Electromagnet Direction 51
(Reversing current)
51 Wire Magnet 51
(Magnetic field from wire)
52 Better Wire Magnet 52

53 Build-Your-Own Electromagnet 53

54 Build-Your-Own Electromagnet (II) 53
55 Magnetic Induction 54
(Induce a current in a coil)

56 Electromagnetic Induction 54

(Induce a current in another circuit)
57 Electromagnet Challange 55
58 Coil Resistance 55

Generators

59 Generator 56
(Harnessing fan energy)
60 Generator with Light 56

61 Motor with Flashes 57

62 Make Your Own Generator 57

63 High Speed Generator 58
(Use string to spin the motor faster)
64 Magnetic Energy Released 58
65 Relay Magnetic Energy Released 59

Magnetic Switches

66 Reed Switch 59

(Magnetically controlled switch)

67 Reed Switch with Electromagnet 60
68 Build-Your-Own Reed Switch 60

Relay Circuits

69 Relay 61
70 Relay Buzzer 62
71 Relay Buzzer Meter 62

72 Alternating Voltage 63

(Make an AC voltage using relay)
73 Super Buzzer 63
74 Transformer (Build a transformer) 64
75 Relay Memory 65
76 Relay Circuit 65
77 Build Your Own Relay 66
78 Build Your Own Buzzer 67
79 Build our Own Vibrating Circuit 67

Electricity from Liquids

80 Cola Power 68

(Use soda as a battery)

81 Fruit Power 68
(Use fruit as a battery)
82 Water Impurity Detector 69
(Current from water)

Fun Circuits

83 Swing the Magnet 70
84 Magic Rope Trick 70
(Suspend objects in air)
85 Morse Code 71
86 Hypnotic Discs (Spin patterns) 72
87 Spin Draw 73

88 2-Way Circuit 74

89 Electromagnet Music 74
90 Electromagnet Controlled Switch 75
91 Electromagnetic Playground 75
92 Magnetic Switcher 76
93 Circuits Fun 76

-12-

SC_STEM1_manual_PRINT.qxp_Layout 1 7/13/17 4:41 PM Page 13

Project 1

Lots of Lights

Build the circuit shown by placing all the parts with a black 1 next to them on the board first.
Then, assemble parts marked with a 2. Install three (3) “AA” batteries (not included) into the
battery holder (B3). Turn on the slide switch (S1); the lamps (L4) and white LED (D6) light.

Placement Level Numbers

+

NOTE: this circuit (and many others in this book) have an LED
being used without a resistor or other component to limit the
electric current through it. Normally this could damage an LED
but your Snap Circuits® LEDs include internal protection re­sistors, and will not be damaged. Be careful if you later use
other electrical sets with unprotected LEDs.

Project 2

Build the circuit as shown and place
the fan on the motor (M1). Be sure
the “+” side of the motor is on the left.

Push the press switch (S2) until the
motor reaches full speed, then re­lease it. The fan blade should rise and
float through the air like a flying
saucer. Be careful not to look directly
down on fan blade when it is spinning.

If the fan doesn’t fly off, then turn the
switch on and off several times rapidly
when it is at full speed. New alkaline
batteries work best.

+

!

WARNING: Moving parts. Do not

touch the fan or motor during operation.

!

WARNING: Do not

lean over the motor.

The air is being blown down through the blade and the motor rotation
locks the fan on the shaft. When the motor is turned off, the blade
unlocks from the shaft and is free to act as a propeller and fly through
the air. If speed of rotation is too slow, the fan will remain on the
motor shaft because it does not have enough lift to propel it. The
motor will spin faster when the batteries are new.

How does the fan rise? Think first about how you swim. When your
arms or legs push water behind you, your body moves ahead. A sim­ilar effect occurs in a helicopter - the spinning blades push air down,
and create an upward force on the blades. If the blades are spinning
fast enough, the upward force will be strong enough to lift the heli­copter off the ground.

While the switch is pressed, the motor rotation locks the fan on the
motor shaft. The fan does not spin fast enough to lift the entire circuit
off the ground. When the motor is turned off, the fan unlocks from
the shaft. The fan rises into the air like a helicopter, since it is no
longer held down by the weight of the full circuit.

