Elenco SC-300 Snap Circuits 300-in-1 Electronics Kit User Manual

AGES 8 to 108

FUN SOUNDS

LEARN THE

FUNDAMENTALS

OF ELECTRICITY

Projects

PRINTED

150

150+

Projects

ONLINE

Go to shop.elenco.com/consumers/

snap-circuits-classic.html to

download projects 151-305

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

Patent # 7144255

SOURCE CODE:SC-300V1

Project #139

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. Be sure

that it is at the top of the shaft.

Elenco

is not responsible for parts damaged

due to incorrect wiring.

Basic Troubleshooting

Note: If you suspect you have damaged

parts, follow the Advanced Troubleshooting

procedure on page 7 to determine which

ones need replacing.

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.

Basic Troubleshooting 1

How to Use It 2

Parts List 3-4

About Your Snap Circuits

Parts 5-6

Advanced Troubleshooting 7-8

DOs and DON’Ts of Building Circuits 9

Projects 1 - 150 10-60

Table of Contents

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.

●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.

Batteries:

Conforms to all applicable U.S.

government requirements and

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

WARNING: SHOCK HAZARD - Never connect Snap

Circuits

to electrical outlets in your home in any way!

WARNING: CHOKING HAZARD -

Small parts. Not for children under 3.

Go to shop.elenco.com/consumers/

snap-circuits-classic.html to

download projects 151-305

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, lamp blocks, battery blocks,

different length wire blocks, etc. These

blocks are in different colors and have

numbers on them so that you can easily

identify them. The circuit you will build

is shown in color and with numbers,

identifying the blocks that you will use

and snap together to form a circuit.

For Example:

This is the switch block which is green

and has the marking on it as shown

in the drawings. Please note that the

drawing doesn’t reect the real switch

block exactly (it is missing the ON and

OFF markings), but gives you the general

idea of which part is being used in the

circuit.

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.

This is a 1-snap wire that is used as a

spacer or for interconnection between

different layers.

To build each circuit, you have a power

source block number that needs two

(2) “AA” batteries (not included with the

Snap Circuits

kit).

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.

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. You do not need this base

to build your circuits, but it does help in

keeping your circuit together neatly. 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.

Usually when the motor is used, the

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.

Some circuits use the jumper wires to

make unusual connections. Just clip them

to metal snaps or as indicated.

Note: While building circuits, 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.

How To Use It

2 3 4 5

SWITCHPRESS

Note: If you have the more advanced Models SC-300, SC-500, or SC-750, there are additional part lists in the other project manuals.

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

at: [email protected]. Customer Service • 150 Carpenter Ave. • Wheeling, IL 60090 U.S.A.

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

r 1

Base Grid

(11.0” x 7.7”)

6SCBG

r 1

0.1mF Capacitor 6SCC2

r 6

1-Snap Wire 6SC01

r 1

10mF Capacitor 6SCC3

r 9

2-Snap Wire 6SC02

r 1

100mF Capacitor 6SCC4

r 4

3-Snap Wire 6SC03

r 1

470mF Capacitor 6SCC5

r 2

4-Snap Wire 6SC04

r 1

Variable Capacitor 6SCCV

r 1

5-Snap Wire 6SC05

r 1

Red Light Emitting

Diode (LED)

6SCD1

r 1

6-Snap Wire 6SC06

r 1

Green Light Emitting

Diode (LED)

6SCD2

r 1

7-Snap Wire 6SC07

r 1

Jumper Wire (Black) 6SCJ1

r 1

Antenna Coil 6SCA1

r 1

Jumper Wire (Red) 6SCJ2

r 2

Battery Holder -

uses 2 1.5V type AA

(not Included)

6SCB1

r 1

2.5V or 3V Lamp 6SCL1

r 1

0.02mF Capacitor 6SCC1

r 1

6V Lamp 6SCL2

L 1

LAMP

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

COIL

ANTENNA

L 2

LAMP

C 1

0.02

100

C 4

C 5

470

10µF

C 3

C 2

0.1

C V

L2C1

D 1

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

r 1

Motor 6SCM1

r 1

Alarm

Integrated Circuit

6SCU2

r 1

Fan 6SCM1F

r 1

Space War

Integrated Circuit

6SCU3

r 1

PNP Transistor 6SCQ1

r 1

Power Amplier

Integrated Circuit

6SCU4

r 1

NPN Transistor 6SCQ2

r 1

High Frequency

Integrated Circuit

6SCU5

r 1

100W Resistor 6SCR1

r 1

Whistle Chip 6SCWC

r 1

1kW Resistor 6SCR2

r 1

Microphone 6SCX1

r 1

5.1kW Resistor 6SCR3

r 1

10kW Resistor 6SCR4

r 1

100kW Resistor 6SCR5

r 1

Photoresistor 6SCRP

r 1

Adjustable Resistor 6SCRV

r 1

Slide Switch 6SCS1

r 1

Press Switch 6SCS2

r 1

Speaker 6SCSP

r 1

Music

Integrated Circuit

6SCU1

SPACE WAR IC

MOTOR

ALARM IC

MUSIC IC

RESIS

TOR

100Ω

ISTLE CH

SWITCH

SLIDE

SWITCHPRESS

PHOTO

RESISTOR

SPEAKER

(STANDING)

AMPLIFIER IC

MICROPHONE

RESIS

1KΩ

RESIS

TOR

5.1KΩ

NPN

INTEGRATED CIRCUIT

PNP

RESISTOR

100KΩ

RESIS

TOR

10KΩ

You may order additional / replacement

parts at our website:

www.elenco.com/replacement-parts/

(Part designs are subject to change without notice).

The

base grid functions like the printed circuit boards found in most

electronic products. It is a platform for mounting parts and wires (though the

wires are usually “printed” on the board.

The blue

snap wires are just wires used to connect other 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 (like the projects using water).

The

batteries (B1) produce an electrical voltage using a chemical reaction.

This “voltage” can be thought of as electrical pressure, pushing electrical

“current” through a circuit. This voltage is much lower and much safer than

that used in your house wiring. Using more batteries increases the “pressure”

and so more electricity ows.

The

slide switch (S1) connects (ON) or disconnects (OFF) the wires in a

circuit. When ON it has no effect on circuit performance.

The

press switch (S2) connects (pressed) or disconnects (not pressed) the

wires in a circuit, just like the slide switch does.

Resistors “resist” the ow of electricity and are used to control or limit the

electricity in a circuit. Snap Circuits

includes

100W (R1), 1KW (R2), 5.1KW

(R3), 10KW (R4), and 100KW (R5) resistors

(“K” symbolizes 1,000, so R3

is really 5,100W). Materials like metal have very low resistance (<1W) and

are called conductors, while materials like paper, plastic, and air have near-

innite resistance and are called insulators. Increasing circuit resistance

reduces the ow of electricity.

The

adjustable resistor (RV) is a 50KW resistor but with a center tap that

can be adjusted between 0W and 50KW. At the 0W setting, the current must

be limited by the other components in the circuit.

The

photoresistor (RP) is a light-sensitive resistor, its value changes from

nearly innite in total darkness to about 1000W when a bright light shines on it.

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 from around 1KW in silence to around 10KW when you blow

on it.

A light bulb, such as in the

2.5V and 6V lamps (L1 and L2), contains a

special wire that glows bright when a large electric current passes through it.

Voltages above the bulb’s rating can burn out the wire.

The

motor (M1) converts electricity into mechanical motion. 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

three coils of wire with many loops. If a large electric current ows through

the loops, the magnetic effects become concentrated enough to move the

coils. The motor has a magnet inside so, as the electricity moves the coils to

align them with the permanent magnet, the shaft spins.

