Elenco Circuit Maker Skill Builder 125 User Manual

Copyright © 2014 by Elenco®Electronics, Inc. All rights reserved. No part of this book shall be reproduced by 753095
any means; electronic, photocopying, or otherwise without written permission from the publisher.

Table of Contents

Basic Troubleshooting 1
Parts List 2
How to Use Circuit Maker Skill Builder 125
About Your Circuit Maker Skill Builder 125 Parts

3

4, 5

Introduction to Electricity 6
DOs and DON’Ts of Building Circuits 7

WARNING: SHOCK HAZARD -

Skill Builder 125 to the electrical outlets in your home in any way!

WARNING FOR ALL PROJECTS WITH A
SYMBOL

Moving parts. Do not touch the motor or fan

!

during operation. Do not lean over the motor. Do
not launch the fan at people, animals, or objects.
Eye protection is recommended.

Basic Troubleshooting

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

2. Be sure the motor (M1) “+” marking is
positioned as per the drawing.

Never connect Circuit Maker

!

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

Advanced Troubleshooting 8
Project Listings 9, 10
Projects 1 - 125

11-60
Other Circuit Maker Products 61
Project Shapes 62

WARNING: CHOKING HAZARD -

Small parts. Not for children under 3 years.

!

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.

Conforms to all applicable

U.S. government

requirements.

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.

Note: If you suspect you have damaged parts,

you can follow the Advanced Troubleshooting
procedure on page 8 to determine which ones
need replacing.

-1-

Batteries:

!

● 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 supervision, 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 (carbon­zinc), or rechargeable (nickel-cadmium)
batteries.

● Remove batteries when they are used up.

● Do not short circuit the battery terminals.

● Never throw batteries in a fire or attempt

to open its outer casing.

● Batteries are harmful if swallowed, so
keep away from small children.

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

Important: If any parts are missing or damaged in shipping, DO NOT RETURN TO Target. Call toll-free [phone] or e-mail to

[e-mail]. Customer Service ● 150 Carpenter Ave. ● Wheeling, IL 60090 U.S.A.

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

r 1

r 3

r 6

r 3

r 1

r 1

r 1

r 1

1

2

3

4

5

6

B1

Base Grid
(11.0” x 7.7”)

1-Snap Wire 6SC01

2-Snap Wire 6SC02

3-Snap Wire 6SC03

4-Snap Wire 6SC04

5-Snap Wire 6SC05

6-Snap Wire 6SC06

Battery Holder ­Two 1.5V type AA (not incl.)

uses

6SCBG

6SCB1

r 1
r 1

r 1

r 1

r 1

r 1

r 1

r 1

r 1

M1

Q2

R1

R2

RP

S1

S2

SP

Motor
Glow Fan

NPN Transistor 6SCQ2

100W Resistor 6SCR1

1KW Resistor 6SCR2

Photoresistor 6SCRP

Slide Switch 6SCS1

Press Switch 6SCS2

Speaker 6SCSP

6SCM1

6SCM1FG

r 1

r 1

r 1

C5

D1

L1

470mF Capacitor 6SCC5

Red Light Emitting
Diode (LED)

2.5V Lamp 6SCL1

6SCD1

r 1

r 1

r 1

U1

U2

U3

Music
Integrated Circuit

Alarm
Integrated Circuit

Space War
Integrated Circuit

6SCU1

6SCU2

6SCU3

-2-

How to Use Circuit Maker Skill Builder 125

Circuit Maker Skill Builder 125 uses building
blocks with snaps to build the different
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.

S2

You need a power source to build each circuit.
This is labeled and requires two (2) 1.5V
“AA” batteries (not included).

B1

Usually when the motor is used, the glow
fan will 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.

M1

This is a wire block which is blue and comes
in different wire lengths.

3 4 5

This one has the number , , , ,
or on it depending on the length of the wire

6

connection required.

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

2

-3-

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.

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.

About Your Circuit Maker Skill Builder 125 Parts

(Part designs are subject to change without
notice).

BASE GRID

The base grid is a platform for mounting parts
and wires. It functions like the printed circuit
boards used in most electronic products, or like
how the walls are used for mounting the
electrical wiring in your home.

