Elenco LIGHT User Manual

Copyright © by Elenco®Electronics, Inc. All rights reserved. No part of this book shall be reproduced by 753285
any means; electronic, photocopying, or otherwise without written permission from the publisher.

Patents: 7,144,255; 7,273,377; & other patents pending

-1-

1. Most circuit problems are due to incorrect assembly,
always double-chec k that your cir cuit exactl y 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.

5. If the motor spins but does not balance the fan, c heck
the black plastic piece with three prongs on the motor
shaft, and replace it if it is damaged (this kit includes
a spare). To replace , pry the broken one off the motor
shaft using a screwdriver, then push the new one on.

6. If a fiber optics circuit isn’t working, make sure the
clear & black cable holder s are pushed all the way onto
the LED/phototransistor, and the fiber optic cable is
pushed into the holders as far as it will go. The cable
should be standing straight up in th holders.

ELENCO

®

is not responsible for parts damaged due to

incorrect wiring.

Basic T roubleshooting

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

Advanced Troubleshooting procedure on page 15 to determine which ones
need replacing.

Basic T roubleshooting 1
Parts List 2, 3
How to Use Snap Circuits

®

4, 5

About Your Snap Circuits

®

LIGHT Parts 6-8
Introduction to Electricity 9
Light in Our World 10-12

DO’s and DON’Ts of Building Circuits 13
Advanced T roubleshooting 14, 15
Project Listings 16, 17
Projects 1 - 182 18 - 81
Other Snap Circuits

®

Projects 82

WARNING: SHOCK HAZARD - Never connect Snap

Circuits®to the electrical outlets in your home in any wa y!

Table of Contents

WARNING: Al ways chec k your wiring bef ore

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 cir cuits. Discard
any cracked or broken parts.

Adult Supervision: Because children’s

abilities var

y so much, e ven 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 y our 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.

CAUTION: Persons who are extremely

sensitive to flashing lights and rapidl

y

c

hanging colors or patterns should exercise

caution when playing with this toy.

CAUTION: High intensity light. Do not look

directly at white LED (D6).

W ARNING 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.

!

!

!

WARNING: CHOKING HAZARD -

Small parts. Not for children under 3 years.

!

Conforms to

ASTM

F963-96A

• 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 (carbon-zinc),
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.

Batteries:

!

Apple Inc. is not affiliated with nor endorses this product. iPod®is a registered trademark of Apple Inc.

-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 (page 1)

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

 1

Base Grid
(11.0” x 7.7”)

6SCBG

 1

White Light Emitting
Diode (LED)

6SCD6

 3

1-Snap Wire 6SC01

 1

Color Light Emitting
Diode (LED)

6SCD8

 6

2-Snap Wire 6SC02

 1

Jumper Wire (black) 6SCJ1

 3

3-Snap Wire 6SC03

 1

Jumper Wire (red) 6SCJ2

 1

4-Snap Wire 6SC04

 1

Motor 6SCM1

 1

5-Snap Wire 6SC05

 1

Spare Motor Top 6SCM1T

 1

6-Snap Wire 6SC06

 1

Glow Fan Blade 6SCM1FG

 2

Battery Holder - uses
two (2) 1.5V type “AA”
(not Included)

6SCB1

 1

Disc Holder 6SCM1DH

 1

0.1µF Capacitor

6SCC2

 1

Set of Disc Cutouts
(6 pcs. / set)

6SCM1DS

 1

100µF Capacitor

6SCC4

 1

PNP Transistor 6SCQ1

 1

Red Light Emitting
Diode (LED)

6SCD1

 1

NPN Transistor 6SCQ2

You may order additional / replacement parts at our website: www.snapcircuits.net

5

4

3

2

1

Q1

C2

D1

C4

Q2

6

B1

D8

M1

D6

-3-

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 (page 2)

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

 1

Phototransistor 6SCQ4

 1

Strobe IC 6SCU23

 1

100Ω Resistor

6SCR1

 1

Infrared Receiver 6SCU24

 1

5.1kΩ Resistor

6SCR3

 1

Fiber Optic Cable 6SCFC

 1

100kΩ Resistor

6SCR5

 1

Fiber Optic Cable
Holder, clear

6SCFCHC

 1

Adjustable Resistor 6SCRV

 1

Fiber Optic Cable
Holder, black

6SCFCHB

 1

Slide Switch 6SCS1

 1

Fiber Optic Tree 6SCFT

 1

Press Switch 6SCS2

 1

Mounting Base
(for fiber optic tree)

6SCFMB

 1

Speaker 6SCSP

 1

Tower LED
Attachment

6SCTOWER

 1

Microphone 6SCX1

 1

Egg LED Attachment 6SCEGG

 1

Color Organ 6SCU22

 1

Prismatic Film 6SCFILM

 1

Stereo Cable 9TLSCST

 1

Red/Green/Blue
Filters Set

6SCFRGB

You may order additional / replacement parts at our website: www.snapcircuits.net

S1

RV

R5

R3

R1

X1

U22

S2

SP

U24

U23

Q4

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 b locks , 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 bloc k which is green and has
the marking on it. The par t symbols in this
booklet may not exactly match the appear ance
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 diff erent
layers.

