Elenco SCL-175 Snap Circuits Light Electronics Kit User Manual

Project 22

Go to https://shop.elenco.com/

consumers/snap-circuits-light.html

to download projects 84-177

and Bonus Projects 1-11!

2021 by Elenco

by any means; electronic, photocopying, or otherwise without written permission from the publisher.

SOURCE CODE:SCL-175V1 | REV-B | 753285

1. Most circuit problems are due to incorrect assembly,

always double-check that your circuit exactly matches

the drawing for it.

2. Be sure that parts with positive/negative markings are

positioned as per the drawing.

3. Be sure that all connections are securely snapped.

4. Try replacing the batteries.

5. If the motor spins but does not balance the fan, check

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beropticscircuitisn’tworking, make sure the

clear & black cable holders are pushed all the way

ontotheLED/phototransistor,andtheberopticcable

is pushed into the holders as far as it will go. The cable

should be standing straight up in the holders.

ELENCO

is not responsible for parts damaged due to

incorrect wiring.

Basic Troubleshooting

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

Advanced Troubleshooting procedure on page 14 to determine which ones

need replacing.

Basic Troubleshooting 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 Troubleshooting 14-15

Projects 1 - 83 16-42

WARNING: SHOCK HAZARD - Never connect Snap

Circuits

to the electrical outlets in your home in any way!

Table of Contents

WARNING: Always check your wiring

before turning on a circuit. Never leave a

circuit unattended while the batteries are

installed. Never connect additional batteries

or any other power sources to your circuits.

Discard any cracked or broken parts.

Adult Supervision:  Because children’s

abilities vary so much, even with age

groups, adults should exercise discretion as

to which experiments are suitable and safe

(the instructions should enable supervising

adults to establish the experiment’s

suitability for the child). Make sure your

child reads and follows all of the relevant

instructions and safety procedures, and

keeps them at hand for reference.

This product is intended for use by adults

and children who have attained sufcient

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 rapidly

changing colors or patterns should exercise

caution when playing with this toy.

CAUTION: High intensity light. Do not look

directly at white LED (D6).

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.

● 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reorattemptto

open its outer casing.

● Batteries are harmful if swallowed, so keep

away from small children.

Batteries:

WARNING: CHOKING HAZARD -

Small parts. Not for children under 3 years.

Conforms to all applicable

government requirements

Go to https://shop.elenco.com/

consumers/snap-circuits-light.html

to download projects 84-177

and Bonus Projects 1-11!

Important: If any parts are missing or damaged, DO NOT RETURN TO RETAILER. Call toll-free (800) 533-2441 or e-mail us at: help@

elenco.com. 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 #

r 3 1-Snap Wire 6SC01 r 1

White Light Emitting

Diode (LED)

6SCD6

r 6 2-Snap Wire 6SC02 r 1

Color Light Emitting

Diode (LED)

6SCD8

r 3 3-Snap Wire 6SC03 r 1 Egg LED Attachment 6SCEGG

r 1 4-Snap Wire 6SC04 r 1 Fiber Optic Cable 6SCFC

r 1 5-Snap Wire 6SC05 r 1

Fiber Optic Cable

Holder, black

6SCFCHB

r 1 6-Snap Wire 6SC06 r 1

Fiber Optic Cable

Holder, clear

6SCFCHC

r 2

Battery Holder - uses

two (2) 1.5V type “AA”

(not Included)

6SCB1 r 1 Prismatic Film 6SCFILM

r 1

Base Grid

(11.0” x 7.7”)

6SCBG r 1

Mounting Base

(for ber optic tree)

6SCFMB

r 1 0.1mF Capacitor 6SCC2

r 1

Red/Green/Blue

Filters Set

6SCFRGB

r 1 100mF Capacitor 6SCC4 r 1 Fiber Optic Tree 6SCFT

r 1

Red Light Emitting

Diode (LED)

6SCD1

r 1 Jumper Wire (black) 6SCJ1

You may order additional / replacement parts at our website: www.elenco.com/replacement-parts/

Important: If any parts are missing or damaged, DO NOT RETURN TO RETAILER. Call toll-free (800) 533-2441 or e-mail us at: help@

elenco.com. 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 #

r 1 Jumper Wire (red) 6SCJ2 r 1 100kW Resistor 6SCR5

r 1 Motor 6SCM1 r 1 Adjustable Resistor 6SCRV

r 1 Disc Holder 6SCM1DH r 1 Slide Switch 6SCS1

r 1

Set of Disc Cutouts

(6 pcs. / set)

6SCM1DS r 1 Press Switch 6SCS2

r 1 Glow Fan Blade 6SCM1FG r 1 Speaker 6SCSP

r 1 Spare Motor Top 6SCM1T r 1

Tower LED

Attachment

6SCTOWER

r 1 PNP Transistor 6SCQ1 r 1 Color Organ 6SCU22

r 1 NPN Transistor 6SCQ2

r 1 Strobe IC 6SCU23

r 1 Phototransistor 6SCQ4 r 1 Infrared Receiver 6SCU24

r 1 100W Resistor 6SCR1 r 1 Microphone 6SCX1

r 1 5.1kW Resistor 6SCR3

You may order additional / replacement parts at our website: www.elenco.com/replacement-parts/

U22

U24

U23

How to Use Snap Circuits

Snap Circuits

uses building blocks with snaps

to build the different electrical and electronic

circuits in the projects. Each block has a

function: there are switch blocks, light blocks,

battery blocks, different length wire blocks,

etc. These blocks are different colors and

have numbers on them so that you can easily

identify them. The blocks you will be using are

shown as color symbols with level numbers

next to them, allowing you to easily snap them

together to form a circuit.

For Example:

This is the switch block which is green and has

the marking on it. The part symbols in this

booklet may not exactly match the appearance

of the actual parts, but will clearly identify them.

This is a wire block which is blue and comes in

different wire lengths.

This one has the number , , , ,

or on it depending on the length of the wire

connection required.

There is also a 1-snap wire that is used as a

spacer or for interconnection between different

layers.

You need a power source to build each circuit.