The

speaker (SP) converts electricity into sound. It does this by using

the energy of a changing electrical signal to create mechanical vibrations

(using a coil and magnet similar to that in the motor), these vibrations create

variations in air pressure which travel across the room. You “hear” sound

when your ears feel these air pressure variations.

The

whistle chip (WC) contains two thin plates. When an electrical signal is

applied across them they will stretch slightly in an effort to separate (like two

magnets opposing each other), when the signal is removed they come back

together. If the electrical signal applied across them is changing quickly, then

the plates will vibrate. These vibrations create variations in air pressure that

your ears feel just like sound from a speaker.

The

red and green LEDs (D1 and D2) are light emitting diodes, and may

be thought of as a special one-way light bulb. 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 and 2V for green); brightness then

increases. A high current will burn out the LED, Snap Circuits

LEDs have

internal resistors to protect them. LEDs block electricity in the “reverse”

direction.

Capacitors are components that can store electrical pressure (voltage) for

periods of time, higher values have more storage. Because of this storage

ability they block unchanging voltage signals and pass fast changing

voltages. Capacitors are used for ltering and oscillation circuits. Snap

Circuits

includes

0.02mF (C1), 0.1mF (C2), 10mF (C3), 10mF (C4), 470mF

(C5) capacitors, and a variable capacitor (CV).

The variable capacitor can

be adjusted from .00004 to .00022mF and is used in high frequency radio

circuits for tuning. The whistle chip (WC) also acts like a 0.02mF capacitor in

addition to its sound properties.

The

antenna (A1) contains a coil of wire wrapped around an iron bar.

Although it has magnetic effects similar to those in the motor, those effects

are tiny and may be ignored except at high frequencies (like in AM radio).

About Your Snap Circuits

Parts

Our Student Guides give much more information about your parts along with a complete lesson

in basic electronics. See www.elenco.com/faqs for more information.

Its magnetic properties allow it to concentrate radio signals for reception. At

lower frequencies the antenna acts like an ordinary wire.

The

PNP (Q1) and NPN (Q2) transistors 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. Projects #65-66 demonstrate their properties.

A high current may damage a transistor, so the current must be limited by

other components in the circuit.

Some types of electronic components can be super-miniaturized, allowing

many thousands of parts to t into an area smaller that your ngernail. These

“integrated circuits” (ICs) are used in everything from simple electronic toys

to the most advanced computers. The music, alarm, and space war ICs (U1,

U2, and U3) in Snap Circuits

are actually modules containing specialized

sound-generation ICs and other supporting components (resistors,

capacitors, and transistors) that are always needed with them. This was done

to simplify the connections you need to make to use them. The descriptions

for these modules are given here for those interested, see the projects for

connection examples:

The

power amplier IC (U4) is a module containing an integrated circuit

amplier and supporting components that are always needed with it. A

description of it is given here for those interested:

The

high frequency IC (U5) is a specialized amplier used only in high

frequency radio circuits. A description of it is given here for those interested:

About Your Snap Circuits

Parts

INTEGRATED CIRCUIT

INP INP(–)

OUT

High Frequency IC:

INP - input connection (2 points are same)

OUT - output connection

(–) power return to batteries

See project #52 for example of connections.

SPACE WAR IC

IN1

(+)

OUT

IN2

(–)

Space War IC:

(+) - power from batteries

(–) - power return to batteries

OUT - output connection

IN1, IN2 - control inputs

Connect each control input to (–)

power to sequence through 8 sounds.

MUSIC IC

(+)

HLD

OUT

(–)

TRG

Music IC:

(+) - power from batteries

(–) - power return to batteries

OUT - output connection

HLD - hold control input

TRG - trigger control input

Music for a few seconds on power-up, then hold HLD to

(+) power or touch TRG to (+) power to resume music.

ALARM IC

IN1

(–)

IN2

IN3

OUT

Alarm IC:

IN1, IN2, IN3 - control inputs

(–) - power return to batteries

OUT - output connection

Connect control inputs to (+) power to make ve

alarm sounds, see project 14 for congurations.

AMPLIFIER IC

INP

FIL

(+)

OUT

(–)

Power Amplier IC:

(+) - power from batteries

(–) - power return to batteries

FIL - ltered power from batteries

INP - input connection

OUT - output connection

See project #52 for example of connections.

If you suspect you have damaged parts, you can follow this

procedure to systematically determine which ones need

replacing:

1. 2.5V/3V lamp (L1), 6V lamp (L2), motor (M1), speaker (SP), and

battery holder (B1): Place batteries in holder. Place each lamp

directly across the battery holder, each should light and L1 should

be brighter. Do the same with the motor (motor + to battery +), it

should spin to the right at high speed. “Tap” the speaker across the

battery holder contacts, you should hear static as it touches. If none

work, then replace your batteries and repeat, if still bad then the

battery holder is damaged.

2. Jumper wires: Use this mini-circuit

to test each jumper wire, the lamp

should light.

3. Snap wires: Use this mini-circuit to

test each of the snap wires, one at

a time. The lamp should light.

Slide switch (S1) and Press switch (S2): Build project #1, if the

lamp (L1) doesn’t light then the slide switch is bad. Replace the

slide switch with the press switch to test it.

100W (R1), 1KW (R2), 5.1KW (R3), and 10KW (R4) resistors, red

LED (D1), and green LED (D2): Build project #7 except initially use

the speaker (SP) in place of the resistor, the red LED should light.

Replace the red LED with the green LED and it should light. Then

replace the speaker with each resistor; the LED should light and

the brightness decreases with the higher value resistors.

6. Alarm IC (U2): Build project #14, you should hear a siren. Then

place a 3-snap wire between grid locations A1 and C1, the sound is

different. Then move the 3-snap from A1-C1 to A3-C3 to hear a 3rd

sound.

7. Music IC (U1): Build project #13. Turn it on and the sound plays for

a while and stops, it resumes if you press and hold down the press

switch. Then touch a 3-snap wire across base grid points A1 and C1

and the sound resumes for a while.

8. Space war IC (U3) and photoresistor (RP): Build project #15, both

switches (S1 and S2) should change the sound. Then replace the

slide switch with the photoresistor, waving your hand over it should

change the sound.

9. Whistle chip (WC): Build project #35 and if there is light on the

photoresistor (RP) then you will hear sound from the whistle chip.

10. Antenna (A1): Build

the mini-circuit shown

here, you should hear

sound.

Advanced Troubleshooting (Adult supervision recommended)

Elenco

is not responsible for parts damaged due to

incorrect wiring.

11. NPN transistor (Q2):

Build the mini-circuit

shown here. The LED

(D2) should only be on

if the press switch (S2)

is pressed. If otherwise,

then the NPN is

damaged.

12. PNP transistor

(Q1): Build the

mini-circuit shown

here. The LED (D1)

should only be on

if the press switch

(S2) is pressed.

Otherwise, the PNP

is damaged.

13. Adjustable resistor (RV): Build project #65, the resistor control

can turn the Lamp (L2) on and off.

14. 100WK resistor (R5) and 0.02mF (C1), 0.1mF (C2), and 10mF (C3)

capacitors: Build project #147, it makes sound unless the resistor

is bad. Place the 0.02mF capacitor on top of the whistle chip (WC)

and the sound changes (pitch is lower). Replace the 0.02mF with

the 0.1mF and the pitch is even lower. Replace the 0.1mF with the

10mF and the circuit will “click” about once a second.

15. 100mF (C4) and 470mF (C5) capacitors: Build project #120,

press the press switch (S2) and turn on the slide switch (S1). The

LED (D1) should be lit for about 15 seconds then go out (press

the press switch again to reset this). Replace the 470mF with the

100mF and the LED is only lit for about 4 seconds now.

16. Power Amplier IC (U4): Build project 124, adjusting RV should

change the sound.

17. Microphone (X1): Build project #23, blowing into the microphone

should turn off the lamp (L2).