SNAP WIRES

The blue snap wires

are wires used to

connect components.

They are used to transport

electricity and do not affect

circuit performance. They come in

different lengths to allow orderly

arrangement of connections on the base grid.

SLIDE & PRESS 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.

BATTERY HOLDER

The batteries (B1) 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.

Battery Holder (B1)

LAMP

A light bulb, such as in the 2.5V lamp (L1),
contains 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.

RESISTORS

Resistors “resist” the flow of electricity and are
used to control or limit the current in a circuit.
Circuit Maker Skill Builder 125 includes 100W
(R1) and 1KW (R2) resistors (“K” symbolizes
1,000, so R2 is really 1,000W). Materials like
metal have very low resistance (<1W), while
materials like paper, plastic, and air have near­infinite resistance. Increasing circuit resistance
reduces the flow of electricity.

Resistors (R1 & R2)

The photoresistor (RP) is a light-sensitive
resistor, its value changes from nearly infinite in
total darkness to about 1,000W when a bright
light shines on it.

Photoresistor (RP)

CAPACITOR

The 470mF capacitor (C5) can store electrical
pressure (voltage) for a period of time. This
storage ability allows it to block stable voltage
signals and pass changing ones. Capacitors are
used for filtering and delay circuits.

Slide & Press

Switches
(S1 & S2)

Lamp (L1)

Capacitor (C5)

-4-

About Your Circuit Maker Skill Builder 125 Parts

MOTOR

The motor (M1) converts electricity into
mechanical 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.

Motor (M1)

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.

Power Contacts

Magnet

Shell

Shaft

Electromagnet

SPEAKER

The speaker (SP) converts electricity into
sound by making mech­anical vibrations. These
vibrations create vari­ations in air pressure,
which travel across the
room. You “hear” sound
when your ears feel
these air pressure
variations.

Speaker (SP)

TRANSISTOR

The NPN transistor (Q2) is a component that
uses a small electric current to control a large
current, and is used in switching, amplifier, and
buffering applications. Transistors are easy to
miniaturize, and are the
main building blocks of
integrated circuits
including the micro­processor and memory
circuits in computers.

NPN Transistor (Q2)

LED

The red LED (D1) 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 (about

1.5V); brightness then increases. A high current
will burn out an LED, so the current must be
limited by other components in the circuit. LEDs
block electricity in the “reverse” direction.

LED (D1)

INTEGRATED CIRCUITS (ICs)

Some types of electronic components can be
super-miniaturized, allowing many thousands of
parts to fit into an area smaller than your
fingernail. These “integrated circuits” (ICs) are
used in everything from simple electronic toys to
the most advanced computers. The music,
alarm, and space war ICs (U1, U2, and U3) in
Circuit Maker Skill Builder 125 are actually
modules containing specialized sound­generation ICs and other supporting components
(resistors, capacitors, and transistors) that are
always needed with them. This was done to
simplify the connections you need to make to use
them. The descriptions for these modules are
given here for those interested, see the projects
for connection examples:

Music IC:

Connections:

TRG

(+) HLD

Alarm IC:

IN1

IN2 IN3

(–)

Space War IC:

(+)

IN1

OUT(–)

OUT

OUT

IN2(–)

(+) - power from batteries
(–) - power return to batteries
OUT - output connection
HLD - hold control input
TRG - trigger control input

Music for a few seconds on power­up, then hold HLD to (+) power or
touch TRG to (+) power to resume
music.

Connections:

IN1, IN2, IN3 - control inputs
(–) - power return to batteries
OUT - output connection

Connect control inputs to (+) power
to make five alarm sounds, see
project 22 for configurations.

Connections:

(+) - power from batteries
(–) - power return to batteries
OUT - output connection
IN1, IN2 - control inputs

Connect each control input to (–)
power to sequence through 8
sounds.

-5-

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
voltage 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, 1/1,000 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,
1,000 ohms).

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

Series Circuit

Parallel Circuit

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.

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.