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

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.

This set contains 6 pre-punched cardboard
discs. These will be used with a strobe light in
project 46 and others. The discs may be
supplied as a single sheet; just punch them
out.

To remove a disc
from the holder, use
your fingernail, or
use a pencil to push
it up from beneath
one of the tabs.

S2

2

3 4 5

6

B1

M1

-4-

-5-

How to Use Snap Circuits

®

This set contains three LED attachments,
which can be mounted on the LED modules
(D1, D6, D8, and on U22) to enhance their
light eff

ects. The egg and tower attachments
are mounted directly on the LEDs, but the fiber
optic tree must be mounted using the
mounting base, as shown. This is described in
the projects.

In some projects, the fiber optic cable will be
mounted on the LEDs (D1, D6, D8, and on
U22) or the phototransistor (Q4). This is done
by placing the clear and black cable holders
onto the LED/phototransistor, then inserting
the fiber optic cable all the way into the holder.
For best performance the cable should stand
straight up in the holders, without bending
them. This is described in the projects.

Light T ower

Correct

Incorrect

Fiber Optic Tree
LED attachment

mounted to D8

Light T ower

LED attachment

mounted to D1

Fiber Optic Tree
LED attachment
mounted to U22

Egg LED attachment

mounted to D6

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.

Egg

Fiber Optic Tree

Black cable holder

mounted to Q4

Clear cable holder

mounted to D1

-6-

About Your Snap Circuits

®

LIGHT Parts

(Part designs are subject to change without
notice).

BASE GRID

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.

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.

Glow-in-the-dark Fan

Electromagnet

Shaft

Shell

Magnet

Power Contacts

BATTERY HOLDER

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.

Motor (M1)

The base grid is a platfor m 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 & JUMPER WIRES

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.

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 v oltage 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)

MOTOR

About Your Snap Circuits

®

LIGHT Parts

RESISTORS LEDs

-7-

Adjustable Resistor (RV)

Resistors (R1, R3, & R5)

SLIDE & PRESS SWITCHES

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

Speaker (SP)

The adjustable resistor (RV) is a 50kΩ resistor
but with a center tap that can be adjusted
between 200Ω and 50kΩ.

Resistors “resist” the flow of electricity and are
used to control or limit the current in a circuit.
Snap Circuits

®

LIGHT includes 100Ω (R1), 5.1kΩ
(R3), and 100kΩ (R5) resistors (“k” symbolizes
1,000, so R5 is really 100,000Ω). Materials like
metal have very low resistance (<1Ω), while
materials like paper, plastic, and air have near­infinite resistance. Increasing circuit resistance
reduces the flow of electricity.

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.

Slide & Press

Switches
(S1 & S2)

LED’s

(D1, D6, & D8)

The red, white, and color LED’s (D1, D6, & D8)
are light emitting diodes, and may be thought of
as a special one-way light bulbs. In the “forward”
direction, (indicated by the “arrow” in the symbol)
electricity flows if the voltage exceeds a turn-on
threshold (about 1.5V for red, about 3.0V for
white, and in between for other colors);
brightness then increases. The color LED
contains red, green, and blue LEDs, with a micro­circuit controlling then. A high current will bur n
out an LED, so the current must be limited by
other components in the circuit. LED’s block
electricity in the “reverse” direction.

CAPACITOR

The 0.1µF and 100µF capacitors (C2 & C4)can
store electrical pressure (voltage) for periods of
time. This storage ability allows them to block
stable voltage signals and pass changing ones.
Capacitors are used for filtering and delay
circuits.

Capacitors

(C2 & C4)

Microphone (X1)

The microphone (X1) is actually a resistor that
changes in value when changes in air pressure
(sounds) apply pressure to its surface. Its
resistance typically varies between 1kΩ and
10kΩ.

MICROPHONE

-8-

About Your Snap Circuits

®

LIGHT Parts

TRANSISTORS

The phototransistor (Q4) is a transistor that
uses light to control electric current.

Phototransistor (Q4)

ELECTRONIC MODULES

(+)

NC

OUT

(–)

CTL

Connections:

(+) - power from batteries
(–) - power return to batteries
OUT - output connection
CTL - strobe speed control
NC - not used

See project 46 for example of
proper connections.

B

(+)

FB

Connections:

R - red color control
G - green color control
B - blue color control
(+) - power from batteries
INP - circuit input
FB - feedback connection
(–) - power return to batteries
IN - audio input jack
OUT - audio output jack

See projects 5, 6, 33, and 34 for
examples of proper connections.

INP(–)

G

R

The color organ (U22) contains resistors, capacitors,
transistors, a tri-color LED, and integrated circuits. The
LED in it can change colors by direct control, or in synch
with an audio input signal. A schematic f or it is a vailab le at
www.snapcircuits.net/faq.