18. Variable Capacitor (CV): Build project #113 and place it near an

AM radio, tune the radio and the capacitor to verify you hear the

music on your radio.

19. High Frequency IC (U5): Build project #52 and adjust the variable

capacitor (CV) and adjustable resistor (RV) until you hear a radio

station.

Advanced Troubleshooting (Adult supervision recommended)

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/

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, lamp, 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 below) as this will

damage components and/or quickly drain your batteries.

Only connect the ICs using

congurations given in the projects, incorrectly doing so may damage them. Elenco

not responsible for parts damaged due to incorrect wiring.

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/for-makers. Send your suggestions 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.

Examples of SHORT CIRCUITS - NEVER DO THESE!!!

WARNING: SHOCK HAZARD - Never connect Snap Circuits

the electrical outlets in your home in any way!

DOs and DON’Ts of Building Circuits

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!

Here are some important guidelines:

ALWAYS USE EYE PROTECTION WHEN EXPERIMENTING ON YOUR OWN.

ALWAYS include at least one component that will limit the current through a circuit,

such as the speaker, lamp, whistle chip, capacitors, ICs (which must be

connected properly), motor, microphone, photoresistor, or resistors (the

adjustable resistor doesn’t count if it’s set at/near minimum resistance).

ALWAYS use transistors, the high frequency IC, the antenna, 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 the adjustable resistor so that if set to its 0 setting, the current

will be limited by other components in the circuit.

ALWAYS connect position 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 ICs using congurations given in the projects or as per the

connection descriptions for the parts.

NEVER try to use the high frequency IC as a transistor (the packages are similar,

but the parts are different).

NEVER use the 2.5V lamp in a circuit with both battery holders unless you are sure

that the voltage across it will be limited.

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.

Warning to Snap Circuits

owners: Do not connect additional

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

Contact ELENCO

if you have questions or need guidance.

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.

Project #1 Electric Light & Switch

OBJECTIVE: To show how electricity is turned “ON” or

“OFF” with a switch.

Project #2

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

next to them on the base grid rst. Then, assemble parts marked with a 2.

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

(B1) through the motor (M1) making it rotate. Place the fan blade on the

motor shaft and close the slide switch. The motor will rotate forcing the

fan blade to move air past the motor.

In this project, you changed electrical power into mechanical power. DC

motors are used in all the battery powered equipment requiring rotary

motion, such as a cordless drill, electric toothbrush, and toy trains that

run on batteries just to name a few. An electric motor is much easier to

control than gas or diesel engines.

DC Motor & Switch

OBJECTIVE: To show how electricity is used to run a Direct

Current (DC) Motor.

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

next to them on the base grid rst. Then, assemble parts marked with a 2.

Install two (2) “AA” batteries (not included) into the battery holder (B1).

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.

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

through the lamp and back to the battery through the switch. The closed

switch completes the circuit. In electronics this is called a closed circuit.

When the slide switch is opened, the current can no longer ow back to

the battery, so the lamp goes out. In electronics this is called an open

circuit.

You may have received a 3V lamp instead of a 2.5V lamp or socket, this

will not affect any of your circuits.

Placement Level

Numbers

Placement Level

Numbers

WARNING: Moving parts. Do not touch the fan or

motor during operation. Do not lean over the motor.

Project #3

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

next to them on the base grid rst. Then, assemble parts marked with a

2. Finally, lay the speaker (SP) on the table and connect it to the circuit

using the jumper wires as shown.

When you close the slide switch (S1), the music may play for a short

time, and then stop. After the music has stopped, tap on the whistle chip

(WC) and the music should play again. You may also be able to re-start

the sound by clapping loudly next to the whistle chip or by blowing on it.

You could connect the speaker using snap wires instead of the jumper

wires, but then the speaker may create enough sound vibrations to re-

activate the whistle chip.

Sound Activated Switch

OBJECTIVE: To show how sound can turn “ON” an electronic

device.

Project #4

Build the circuit shown on the left. When you close the slide switch (S1),

the music may play for a short time and then stop. After the music has

stopped, tap on the whistle chip (WC) and the music should play again.

You may also be able to re-start the sound by clapping loudly next to

the whistle chip or by blowing on it.

In this project, you changed the amount of current that goes through the

speaker (SP) and reduced the sound output of the speaker. Resistors

are used throughout electronics to limit the amount of current that ows.

Adjusting Sound Level

OBJECTIVE: To show how resistance can lower the sound from

the speaker.

(STANDING)

Project #5

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

next to them on the base grid rst. Then, assemble parts marked with a

2. Finally, place the fan blade on the motor (M1).

When you close the slide switch (S1), the fan will spin and the lamp (L1)

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

Inertia is the property that tries to keep a body at rest from moving and

tries to keep a moving object from stopping.

The light helps protect the motor from getting the full voltage when the

slide switch is closed. Part of the voltage goes across the lamp and the

rest goes across the motor. Remove the fan and notice how the lamp

gets dimmer when the motor does not have to spin the fan blade.

Lamp & Fan in Series

OBJECTIVE: To show how a lamp can indicate when a fan is

running.

Project #6

OBJECTIVE: To show how an indicator light can be connected

without affecting the current in the motor.

Build the circuit shown on the left.

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

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

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

(M1). The motor should start a little faster than in Project #5.

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

as the motor picks up speed. It has its own path to the battery (B1).

Lamp & Fan in Parallel

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 #7

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

next to them on the base grid rst. Then, assemble parts marked with a 2.

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

(B1) through the slide switch, through the resistor (R1), through the

LED (light emitting diode, D1) and back to the battery. The closed slide

switch completes the circuit. The resistor limits the current and prevents

damage to the LED. NEVER PLACE AN LED DIRECTLY ACROSS THE

BATTERY! If no resistor is in the circuit, the battery may push enough

current through the LED to damage the semiconductor that is used to

produce the light. LEDs are used in all types of electronic equipment to

indicate conditions and pass information to the user of that equipment.

Can you think of something you use everyday that has an LED in it?

Light Emitting Diode

OBJECTIVE: To show how a resistor and LED are wired to

emit light.

Project #8

Rebuild the circuit from Project #7 but leave the slide switch (S1) out as

shown on the left.

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

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

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

clip completes the circuit and current ows through the LED. Place your

ngers across the terminals and the LED does not light. Your body has

too high of a resistance to allow enough current to ow to light the LED.

If the voltage, which is electrical pressure, was higher, current could be

pushed through your ngers and the LED would light. This detector can

be used to see if a material like plastic is a good conductor or a poor

conductor.

Conduction Detector

OBJECTIVE: To make a circuit that detects the conduction of

electricity in different materials.

Project #9

Rebuild the circuit from Project #2, but reverse the polarity on the motor

(M1) so the negative (–) on the motor goes to the positive (+) on the battery

(B1). New alkaline batteries are recommended for this project.

When you close the slide switch (S1), the motor will slowly increase in

speed. When the motor has reached maximum rotation, turn the slide

switch off. 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.

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 motor shaft because it does not

have enough lift to propel it. The motor will spin faster when both batteries

are new.

If the fan doesn’t y off, then turn the switch on and off several times rapidly

when it is at full speed.

Flying Saucer

OBJECTIVE: To make a circuit that launches the fan blade to

simulate a ying saucer.

Project #10

OBJECTIVE: To show how voltage affects speed of a DC motor

and can decrease the lift of the saucer.

Change the circuit in Project #9 by adding the lamp (L1) in series with the

motor as shown in the diagram on the left.

When you place the lamp in series with any electronic device, it will draw

less current because it adds resistance. In this case, the lamp in series

reduces the current through the motor, and that reduces the top speed

of the motor. Close the slide switch (S1), and wait until the fan reaches

maximum speed. Open the switch and observe the difference in the

height due to the lamp. In most cases, it may not even launch.