This is labeled and requires two (2) 1.5V

“AA” batteries (not included).

When installing a battery, be sure the spring

is compressed straight back, and not bent up,

down, or to one side.

A large clear plastic base grid is included with

this kit to help keep the circuit blocks properly

spaced. You will see evenly spaced posts that

the different blocks snap into. The base has

rows labeled A-G and columns labeled 1-10.

Next to each part in every circuit drawing is

a small number in black. This tells you which

level the component is placed at. Place all

parts on level 1 rst, 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

ngernail, or use a pencil to push it up from

beneath one of the tabs.

3 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 effects. The egg and tower attachments

are mounted directly on the LEDs, but the

ber optic tree must be mounted using the

mounting base, as shown. This is described

in the projects.

In some projects, the ber 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 ber 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 Tower

Correct

Incorrect

Fiber Optic Tree

LED attachment

mounted to D8

Light Tower

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

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

exible connections

for times when using

the snap wires would be

difcult. 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

owing in a wire has a magnetic eld 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 ows through the loops, it

will turn ordinary metal into a magnet. The motor

shell also has a magnet on it. When electricity

ows 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 airow.

Motor (M1)

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 & 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 voltage is much

lower and much safer than that used in your

house wiring. Using more batteries increases

the “pressure”, therefore, more electricity ows.

Battery Holder (B1)

MOTOR

About Your Snap Circuits

LIGHT Parts

RESISTORS LEDs

Adjustable Resistor (RV)

Resistors (R1, R3, & R5)

SLIDE & PRESS SWITCHES

The speaker (SP) converts

electricity into sound by

making mechanical vib-

rations. 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 50kW resistor

but with a center tap that can be adjusted

between 200W and 50kW.

Resistors “resist” the ow of electricity and are

used to control or limit the current in a circuit.

Snap Circuits

LIGHT includes 100W (R1), 5.1kW

(R3), and 100kW (R5) resistors (“k” symbolizes

1,000, so R5 is really 100,000W). Materials like

metal have very low resistance (<1W), while

materials like paper, plastic, and air have near-

innite resistance. Increasing circuit resistance

reduces the ow 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 ows 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

micro-circuit controlling then. A high current will

burn 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 0.1mF and 100mF 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 1kW and

10kW.

MICROPHONE

About Your Snap Circuits

LIGHT Parts

TRANSISTORS

The phototransistor (Q4) is a transistor that

uses light to control electric current.

Phototransistor (Q4)

ELECTRONIC MODULES

(+)

OUT

(–)

CTL

Connections:

(+) - power from batteries

(–) - power return to batteries

OUT - output connection

CTL - strobe speed control

NC - not used

See project 31 for example of

proper connections.

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, 12, and 83 for

examples of proper connections.

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 for it is available

at www.elenco.com/faqs/

(+)

INP(–)

OUT

The

strobe IC (U23) contains resistors, capacitors, and

transistors that are needed to make a strobe light circuit.

A schematic for it is available at www.elenco.com/faqs/

Infrared module (U24)

OTHER PARTS

Prismatic film separates light into

different colors. The red, green, & blue

lters lter out colors.

The disc holder and discs produce amazing effects when

used with the Strobe Effects circuit (project 31).

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, amplier, 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

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 ow of electricity like valves and faucets control water.

Resistors limit the ow 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 owing in a wire, just

as the water current describes how fast water is owing 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 ow of electric current. The relationship

is Voltage = Current x Resistance. When the resistance increases, less current

ows. Resistance is measured in ohms (W), or kilo ohms (kW, 1000 ohms).

Nearly all of the electricity used in our world is produced at enormous generators

driven by steam or water pressure. Wires are used to efciently transport this

energy to homes and businesses where it is used. Motors convert the electricity

back into mechanical form to drive machinery and appliances. The most important

aspect of electricity in our society is that it allows energy to be easily transported

over distances.

Note that “distances” includes not just large distances but also tiny distances. Try

to imagine a plumbing structure of the same complexity as the circuitry inside a

portable radio - it would have to be large because we can’t make water pipes so

small. Electricity allows complex designs to be made very small.

There are two ways of arranging parts in a circuit, in series or

in parallel. Here are examples:

Placing components in series increases the resistance; highest

value dominates. Placing components in parallel decreases

the resistance; 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

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 eyes, to learn

what is around us. In ber 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 ying off in all

directions.

This happens when a material has too much

energy, and some of the energy changes

form. For example, a light bulb makes light

when an electric current makes the lament

so hot that it glows. Some of the energy in

a burning re escapes by changing to light.

Our bright 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 reected off. The absorbed

light is converted to heat, and the reected

light is scattered around the room. Some of

the shining and reected light might reach

your eyes. Your brain interprets the light into

your eyes, and makes the mental picture you

see.

When all the light shining on something is

absorbed, with none reected towards your

eyes, then you can’t see it. The object will

appear dark. The brighter an object appears,

the more light was reected 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 reects 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

oating 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

reection 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 reections.

Try looking through a window in your home at

really wide angles.

Light bulb

lament

Glowing

light bulb

lament

Close-up

view of the

Sun

Glowing

white LED

(D6)

White light beam

Reected light

Mental picture

Light in Our World

When light hits a glass surface at a wide

enough angle, all the light is reected. Fiber

optic cables have arrays of exible glass bers.

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 even if it is bent a little, but if

there is a tight bend then most of the light will

be absorbed instead of reected 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 reected off. The reected 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 51.

Sometimes water in the air can bend sunlight

by just the right amounts, and make a rainbow.

Color lters allow one color to pass through,

and absorb the other colors. When you look

through a red lter, everything looks red (or

black, if there isn’t any red in what you are

looking at). This set includes red, green, and

blue lters, 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 you 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-efcient

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 34, several colors are mixed

together on a spinning disc.

Red

Green

YellowMagenta

Blue

Cyan

White

Orange

Orange reected light

White light beam

Red lter

Red light beam

Cable slightly bent

Cable with

tight bend

Light beam

(full strength)

Weak light beam

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 elds. 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

wavelengths. In the right conditions white light from the sun can be separated

according to wavelength, producing a rainbow of color. This happens with an

actual rainbow, and with prismatic lm.