OUT

IN

The strobe IC (U23) contains resistors, capacitors, and
transistors that are needed to make a strobe light circuit.
A schematic for it is av ailab le at www.snapcircuits.net/faq.

Infrared module (U24)

OTHER PARTS

The stereo cable is used to connect
your music device to the color organ
(U22).

Prismatic film separates light into
different colors. The red, green, & blue
filters filter out colors.

The disc holder and discs produce amazing effects when
used with the Strobe Effects circuit (project 46).

The Infrared module (U24) is a miniaturized
infrared receiver circuit for remote control.

The PNP & NPN transistors (Q1 & Q2) are
components that use a small electric current to
control a large current, and are used in switching,
amplifier, and buffering applications. They are
easy to miniaturize, and are the main building
blocks of integrated circuits including the
microprocessor and memory circuits in
computers.

PNP & NPN Transistors (Q1 & Q2)

The LED attachments can be used with
any of the LEDs (red, white, color, and
the color organ) to enhance the light
effects.

The fiber optic cable carries light
between two places. The light can be
encoded to transmit information. The
clear and black holders are used to
attach it to circuits.

Fiber Optic Tree

Light

Tower

Egg

-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 mov ement of sub­atomic 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 , lik e pipes carry water . De vices
like LEDs, motors, and speak ers 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, 1/1000 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 (Ω), or kilo ohms (kΩ, 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 electr icity
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 par allel decreases the
resistance; lower 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

Light in Our World

-10-

What would our world be like without light?
Moving and doing things in total darkness
would be much more difficult, because
everyone would be blind. Plants rely on
sunlight for energy and would die without it. If
all the plants die, then people and animals
would have nothing to eat, and would starve.
Let’s hope we never have to live in a world
without light.

Light is energy, traveling at high speed.
Sunlight can warm up your skin, as can bright
lights in a concert hall or playhouse. Light can
carry information. For example, our brains
analyze the light received in our ey es , to learn
what is around us. In fiber optic cables , beams
of light carry data between cities. Infrared light
from a remote control can tell a TV to change
to a different channel.

Light moves as super-tiny charges, which are
so full of energy they go flying off in all
directions.

This happens when a material has too much
energy , and some of the energy changes f orm.
For example , a light b ulb makes light when an
electric current makes the filament so hot that
it glows. Some of the energy in a burning fire
escapes by changing to light. Our br ight sun
makes so much light because it is basically a
gigantic ball of thermonuclear reactions. Light
emitting diodes (LEDs) make light by
converting excess electrical energy.

You “see” when light enters your eyes. When
you turn on a light in a room, the light shines
on everything around it. When light shines on
something, some of the light is absorbed into
it, and the rest is reflected off. The absorbed
light is converted to heat, and the reflected
light is scattered around the room. Some of the
shining and reflected light might reach your
eyes. Your brain inter prets the light into your
eyes, and makes the mental picture you see.

When all the light shining on something is
absorbed, with none reflected towards your
eyes, then you can’t see it. The object will
appear dark. The brighter an object appears,
the more light was reflected off it and into your
eyes. Some materials, like air and clear glass,
let light pass through them.

You can only see the
moon when light from the
sun bounces off it, and
reflects to earth.

You can’t see a beam of light traveling across
a room, unless something scatters the light
and some reaches your eyes . In a dusty room,
sometimes you can see the dust particles
floating in the air when sunlight hits them.

In this photograph,
sand has been
tossed into the air,
which is illuminated
by a narrow beam of
sunlight coming down
into the canyon.

When you turn on a
light, you instantly
see everything. This
happens because
light is very fast, and
travels about 186,000
miles a second in air.

Light rays can bend when they pass between
different materials, such as air and water . Light
bends because its speed changes. The speed
of light in water is only about 125,000 miles a
second.

The part of the pen in water
looks distorted, because light
changes speed when entering
and leaving the water.

When you look directly out a
glass window, you can see
clearly through it. When you
look through the window at a
wide angle, you can see
through it, but also see a reflection in it. When
you try to look through the window at a really
wide angle, you can’t see through it at all, and
only see reflections. Try looking through a
window in your home at really wide angles.

Light bulb

filament

Glowing

light bulb

filament

Close-up

view of the

Sun

Glowing

white LED

(D6)

White light beam

Reflected light

Mental picture

-11-

Light in Our World

When light hits a glass surface at a wide
enough angle, all the light is reflected. Fiber
optic cables have arr ays of fle xib le glass fibers.
In these cables, light rays move through by
bouncing along the inside walls at wide angles,
and can travel great distances. Light moves
through the cable ev en if it is bent a little, b ut if
there is a tight bend then most of the light will
be absorbed instead of reflected forward.
Translucent materials, such as the tower and
egg LED attachments in this set, allow some
light to pass through but scatter it around.

Color

The things around you have different colors
because they reflect the colors that you see,
while absorbing the other colors. Light
produced by the sun or a light bulb is called
white light. White light is not really a color itself ,
but is a mixture of all the colors seen in a
rainbow.