-6-

DOs 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 resistor, capacitor,
speaker, integrated circuit, etc.), and wiring paths between them and back. You

must be careful not to create “short circuits” (very low-resistance paths across
the batteries, see examples at right) as this will damage components
quickly drain your batteries. Only connect the ICs using configurations given in

the projects, incorrectly doing so may damage them. 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 the speaker, lamp, ICs (which must be connected
properly), motor, photoresistor, or resistor.

ALWAYS use the LED, NPN transistor, and switches in conjunction with other

components 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.

ALWAYS connect capacitors so that the “+” side gets the higher voltage.

ALWAYS connect ICs using configurations given in the projects or as per the

connection descriptions for the parts.

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.

and/or

Examples of SHORT CIRCUITS - NEVER DO THESE!!!

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

!

NEVER

DO!

This is also a

SHORT CIRCUIT.

NEVER

!

When the slide switch (S1) 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.

DO!

!

NEVER

DO!

-7-

WARNING: SHOCK HAZARD -

Skill Builder 125 to the electrical outlets in your home in any way!

!

Warning to Circuit Maker owners: Do not connect

additional voltage sources from other sets, or you

!

may damage your parts. Contact ELENCO®if you
have questions or need guidance.

Never connect Circuit Maker

!

NEVER

DO!

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.

2.5V lamp (L1), motor (M1), speaker
(SP), and battery holder (B1): Place

batteries in holder. Place the 2.5V lamp
directly across the battery holder, it
should light. Do the same with the
motor (motor + to battery +), it should
spin to the right at high speed. “Tap” the
speaker across the battery holder
contacts, you should hear static as it
touches. If none work then replace your
batteries and repeat, if still bad then the
battery holder is damaged. If the motor
spins but does not balance the fan,
check the black plastic piece on the
motor shaft; it should have 3 prongs.

3. Slide switch (S1) and Press switch

(S2): Build Project #1, if the lamp (L1)

doesn’t light then the slide switch is
bad. Replace the slide switch with the
press switch to test it.

4. 100W resistor (R1), 1KW resistor

(R2), and LED (D1): Build Project #11

except initially use the speaker (SP) in
place of the resistor, the LED should
light. Then, replace the speaker with
the 100W resistor; the LED should still
light. Then, replace the 100W resistor
with the 1KW resistor; the LED should
light but not as brightly.

5. Alarm IC (U2): Build Project #21, you

should hear a siren. Then place a 3­snap wire between grid locations A1
and C1, the sound is different. Then
move the 3-snap from A1-C1 to A3-C3
to hear a third sound.

7. Space war IC (U3) and photoresistor

(RP): Build Project #4, both switches

(S1 and S2) should change the sound.
Then replace the slide switch (S1) with
the photoresistor, waving your hand
over it should change the sound.

8. NPN transistor (Q2): Build Project

#31. When both switches are on, the
lamp lights and motor spins. If one
switch is off, nothing happens.

9. 470mF capacitor (C5): Build Project

#50, then press and release the switch.
The LED should go off slowly.

Customer Service

Call toll-free: [phone]

e-mail: [e-mail]

2. Snap wires: Use this mini-circuit to test

the 5-snap and 6-snap wires. The lamp
should light. Then test each of the 1­snap, 2-snap, 3-snap, and 4-snap
wires by connecting them
b e t w e e n
the ends of
the 5-snap
and 6-snap.

6. Music IC (U1): Build Project #86 but

use the press switch (S2) in place of
the photoresistor (RP). Turn it on and
the LED (D1) flickers for a while and
stops, it resumes if you press and hold
down the press switch. Then touch a 3­snap wire across base grid points A1
and C1 and the flickering resumes for a
while.