Why is the sky blue? Some sunlight is scattered by tiny particles in the earth’s

atmosphere. The shorter wavelength blue 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 infrared

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 18 and 25 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 glow

fan blade in this set has a glow powder mixed in the plastic.

It’s like a slow, delayed reection of the light.

Sound

Sound, like light, spreads out like waves from where it was 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 vibration, and can travel through water and solid

objects. Sound travels about 1,000 feet per second in air, and about

5,000 feet per second in water.

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 congurations 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 short 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 congurations 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 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.

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.

WARNING: SHOCK HAZARD

- Never connect Snap Circuits

to the electrical outlets in your home in any way!

!

↯

! !

You are encouraged to tell us about new circuits you create. If they are

unique, we will post them with your name and state on our website at

www.elenco.com/showcase.

Send your suggestions (with photos) to [email protected].

Elenco

provides a circuit designer so that you can make your own

Snap Circuits

drawings. This Microsoft

Word document can be

downloaded from www.elenco.com/for-makers.

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:

(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 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.

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. 100W(R1) and 5.1kW(R3) resistors: Use

the mini-circuit from test 4 but replace the

switch with the 100W resistor (R1); the LED

will be bright if the resistor is good. Next

use the 5.1kW resistor in place of the 100W

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 100W 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 81,

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.

Advanced Troubleshooting (Adult supervision recommended)

11. Strobe IC (U23) and 100kW resistor

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

and turn on the switch (S1). The speaker

should make a buzzing sound or U23 is

bad. Next use the 100kW resistor in place

of the 5.1kW resistor; the sound should be

a beeping sound now or R5 is bad.

12. Infrared module (U24): Build project

18, the remote control should turn the red

LED (D1) on; otherwise U24 is bad.

13. 0.1mF capacitor (C2) and 100mF

capacitor (C4): Build this circuit. There

should be a buzzing sound, or C2 is bad.

Next, 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 83. If parts

A or B do not work, U22 is damaged.

ELENCO

150 Carpenter Avenue

Wheeling, IL 60090 U.S.A.

Phone: (847) 541-3800

Fax: (847) 520-0085

e-mail: [email protected]

Website: www.elenco.com

You may order additional /

replacement parts at: www.

elenco.com/replacement-parts/

Project 1

Color Light

Build the circuit shown on the left by placing all the parts with a black 1 next

to them on the board rst. 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. When installing a battery, be sure the spring

is compressed straight back, and not bent up, down, or to one side.

Battery installation should be supervised by an adult.

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 ber optic tree) on the color LED, and dim the room lights. The ber 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 ashlights. They

are more efcient 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 micro-

circuit controlling them.

LED Attachments

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 above by placing all the parts

with a black 1 next to them on the board rst. Then,

assemble parts marked with a 2.

If desired, place any of the LED attachments (tower,

egg, or ber 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 ber 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 convert electrical

energy into light; the color of the light

emitted depends on the characteristics

of the material used in them.

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 ber 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 your ngers, 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, green, 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 red-

green-blue LED.

LED Attachments

Replace the microphone (X1) with the phototransistor (“+” on top) and

vary the amount of light shining on it. The light on the color organ is

changing only if there is enough light on the phototransistor.

Project NEW1 Light Changer

This circuit will make the fan spin faster and y 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 oat through the air like a ying 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 oat through the air like a ying saucer. Be

careful not to look directly down on fan blade when it is spinning.

If the fan doesn’t y off, then press the switch several 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 y

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: Moving parts. Do not touch the fan or

motor during operation. Do not lean over the motor.

WARNING: Moving parts. Do not touch the fan or

motor during operation. Do not lean over the motor.

Project 9

Super Voice Light Show

This circuit is similar to project 5, but more sensitive. Build the circuit as

shown, initially set the adjustable resisitor (RV) to the middle, and place one

of the LED attachments (tower, egg, or ber optic tree) over the LED on

the color organ (U22). Turn on the switch (S1) and talk, or place a device

playing music near the micorphone (X1). The color organ light will follow the

sound, in tone and loudness.The speaker (SP) is used here to regulate a

transistor amplier for the microphone, and will not make sound.

Project 12

Color Oscillator

Build the circuit as shown, and place one of the LED attachments (tower,

egg, or ber optic tree) over the LED on the Color Organ (U22). Turn on the

switch (S1) and watch. The color organ light will change colors on its own.

This circuit is an oscillator;

it uses the color organ to

control itself.

LED

Attachments

Replace the 3-snap wire that is across base grid locations C2-E2 (next

to the 0.1mF capacitor (C2)) with the 100kW resistor (R5). Now the

color organ light changes more slowly.

Project 13 Slower Oscillator

Replace the microphone (X1) with the motor (M1). Spin the motor top

with your ngers to change the color organ light.

Project 10 Finger Light Show

Replace the motor with the color LED (D8) to create some interesting

effects.

Project 11 Funky Show

LED Attachments

Project 14

Sound Maker

Build the circuit and turn on the switch (S1). You hear sound from the speaker.

Adjust the sound using the lever on the adjustable resistor (RV), and by

pushing the press switch (S2).

Note: In rare cases the circuit may not work at all settings on RV. If this

happens, move the RV lever to the side near the strobe IC, turn the slide switch

off and on to reset the circuit, and only move the RV lever over a small range.

The strobe IC (U23) produces an electrical “tone”. The

pitch of the “tone” is adjusted by changing how much

electricity ows into its upper-left snap, using a resistor.

The electrical tone it produces can be used to make sound

using a speaker, or to control the ash rate of an LED.

The color LED will not be changing colors like it does in

other circuits. When the strobe IC (U23) turns the color

LED on and off, it resets the color-control microcircuit in the

color LED. Even your slowest strobe speed is too fast for

the color LED.

Use the preceding circuit, but replace the speaker with the white

LED (D6). Now you have a strobe light! When S2 is pressed, the light may

be blinking so fast that it appears to be on continuously.

Use the preceding circuit, but replace the white LED with the color LED (D8).