White light shines on an orange. All colors in
the light are absorbed except orange, which is
reflected off. The reflected orange light
reaches our eyes, so we see it as having
orange color.

White light can be split up into its different
colors. This happens when light passes
between different materials, and the different
colors in it are bent by different amounts. You
can see this by viewing white light through
prismatic film, as you do in project 67.
Sometimes water in the air can bend sunlight
by just the right amounts, and make a rainbow.

Color filters allow one color to pass through,
and absorb the other colors. When you look
through a red filter, everything looks red (or
black, if there isn’t any red in what you are
looking at). This set includes red, green, and
blue filters, so try looking through them.

Any color of light can be made, by mixing
different amounts of red, green, and blue light.
Mixing equal amounts of these colors
produces white light. If y ou look at a TV screen
with a magnifying glass, you will see it actually
consists of tiny red, green, and blue lights,
using different intensities to make all the
colors.

This set includes several LEDs (D1, D6, D8,
and in U22) with different colors. The color
emitted by an LED depends on the material
used in it. LEDs are more energy-efficient than
incandescent light bulbs, can be made smaller ,
and last longer.

The LED in the color organ module (U22)
contains separate red, green, and blue LEDs.
The color organ can combine these colors to
make yellow, cyan, purple, and white, as
shown in project 6. The color organ does not
allow you to adjust the amount of each color.
In project 49, several colors are mix ed together
on a spinning disc.

Red

Green

YellowMagenta

Blue

Cyan

White

Orange

Orange reflected light

White light beam

White light beam

Red filter

Red light beam

Cable slightly bent

Cable with

tight bend

Light beam

(full strength)

Weak light beam

-12-

Light in Our World

The Spectrum of Light

The light our eyes see is only part of what is around us. Visible light,
infrared light, radio waves (including TV broadcasting and cell phones),
microwaves, and x-rays are all forms of electromagnetic radiation. They
are actually changing electric and magnetic fields. This radiation travels
like waves in water, spreading out from where it was created. These
waves all travel at the speed of light, but some are longer (higher
wavelength) and some repeat faster (higher frequency). Together they
are called the electromagnetic spectrum:

The visible colors (red, orange, yellow, green, blue, and violet) have
different wav elengths . In the right conditions white light from the sun can
be separated according to wav elength, producing a rainbow of color . This
happens with an actual rainbow, and with prismatic film.

Why is the sky blue? Some sunlight is scattered by tiny particles in the
earth’s atmosphere. The shorter wavelength b lue light is scattered more
than the other colors, so the sky appears blue. At sunrise or sunset,
longer wavelength
colors like red or
yellow are more
visible in the sky,
because sunlight
passes through more
of the atmosphere
before reaching your
eyes. In space, the
sky always appears
black because there
is no atmosphere or
scattering effect.

Infrared

Infrared light is invisible light given off by
anything warm. Infrared is used in remote
controls to control TVs and appliances.
Infrared is invisible, so it doesn’t disrupt
your view of the TV. Infrared doesn’t go
through walls, so it doesn’t interfere with
devices in other rooms.

The remote control sends a stream of
infrared light pulses to the TV, encoded with
the desired commands. The infr ared light is
created using an infrared light emitting
diode (LED). Infrared detectors convert the
received light to electric current, and
decode the commands. The detectors are
tuned to focus on the infrared light, and
ignore visible light. This set contains an
infrared detector (U24), which can be
activated by a TV remote control; see
projects 41 and 42 for examples.

Infrared has other uses such as night vision
devices help to see people and animals in
the dark, by looking at the heat they give off
as infrared light. You probably saw this in the
movies.

Glow-in-the-dark

Some materials can absorb light, store it for a while, and slowly release
it back out. “Glow-in-the-dark” materials can be “charged” by bright light,
then will slowly emit light and “glow” for a while in a dark room. The glo w
fan blade in this set has a glow powder mixed in the plastic.
It’s like a slow, delayed reflection of the light.

Sound

Sound, like light, spreads out like wa ves from where it w as made. Sound
is variations in air pressure. You “hear” sound when your ears feel these
air pressure variations. Sound has much longer wavelength than light,
which enables sound to travel around corners. Sound can also be
thought of as a wave of vibr ation, and can tra v el through water and solid
objects. Sound travels about 1,000 feet per second in air, and about
5,000 feet per second in water.

-13-

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 resistor, capacitor, motor, 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 and/or quickly drain your batteries. Only connect the color organ (U22), strobe

IC (U23) and infrared module (U24) 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, capacitors, ICs (which must be connected properly), motor,
microphone, phototransistor, or resistors.

ALWAYS

use LEDs, transistors, and switches in conjunction with other components that
will limit the current through them. Failure to do so will create a shor t circuit
and/or damage those parts.

ALWAYS

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

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 the color organ (U22), strobe IC (U23) and infrared module (U24)
using configurations given in the projects or as per the connection description
on page 8.