-8-

Project Listings

Project # Description Page #

1 Turn on the Light

2 Up, Up, and Away! 11

3 Super Circuit 12

4 Space War 13

5 Loud in Light 13

6 Paper Player 13

7 Stick Around Saucer 14

8 Rotate & Roar 14

9 Spin & Dim 15

10 Balanced Buddies 15

11 The Diode Dude 16

12 One Way Works 16

11

Project # Description

22 Laser Blaster 21

23 Mind Reader Game 22

24 Don’t Make a Sound 23

25 Discover the Diode 23

26 Shine On Siren 24

27 Shooting Sounds 24

28 Song & Siren 24

29 Ambulance Melody 24

30 Static Song 24

31 Transistor Control 25

32 Slow & Bright 25

33 Stop & Shine 25

Page #

Project # Description Page #

43 Motor Magic 28

44 Spin & Shoot 28

45 Spin Out Siren 28

46 Whirl Out Warning 28

47 Turn a Tune 28

48 Wave & Watch 29

49 Switching Sounds 29

50 Lingering Light 30

51 Current Splitter 30

52 Light Up & Listen 30

53 Auto-Off Night Light 31

54 Auto-Off Day Light 31

13 Clippy the Conductor 17

14 Nifty Noises 17

15 Mumbling Motor 18

16 Lift Loss 18

17 Hi-Low Fan 19

18 Fuse or Lose 19

19 Magical Music 20

20 Press & Play 20

21 Simple Siren 21

-9-

34 Murky Motor 25

35 Mixed Up Music 26

36 Blaster Disaster 26

37 Siren & Song 26

38 Ambulance Song 26

39 Space Battle 27

40 Bizarre Blinker 27

41 Sporadic Sounds 27

42

Blinking Double Flashlight

27

55 Reflection Detector 32

56 Music Reflection Detector 32

57 Laser Flasher 33

58 Flash & Flicker 33

59 Spinning Rings 34

60 Strobe the House Lights 34

61 Race Game 35

62

63 Spin Draw 36

Using Parts as Conductors

35

Project Listings

Project # Description Page #

64 Singing Motor 36

65 Visual Volume 37

66 Daylight Alarm 37

67 Bang-Bang Bright 37

68 Daylight Danger 37

69 Crooks & Cars 37

70 Pop On, Pop Off 38

71 Little R Rules 38

72 Big R Rules 38

73 Little to Big 39

74 Luminate & Rotate 39

75 Light to Light 39

Project # Description

85 Electron Warehouse 44

86 Light Makes Light 45

87 Go & Glow 45

88 Spin & Stop 45

89 Flashing Flare 46

90 Touch & Go 46

91 Two-Tone Twinkler 46

92 Fan Flash Energy 47

93 Photo Timer Light 47

94 Room Light to Red Light 47

95 Fun with the Alarm IC 48

96 Dancing Motor 48

Page #

Project # Description

106 Lagging Light 52

Sonic Flasher 53

107

108 Stay or Blink 53

109 Glow & Go 54

110 Fading Siren 54

111 Light the Motor 55

112 Motor Space Sounds 55

113 Twist & Blink 55

114 Morse Code 56

115 Light to Dark 56

116 Power Shifter 56

117 Touch of Light 57

Page #

76 Switch & Store 40

77 Crazy Combo 40

78 Alien Alarm 41

79 Same or “NOT” 41

80 This OR That 42

81 This AND That 42

82 Neither This NOR That 43

83 NOT This AND That 43

84 Two-way Light Switch 44

97 Musical Light 48

98 Music Alarm Combo 49

99 Hit the Target 49

100 Many Missiles 49

101 Sing & Fling 50

102 Power Pitch 50

103 Long Gone Light 51

104 Slow Siren Changer 51

105 The Dark Dimmer 52

118 Change & Charge 57

119 Electricity You Can Wear 58

120 Electricity In Your Hair 58

121 Bending Water 59

122 Static Tricks 59

123 Sunrise Light 60

124 Light-controlled Lamp 60

125 Motor-controlled Lamp 60

-10-

Project #1

Turn on the Light

Circuit Maker Skill Builder 125 uses electronic blocks
that snap onto a clear plastic grid to build different
circuits. These blocks have different colors and
numbers on them so that you can easily identify them.

Build the circuit shown on the left by placing all the
parts with a black 1 next to them on the board first.
Then, assemble parts marked with a 2. Install two (2)
“AA” batteries (not included) into the battery holder
(B1) if you have not done so already.

Placement Level Numbers

Project #2

+

Snappy says the lamp contains
a special thin high-resistance
wire. When a lot of electricity
flows through it, it gets so hot it
glows bright.