Use the preceding circuit but replace the color LED (D8) with the red

LED (D1).

Project 15 Strobe Light

Project 16 Color Strobe Light

Project 17 Red Light Strobe

Project 18 Infrared Detector

You need an infrared remote control for this project, such as any TV/stereo/

DVD remote control in your home.

Build the circuit and turn on the switch (S1). Point your remote control toward

the infrared module (U24) and press any button to activate the red LED (D1).

Sometimes this circuit may activate without a remote control, due to infrared

in sunlight or some room lights. If this happens, try moving to a dark room.

TV remote controls transmit a sequence of

pulses representing the TV model and the

button that was pressed. The U24 infrared

detector is just looking any infrared signal.

Remote

Build the circuit as shown. Place the clear cable holder on the red LED (D1)

and the black cable holder on the phototransistor (Q4), then place the ber

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 19 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 much dimmer or 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 may

dimly light the white LED but the red LED will hardly be affected.

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 20

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 ber 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 ber optics! If your ber

optic cable was longer, the two halves of the circuit could be many

miles apart.

This circuit is an example of using ber optic cables for

communication. Fiber optics allows information to be transmitted

across great distances at very high speeds with very low

distortion, by using light.

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 ber

optic holder on the color LED (D8) and the black ber

optic holder on the phototransistor (Q4), then insert

the ber optic cable between them, but don’t let it lay

close to the fan on the motor. For best performance

the ber 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.

Turn on slide switch (S1). Talk into the microphone

(X1) and adjust the lever on the adjustable resistor

(RV) 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 ying saucer.

“Playing the Color Organ”: Wet your ngers, and

touch them between the point marked “X”, and “R”,

“G”, or “B” in the drawing.

Project 21

Big Circuit

This circuit does a lot of

different things at once.

LED Attachments

Black

Clear

WARNING: Moving parts. Do not touch the fan or

motor during operation. Do not lean over the motor.

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 ber optic holder on the white LED (D6). and the

black ber optic holder on the phototransistor (Q4), then

insert the ber optic cable between them, but don’t let it

lay close to the fan on the motor. For best performance the

ber 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 heard 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

ying saucer. Be careful not to look down on the fan when it

is spinning.

This circuit also works if you move the clear ber optic

holder from the white LED (D6) to the color LED (D8).

Project 22 Super Circuit

Headphones

(optional)

Music device

(optional)

Black

Clear

Project 23

Triple Strobe Light

Build this circuit and turn on the slide switch (S1). Adjust

the blink rate using the lever on the adjustable resistor

(RV), and by pushing the press switch (S2).

Note: In rare cases the circuit may not work at all settings

on RV. If this happens, move the RV lever to the side near

the strobe IC, turn the slide switch off and on to reset the

circuit, and only move the RV lever over a small range.

Use the preceding circuit but replace one of the LEDs

(D1, D6, or D8) with the speaker (SP).

Project 24 Noisy Double

Strobe Light

WARNING: Moving parts. Do not touch the fan or

motor during operation. Do not lean over the motor.

Project 25

Audio Infrared Detector

You need an infrared remote control for this project, such as any TV/stereo/

DVD remote control in your home.

Build the circuit, set the lever on the adjustable resistor (RV) all the way towards

the infrared module (U24), and turn on the switch (S1). Point your remote

control toward the infrared module and press any button to activate an alarm

sound. The lever on the adjustable resistor sets how long the alarm plays for,

but it only works over a narrow range.

Next, replace the 100W resistor (R1) with the 5.1kW resistor (R3). The alarm

sound is a little different, but the control range on RV is wider.

Sometimes this circuit may activate without a remote control, due to infrared

in sunlight or some room lights. If this happens, try moving to a dark room.

Remote

Project 26

Photo Infrared Detector

Remote

You need an infrared remote control for this project, such as any TV/stereo/

DVD remote control in your home.

Build the circuit and turn on the switch (S1). Place the mounting base

(normally used with the ber optic tree) on the phototransistor (Q4). Set

the lever on the adjustable resistor (RV) so the red LED (D1) just turns off;

if it never turns off, move away from room lights. Point your remote control

directly into the mounting base on Q4, and press any button to activate the

red LED (D1).

The phototransistor can

detect light, and infrared

light is light. The

infrared module (U24) is

designed to focus only

on infrared light.

Sunlight and other light

sources emit some infrared

light, and may activate the

infrared detector. See if

you can activate it without

a remote control.

Project 30

Suspended Raindrops

Build the circuit as shown. Connect the white LED (D6) to the red & black jumper

wires. Turn on the slide switch (S1). Go to a water faucet and adjust the faucet so

water is dripping at a steady rate. Dim the room lights and hold the white LED so

it shines on the dripping water. Try to set the lever on the adjustable resistor (RV)

so that the dipping water drops appear suspended in mid-air. You may need to

adjust the drip rate on the faucet to make this work. You may get better results if

you replace the 100kW resistor (R5) with the 5.1kW resistor (R3). Also, try setting

the strobe rate to minimum and adjusting the drip rate.

Faucet

Project 27

Turn on the slide switch (S1) and move the lever on the adjustable resistor (RV) to

change how fast the light in the color organ (U22) changes colors.

Here the color organ light

changes colors in sync

with the strobe IC (U23),

but at a much slower rate.

Use the preceding circuit but replace the 5.1kW resistor (R3) with the speaker

(SP). Now you also hear the sound change as you adjust the lever on RV.

Project 28 Audio Adjustable Color

Changer

Replace the speaker with one of the LEDs (D1, D6, or D8). The LED is a

strobe light, changing much faster than the LED in the color organ.

Project 29 Double Adjustable Strobe

Adjustable Color Changer

Use the preceding circuit, but replace the 3-snap on the adjustable resistor

(RV) with the 100kW resistor (R5). The circuit works the same, but the strobe

rate is much slower (now you can see the LED ashing), so the strobe effects

are different. Slowly adjust the setting on RV as before, and watch the patterns

on the spinning disc.

Note: In rare cases the LED may not ash at all settings on RV. If this

happens, move the RV lever to the side near the strobe IC, turn the slide

switch off and on to reset the circuit, and only move the RV lever over a small

range.