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 diff erent wa ys without
changing the circuit. F or 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.

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

This is also a

SHORT CIRCUIT.

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.

NEVER

DO!

NEVER

DO!

NEVER

DO!

NEVER

DO!

Examples of SHORT CIRCUITS - NEVER DO THESE!!!

Warning to Snap Circuits®owners: Do not use

parts from other Snap Circuits

®

sets with this kit.
Other sets use higher voltage which could damage
parts.

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 y our 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 Snap Circuits

®

to the electrical outlets in your home in any way!

`

`

`

-14-

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 f

ollow this procedure to
systematically determine which ones need
replacing:

(Note: Some of these tests connect an LED
directly across the batteries without another
component to limit the current. Normally this
might damage the LED, however Snap Circuits

®

LEDs have internal resistors added to protect
them from incorrect wiring, and will not be
damaged.)

1. Red LED (D1), motor (M1), speaker (SP),

and battery holder (B1): Place batteries in

holder. Place the red LED directly across the
battery holder (LED + to battery +), it should
light. Do the same for the motor, it should
spin. “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 b lac k plastic piece with three
prongs on the motor shaft, and replace it if
it is damaged (this kit includes a spare). To
replace, pry the broken one off the motor
shaft using a screwdriver , then push the new
one on.

2. Red & black jumper wires: Use this mini-

circuit to test each jumper wire, the LED
should light.

3. Snap wires: Use this mini-circuit to test
each of the snap wires, one at a time

. The

LED should light.

4. Slide switch (S1) and Press switch (S2):
Use this mini-circuit; if the LED doesn’t light
then the slide switch is bad.

Replace the
slide switch
with the press
switch to test it.

5. 100Ω (R1) and 5.1kΩ (R3) resistors: Use
the mini-circuit from test 4 but replace the
s

witch with the 100Ω resistor (R1); the LED
will be bright if the resistor is good. Ne xt use
the 5.1kΩ resistor in place of the 100Ω
resistor; the LED should be much dimmer
but still light.

6. White LED (D6) and color LED (D8): Use
this mini circuit; if the white LED

doesn’t light
then D6 is bad. Replace the white LED with
the color LED; it should change colors in a
repetitive pattern, otherwise D8 is bad.

7. Microphone (X1) and Phototransistor

(Q4): Use the mini-circuit from test 6 but

replace the 100Ω resistor with the
microphone (+ on right);

if blowing into the
microphone does not change the LED
brightness then X1 is bad. Replace the
microphone with the phototransistor (+ on
right). Waving your hand over the
phototransistor (changing the light that
shines on it) should change the brightness
of the LED or Q4 is bad.

8. Adjustable resistor (RV): Build project
160, but use the red LED (D1) in place of
the color LED (D8).

Move the resistor control
lever to both sides. When set to each side,
one LED should be bright and the other off
(or very dim); otherwise RV is bad.

9. PNP transistor (Q1): Build the mini-circuit
shown here

. The red LED (D1) should only
be on if the press switch (S2) is pressed. If
otherwise, then Q1 is damaged.

10. NPN transistor (Q2): Build the mini-
circuit shown here

. The red LED (D1)
should only be on if the press switch (S2)
is pressed. If otherwise, then Q2 is
damaged.

-15-

Advanced Troubleshooting

(Adult supervision recommended)

11. Strobe IC (U23) and 100kΩ resistor

(R5): Build the mini-circuit shown here,

and turn on the s

witch (S1). The speaker
should make a buzzing sound or U23 is
bad. Next use the 100kΩ resistor in place
of the 5.1kΩ resistor; the sound should be
a beeping sound now or R5 is bad.

12. Infrared module (U24): Build project 41,
the remote control should turn the red LED
(D1) on;

otherwise U24 is bad.

13. 0.1µF capacitor (C2) and 100µF

capacitor (C4): Build this circuit. There

should be a buzzing sound, or C2 is bad.
Ne

xt, replace C2 with C4; now you should
hear beeps every 5 seconds, or C4 is bad.
The setting on RV does not matter.

15. Color organ (U22): Do project 182. If
parts A or B do not work, U22 is damaged.
If part C does not work, then there may be
a problem with U22, with your stereo
cable, with your music device, or you may
not have your music device on the right
settings.