Up, Up, and Away!

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.

When you turn on the slide switch (S1), electricity
flows from the batteries through the lamp (L1) and
back to the batteries through the switch. The switch
completes the circuit. The lamp gets bright as
electricity flows through it.

Build the circuit shown on the left by placing the parts
with a black 1 next to them on the base grid first.
Then, assemble parts marked with a 2. Place the
glow fan on the motor. New alkaline batteries are
recommended for this project.

Turn on the slide switch (S1), wait for the motor to
reach full speed, then turn off the switch. The glow
fan should rise and float through the air like a flying
saucer. Be careful not to look directly down on the
glow fan 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.

-11-

Placement Level Numbers

WARNING: Moving parts. Do not touch the

!

fan or motor during operation. Do not lean
over the motor.

WARNING: Fan may not rise until switch is

!

released.

The glow fan will glow in the dark. It will glow best
after absorbing sunlight for a while. The glow fan is
made of plastic, so be careful not to let it get hot
enough to melt. The glow looks best in a dimly lit
room.

Project #3 Super Circuit

This complex circuit is pictured
on the box cover. Use that as a
guide to help in building it.

WARNING: Moving parts. Do not touch the

!

fan or motor during operation. Do not lean
over the motor.

WARNING: Fan may not rise until switch is

!

released.

Placement Level Numbers

+

Placement

Level

Numbers

Circuit Maker Skill Builder 125 uses electronic
blocks that snap onto a clear plastic grid to
build different circuits. These blocks have
different colors and numbers on them so that
you can easily identify them.

Build the circuit shown above by placing all the
parts with a black 1 next to them on the board
first. Then, assemble parts marked with a 2.
Then, assemble parts marked with a 3. Then,
assemble the part marked with a 4 (the alarm
IC (U2), which should be placed directly over
the music IC (U1)). Install two (2) “AA” batteries
(not included) into the battery holder (B1).

Place the glow fan on the motor (M1).

Turn on the slide switch (S1). You hear music
and alarm sounds, and the red LED (D1) lights.
The lamp (L1) may light briefly before the red
LED turns on. Cover the photoresistor (RP) to
change the sound a little.

Push the press switch (S2) to spin the motor
and glow fan. Release the press switch when
the motor is spinning at full speed. The glow fan
should float through the air like a flying saucer.
Be careful not to look directly down on the glow
fan when it is spinning.

If the fan doesn’t fly off, then push and release
the press switch several times rapidly when it is
at full speed.

If the 470mF capacitor (C5) is discharged when
you turn on the slide switch, then the lamp will
light for a few seconds as the circuit charges up
C5. L1 will not light again until C5 is
discharged. To discharge C5, remove it from
the circuit and place it directly on the 4-snap
wire for an instant, then move it back to its
normal spot in the circuit.

-12-

Project #4 Space War

Build the circuit shown on the left, which uses the space war integrated
circuit. Activate it by flipping the slide switch (S1) or pressing the press
switch (S2), do both several times and in combination. You will hear an
exciting range of sounds, as if a space war is raging!

The space war IC (U3) is a super-miniaturized electronic circuit that
can play a variety of cool sounds stored in it by using just a few extra
components.

In movie studios, technicians are paid to insert these sounds at the
precise instant a gun is fired. Try making your sound occur at the same
time an object hits the floor. It is not as easy as it sounds.

The Space War, Alarm, and Music ICs contain
specialized ICs combined with other electrical
components (resistors, capacitors, transistors)
designed to produce various cool sounds and music.

Project #5

Loud in Light

Use the circuit from Project #4 above, but replace the slide switch (S1)
with the photoresistor (RP). The circuit immediately makes noise. Try
turning it off. If you experiment, then you can see that the only ways to
turn it off are to cover the photoresistor, or to turn off the lights in the room
(if the room is dark). Since light is used to turn on the circuit, you might
say it is a “light switch”.

The photoresistor contains material that changes its
resistance when it is exposed to light; as it gets more
light, the resistance of the photoresistor decreases.
Parts like this are used in a number of ways that affect
our lives. For example, you may have streetlights in
your neighborhood that turn on when it starts getting
dark and turn off in the morning.