Bonus for owners of other Snap Circuits

sets:

If you have a second 100kW

resistor (from model SC-100 / 300 / 500 / 750 or other sets), place it directly

over the R5 that replaced the 3-snap in the above circuit (and place a 1-snap

under one side of the additional R5). Stacking the two 100kW resistors together

creates a “medium” range of strobe speeds, in between the speeds created

with the 3-snap and single 100kW. Adjust the RV setting and watch the strobe

effects as before.

Project 31

Strobe Effects

Build the circuit as shown. Take the colored disc shown and install it into the disc

holder, then place the disc holder on the motor (M1). Connect the white LED (D6) to

the red & black jumper wires.

For best effects, do this in a dimly lit room. Turn on the slide switch (S1). Push the

press switch (S2) until the motor spins continuously (if it stops after you release the

press switch, replace your batteries). Hold the white LED upside down over the disc

holder so it shines on the spinning disc, and move the lever on the adjustable resistor

(RV) slowly while watching the pattern on the spinning disc.

The motor spins the disc so fast that it looks like a blur. However, as you slowly

adjust RV the pattern on the disc appears to slow down, stop, and reverse direction.

Patterns close to the disc center may be moving at different speeds, or in different

directions, from patterns farther from the center! Some patterns may become clear

while others are still blurred.

If the motor does not continue spinning after you release S2, then replace your batteries.

If it still won’t keep spinning then replace the 5.1kW resistor (R3) with a 3-snap wire.

Tab

Slide tabs into slots.

Tab Tab

Place disc holder onto

the motor as shown.

Hold white LED (D6)

over disc as shown.

How does this work? The strobe IC is making the

white LED ash so fast that your eyes think it is on

continuously. RV sets the ash rate, and at some

settings the LED ashes are synchronized with

speed of the patterns spinning on the disc, making

them appear visible instead of blurred.

When the disc pattern is totally blurred, it will appear

as purple, orange, and light green. Combining equal

amounts of red & blue makes purple, red & yellow

makes orange, and yellow & blue makes green.

OPTIONAL (Adult supervision required)

The disc holder rests on the motor top loosely and vibrates, making the disc pattern blurry even when the RV setting makes

the pattern “stop”. The disc patterns will appear clearer if you permanently mount the disc holder to the motor top. This set

contains a spare motor top, which can be used for this. This requires removing the motor top from the motor whenever you

want to switch from using the disc holder to using the glow fan, so is optional, and requires adult supervision.

Project 32 Slow Strobe Effects

If you want

to do this,

pry the

motor top off

the motor

shaft using a

screwdriver.

Lay the spare

motor top in

the disc holder

upside down, and

bond together

with glue (glue

not included).

After the glue dries, push the

modied disc holder on the

motor shaft and install a disc

cutout. When you want to return

to using the glow fan, replace

the motor top disc holder with

the normal motor top.

Replace the disc in the disc holder with the one shown

here, and repeat projects 31-33. Observe the strobe

effects. At some RV settings, the rainbow of colors

comes into view.

Project 33

Use the circuits from projects 31 and 32, but add the 0.1mF capacitor (C2) next to the motor, as shown

here. Set the strobe speed so the patterns are visible, and see if they look less blurred than before.

The 0.1mF capacitor has no electrical

effect,but it helps to hold the motor in place

better and reduce vibrations. Less motor

vibration makes the disc holder more

stable, and so makes the patterns a little

clearer. See if you can notice a difference.

Replace the disc in the disc holder with the one

shown here, and repeat projects 31-33. Observe the

strobe effects. To remove a disc from the holder,

use your ngernail, or use a pencil to push it up from

beneath one of the tabs.

When the disc pattern is totally blurred,

it appears to be white. Combining equal

amounts of red, green, and blue makes

white. The LED in the color organ IC

combines red, green, and blue lights to

make white.

Replace the disc in the disc holder with the one

shown here, and repeat projects 31-33. Observe the

strobe effects. With this pattern, some areas may

appear to be moving at different speeds or directions.

Sometimes you can see all the colors on the disc, but

sometimes you can see all the colors except blue,

which is hidden.

Replace the disc in the disc holder with the one

shown here, and repeat projects 31-33. Observe the

strobe effects. This unusual pattern produces several

amazing displays at different RV settings.

Project 34 Strobe Effects (II)

Project 35 Strobe Effects (III)

Project 36 Strobe Effects (IV)

Project 37 Strobe Effects (V)

Project 38 Strobe Effects (VI)

Project 39 Make Your Own Strobe Effects

Replace the disc in the disc holder with the one

shown here, and repeat projects 31-33. Observe the

strobe effects. When the disc pattern is totally blurred,

it will appear as purple, cyan, and yellow. Combining

equal amounts of red & blue makes purple, green &

blue makes cyan, and red & green makes yellow.

Draw your own patterns on paper or cardboard, then cut them to the same

size as our discs. You can also draw patterns on the backs of our discs.

Put them on the disc holder and repeat projects 31-33. Have a contest with

your friends to see who can make the most interesting strobe effects! You

can also nd lots of fun patterns and visual illusions by doing a search on

the internet. There is no limit to what you can do!

Stable Strobe Effects

Project 40

LEDs Together

Project 41

LEDs Together (II)

Turn on the slide switch (S1), and compare the brightness of the three LEDs.

Next, remove any of the LEDs and see how the brightness of the others changes.

Modify the preceding circuit by moving the slide switch (S1) to the location shown

here. Compare the brightness of the LEDs. Some LEDs may not turn on.

Next, remove any of the LEDs and see how the brightness of the others changes.

This circuit reduces the voltage to the circuit,

because only one set of batteries is connected.

The limited battery voltage is split between the

R1 resistor and the LEDs. The remaining voltage

across the LEDs is enough to activate the red

LEDs, but may not be enough to activate the other

colors. With the reduced voltage, the red LED will

dominate even more than in the preceding circuit.

The voltage needed for an LED to turn on

depends on the light color. Red light needs the

least, green needs more, but blue and white

need the most. The color LED (D8) contains

red, green, and blue LEDs.