Flying Saucer

-13-

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Project 3 Electronic Playground

Electronics is the science of working with
and controlling electricity. This circuit is
shown on the front of the Snap Circuits

®

STEM box, use that picture to help in
building it.

!

WARNING: Moving parts. Do not

touch the fan during operation.

Build the circuit as shown. Set the meter
(M5) to the 1A setting. Place the thin rod in
the electromagnet (M3). Place the glow fan
on the motor (M1). Assemble the build-your­own electromagnet as per the instructions
on page 5 (or you can assemble it later and
replace the 2-spring socket (?1) with a 3­snap wire).

Set the switcher (S6) to either side to light
the lamps (L4), spin the motor & fan, suck
the thin rod up into the electromagnet (M3),
and activate the build-your-own electromag­net. When activated, hold the build-your­own electromagnet near the compass to
attract the needle. The meter measures the
current.

Hold the magnet near the reed switch (S9)
to light the white LED (D6).

1A

!

WARNING:

Do not lean over the motor.

+

-14-

SC_STEM1_manual_PRINT.qxp_Layout 1 7/13/17 4:41 PM Page 15

Project 4

Static Electricity

These effects are caused by electricity. We call this
static electricity because the electrical charges are
not moving, although pulling clothes apart sounds like
static on a radio. When electricity is moving (usually
through wires) to do something in another place, we
call it an electric current.

Electricity is an attraction and repulsion of particles in
a material. All materials are made up of atoms, which
are really, really tiny. Atoms have a nucleus (which has
positive electrical charges), which is surrounded by tiny
electrons (negative electrical charges). When you rub
a material, electrons can move on or off the atoms, giv­ing them an electrical charge.

Electricity exists everywhere, but is so well balanced,
that you seldom notice it. But, sometimes differences
in electrical charges build up between materials, and
sparks can fly. Lightning is the same effect as the
sparks between clothes, but on a much greater scale.
A cloud holds static electricity just like a sweater.

Photo courtesy of: NOAA Photo Library, NOAA Central Library;
OAR/ERL/National Severe Storms Laboratory (NSSL) [via pingnews].

Why do
you often “see”
lightning before

you “hear” it? It is

because light trav-

els faster than

sound.

+

+

+

+

+

Electrons

–

–

–

–

–

–

Nucleus

This diagram shows the
structure of an atom, except
that the nucleus and elec­trons are actually much far­ther apart.

Find some clothes that cling together in
the dryer, and try to uncling them.

Rub a sweater (wool is best) and see how
it clings to other clothes.

Take off a sweater (wool is best) and listen
for crackling noises. Try it in a dark room
and see if you see sparks. Compare the
effects with different fabrics (wool, cotton,
etc.).

Note: This project works best on a cold dry day. If
the weather is humid, the water vapor in the air al­lows the static electric charge to dissipate, and this
project may not work.

If you wet the clothes then the static charge should
mostly dissipate. (Try it.)

You need a comb (or plastic ruler) and a
water faucet for this part. Run the comb
through your hair several times then hold it
next to a slow, thin stream of water from a
faucet. The water will bend towards it. You
can also use a plastic ruler. Rub it on your
clothes (wool works best).

Rubbing the comb
through your hair
builds up a static
electrical charge on
it, which attracts the
water.

-15-

SC_STEM1_manual_PRINT.qxp_Layout 1 7/13/17 4:41 PM Page 16

Next, hold your magnet near the paper pieces; nothing happens.

Run the comb in your hair again and place it next to the iron filings case; not much
happens (there may be a weak attraction). Now hold the magnet near the iron fil­ings; they jump to it easily.

What’s happening?

Iron filings are

weakly attracted

to the comb.

Iron filings are

strongly attracted

to the magnet.

Find a comb (or a plastic ruler) and some paper. Rip up the paper
into small pieces. Run the comb through your hair several times
then hold it near the paper pieces to pick them up. You can also
use a pen or plastic ruler, rub it on your clothes (wool works best).