-13-

Project #6

Paper Player

Use the same circuit as for Project #5. Find a piece of white paper that
has a lot of large black or dark areas on it, and slowly slide it over the
photosensitive resistor. You may need to shine a flashlight over the paper.
You should hear the sound pattern constantly changing, as the white and
dark areas of the paper control the light to the photosensitive resistance.
You can also try the pattern below or something similar to it.

Project #7

Stick Around Saucer

+

Build the circuit shown on the left which is the same as the circuit in
Project #2 but with the motor part reversed. Place the glow fan on the
motor.

Turn on the slide switch (S1), wait for the motor to reach full speed,
then turn off the switch. This time, the glow fan does not fly because
the fan is now rotating in the opposite direction such that the airflow is
pushing the fan downward.

WARNING: Moving parts. Do not touch the fan or

!

motor during operation.

Project #8 Rotate & Roar

Build the circuit shown on the left, but leave the fan off the motor (M1).
When you turn on the slide switch (S1), the music may play for a short
time and then stop. After the music has stopped, spin the motor with
your fingers. The music should play again for a short time, then stop.

Now replace the 100W resistor (R1) with a 3-snap wire, and notice how
the sound is affected.

In this project, you changed the amount of current that goes through
the speaker (SP) and increased the sound output of the speaker.

Resistors are used throughout electronics
to limit the amount of current that flows.

-14-

Project #9 Spin & Dim

+

The parts are arranged
as a series circuit. You
can swap the locations
of any of the parts
without affecting circuit
operation.

Build the circuit shown on the left.

When you turn on the slide switch (S1), the fan will spin and the lamp
(L1) should turn on. The fan will take a while to start turning due to
inertia. Inertia is the property that tries to keep a body at rest from
moving and tries to keep a moving object from stopping.

The lamp helps protect the motor from getting the full voltage when the
switch is turned on. Part of the voltage goes across the lamp and the
rest goes across the motor. Remove the fan and notice how the lamp
gets dimmer when the motor does not have to spin the fan blade.

WARNING: Moving parts. Do not touch the fan or

!

motor during operation.

Project #10 Balanced Buddies

Build the circuit shown on the left.

The parts are arranged as a
parallel circuit. Parallel
circuits are often used in
residential homes so that
turning on one device
doesn’t limit the current to
other devices.

When you turn on the slide switch (S1), both the fan and the lamp (L1)

should turn on. The fan will take a while to start turning due to inertia.

In this connection, the lamp does not change the current to the motor

(M1). The motor should start a little faster than in Project #9.

Remove the fan and notice how the lamp does not change in

brightness as the motor picks up speed. It has its own path to the

battery (B1).

-15-

WARNING: Moving parts. Do not touch the fan or

!

motor during operation.

+

Project #11 The Diode Dude

Build the circuit shown on the left.

When you turn on the slide switch (S1), current flows from the batteries
(B1) through the switch, through the 100W resistor (R1), through the
LED (D1, light emitting diode) and back to the battery. The turned on
switch completes the circuit. The resistor limits the current and prevents
damage to the LED. NEVER PLACE AN LED DIRECTLY ACROSS
THE BATTERY! If no resistor is in the circuit, the battery may push
enough current through the LED to damage the semiconductor that is
used to produce the light.

LEDs are used in all types of electronic
equipment to indicate conditions and
pass information to the user of that
equipment. Can you think of something
you use everyday that has an LED in it?

Project #12 One Way Works

+

Rebuild the circuit used in Project #11 but put the LED in as shown on
the left.

This time when you turn on the slide switch (S1), current does not flow
from the batteries (B1) through the 100W resistor (R1) or through the
LED (D1), and hence the LED does not light up. This is because the
LED is in backwards. The LED is like a check valve that lets current
flow in only one direction (into the + end and out the other end).

An electronic component that
needs to be connected in one
direction is said to have polarity.
Other parts like this will be
discussed in future projects.
Placing the LED in backwards does
not harm it because the voltage is
not large enough to break down this
electronic component.