Decreasing Saucer Lift

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.

WARNING: Fan may not

rise until switch is released.

WARNING: Fan may not

rise until switch is released.

WARNING: Moving parts. Do not touch the fan or

motor during operation. Do not lean over the motor.

Project #11

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. Finally, add the 2-snap wires that are marked for level three.

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

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

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

shorted and motor speed increases.

The principle of removing resistance to increase motor speeds is only

one way of changing the speed of the motor. Commercial fans do not

use this method because it would produce heat in the resistor and

fans are used to cool circuits by moving air over them. Commercial

fans change the amount of voltage that is applied to the motor using a

transformer or other electronic device.

Two-Speed Fan

OBJECTIVE: To show how switches can increase or decrease

the speed of an electric fan.

Project #12

Build the circuit shown on the left. When you close the slide switch

(S1), the music integrated circuit (U1) may start playing one song then

stop. Each time you press the press switch “doorbell button” (S2) the

song will play again and stop. Even if you let go of the press switch

(S2), the integrated circuit keeps the song playing until it has reached

the end of the song.

Musical integrated circuits are used to entertain young children

in many of the toys and chairs made to hold infants. If the music

is replaced with words, the child can also learn while they are

entertained. Because of great advances in miniaturization, many songs

are stored in a circuit no bigger than a pinhead.

Musical Doorbell

OBJECTIVE: To show how an integrated circuit can be used as

a musical doorbell.

(STANDING)

These are single

snaps, placed beneath

other parts as spacers

Project #13

When you close the slide switch (S1), the music integrated circuit (U1)

may start playing one song then stop. The song will be much louder than

in the previous project because it is now being used as an alarm. Each

time you press the press switch “alarm button” (S2) after the song stops

playing, the song will play again, but only while you hold the button down.

Momentary Alarm

OBJECTIVE: To show how integrated circuits can also create

loud alarm sounds in case of emergencies.

(STANDING)

Project #14

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.

When you close the slide switch (S1), the integrated circuit (U2) should

start sounding a very loud alarm sound. This integrated circuit is

designed to sweep through all the frequencies so even hard of hearing

people can be warned by the alarm.

If the alarm sound was passed through an amplier and installed into a

police car, it would also serve as a good police siren.

Option A: Modify the circuit by connecting points X & Y. The circuit

works the same way but now it sounds like a machine

gun with music.

Option B: Now remove the connection between X & Y and then make

a connection between T & U. The circuit works the same way

but now it sounds like a re engine with music.

Option C: Now remove the connection between T & U and then make

a connection between U & Z. The circuit works the same way

but now it sounds like an ambulance with music.

Alarm Circuit

OBJECTIVE: To show how an integrated circuit can be used to

make real alarm sounds.

(STANDING)

Project #15

Build the circuit shown on the left, which uses the space war integrated

circuit (U3). Activate it by ipping the slide switch (S1) or pressing the

press switch (S2); do both several times and in combination. You will

hear an exciting range of sounds, as if a space war is raging!

Like the other integrated circuits, the space war IC is a super-

miniaturized electronic circuit that can play a variety of cool sounds

stored in it by using just a few extra components.

In movie studios, technicians are paid to insert these sounds at the

precise instant a gun is red. Try making your sound occur at the same

time an object hits the oor. It is not as easy as it sounds.

Space War

OBJECTIVE: To introduce you to the space war integrated

circuit and the sounds it can make.

Project #16

Light Switch

OBJECTIVE: To show how light can control a circuit using

a photoresistor.

Use the circuit from Project #15 above, but replace the slide switch

(S1) with the photoresistor (RP). The circuit immediately makes

noise. Try turning it off. If you experiment, then you can see that

the only ways to turn it off are to cover the photoresistor, or to turn

off the lights in the room (if the room is dark). Since light is used to

turn on the circuit, you might say it is a "light switch".

The photoresistor contains material that changes its resistance

when it is exposed to light. As it gets more light, the resistance of

the photoresistor decreases. Parts like this are used in a number of

ways that affect our lives. For example, you may have streetlights

in your neighborhood that turn on when it starts getting dark and

turn off in the morning.

PHOTO

RESISTOR

Project #17

Paper Space War

OBJECTIVE: To give a more dramatic demonstration of

using the photoresistor.

Use the same circuit as for Project #16. Find a piece of white paper

that has a lot of large black or dark areas on it, and slowly slide it

over the photosensitive resistor. You should hear the sound pattern

constantly changing, as the white and dark areas of the paper

control the light to the photosensitive resistance. You can also try

the pattern below or something similar to it:

(STANDING)

Project #18

Cover the photoresistor (RP) and turn on the slide switch (S1). A police

siren with music is heard for a while and stops, then you can control it

by covering or uncovering the photoresistor.

Light Police Siren

OBJECTIVE: To build a police siren that is controlled by light.

(STANDING)

Project #19 More Loud Sounds

Project #20 More Loud Sounds (II)

Project #21 More Loud Sounds (III)

Project #22 More Loud Sounds (IV)

Modify the Project #18 by connecting points X & Y. The circuit works the

same way but now it sounds like a machine gun with music.

Now remove the connection between X & Y and then make a connection

between T & U. The circuit works the same way but now it sounds like a

re engine with music.

Now remove the connection between T & U and then make a connection

between U & Z. The circuit works the same way but now it sounds like an

ambulance with music.

Now remove the connections between U & Z and between V & W, then

make a connection between T & U. The circuit works the same way but

now it sounds like a familiar song but with static.

Blowing Off the

Electric Light

OBJECTIVE: To show how light is stimulated by sound.

Install the parts. The lamp (L2) will be on. It will be off as long as

you blow on the mic (X1). Speaking loud into the mic will change the

brightness of the lamp.

Project #23

Build the circuit shown on the left and turn it on. The lamp (L1)

alternates between being on and off while the speaker (SP)

alternates between two musical tones... like someone is ipping a

switch, but at a very consistent rate. Periodic signals like this are very

important in electronics. The lamp may not be very bright.

Periodic Sounds

OBJECTIVE: To build a circuit with light and sound that

change and repeat.

(STANDING)

Project #24

Project #25 Blinking Double Flashlight

OBJECTIVE: To build a circuit with two lights that alternate.

In the circuit at left, replace the speaker (SP) with the color LED (D8, “+” on top).

The lamp alternates between being on and off while the LED alternates between

being dimmer and brighter.

Project #26

Build the circuit shown and add the jumpers to complete it. Turn it on,

press the press switch (S2) several times, and wave your hand over the

photoresistor (RP) to hear all the sound combinations. If the sound is

too loud you may replace the speaker (SP) with the whistle chip (WC).

Space War Alarm Combo

OBJECTIVE: To combine the sounds from the space war and

alarm integrated circuits.

(STANDING)

Project #27

This circuit is controlled by spinning the motor (M1) with your hands.

Turn on the slide switch (S1). A police siren is heard and then stops.

Spin the motor and it will play again. Note however, that music can be

heard faintly in the background of the siren.

Motor-Controlled Sounds

OBJECTIVE: To show how motion can trigger electronic circuits.

(STANDING)

Project #28 More Motor Sounds

Project #29 More Motor Sounds (II)

Project #30 More Motor Sounds (III)

Project #31 More Motor Sounds (IV)

Modify the last circuit by connecting points X & Y with the lamp (L1). The

circuit works the same way but now it sounds like a machine gun.

Now remove the connection between X & Y and then make a connection

between T & U with the lamp (L1). The circuit works the same way but now it

sounds like a re engine.

Now remove the connection between T & U and then make a connection

between U & Z. The circuit works the same way but now it sounds like an

ambulance.

Now remove the connections between U & Z and between V & W, then make

a connection between T & U. The circuit works the same way but now it

sounds like a familiar song but with static.