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 /

replacement parts at:

www.snapcircuits.net

1

1

1

1

1

1

2

2

2

2

2

2

2

2

3

3

3

1

1

1

1

1

2

2

2

2

2

2

2

-16-

Project # Description Page #

1 Color Light 18
2 White Light 18
3 Red Light 18
4 Light Show 19
5 Voice Light Show 20
6 Play the Color Organ 20
7 Flying Saucer 21
8 Super Flying Saucer 21
9 Big Circuit 22
10 Box Cover Circuit 23
11 Blinking Colors 24
12 Fiber Optics 24
13 Tones Over Light 25
14 Color Optic Sounds 25
15 Color Light Transporter 26
16 Color Optics 26
17 High Power Fiber Optics 27
18 High Color Optics Sounds 27
19 Sound Maker 28
20 Strobe Light 28
21 Color Strobe Light 28
22 Red Strobe Light 28
23 Noisy Strobe Light 29
24 Noisy Red Strobe Light 29
25 Double Strobe Light 29
26 Louder Strobe Light 29
27 Louder Color Strobe Light 29
28 Triple Strobe Light 30
29 Noisy Double Strobe Light 30
30 Noisy Triple Strober 30
31 Triple Light Noisy Motion Strober 30

Project # Description Page #

32 Automatic Light 31
33 Color Oscillator 31
34 Dance to the Music 32
35 Super Dance to the Music 32
36 Super Dance to the Music (II) 32
37 Follow the Music 33
38 Color Organ - Headphones 33
39 Adjustable Light Dance 34
40 Suspended Raindrops 34
41 Infrared Detector 35
42 Audio Infrared Detector 35
43 Photo Infrared Detector 36
44 Photo Audio Infrared Detector 36
45

Photo Audio Infrared Detector (II)

36
46 Strobe Effects 37
47 Slow Strobe Effects 37
48 Stable Strobe Effects 38
49 Strobe Effects (II) 38
50 Strobe Effects (III) 38
51 Strobe Effects (IV) 38
52 Strobe Effects (V) 38
53 Strobe Effects (VI) 39
54 Make Your Own Strobe Effects 39
55 Another Strobe Light 39
56 Motor Strobe Effects 40
57 Motor Strobe Effects (II) 40
58 Motor Strobe Effects (III) 40
59 LEDs Together 41
60 LEDs Together (II) 41
61 Brightness Control 42
62 Resistors 42

Project # Description Page #

63 Resistors & LEDs 42
64 Low Power Brightness Control 43
65 Low Power Resistors & LEDs 43
66 Persistence of Vision 43
67 Prismatic Film 44
68 Look at the Lights 44
69 Scattering Light 44
70 Color Fiber Light 44
71 One Way Plastic 45
72 White Blinker 45
73 Red Blinker 45
74 Red & White 45
75 Color Selector - Red 46
76 Color Selector - Green 46
77 Color Selector - Blue 46
78 Color Selector - Cyan 46
79 Color Selector - Yellow 46
80 Color Selector - Purple 46
81 Color Selector - White 46
82 LED Color Spectrum 47
83 LED Color Spectrum (II) 47
84 LED Color Spectrum (III) 47
85 LED Color Spectrum (IV) 47
86 LED Color Spectrum (V) 47
87 Blinking Beeping 48
88 Blinking Blinking 48
89 Blinking Control 48
90 Blinking Control Beeping 48
91 Triple Blinker 49
92 Funny Speed Motor 49
93 Funny Speed Motor with Light 49

Project Listings

-17-

Project # Description Page #

94 Light Dance Audio Override 50
95 Light Dance Light Override 50
96 Counting Light 51
97 Adjustable Counting Light 51
98 Bright Off Light 52
99 R/C Blink & Beep 52
100 Stuck On Light 53
101 Stuck On Lights 53
102 White Blinker 53
103 Low Voltage Stuck On Lights 53
104 Stuck On Motor & Lights 53
105 Funky Light & Sound 54
106 Light & Sound 54
107 Light & Motion 54
108 Adjustable Light & Sound 54
109 Adjustable Light & Motion 54
110 Blinking Step Motor 55
111 Blink Step Beep 55
112 Day Blinker 56
113 Night Blinker 56
114 Night Light Show 56
115 Daylight Light Show 56
116 Buzzer 57
117 Higher Pitch Buzzer 57
118 Photo Light & Motion 57
119 Slow Light & Motion 57
120 Light Up the Fan 57
121 High Power Buzzer 58
122 Buzz Fan 58
123 Photo Buzzer 58
124 Step Beeper 58

Project # Description Page #

125 Wacky Buzzer 58
126 Fiber Fun 59
127 Fiber Fun Backwards 59
128 More Fiber Fun 59
129 Other Fiber Fun 59
130 Morse Code 60
131 Fiber Shut-Off 60
132 Blow On Fiber 61
133 Fiber Music 61
134 Fiber Color Organ 62
135 Bright Fiber Color Organ 62
136 Motor Power 63
137 More Motor Power 63
138 Reflection Detector 63
139 Cup & String Communication 64
140 Slow Motor Speed Control 65
141 Slow Motor Start Aid 65
142 R/C Motor 65
143 Series Lights 66
144 Wacky Sound Control 66
145 Musical Shapes 67
146 Human & Liquid Sounds 67
147 Human & Liquid Light 67
148 Blow On the Light 68
149 Blow Off the Light 68
150 Transistor 69
151 Another Transistor 69
152 Charging & Discharging 70
153 Mini Capacitor 70
154