Rubbing the comb through your hair pulls extremely tiny charged
particles from your hair onto the comb. These give the comb a
static electrical charge, which attracts the paper pieces.

Running the comb through your
hair builds up an electric charge
in it, which is different from the
magnetic charge in the magnet.
The paper pieces are attracted
to an electric charge, while the
iron filings are attracted to a
magnetic charge.

You will learn more about the
differences between electricity
and magnetism later.

Notice how your hair can “stand up” or be attracted to the comb when
the air is dry. How will this change if you wet your hair? (Try it.)

Take a piece of newspa­per or other thin paper
and rub it vigorously with
a sweater or pencil. It will
stick to a wall.

Cut the paper into two
long strips, rub them, then
hang them next to each
other. See if they attract
or repel each other.

If you have two balloons, rub
them to a sweater and then
hang the rubbed sides next
to each other. They repel
away. You could also use
the balloons to pick up tiny
pieces of paper.

Electricity is immensely more powerful than gravity (gravity is what causes
things to fall to the ground when you drop them). However electrical attrac­tion is so completely balanced out that you don’t notice it, while gravity’s ef­fects are always apparent because they are not balanced out.

Gravity is actually the attraction between objects due to their weight (or tech­nically, their mass). This effect is extremely small and can be ignored unless
one of the objects is as big as a planet (like the earth). Gravity attraction
never goes away and is seen every time you drop something. Electrical
charge, though usually balanced out perfectly, can move around and
change quickly.

For example, you have seen how clothes can cling together in the dryer due
to static electricity. There is also a gravity attraction between the sweaters,
but it is always extremely small.

-16-

SC_STEM1_manual_PRINT.qxp_Layout 1 7/13/17 4:41 PM Page 17

Project 5

Light the Way

What is really happening here?

1. The batteries (B3) convert chemical energy into
electrical energy and “push” it through the circuit,
just like the electricity from your power company. A
battery pushes electricity through a circuit just like a
pump pushes water through a pipe.

2. The snap wires (the blue pieces) carry the electricity
around the circuit, just like wires carry electricity
around your home. Wires carry electricity just like
pipes carry water.

3. The meter (M5) measures how much electricity is
flowing in a circuit, like a water meter shows how
fast water flows in a pipe.

4. The lamp (L4) converts electrical energy into light,
it is the same as a lamp in your home except
smaller. In an incandescent light bulb, electricity
heats up a high-resistance wire until it glows. A lamp
uses the energy carried by electricity, resisting its
flow like a pile of rocks resists the flow of water in a
pipe.

5. The slide switch (S1) controls the electricity by turn-
ing it on or off, just like a light switch on the wall of
your home. A switch controls electricity like a faucet
controls water.

6. The base grid is a platform for mounting the circuit,
just like how wires are mounted in the walls of your
home to control the lights.

Water Meter

Pump

Valve

Comparing Electric Flow to Water
Flow:

Touch the lamp after it has been on for
a while; it should feel it little warm (es­pecially if you cover the venting holes).
In an incandescent light bulb, only about
5% of the electricity is converted into
light, the rest becomes heat. Don’t
touch incandescent bulbs in your home
because they can be very hot.

Build the circuit shown by placing all the parts with a black 1 next
to them on the board first. Then, assemble parts marked with a

2. Install three (3) “AA” batteries (not included) into the battery
holder (B3). Set the meter (M5) to the 1A setting. Turn on the
slide switch (S1); the lamp (L4) lights and the meter measures
the current.

Placement Level Numbers

1A

-17-

Resistor

SC_STEM1_manual_PRINT.qxp_Layout 1 7/13/17 4:41 PM Page 18

-18-

Use the preceding circuit but replace the lamp (L4) with the white LED
(D6, “+” on top). Turn on the slide switch (S1); the LED lights.

Project 6

Light Bulbs of the Future

Compare the LED current (measured on the meter) to the current with the
lamp (you can also try it with the meter on the 1mA setting instead of the 1A
setting). How do they compare?