-16-

Project #13 Clippy the Conductor

Rebuild the circuit from Project #11 but leave the slide switch (S1) out

as shown on the left.

When you place a paper clip across the terminals as shown in the

picture on the left, current flows from the batteries (B1) through the

100W resistor (R1), through the LED (D1), and back to the battery. The

paper clip completes the circuit and current flows through the LED.

Place your fingers across the terminals and the LED does not light.

Your body is too high of a resistance to allow enough current to flow to

light the LED. If the voltage, which is electrical pressure, was higher,

current could be pushed through your fingers and the LED would light.

This detector can be used to see if a material like plastic is a
good conductor or a poor conductor. Materials that make the
LED bright pass electricity easily, and are called conductors.
Most metals are good conductors, and copper is used in
most house wiring. Materials that block the flow of electricity
are called insulators. Plastic, paper and air are insulators.

Project #14 Nifty Noises

-17-

Build the circuit shown. Turn it on, press the press switch (S2) several

times, and wave your hand over the photoresistor (RP) to hear all the

sound combinations. You can make the sound from the alarm IC (U2)

louder by replacing the 100W resistor (R1) with the 2.5V lamp (L1).

A photoresistor is a light-controlled variable
resistor. The resistance of the photoresistor
decreases with increasing light intensity.

+

Project #15

Place the fan on the motor (M1). Press the press switch (S2) and listen
to the motor. Why does the motor make sound?

If you replace the motor with the 2.5V lamp (L1), then it will work the
same as the “Hear the Motor” project, but only make noise when the
lamp is turned ON or OFF.

A motor uses magnetism to convert electrical
energy into mechanical spinning motion. As the
motor shaft spins around it connects / disconnects
several sets of electrical contacts to give the best
magnetic properties. As these contacts are
switched, an electrical disturbance is created,
which the speaker (SP) converts into sound.

Mumbling Motor

WARNING: Moving parts. Do not touch the

!

fan or motor during operation.

Project #16 Lift Loss

Build the circuit to the left.

Cover the photoresistor (RP) and turn on the slide switch (S1). The
motor (M1) should spin. If not, give it a push to get it started. Now
uncover the photoresistor or get a flashlight and shine it on the
photoresistor. The motor will slow down as more light reaches the
photoresistor, and will stop spinning if enough light reaches the
photoresistor. This circuit demonstrates how darkness can be used to
control a fan. Try this circuit with and without the fan on the motor.

WARNING: Moving parts. Do not touch the

!

fan or motor during operation.

-18-

Project #17 Hi-Low Fan

Build the circuit shown on the left.

WARNING:

!

Moving parts. Do not
touch the fan or motor
during operation.

When you close the slide switch (S1), current flows from the batteries

through the slide switch (S1), motor (M1), the lamp (L1), and back to

the battery (B1). When the press switch (S2) is closed, the lamp is

shorted and motor speed increases.

The principle of removing resistance to
increase motor speeds is only one way of
changing the speed of the motor. Commercial
fans do not use this method because it would
produce heat in the resistor and fans are used
to cool circuits by moving air over them.
Commercial fans change the amount of
voltage that is applied to the motor using a
transformer or other electronic device.

-19-

Project #18

WARNING:

!

Moving parts. Do not
touch the fan or motor
during operation.

Many electronic products in
your home have a fuse that will
open when too much current is
drawn. Can you name some?

Fuse or Lose

Use the circuit built in Project #17.

When you close the slide switch (S1), current flows from the batteries

through the slide switch (S1), the lamp (L1), motor (M1), and back to the

battery (B1). Pretend the 2-snap wire marked fuse in the drawing on the

left is a device that will open the circuit if too much current is taken from

the battery. When press switch (S2) is closed, the light is shorted and

motor speed increases due to an increase in current to the motor. While

still holding press switch (S2) down, remove the 2-snap wire marked

fuse and notice how everything stops. Until the fuse is replaced, the

open circuit path protects the electronic parts. If fuses did not exist,

many parts could get hot and even start fires. Replace the 2-snap wire

and the circuit should return to normal.