Voice-controlled Rays

of Light

OBJECTIVE: To show how light is stimulated by sound.

Turn the slide switch (S1) on. There will be only a weak light emitting

from the green LED (D2). By blowing on the mic (X1) or putting it near

a radio or TV set, the green LED will emit light, and its brightness

changes as the loudness changes.

Project #32

Turn on the slide switch (S1) and tap the whistle chip (WC), it makes a machine

gun sound (with music in the background). Thoroughly cover the photoresistor

(RP) with your hand and the sound becomes a siren. After a while the sound will

stop, tap the whistle chip and it resumes.

Press the press switch (S2) and the LED (D1) lights, but the lamp (L1) does not

light and the motor (M1) does not spin. Electricity is owing through the lamp

and motor, but not enough to turn them on. So in this circuit they are acting like

3-snap wires.

Project #33

Using Parts as Conductors

OBJECTIVE: To show that motors and lamps may sometimes be used as

ordinary conductors.

(STANDING)

Project #34

Setup: Cut out a circular piece of thin cardboard from the back of an old spiral

notebook or note pad. Use the fan blade as a guide. Place the fan on the

cardboard and trace around it with a pencil or pen. Cut the cardboard out with

scissors and tape it to the fan blade. Do the same thing with a piece of white

paper, but tape the paper on top of the cardboard so it can be removed easily later.

Drawing: To make a ring drawing obtain some thin and thick marking pens as

drawing tools. Spin the paper by pressing and holding press switch (S2) down.

Press the marker on the paper to form rings. To make spiral drawings, release

press switch and as the motor (M1) approaches a slow speed move the marker

from the inside outward quickly.

Change the colors often and avoid using too much black to get hypnotic effects.

Another method is to make colorful shapes on the disc then spin the disc and

watch them blend into each other. When certain speeds are reached under

uorescent lights without electronic ballasts, the strobe principle shown in another

project will produce strange effects and backward movement. Make a wheel

with different colored spokes to see this strange effect. Adding more spokes and

removing spokes will give different effects at different motor speeds.

Spin Draw

OBJECTIVE: To produce circular artistic drawings.

Thin Cardboard White Paper

Project #35

Turn on the slide switch (S1), a police siren is hear. The loudness of the

sound depends on how much light reaches the photoresistor (RP), try partially

shielding it or placing near a very bright light, and compare the sound.

Light-Controlled Sounds

OBJECTIVE: To give a more dramatic demonstration of using

the photosensitive resistance.

Project #36

Light-Controlled Sounds (II)

Project #37

Light-Controlled Sounds (III)

Project #38

Light-Controlled Sounds (IV)

Project #39

Light-Controlled Sounds (V)

Modify the last circuit by connecting points X & Y. The circuit works the

same way but now it sounds like a machine gun.

Now remove the connection between X & Y and then make a connection

between T & U. The circuit works the same way but now it sounds like a re

engine.

Now remove the connection between T & U and then make a connection

between U & Z. The circuit works the same way but now it sounds like an

ambulance.

Now remove the connection between U & Z, add a 1-snap at Z (on level 3),

add a second 3-snap between V & W (on level 3), and nally place the music

IC (U1) directly over the alarm IC (U2) on level 4. Listen to the sounds.

Project #40

Turn the slide switch (S1) on and the lamp (L1) and LED (D1) start

ashing. You hear two different tones driving the LED and lamp. ICs can

be connected to control many different devices at the same time.

Flash and Tone

OBJECTIVE: Build a circuit that ashes light and plays sounds.

Project #41

Build the circuit shown and place the fan on the motor (M1), but leave the

jumpers off for the time being. Turn on the slide switch (S1) and tap the whistle

chip (WC), it makes a machine gun sound (with music in the background).

Thoroughly cover the photoresistor (RP) with your hand and the sound

becomes a siren. With the photoresistor covered, press the press switch (S2)

and the sound becomes that of an ambulance. Uncover the photoresistor and

the sound remains that of a machine gun whether the press switch is pressed

or not. After a while the sound will stop, tap the whistle chip and it resumes.

Connect the two jumpers as shown and tap the whistle chip to resume the

sound. The lamp (L1) and LED (D1) light and the motor spins. The sound

continues, but it may become distorted as the motor speeds up. The motor

draws a lot of power from the batteries (B1), and this may reduce the voltage

to the music (U1) and alarm (U2) ICs, distorting the sound. The sound may

even stop if your batteries are weak.

Fun with the Alarm IC

OBJECTIVE: To show some new ways of using the alarm IC.

Project #42 Project 43

Motor

Sounds

Combo

OBJECTIVE: To connect

multiple devices together.

Motor

Sounds

Combo (II)

OBJECTIVE: To connect

multiple devices together.

In the circuit, the outputs from

the alarm and music ICs are

connected together. Build the

circuit shown and then place the

alarm IC (U2) directly over the

music IC (U1), resting on two

1-snaps and a 2-snap. Turn on

the slide switch (S1) and you will

hear a siren and music together

while the lamp (L1) varies in

brightness. Push the press switch

(S2) and the fan spins, while the

sound may not be as loud. The

fan may rise into the air when you

release the press switch.

In the circuit, the outputs from the alarm

and music ICs are connected together.

Build the circuit shown and then place the

alarm IC (U2) directly over the music IC

(U1), resting on three 1-snaps. Turn on the

slide switch (S1) and you will hear a siren

and music together. Push the press switch

(S2) and the fan spins, while the sound

may not be as loud. The fan may rise into

the air when you release the switch.

This circuit is similar to project #42, but the

fan will y a little higher since the sound

circuit no longer drives the lamp (L1) and

therefore uses less battery power.

(STANDING)

WARNING: Moving parts. Do not touch the fan or

motor during operation. Do not lean over the motor.

(STANDING)

In the circuit, the outputs from the alarm and music ICs are connected

together. Build the circuit shown and then place the alarm IC (U2) directly

over the music IC (U1), resting on two 1-snaps and a 2-snap. There is

also a 2-snap on top of the alarm IC. Turn on the switch (S1) and you will

hear a siren and music together while the lamp (L1) varies in brightness.

Project #46

Wacky Sounds

OBJECTIVE: To combine different sounds.

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

times, and wave your hand over the photoresistor to hear all the sound

combinations. You can make the sound from the music IC louder by

replacing the 100W resistor (R1) with the lamp (L1).

Really Wacky Sounds

OBJECTIVE: To combine different sounds.

Project #44

(STANDING)

Project #45

Wackier Sounds

Now remove the 2-snap connection between X & Y and then make a

2-snap connection between X & Z (on level 5). The circuit works the same

way but has different sounds.

Build the circuit shown but initially leave the jumper wires outside the

cup. Turn on the slide switch (S1); nothing happens. Place the jumper

wires into a cup of water and an alarm sounds!

You could use longer wires and lay them on your basement oor, if your

basement oods during a storm, then this circuit will sound an alarm.

Project #47 Simple Water Alarm

OBJECTIVE: To sound an alarm when water is detected.

(STANDING)

Project #48

Simple Salt Water Alarm

Project #49

Ambulance Water Alarm

Project #50

Ambulance Contact Alarm

Add salt to the water and the tone of the alarm is louder and faster, telling

you that salt is in the water you detected. Also, try holding the jumper

wires with your ngers to see if your body can set off the alarm.

Modify the circuit in Project #47 by making a connection between A & B.

The water alarm works the same way but now it sounds like an ambulance.

The same circuit also detects if the jumper wires get touched together, so

connect them to each other. The tone of the sound is now much different.

Therefore, this circuit will tell you if there is water between the jumper

wires or if the wires are touching each other.

Project #51

Build the circuit as shown, and turn on the slide switch (S1). Vary the

amount of light to the photoresistor (RP) by partially covering it with your

hand. You can make screeching sounds by allowing just a little light to

reach the photoresistor.