Would you rather use incandescent light bulbs or LEDs to light your home?

Notice that white LED has a “+” polarity marking, but the lamp does not.
What do you think would happen if you flipped the LED or lamp around in
this circuit? (Try it.)

LEDs are much more efficient than incandescent light bulbs and last
longer. LEDs are also more expensive, but their cost has been declining,
so LEDs are increasingly being used for home lighting.

Project 7

Ohm’s Law

Build the circuit, set the meter (M5) to the 5V setting, and turn on the slide
switch (S1). The lamp (L4) lights and the meter measures the voltage.

You can swap the location of the lamp with the 3-snap wire or slide switch in
this circuit, then measure the voltage across each of those parts and calculate
their resistance using Ohm’s law. What do you think their resistance will be?

5V

Measurements from this circuit and the project 5 circuit can be used
to measure the lamp resistance using Ohm’s Law.

1. Measure the voltage using this circuit.

2. Measure the current using the project 5 circuit (remove the 3-snap
wire, connect the meter where the 3-snap was, and set the meter to
the 1A setting).

3. Calculate the lamp resistance using Ohm’s Law:

The lamp resistance is usually 15-30 ohms, when used at 4.5V. The
other parts in the circuit (switch, meter on 1A scale, blue snap wires,
and batteries) also have resistance but these are much smaller.

Note: Your actual results may vary. Your M5 meter is a simple
meter; don’t expect it to be as accurate as normal electronic test in­struments.

You can also calculate the power of the lamp: using: Power = Voltage
x Current.
It should be about 1 watt. Compare this to incandescent light bulbs
in your home, which are usually about 40-100 watts.

Voltage

Current

Resistance =

LEDs are like one-way, low-current meters. LEDs have a “turn-on” voltage
threshold (about 3V for your white LED) that must be exceeded to turn them
on, then quickly get bright. LEDs can be made to product light in different
colors.

Answers are at www.snapcircuits.net/scstem1

.

Your
calculation:

SC_STEM1_manual_PRINT.qxp_Layout 1 7/13/17 4:42 PM Page 19

Project 8

Switches

Build the circuit, set the meter (M5) to the 5V setting, and initially set the switcher
(S6) to the middle position. Turn on each of the switches:

A. Hold the magnet near the reed switch (S9) to turn on the meter.
B. Push the press switch (S2) to turn on the white LED (D6).
C. Turn on the slide switch (S1) to turn on the left lamp (L4).
D. Set the switcher to the left position to turn on the center lamp.
E. Set the switcher to the right position to turn on the right lamp.

Name at least 10 things in your
home that use switches.

5V

Switches come in almost every shape
and size imaginable. There are mem­brane, rocker, rotary, DIP, push button,
magnetic, and momentary types just to
name a few.

The “on” position of a switch is also
called the “closed” position. Similarly, the
“off” position is also called the “open” po­sition. This is because the symbol for a
slide switch is similar to the symbol for a
door in an architect’s drawing of a room:

The electronics symbol for a simple slide
switch should be thought of as a door to
a circuit, which swings open when the
switch is off. The “door” to the circuit is
closed when the switch is on. This is
shown here:

Push Button

Computer

Keyboards

Rocker

Tools

Rotary

Selector Switch

on Appliances

Slide

Toys,

Household

Items

Walls

Door

Open Switch (turned off)

he current carrying capacity of a switch
depends on the contact material, size,
and the pressure between the contacts.

Closed Switch (turned on)

if you flip the switcher
(S6) around (as shown
below), how will it change
the circuit? (Try it.)

Note that the switcher’s connections look
like this:

-19-

SC_STEM1_manual_PRINT.qxp_Layout 1 7/13/17 4:42 PM Page 20

When wires from different parts of a circuit connect
accidentally then we have a “short circuit”. A short
circuit is a wiring path that bypasses the circuit resist­ance, creating a no-resistance path across the bat­teries. It is the “easiest” path through the circuit, it is
not always the “shortest”. A short circuit will activate
the fuse in your battery holder and/or quickly drain
your batteries. Be careful not to make short circuits
when building your circuits. Always check your wiring
before turning on a circuit. See page 10 for examples
of short circuits.