The R1 resistor reduces the voltage available to

the LEDs. The LED brightness varies because

some of the LEDs need more voltage than is

available. The red LED (D1) will dominate the

other colors because it turns on more easily.

Project 42

Brightness Control

Build the circuit and turn on the slide switch (S1). Move the lever on the

adjustable resistor (RV) to vary the brightness of the light from the white

LED (D6). If desired, you may place any of the LED attachments (tower,

egg, or ber optic tree) on the LED.

Resistors are used to control or limit the ow of electricity in a circuit.

Higher resistor values reduce the ow of electricity in a circuit.

In this circuit, the adjustable resistor is used to adjust the

LED brightness, to limit the current so the batteries last longer, and

to protect the LED from being damaged by the batteries.

What is Resistance? Take your hands and rub them together very

fast. Your hands should feel warm. The friction between your hands

converts your effort into heat. Resistance is the electrical friction

between an electric current and the material it is owing through.

The adjustable resistor can be set for as low as 200W, or as high as

50,000W (50kW).

The R1 resistor (100W) will have little

effect, since it will be dominated by the

adjustable resistor. Resistor R5 (100kW)

is a high resistance, which greatly

restricts the ow of electricity, so the

LED will be very dim or off. Resistor R3

(5.1kW) will be in between those.

Use the preceding circuit, but replace the 3-snap with one of the yellow

resistors in this set (R1, R3, or R5). Observe how each changes the

LED brightness at different settings for the adjustable resistor.

Use the two preceding circuits, but replace the white LED (D6) with the

red LED (D1) or color LED (D8). Vary the adjustable resistor lever and

change the yellow resistors to see how the light varies with each LED.

Project 43 Resistors

Project 44 Resistors & LEDs

Light Up the FanProject 45

Build the circuit as shown, place the glow fan on the motor (M1), and turn

on the slide switch (S1). Place the circuit in a dark room and push the press

switch (S2) to spin the fan. The color LED (D8) lights up the spinning fan.

The circuit with the color LED is not

electrically connected to the circuit with the

motor. This was done because the motor

produces electrical pulses as it spins, and

these pulses can confuse the color LED.

WARNING: Moving parts. Do not touch the fan or

motor during operation. Do not lean over the motor.

Project 50

Persistence of Vision

Build the circuit as shown. Place the black ber optic cable holder on the

white LED (D6) and insert the ber cable into the black holder as far as it will

go. Turn on the slide switch (S1). Take the circuit into a dark room and wave

the cable around while watching the loose end. Try it with the lever on the

adjustable resistor (RV) at different settings. The light coming out the loose

end of the ber optic cable will separate into short segments or dashes of light.

Black

“Persistence of Vision” works because the

light is changing faster than your eyes can

adjust. Your eyes continue seeing what they

have just seen.

In a movie theater, lm frames are ashed

on the screen at a fast rate (usually 24 per

second). A timing mechanism makes a light

bulb ash just as the center of the frame is

passing in front of it. Your eyes see this fast

series of ashes as a continuous movie.

Project 46

Turn on the switch (S1), the motor (M1) spins. As you move your hand over

the phototransistor (Q4), the motor slows. Cover the phototransistor with

your hand. The motor slows down and may stop, but will speed up in a few

seconds. Also try shining a ashlight into the phototransistor.

Use the preceding circuit, but replace the 100mF capacitor (C4) with

the much smaller 0.1mF capacitor (C2). Now varying the light to the

phototransistor has only a small effect on the motor speed.

Use the circuit from project 46, but swap the locations of the phototransistor

(Q4) and 5.1kWresistor (R3); put “+” on Q4 towards C4. Now increasing the

light to the phototransistor slows down the motor, instead of speeding it up.

Project 47 Delayed Speed Control

Project 48 Delayed Speed Control (II)

Use the circuit from project 46, but replace the phototransistor (Q4) with the

microphone (X1, “+” on top). Clap, talk loudly, or blow into the microphone to

change the motor speed.

Project 49 Audio Delayed Speed Control

Delayed Photo

Speed Control

WARNING: Moving parts. Do not touch the fan or

motor during operation. Do not lean over the motor.

Project 51

This is the same circuit as project 1, but you will view it differently. Turn on

the switch (S1), and view the LED through the prismatic lm (the clear slide).

Prismatic lm makes interesting light effects.

Replace the color LED (D8) with the white LED (D6) and red LED (D1); view

them through the prismatic lm.

View different light sources in and around your home through the

prismatic lm.

Project 52 Look at the Lights

Use the project 51 circuit, but view the color LED through various semi-

transparent liquids, glassware, and plastics. Juices, jello, and cloudy

glass or plastic work well.

Replace the color LED with the white LED (D6). The white LED is

brighter, but does not change color.

Project 53 Scattering Light

Prismatic lm separates light into

different colors. White light is a

combination of all colors.

Semi-transparent materials scatter the

light without completely blocking it, so

a wide area of the liquid or material is

lit up by the light. This happens in the

egg and tower LED attachments.

Use the circuit from project 51, but place the clear cable holder on the

color LED (D8), then place the ber optic cable into the holder as far as

it will go. Turn on the switch, then take the circuit into a dimly lit room

and see the light coming out the open end of the cable. The light travels

through the cable even as you bend it around.

Project 54 Color Fiber Light

Project 55

Blinking Beeping

Build the circuit as shown and turn on the switch (S1). The color LED (D8) will be

blinking and you hear beeping from the speaker. The sound will not be very loud.

The color LED (D8) has a

microcircuit that changes the

light colors. As it does this, it

changes the current through

the circuit. The transistor

(Q2) amplies the changing

current and uses it to control

the speaker (SP).

Use the preceding circuit, but replace the speaker with the red LED (D1).

Now the red LED will also be blinking.

Project 56 Blinking Blinking

Prismatic Film

Project 58

Funny Speed Motor

Build the circuit as shown and turn on the switch (S1). The color LED (D8) is

blinking and the motor (M1) spins at different speeds. Try this circuit with the

glow fan on the motor, and without the fan.