Adjustable Charging & Discharging

70

155 Mini Battery 70

Project # Description Page #

156 Photo Current Amplifier 71
157 LEDs &

Transistors 71
158 PNP Amplifier 71
159 Photo Control 72
160 Resistance Director 72
161 Current Controllers - Series 73
162 Current Controllers - Parallel 73
163 Blow Sound Changer 74
164 Short Light 74
165 Shorter Light 74
166 Photo Light Control 75
167 Air Pressure Light Control 75
168 Slow On, Slower Off 75
169 Delayed Photo Speed Control 76
170 Delayed Speed Control 76
171 Delayed Speed Control (II) 76
172 Audio Delayed Speed Control 76
173 Photo Speed Control 76
174 Light Buzz 77
175 Delay Lights 77
176 Touch Light 78
177 Narrow Range Tone 78
178 Slow Off Lights 78
179 3D Pictures 79, 80
180 Super Infrared Detector 80
181 Infrared Optical Audio 81
182 Test the Color Organ 81

Project Listings

-18-

Project 1 Color Light

Snap Circuits®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 each of the battery holders (B1)
if you have not done so already.

Turn on the slide switch (S1), and enjoy the
light show from the color LED (D8). For best
effects, place one of the LED attachments
(tower, egg, or fiber optic tree) on the color
LED, and dim the room lights. The fiber optic
tree must be used with its mounting base.

+

Use the circuit built in project 1, but replace
the color LED (D8) with the white LED (D6).
Try it with one of the LED attachments, and
in a dark room.

Use the circuit built in project 2, but replace the
white LED (D6) with the red LED (D1). Try it with
one of the LED attachments, and in a dark room.

Project 2 White Light Project 3 Red Light

+

The white LED produces very bright light.
LEDs are this one are increasingly being
used for home lighting and flashlights. They
are more efficient than normal light bulbs.

The red LED is not nearly as bright as the
other LEDs. LEDs like this one are used as
indicators in many products in your home.
They are inexpensive, but don’t produce
much light.

Placement Level

Numbers

Snappy says the color
LED actually contains
separate red, green, and
blue lights, with a micro­circuit controlling them.

LED Attachments

-19-

Snap Circuits®uses electronic blocks that
snap onto a clear plastic grid to build different
circuits. These bloc ks hav e diff erent colors and
numbers on them so that you can easily
identify them.

Build the circuit shown above b y 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 parts marked with a 4 (just one end
of the red jumper wire, in this circuit). Install
two (2) “AA” batteries (not included) into each
of the battery holders (B1) if you have not
done so already.

If desired, place any of the LED attachments
(tower, egg, or fiber optic tree) on any of the
LEDs (red (D1), color (D8), white (D6), or the
LED on the color organ IC (U22). Note that the
fiber optic tree requires its mounting base.

Turn on slide switch (S1) and enjoy the show!

Project 4 Light Show

+

+

+

Placement Level

Numbers

LED Attachments

All the lights in this set are LEDs - Light
Emitting Diodes. LEDs conv ert electrical
energy into light; the color of the light
emitted depends on the characteristics
of the material used in them.

-20-

Project 5 Voice Light Show

Project 6 Play the Color Organ

Build the circuit as shown, and place one of the LED attachments (tower,
egg, or fiber optic tree) over the LED on the color organ (U22). Turn on
the switch (S1) and talk. The color organ light will follow your voice, in
tone and loudness.

Build the circuit as shown, and turn on the switch (S1). Place one of the
LED attachments on the color organ (U22). Wet y our fingers, and touch
them between the point marked “X”, and points marked “R”, “G”, or “B”
in the drawing. Try X with every combination of R, G, and B, including
touching them all at the same time.

The light in the color organ module is
actually red, gree

, and blue LEDs together.
The points marked R, G, and B control the
light for those colors. Combining red and
green makes yellow, green and blue makes
cyan, red and blue makes purple, and
combining all three colors makes white.

How does it work? The
microphone converts your
voice to an electrical signal,
which controls an electronic
counter in the color organ.
The counter controls a red­green-blue LED.

LED

Attachments

LED Attachments

-21-

!

WARNING: Moving parts. Do not

touch the fan or motor during operation.
Do not lean over the motor. Fan may
not rise until switch is released.

This circuit will make the fan spin faster and fly higher than the
preceding circuit, making it easy to lose your fan.

WARNING: Elenco

®

Electronics Inc. is not responsible for lost or

broken fans! You may purchase replacement fans at www.

snapcircuits.net.
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.

Project 7 Flying Saucer

Project 8 Super Flying Saucer

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 press the s witch se ver al
times rapidly when it is at full speed. The motor spins
faster when the batteries are new.

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.

+

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.

+

!

WARNING: Mo ving parts. Do not touch the fan

or motor during operation. Do not lean o v er the
motor. Fan may not rise until switch is released.
Eye protection is recommended for this circuit.