Project 9

Fuse

Build the circuit, set the meter (M5) to the 1A setting, and turn on the slide switch
(S1). The lamp (L4) lights.

What do you think would happen if you push the press switch (S2) for a moment?
Try it.

What do you think would happen if you pushed the press switch for a while? Try it.
You should see the current increase, then drop down after a few seconds.

1A

Name some devices in your home that have a fuse.

Pushing the press switch bypasses the lamp, making the
meter the only resistance in the circuit. The meter has very
low resistance on its 1A setting, so there is nothing in the
circuit to limit the current. When you push the press switch,
the high current (>1A) activates a safety fuse in the battery
holder (B3) after a few seconds, which lowers the current
enough to protect the batteries and
other components from being
overloaded. The fuse shuts off
shortly after the circuit problem it
had detected is corrected. The
fuse is the small yellow component
inside the battery holder.

This wire melts to
break the circuit.

Fuses are designed to shut down a circuit when the current
is abnormally high (indicating something is wrong, such as
a component failure, bad design, or a person using it im­properly). This shutdown prevents further damage to the cir­cuit, and can prevent explosions or fires. Fuses are
important for safety and most electrical products have one,
especially if they use electricity supplied by your local elec­tric company.

Some fuses need to be replaced after they “blow”, but oth­ers can be reset by flipping a switch, and some (like the one
in your battery holder) can reset automatically. Every home
has an electrical box of resettable fuses, it may look like this:

Some fuses have spe­cial wires designed to
break when an unex­pectedly high current
flows through them.

-20-

SC_STEM1_manual_PRINT.qxp_Layout 1 7/13/17 4:42 PM Page 21

Project 10

Materials Tester

If you have the build-your-own electromagnet connected to
the two-Spring socket (?1), disconnect its wires for this proj­ect. Build the circuit and set the meter (M5) to the 1A setting.

Turn on the slide switch (S1) and touch (or connect) various
materials between the springs on the two--spring socket
See which materials are good at transporting electricity by
watching the meter current and lamp (L4) brightness. Try
string, the electrodes, a shirt, plastic, paper, two of your fin­gers, wood, or anything in your home.

If the meter reads zero, switch it to the 1mA setting to see if
there is just a very small current. To help protect the meter,
always switch back to the 1A scale before testing a new cir­cuit.

1A

Which materials gave the highest reading on the meter, and
which gave the lowest?

Some materials, such as metals, have very low resistance to electricity will
make the lamp bright and give a large current measurement on the meter.
These materials are called conductors. Conductors have electrons that are
loosely held to the nucleus and can move easily.

Other materials, such as paper, air, and plastic, have very high resistance to
electricity. These will turn off the lamp and give a zero current measurement
on the meter even in the 1mA setting. These materials are called insulators.
Insulators have their electrons locked in tight and have no room for more.

The best conductor ever discovered is silver, which is very expensive. Cop­per is the second best conductor, and it is used in almost all electrical wires.

You can use Ohm’s Law to measure the resistance of the materials you
tested. The voltage is about 4.5V, and use the current measured on the meter.

Voltage
Current

Resistance =

What is Resistance? Take your hands and rub
them together very fast. Your hands should feel
warm. The friction between your hands con­verts your effort into heat. Resistance is the
electrical friction between an electric current and
the material it is flowing through; it is the loss of
energy from electrons as they move through the
material.

-21-

SC_STEM1_manual_PRINT.qxp_Layout 1 7/13/17 4:42 PM Page 22

Project 11

Make Your Own Parts

Build the circuit shown, and set the meter (M5) to the 1mA setting. Make your parts using either the water puddles
method (A), the drawn parts method (B), or the pencil parts method (C), and turn on the slide switch (S1). Touch
the metal in the jumper wires to your parts and read the current in milliamps.

Part B:

Place the ends of the wires in a cup of water, making sure the metal parts aren’t touching each other. Turn on the
slide switch and read the current on the meter.