The motor is controlled by the color LED using the transistor (Q2). If you

remove the color LED from the circuit then the motor will not spin.

If desired add the red LED (D1) across points A & B (“+” to A). This adds

another blinking light.

Project 57

Triple Blinker

Build the circuit as shown and turn on the switch (S1). Three LEDs (D1, D6,

and D8) will be blinking.

The red and white LEDs are controlled by the color LED using the transistor

(Q2). If you remove the color LED from the circuit then the other LEDs will

not blink.

In this circuit the color LED is

the motor is powered by different

set. This was done because the

motor produces electrical pulses

as it spins, and these pulses can

confuse the color LED.

WARNING: Moving parts. Do not touch the fan or

motor during operation. Do not lean over the motor.

Stuck On Light

Build the circuit as shown, and note that several parts are stacked over

others. Turn on the slide switch (S1); nothing happens.

Now push the press switch (S2); the white LED (D6) turns on and stays on.

The white LED will stay on until you turn off the slide switch.

Project 59

The two transistors act

as an electronic device

called an SCR (Silicon

Controlled Rectier). An

SCR is a three-pin device

that once its control pin

is triggered, remains

on until the current ow

through it stops.

Project 61

Build the circuit as shown and turn on the switch (S1). The color LED (D8) is

used to control the strobe IC (U23), producing unusual effects.

Use the preceding circuit, but replace the 100W resistor (R1) with the

color LED (D8) or the red LED (D1).

Project 60 Stuck On Lights

Use the preceding circuit, but

replace the color LED (D8) with the

100kW resistor (R5) or the 5.1kW resistor (R3).

Project 62 Light & Sound

Repeat projects 61 & 62 but replace the speaker with the motor (M1)

and glow fan (motor “+” toward S1).

Project 63 Light & Motion

WARNING: Moving parts. Do not touch the fan or

motor during operation. Do not lean over the motor.

Funky Light & Sound

Project 64 Blinking Step Motor

Build the circuit as shown and turn on the switch (S1). The color LED (D8)

is used to control the strobe IC (U23), which turns on the motor (M1) in short

bursts.

To have 3 LEDs, place the red LED (D1) directly over the white LED (D6).

Project 65 Day Blinker

Build the circuit as shown and turn

on the switch (S1). The color LED

(D8) is on when there is light on the

phototransistor (Q4). Shine light on

or cover the phototransistor to turn

the color LED on or off.

Build the circuit as shown and

turn on the switch (S1). The

color LED (D8) is off when there

is light on the phototransistor

(Q4). Cover or shine light on the

phototransistor to turn the color

LED on or off.

If the color LED comes on too

easily, reduce the sensitivity by

replacing the 5.1kW resistor (R3)

with the 100kW resistor (R5).

Project 66 Night

Blinker

Project 67

This circuit is an

oscillator, which

uses feedback to

control the pitch of

the sound.

Build the circuit as shown and turn on the switch (S1). Move the lever on

the adjustable resistor (RV) to vary the pitch of the buzzing sound.

Use the preceding circuit, but place the 5.1kW resistor directly over the

100kW resistor using a 1-snap. The pitch of the tone is higher now,

but the circuit may not make noise on all settings for the adjustable

resistor.

Project 68 Higher Pitch Buzzer

Use the circuits from projects 67-68, but add the phototransistor (Q4)

across base grid locations B2-B4 (between RV and R1, “+” on the left),

on level 3. Vary the amount of light on the phototransistor to change

the sound, while also varying RV.

Project 69 Photo Light & Motion

Use the circuits from projects 67-68, but replace the 0.1mF capacitor

(C2) with the 100mF capacitor (C4), “+” to the right. Turn the switch on

and patiently wait. The speaker will beep and the color LED (D8) will

ash every 5-20 seconds, depending on the resistors.

Project 70 Slow Light & Motion

You need an infrared remote control for this project, such as any TV/stereo/

DVD remote control in your home.

Build the circuit and turn on the switch (S1). Point your remote control toward

the infrared module (U24) and press any button to spin the motor (M1).

Next, remove the 100mF capacitor (C4). The circuit works the same, except

now the motor moves in small steps.

Sometimes this circuit may activate without a remote control, due to infrared

in sunlight or some room lights. If this happens, try moving to a darker room.

Project 71

R/C Motor

Remote

Buzzer

WARNING: Moving parts. Do not touch the fan or

motor during operation. Do not lean over the motor.

Build the circuit and turn on the slide switch (S1). Vary the amount of light on

the phototransistor (Q4) and push the press switch (S2) to change the sound.

Project 73 Wacky Sound Control

Project 72

Build the circuit and set the lever on the adjustable resistor (RV) towards

the 100mF capacitor (C4). Place the white LED (D6) across the points

marked B & C; the LED lights briey as the capacitor charges. Next, place

the white LED across points A & B instead; now the LED lights briey as

the capacitor discharges. Move the white LED back to B & C and repeat.

Use the lever on RV to vary the charge / discharge rate.

The capacitor is storing

energy like a mini battery.

Mini Battery

Project 74

Blow On the Light

Build the circuit and turn on the slide switch (S1). Set the lever on the

adjustable resistor (RV) to the top. If the white LED (D6) is on, move the lever

on RV until the LED just shuts off. Now blow on the microphone (X1) to turn

the white LED on.

The microphone is a resistor

that changes in value due to

changes in air pressure on its

surface.

Build the circuit and turn on the switch (S1). Touch the metal in the jumper

wire snaps with your ngers. Use the lever on the adjustable resistor (RV)

to adjust the sensitivity of the circuit. You may see a difference in the light

brightness just by pressing the contacts harder with your ngers.

Next, place the loose ends of the jumper wires in a cup of water, make sure

the metal parts aren’t touching each other. The water should change the

light brightness. Readjust sensitivity using RV.

Now add salt to the water and stir to dissolve it. The light should be brighter,

since salt water has less resistance than plain water. Readjust sensitivity

using RV.

WARNING: Don’t drink any water used here.