If you replace the 10mF capacitor (C3) with a 3-snap wire or any of

the other capacitors (C1, C2, C4, or C5), then the sound will be a little

different.

Ticking Screecher

OBJECTIVE: To make fun sounds using light.

Project #52

When you turn on the slide switch (S1), the integrated circuit (U5)

should amplify and detect the AM radio waves all around you. The

variable capacitor (CV) can be tuned to the desirable station. Varying

the adjustable resistor (RV) will make the audio louder or softer. The

power amplier IC (U4) drives the speaker (SP) to complete the AM

radio project.

AM Radio

OBJECTIVE: To make a complete working AM radio.

Project #53

Press the press switch (S2) on and set the adjustable resistor (RV) so

the lamp (L2) just lights. Slowly cover the photoresistor (RP) and the

lamp brightens. If you place more light at the photoresistor the light dims.

This is an automatic street lamp that you can turn on by a certain

darkness and turn off by a certain brightness. This type of circuit is

installed on many outside lights and forces them to turn off and save

electricity. They also come on when needed for safety.

Automatic Street Lamp

OBJECTIVE: To show how light is used to control a street lamp.

Project #54

Turn on the slide switch (S1); the speaker (SP) will sound and the LED

(D1) will light. Adjust the adjustable resistor (RV) to make different

tones. In an oscillator circuit, changing the values of resistors or

capacitors can vary the output tone or pitch.

Adjustable Tone

Generator

OBJECTIVE: To show how resistor values change the

frequency of an oscillator.

Project #55

Photosensitive

Electronic Organ

OBJECTIVE: To show how resistor values change the

frequency of an oscillator.

Project #56

Electronic Cicada

OBJECTIVE: To show how capacitors in parallel change

the frequency of an oscillator.

Use the circuit from project #54 shown above. Replace the

10kΩ resistor (R4) with the photoresistor (RP). Turn on the slide

switch (S1). The speaker (SP) will sound and the LED (D1) will

light. Move your hand up and down over the photoresistor and

the frequency changes. Decreasing the light on the photoresistor

increases the resistance and causes the circuit to oscillate at a

lower frequency. Notice that the LED ashes also at the same

frequency as the sound.

By using your nger, see if you can vary the sounds enough to

make this circuit sound like an organ playing.

Use the circuit from project #54 shown above, replace the

photoresistor (RP) back to the 10kΩ resistor (R4). Place the

0.02μF capacitor (C1) on top of the whistle chip (WC). Place the

slide switch (S1) on and adjust the adjustable resistor (RV). The

circuit produces the sound of the cicada insect. By placing the

0.02μF capacitor on top of the whistle chip, the circuit oscillates

at a lower frequency. Notice that the LED (D1) ashes also at the

same frequency.

It is possible to pick resistors and capacitors that will make the

pitch higher than humans can hear. Many animals, however, can

hear these tones. For example, a parakeet can hear tones up to

50,000 cycles per second, but a human can only hear to 20,000.

Turn on the slide switch (S1). A police siren is heard and the lamp (L1) lights.

Project #57

Light & Sounds

OBJECTIVE: To build a police siren with light.

Project #58

More Light & Sounds

Project #59

More Light & Sounds (III)

Project #60

More Light & Sounds (IV)

Project #61

More Light & Sounds (V)

Modify the last circuit by connecting points X & Y. The circuit works the

same way but now it sounds like a machine gun.

Now remove the connection between X & Y and then make a connection

between T & U. Now it sounds like a re engine.

Now remove the connection between T & U and then make a connection

between U & Z. Now it sounds like an ambulance.

Now remove the connection between U & Z, then place the 470μF capacitor

(C5) between X & Y (“+” side to X). The sound changes after a few seconds.

Project #62

When you turn on the slide switch (S1), current ows from the batteries

through the slide switch, the 100W resistor (R1), the LED (D1), through

the LED (D2), and back to the second group of batteries (B1). Notice

how both LEDs are lit. The voltage is high enough to turn on both

LEDs when the batteries are connected in series. If only one set of

batteries is used, the LEDs will not light up.

Some devices use only one 1.5 volt battery, but they make hundreds of

volts electronically from this small source. A ash camera is an example

of this.

Batteries in Series

OBJECTIVE: To show the increase in voltage when batteries

are connected in series.

Project #63

When building the circuit, be sure to position the motor (M1) with the

positive (+) side snapped to the 470mF capacitor (C5). Turn on the slide

switch (S1), nothing will happen. It is a motor speed detector, and the

motor isn’t moving. Watch the LED (D2) and give the motor a good spin

CLOCKWISE with your ngers (don’t use the fan blade); you should

see a ash of light. The faster you spin the motor, the brighter the ash

will be. As a game, see who can make the brightest ash.

Now try spinning the motor in the opposite direction (counter-clockwise)

and see how bright the ash is — it won’t ash at all because the

electricity it produces, ows in the wrong direction and won’t activate

the diode. Flip the motor around (positive (+) side snapped to the

3-snap wire) and try again. Now the LED lights only if you spin the

motor counter-clockwise.

Motor Speed Detector

OBJECTIVE: To show how to make electricity in one direction.

Project #64

Turn on the slide switch (S1), nothing will happen. Turn the motor

(M1) slowly with your ngers (don’t use the fan blade), you will hear a

clicking that sounds like an old-time manual typewriter keystrokes. Spin

the motor faster and the clicking speeds up accordingly.

This circuit works the same if you spin the motor in either direction

(unlike the Motor Speed Detector project).

By spinning the motor with your ngers, the physical effort you exert

is converted into electricity. In electric power plants, steam is used to

spin large motors like this, and the electricity produced is used to run

everything in your town.

Old-Style Typewriter

OBJECTIVE: To show how a generator works.

Project #65

There are three connection points on an NPN transistor (Q2), called

base (marked B), emitter (marked E), and collector (marked C). When

a small electric current ows from the base to the emitter, a larger

(amplied) current will ow from the collector to the emitter. Build the

circuit and slowly move up the adjustable resistor (RV) control. When

the LED (D2) becomes bright, the lamp (L2) will also turn on and will be

much brighter.

NPN Amplier

OBJECTIVE: To compare transistor circuits.

Project #66

The PNP transistor (Q1) is similar to the NPN transistor (Q2) in project

#65, except that the electric currents ow in the opposite directions.

When a small electric current ows from the emitter to the base, a

larger (amplied) current will ow from the emitter to the collector. Build

the circuit and slowly move up the adjustable resistor (RV) control.

When the LED (D1) becomes bright, the lamp (L2) will also turn on and

will be much brighter.

PNP Amplier

OBJECTIVE: To compare transistor circuits.

Sucking Fan

OBJECTIVE: To adjust the speed of a fan.

Build the circuit, and be sure to orient the motor (M1) with the positive (+)

side down as shown. Turn it on, and set the adjustable resistor (RV) for

the fan speed you like best. If you set the speed too fast then the fan may

y off the motor. Due to the shape of the fan blades and the direction the

motor spins, air is sucked into the fan and towards the motor. Try holding

a piece of paper just above the fan to prove this. If this suction is strong

enough then it can lift the fan blades, just like in a helicopter.

The fan will not move on most settings of the resistor, because the

resistance is too high to overcome friction in the motor. If the fan does not

move at any resistor setting, then replace your batteries.

Modify the circuit by reversing the position of the motor (M1), so the

positive (+) side is towards the PNP (Q1). Turn it on, and set the

adjustable resistor (RV) for the fan speed you like best. Set it for full

speed and see if the fan ies off - it won’t! The fan is blowing air upward

now! Try holding a piece of paper just above the fan to prove this.

Project #68

Project #67

Turn on the slide switch (S1) and place your nger across points A & B.