-22-

Build the circuit as shown. Place either the glow fan or the light fan on
the motor (M1) shaft, so that it is stable on the little black piece. Place
the clear fiber optic holder on the color LED (D8) and the black fiber optic
holder on the phototransistor (Q4), then insert the fiber optic cable
between them, but don’t let it lay close to the fan on the motor. For best
performance the fiber optic cable should stand straight up in the holders,
without bending them. Connect a music device to the color organ (U22)
as shown, and start music on it. For best effects, place one of the LED
attachments over the light on the color organ.

Turn on slide switch (S1). Adjust the le ver on the adjustab le resistor (R V)
and the volume control on your music device for best sound and light
effects.

Push the press switch (S2) until the motor reaches full speed, then
release it. The fan will rise into the air like a flying saucer. Be careful not
to look down on the fan when it is spinning. If desired, connect the light
fan blade to the charger f or a while to charge it, then place it on the motor
to spin or launch it.

“Playing the Color Organ”: turn off or disconnect your music device. W et
your fingers, and touch them between the point marked “X”, and “R”, “G”,
or “B” in the drawing.

The infrared detector (U24) and 100kΩ resistor (R5) are only used to
support the other components.

!

WARNING: Moving parts.

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

Project 9 Big Circuit

+

This circuit does a lot of
different things at once.

MP3

player

LED Attachments

Black

Clear

-23-

!

WARNING: Moving parts. Do

not touch the fan or motor
during operation. Do not lean
over the motor . Fan may not rise
until switch is released.

Build the circuit as shown. Place the glow fan on the motor (M1) shaft, so that it is stable on the little black
piece. Place the clear fiber optic holder on the white LED (D6) and the black fiber optic holder on the
phototransistor (Q4), then insert the fiber optic cable between them, but don’t let it lay close to the fan on
the motor. For best performance the fiber optic cable should stand straight up in the holders, without bending
them. For best effects, place one of the LED attachments over the light on the color organ, and one on the
color LED (D8).

Optional: connect a music device to the color organ (U22) as shown, and start music on it (the color organ
light will change to the music, but you will not hear it unless you also connect headphones).

Turn on slide switch (S1). A tone is hear from the speaker (SP), and all the lights (D1, D6, D8, and on U22)
are on.

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

Project 10 Box Cover Circuit

Headphones

(optional)

Music device

(optional)

This circuit is called the Box Cov er
Circuit because it is pictured on
the front of the Snap Circuits

®

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

+

Black

Clear

-24-

Build the circuit as shown. Place the clear cable holder on the red LED (D1)
and the black cable holder on the phototr ansistor (Q4), then place the fiber
optic cable into the holders as far as it will go. For best performance the
cable should stand straight up in the holders, without bending them.

Turn on slide switch (S1) and move the lever on the adjustable resistor
(RV) around. The sound from the speaker (SP) changes as you move
the lever on RV.

Project 11 Blinking Colors

Build the circuit as shown and turn on
the slide switch (S1). The white and
color LEDs (D6 & D8) are blinking.

Push the press switch (S2). Now the
red LED (D1) is blinking but the white
LED is off.

If you swap the locations of the red
and white LEDs, then the red LED will
be blinking and the white LED will be
off, and pushing the press switch
won’t change anything.

Red light is easier for LEDs to produce than
white light. When the red and white LEDs are
connected in parallel (which happens when S2
is pressed), the red LED will dominate because
it turns on more easily.

Fiber Optics Project 12

Black

Clear

This project is more exciting than it looks. The tone sounds
produced by the strobe IC (U23) are played on the speaker (SP),
even though there is no electrical connection between them.

The left half the circuit makes a coded light signal, which you
see in the red LED (D1). The right half of the circuit decodes the
light signal and plays it on the speaker. The fiber optic cable is
used to transmit the light signal between the two sides of the
circuit. There is no electrical connection between the left and
right halves of the circuit, only a light connection using fiber
optics! If your fiber optic cable was longer, the two halves of the
circuit could be many miles apart.

This circuit is an example of using fiber optic cables for
communication. Fiber optics allo ws information to be transmitted
across great distances at very high speeds with very low
distortion, by using light.

-25-

Project 13 Tones Over Light

Project 14 Color Optic Sounds

Build the circuit as shown. Place the clear cab le holder on the red LED
(D1) and the black cable holder on the phototr ansistor (Q4), then place
the fiber optic cable into the holders as far as it will go. For best
performance the fiber optic cable should stand straight up in the
holders, without bending them.

Turn on the slide switch (S1) and move the lever on the adjustable
resistor (RV) around. The sound from the speaker (SP) changes as you
move the lever on RV.

Build the circuit as shown. Place the clear cable holder on the color LED
(D8) and the black cable holder on the phototr ansistor (Q4), then place
the fiber optic cable into the holders as far as it will go. For best
performance the fiber optic cable should stand straight up in the
holders, without bending them.

Turn on the slide switch (S1) and push the press switch (S2). Light is
transmitted from the color LED , through the fiber optic cable, to control
the strobe IC (U23) and speaker (SP).

This is similar to project 12 but
not as loud. The project 12
circuit uses a two-transistor
amplifier while this circuit only
has one transistor.

Black

Clear

Clear

Black