Project 75 Human & Liquid Light

Photo Current Amplier

Project 76

Build the circuit, turn on the switch (S1), and vary the amount of light on the

phototransistor (Q4) using your hand. Compare the brightness of the white

LED (D6) and color LED (D8).

Swap the locations of the white and color LEDs, and compare the brightness now.

Project 78

PNP Amplier

This circuit is just like the preceding one except it uses a different type of

transistor. Build the circuit, turn on the switch (S1), and vary the amount of

light on the phototransistor (Q4) using your hand. Compare the brightness of

the white LED (D6) and color LED (D8).

Replace either LED (D6 or D8) with the red LED (D1). Compare all three

LEDs, in both locations.

The NPN transistor (Q2) is a current

amplier. When a small current

ows into Q2 through the left branch

(through Q4), a larger current will

ow into Q2 through the right branch

(with R1). Green arrows shown

thecurrentow. So the LED on

the right side will be brighter than

the LED on the left side. The current

in the right branch might be 100

times larger than in the left branch.

LED brightness depends on the

materials used, construction

quality, and the current through

it. The white LED is super-

bright, the red LED is low-

brightness, and the color LED is

between the others.

The PNP transistor (Q1) is just like the

NPN transistor (Q2), except that the

currents ow in opposite directions.

Greenarrowsshownthecurrentow.

Use the preceding circuit but replace either LED (D6 or D8) with the red

LED (D1). Compare all three LEDs, in both locations.

Project 77 LEDs & Transistors

Project 81 Resistance Director

Move the lever on the adjustable resistor (RV) across its range and

watch the brightness of the white and color LEDs (D6 & D8).

Replace either LED with the red LED (D1) and compare it too.

You can also replace one of the battery holders (B1) with a 3-snap

wire, and compare the LED brightnesses at lower voltage.

The adjustable resistor can be

adjusted from about 200 ohms to

about 50,000 ohms.

The white LED is a super-bright

LED, so will be brighter than the

others at comparable resistance.

Project 80

Air Pressure Light Control

Project 79

Photo Light Control

Turn on the switch (S1). Control

the white LED (D6) brightness by

varying the amount of light on the

photo-transistor (Q4). Try holding

the red, green, and blue lters

over the phototransistor and see

how they affect it.

Replace the white LED with

the red LED (D1) or the color

LED (D8) and compare them.

Blow on the microphone (X1).

The white LED (D6) will icker,

because the resistance of the

microphone changes when you

blow on it.

Talking into the microphone also

changes its resistance, but you

will not be able to notice the

difference here.

You can replace the white

LED with the red LED (D1) or the

color LED (D8), but they will not

be very bright.

The phototransistor uses light to control

electric current. As more light shines on

the phototransistor, the current through

it increases, making the LED brighter.

Project 82

3D Pictures

Look at the pictures here; they probably look blurry. Now place the red lter in front of your

left eye and the blue lter in front of your right eye, and look at the pictures again. Now the

pictures look clearer, and you can see them in three dimensions (3D).

These pictures contain separate red

& blue images, taken from slightly

different viewpoints, combined together.

When you view them through the red

& blue lters, each eye sees only one

image. Your brain combines the two

images into the single picture that you

“see”, but the differences between the

two images make the combined picture

seem three-dimensional.

How 3D works:

Most people have two eyes, spaced

about 2 inches apart. So each eye

sees the world a little differently, and

your brain uses the difference in views

to calculate distance. For each object

in view, the greater the difference

between the two scenes, the closer it

must be. If you close one eye, you will

have a harder time judging distance –

try catching a ball with just one eye! (Be

sure to use a soft ball if you try playing

catch with one eye.)

When you watch a 3D movie in a

theater, you wear 3D glasses so that

each eye will see a different image.

The movie screen actually shows two

images, and the glasses lter them so

that only one image enters each eye.

Most movie theaters use polarized

images and glasses with polarized

lenses, so that each eye sees a

different image.

Another way to make 3D is using

red & blue images, then view using

glasses with red & blue lters, as you

are doing in this project. Unfortunately

this method does not give you the color

quality that the polarization method has.

3D Pictures

Project 83

Test the Color Organ

This project tests the features of the color organ (U22), and will be

referenced by the Advanced Troubleshooting section on page 15.

A. Build the circuit, and turn on the switch (S1). The light on top of the color

organ should be changing colors.

B. Remove the 0.1mF capacitor (C2), add a 2-snap across the points

marked Y & Z, and reset the circuit by turning it off and on using the

switch. Connect the red jumper wire between the point marked “X”, and

points marked “R”, “G”, or “B” in the drawing. Touching R should make

the light red, G should make it green, and B should make it blue.

C. Remove the 2-snap that was added across points Y & Z. Connect a

music device (not included) and headphones (optional, and not included)

to the color organ as shown, and start music on it. Set the volume control

on your music device so that the light on the color organ is changing (the

light will not change if your volume is set too high or too low).

Headphones & Device

(Optional, not included)

Music

Device

Go to https://shop.elenco.com/

consumers/snap-circuits-light.html

to download projects 84-177

and Bonus Projects 1-11!

1 Base Grid (7.7”x5.5”) overlays some parts, and 6 other are below.

SCL-175 Snap Circuits

Light Parts Layout

Snap Circuits

, CircuitSafe

, Elenco

Learn By Doing

, and Making Coding

a Snap

are registered trademarks

of Elenco Electronics, Inc. All rights

reserved. Patents: 7,144,255;

7,273,377; & other patents pending

Important: If any parts

are missing or damaged,

DO NOT RETURN TO

RETAILER. Call toll-free at:

(800) 533-2441 or e-mail us

at: [email protected].

Customer Service: 150

Carpenter Ave. Wheeling, IL

60090 U.S.A.

Note: A complete parts list is

on pages 2-3 in this manual.

www.elenco.com

Not responsible for typographical errors. Colors, styles and case quantities are subject to change without notice.

Go to https://shop.elenco.com/

consumers/snap-circuits-light.html

to download projects 84-177

and Bonus Projects 1-11!

Elenco SCL-175 Snap Circuits Light Electronics Kit

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User Manual

Specifications

Elenco SCL-175 Questions and Answers

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