The speaker (SP) will output a tone and the LED (D2) will ash at the

same frequency. Your nger acts as a conductor connecting points A &

B. When a person is lying, one thing the body starts to do is sweat. The

sweat makes the nger a better conductor by reducing its resistance.

As the resistance drops, the frequency of the tone increases. Lightly

wet your nger and place it across the two points again. Both the output

tone and LED ashing frequency increase, and the lamp (L2) may begin

to light. If your nger is wet enough, then the lamp will be bright and

the sound stops - indicating you are a big liar! Now change the wetness

of your nger by drying it and see how it affects the circuit. This is the

same principle used in lie detectors that are sold commercially.

The Lie Detector

OBJECTIVE: To show how sweat makes a better conductor.

Project #69

High Sensitivity Voice

Doorbell

OBJECTIVE: To build a highly sensitive voice-activated doorbell.

Build the circuit and wait until the sound stops. Clap or talk loud a few

feet away and the music plays again. The microphone (X1) is used here

because it is very sensitive.

Project #71

Very Loud Doorbell

Project #72

Doorbell with Button

Project #73

Darkness Announcer

Project #74

Musical Motion Detector

Replace the 6V lamp (L2) with the antenna coil (A1), the sound is louder now.

Replace the antenna coil (A1) with the speaker (SP), the sound is now louder.

Replace the microphone (X1) with the press switch (S2) and wait until the

music stops. Now you have to push the press the switch to activate the

music, just like the doorbell on your house.

Replace the press switch (S2) with the photoresistor (RP) and wait until the

sound stops. If you cover the photoresistor now the music will play once,

signaling that it has gotten dark. If the speaker (SP) is too loud then you may

replace it with the antenna coil (A1).

Replace the photoresistor (RP) with the motor (M1), oriented in either

direction. Now spinning the motor will re-activate the music.

Project #70

Louder Doorbell

Project #75

This circuit will make the fan spin faster and y higher than the

preceding circuit, making it easy to lose your fan.

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.

Super Flying Saucer

OBJECTIVE: To make the fan blade y.

Project #76

Blow Off a Space War

OBJECTIVE: To turn off a circuit by blowing on it.

Project #77

Series Lamps

OBJECTIVE: To compare types of circuits.

Turn on the slide

switch (S1) and both

lamps (L1 & L2) will

light. If one of the

bulbs is broken then

neither will be on,

because the lamps are

in series. An example

of this is the strings of

small Christmas lights;

if one bulb is damaged

then the entire string

does not work.

Project #78

Parallel Lamps

OBJECTIVE: To compare types of circuits.

Build the circuit and turn it on, you hear a space war. Since it is loud and

annoying, try to shut it off by blowing into the microphone (X1). Blowing

hard into the microphone stops the sound, and then it starts again.

Turn on the slide switch

(S1) and both lamps (L1

& L2) will

light

. If one of

the bulbs is broken then

the other will still be on,

because the lamps are

in parallel. An example

of this is most of the

lights in your house;

if a bulb is broken on

one lamp then the other

lamps are not affected.

Project #79

Project #81

Fire Fan Symphony

OBJECTIVE:

To combine sounds from the music, alarm, and space

war integrated circuits.

Build the circuit shown and add the jumper to complete it. Note that in

one place two (2) single snaps are stacked on top of each other. Also,

note that there is a 2-snap wire on layer 2 that does not connect with a

4-snap wire that runs over it on layer 4 (both touch the music IC). Turn

it on and press the press switch (S2) several times and wave your hand

over the photoresistor (RP) to hear the full spectrum of sounds that this

circuit can create. Have fun!

Project #82

Fan Symphony (II)

The preceding circuit may be too loud, so replace the speaker (SP) with

the whistle chip (WC).

The preceding circuit may be too loud, so replace the speaker (SP) with

the whistle chip (WC).

Project #80

Fire Fan Symphony (II)

Fan Symphony

OBJECTIVE: To combine sounds from the music, alarm, and

space war integrated circuits.

Modify the circuit from project #79 to match the circuit shown on the left.

The only differences are the connections around the alarm IC (U2). It

works the same way.

Project #83

Project #84

Capacitors in Series

OBJECTIVE: To compare types of circuits.

Capacitors in Parallel

OBJECTIVE: To compare types of circuits.

Turn on the slide switch (S1), then press and release the press switch

(S2). The LED (D1) becomes bright when the 470μF capacitor charges

up with the press switch on, then the LED slowly gets dim after you

release the press switch.

Now turn off the slide switch. Repeat the test with the slide switch off;

you’ll notice the LED goes out much faster after you release the press

switch. The much smaller 100μF capacitor (C4) is now in series with

the 470μF and so reduces the total capacitance (electrical storage

capacity), and they discharge much faster. (Note that this is opposite to

how resistors in series work).

Turn off the slide switch (S1), then press and release the press switch

(S2). The LED (D1) becomes bright when the 100μF capacitor charges

up with the press switch on, then the LED slowly gets dim after you

release the press switch.

Now turn on the slide switch and repeat the test; you’ll notice the LED

goes out much slower after you release the press switch. The much

larger 470μF capacitor (C5) is now in parallel with the 100μF and so

increases the total capacitance (electrical storage capacity), and they

discharge much slower. (Note that this is opposite to how resistors in

parallel work.)

Project #85

NPN Light Control

OBJECTIVE: To compare transistor circuits.

Project #86

NPN Dark Control

OBJECTIVE: To compare transistor circuits.

Turn on the slide switch (S1),

the brightness of the LED (D2)

depends on how much light

shines on the photoresistor

(RP). The resistance drops as

more light shines, allowing more

current to the NPN (Q2).

Turn on the slide switch (S1),

the brightness of the LED (D2)

depends on how LITTLE light

shines on the photoresistor (RP).

The resistance drops as more

light shines, diverting current

away from the NPN (Q2).

Project #87

Red & Green Control

OBJECTIVE: To show how the adjustable resistor works.

Project #88

Current Controllers

OBJECTIVE: To compare types of circuits.

Turn on the circuit using the

slide switch (S1) and/or the

press switch (S2) and move

the adjustable resistor’s (RV)

control lever around to adjust

the brightness of the LEDs (D1

& D2). When the adjustable

resistor is set to one side, that

side will have low resistance and

its LED will be bright (assuming

the switch on that side is ON)

while the other LED will be dim

or OFF.

Build the circuit and turn on

the slide switch (S1), the LED

(D1) will be lit. To increase the

LED brightness, turn on the press

switch (S2). To decrease the LED

brightness, turn off the slide switch.

With the slide switch on, the 5.1KW

resistor (R3) controls the current.

Turning on the press switch places

the 1KW resistor (R2) in parallel

with it to decrease the total circuit

resistance. Turning off the slide

switch places the 10KW resistor

(R4) in series with R2/R3 to

increase the total resistance.

Project #89 Screaming Fan

OBJECTIVE: To have an adjustable resistance control a fan

and sounds.

Build the circuit on the left and place the fan onto the motor (M1). Turn

on the slide switch (S1) and move the setting on the adjustable resistor

(RV) across its range. You hear screaming sounds and the fan spins.

Project #91 Light Whining

Project #92 More Light Whining

Project #93 Motor That Won’t Start

Replace the 0.1μF capacitor (C2) with the 0.02μF capacitor (C1). The sounds

are now a high-pitch whine and the motor (M1) starts a little sooner.

Replace the 100W resistor (R1) at the upper-left of the circuit (points

A1 & A3 on the base grid) with the photoresistor (RP), and wave your

hand over it. The whining sound has changed a little and can now be

controlled by light.

Replace the 0.02mF capacitor (C1) with the 0.1mF capacitor (C2). The

sounds are lower in frequency and you can’t make the fan spin now.