Add salt to the water and stir to dissolve it. The current should be higher now (if not already at full scale), since salt
water has less resistance than plain water.

Now add more water to the cup and watch the current.

If you have some distilled water, place the jumper wires in it and measure the current. You should measure close
to zero current, since distilled (pure) water has very high resistance. Normal water has impurities which lower its
resistance. Now add salt to the distilled water and watch the current increase as the salt dissolves!

You can also measure the current through other liquids.

Don’t drink any water or liquids used here.

Note: Depending on your local water supply, your current measurement may exceed the 1mA scale. You can switch
the meter to the 5V scale to get a better comparison, though it isn’t really a voltage measurement. (In the 5V setting,
the water resistance is compared to the internal resistance of the meter. A low reading means the water has relatively
high resistance, and a high reading means the water has relatively low resistance.)

Which gave a higher reading on the meter,
long narrow shapes or short wide shapes?

You can use Ohm’s Law to measure the resistance of
your puddles and drawings. The voltage is about 4.5V,
and use the current measured on the meter.

The black core of pencils is graphite, the same mate­rial used in resistor components throughout the elec­tronics industry.

Pure water has very high resistance because
its atoms hold their electrons tightly and have
no room for more. Impurities (such as dis­solved dirt, minerals, or salt) decrease the re­sistance because their atoms have loose
electrons, which make it easier for other elec­trons to move through.

1mA

Voltage
Current

Resistance =

Method A (easy): Spread
some water on the table
into puddles of different
shapes, perhaps like the
ones shown below. Touch
the jumper wires to points
at the ends of the puddles.

Method C (adult supervision and permission required): Change
the setting on the meter to the 1A scale. Use some double-sided pencils
if available, or VERY CAREFULLY break some pencils in half. Touch
the jumper wires to the black core of the pencil at both ends.

Method B (challenging): Use a SHARP pencil
(No. 2 lead is best) and draw shapes, such as the
ones here. Draw them on a hard, flat surface.
Press hard and fill in several times until you have a
thick, even layer of pencil lead. Touch the jumper
wires to points at the ends of the drawings. You
may get better electrical contact if you wet the metal
with a few drops of water. Wash your hands when
finished.

-22-

SC_STEM1_manual_PRINT.qxp_Layout 1 7/13/17 4:42 PM Page 23

Project 12

Motor Resistance

Build the circuit, set the meter (M5) to the 1A
setting, and turn on the slide switch (S1). The
motor (M1) spins and the meter measures the
current. Do this with and without the fan on the
motor.

Calculate the resistance of the motor,
with and without the fan. How does
your calculation of the motor’s resist­ance compare with its typical resist­ance? What factors could have
caused the difference?

Calculate the power of the motor, with
and without the fan. Does the motor
use more power when the fan is on
it? Why?

The battery voltage is 4.5V, so use your current
measurements to determine the motor resistance
using Ohm’s Law.

The motor resistance is typically 5-20 ohms with
the fan and 25-100 ohms without the fan.

Note: Your actual results may vary. Your M5
meter is a simple meter; don’t expect it to be as
accurate as normal electronic test instruments.

Calculate the power of the motor using: Power =
Voltage x Current.

Voltage

Current

Resistance =

!

WARNING: Moving parts. Do not

touch the fan during operation.

!

WARNING:

Do not lean over the motor.

1A

Project 13

1A

Build the circuit, set the meter (M5) to the 1A
setting, and turn on the slide switch (S1). The
meter measures the current through the elec­tromagnet. Drop the thin rod into the electro­magnet; it will be suspended in mid-air.

Use Ohm’s Law to calculate the resistance
of the electromagnet’s resistance, and com­pare with its typical resistance.

The electromagnet is just a large coil of wire, its
resistance is about 30 ohms.

Wires can generally be as long as desired with­out affecting performance, just as using garden
hoses of different lengths has little effect on the
water pressure as you water your garden. How­ever there are cases where the length and size
of a pipe does matter, such as in the water lines
for your city. Similarly, wire length and size are
important for electric power lines transporting
electricity from a power plant in a remote area
to a city.

Electromagnet Resistance

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