Replace the 0.1μF capacitor (C2) with the 10μF capacitor (C3), put

the positive (+) side towards the left). It now makes clicking sounds

and the fan moves only in small bursts, like a motor that won’t start.

Project #90

Whining Fan

Project #94

Space War Radio

OBJECTIVE: To transmit Space War sounds to a AM radio.

Place the circuit next to an AM radio. Tune the radio so no stations are

heard and turn on the slide switch (S1). You should hear the space war

sounds on the radio. The red LED (D1) should also be lit. Adjust the

variable capacitor (CV) for the loudest signal. Push the press switch (S2)

to change the sound.

You have just performed the experiment that took Marconi (who invented

the radio) a lifetime to invent. The technology of radio transmission has

expanded to the point that we take it for granted. There was a time,

however, when news was only spread by word of mouth.

Project #95

Project #100

Whiner

OBJECTIVE: To build a circuit that makes a loud whine.

Light-controlled Alarm

OBJECTIVE: To show how light is used to turn an alarm.

Build the circuit, turn it on, and move the setting on the adjustable

resistor (RV). It makes a loud, annoying whine sound. The green LED

(D2) appears to be on, but it is actually ashing at a very fast rate.

The alarm will sound, as long as light is present. Slowly cover the

photoresistor (RP), and the volume goes down. If you turn off the lights,

the alarm will stop. The amount of light changes the resistance of the

photoresistor (less light means more resistance). The photoresistor and

transistor (Q2) act like a dimmer switch, adjusting the voltage applied to

the alarm.

This type of circuit is used in alarm systems to detect light. If an intruder

turned on a light or hit the sensor with a ashlight beam, the alarm

would trigger and probably force the intruder to leave.

Project #97 Hummer

Project #98 Adjustable Metronome

Project #99 Quiet Flasher

Place the 0.02μF capacitor (C1) above the whistle chip (WC) and vary the

adjustable resistor (RV) again. The frequency (or pitch) of the whine has been

reduced by the added capacitance.

Now place the 0.1μF capacitor (C2) above the whistle chip (WC) and

vary the adjustable resistor (RV) again. The frequency (or pitch) of

the whine has been reduced by the greater added capacitance and it

sounds more like a hum now.

Now place the 10μF capacitor (C3, “+” side on right) above the

whistle chip (WC) and vary the adjustable resistor (RV) again.

There is no hum now but instead there is a click and a ash of light

repeating about once a second, like the “beat” of a sound. It is like a

metronome, which is used to keep time for the rhythm of a song.

Leave the 10μF capacitor (C3) connected but replace the speaker

(SP) with the 2.5V lamp (L1).

Project #96

Lower Pitch Whiner

Project #101

Hissing Foghorn

OBJECTIVE: To build a transistor oscillator that can make a

foghorn sound.

Build the circuit on the left and move the adjustable resistor (RV)

setting. Sometimes it will make a foghorn sound, sometimes it will

make a hissing sound, and sometimes it will make no sound at all.

Project #103 Video Game Engine Sound

Modify the circuit in project #101 by replacing the 100kΩ resistor (R5) with the

photoresistor (RP). Move the adjustable resistor (RV) setting until you hear hissing

sounds, and then shield the photoresistor while doing so and you hear clicking sounds.

Remove the photoresistor (RP) from the circuit in project #102 and instead

touch your ngers between the contacts at points A4 and B2 on the base grid

while moving the adjustable resistor (RV). You hear a clicking that sounds

like the engine sound in auto-racing video games.

Project #102

Hissing & Clicking

Project #104

Build the circuit shown. Connect the photoresistor (RP) to the circuit

using the red & black jumper wires. Place the photoresistor upside

down over the red LED (D1), so the LED goes inside the photoresistor.

Turn on both switches (hold down the press switch button). Music

plays on the speaker, even though the two parts of the circuit are not

electrically connected.

The left circuit, with the LED and music IC (U1) creates a music signal

and transmits it as light. The right circuit, with the photoresistor and

speaker, receives the light signal and converts it back to music. Here

the photoresistor has to be on top of the LED for this to work, but better

communication systems (such as ber optic cables), can transmit

information over enormous distances at very high speeds.

Optical Transmitter &

Receiver

OBJECTIVE: To show how information can be transmitted

using light.

Pitch

OBJECTIVE: To show how to change the pitch of a sound.

Build the circuit on the left, turn it on, and vary the adjustable resistor

(RV). The frequency or pitch of the sound is changed. Pitch is the

musical profession’s word for frequency. If you’ve had music lessons, you

may remember the music scale using chords such as A3, F5, and D2 to

express the pitch of a sound. Electronics prefers the term frequency, as

in when you adjust the frequency on your radio.

Project #105

You need an AM radio for this project. Build the circuit shown but do

not turn on the slide switch (S1). Place it within a foot of your AM radio

and tune the radio frequency to the middle of the AM band (around 1000

kHz), where no other station is transmitting. Turn the volume up so

you can hear the static. Set the adjustable resistor (RV) control to the

middle setting. Turn on the slide switch and slowly tune the adjustable

capacitor (CV) until the static on the radio becomes quiet. You may

hear a whistle as you approach the proper tuning. In some cases you

may also need to set the adjustable resistor slightly off-center.

When the radio static is gone, tap on the speaker (SP) with your nger

and you should hear the sound of tapping on the radio. Now talk loudly

into the speaker (used here as a microphone) and you will hear your

voice on the radio. Set the adjustable resistor for best sound quality at

the radio.

Radio Announcer

OBJECTIVE: To hear your voice on the radio.

Project #106

Project #108 Pitch (III)

We’ve seen we can adjust the frequency by varying the resistance in the

adjustable resistor. You can also change frequency by changing the capacitance

of the circuit. Place the 0.1μF capacitor (C2) on top of the 0.02μF capacitor

(C1); notice how the sound has changed.

Remove the 0.1μF (C2) capacitor and replace the 100kΩ resistor (R5) with

the photoresistor (RP). Wave your hand up and down over the photoresistor to

change the sound. Changing the light on the photoresistor changes the circuit

resistance just like varying the adjustable resistance does.

Project #107

Pitch (II)

Note: If you have the adjustable resistor (RV) set to the right and light shining on the

photoresistor, then you may not get any sound because the total resistance is too

low for the circuit to operate.

Project #109

Build the circuit, then connect points Y & Z (use a 2-snap wire) for a moment.

Nothing appears to happen, but you just lled up the 470mF capacitor (C5) with

electricity. Now disconnect Y & Z and instead touch a connection between X & Y.

The green LED (D2) will be lit and then go out after a few seconds as the electricity

you stored in it is discharged through the LED and resistor (R2).

Notice that a capacitor is not very efcient at storing electricity - compare how long

the 470mF kept the LED lit for with how your batteries run all of your projects! That is

because a capacitor stores electrical energy while a battery stores chemical energy.

Make Your Own Battery

OBJECTIVE: To demonstrate how batteries can store electricity.

Project #111 Make Your Own Battery (III)

In the preceding circuit, replace the 470μF capacitor (C5) with the 100μF

capacitor (C3) and repeat the test. You see that the LED (D2) goes out faster,

because the 100μF capacitor does not store as much electricity as the 470μF.

Now replace the 1kW resistor (R2) with the 100W resistor (R1)

and try it. The LED (D2) gets brighter but goes out faster because

less resistance allows the stored electricity to dissipate faster.

Project #110

Make Your Own Battery (II)

Project #112

Turn on the slide switch (S1) for a few seconds, then turn it off. The

green LED (D2) is initially bright but goes dim as the batteries (B1)

charge up the 470mF capacitor (C5). The capacitor is storing electrical

charge.

Now press the press switch (S2) for a few seconds. The red LED (D1) is

initially bright but goes dim as the capacitor discharges itself through it.

The capacitor value (470mF) sets how much charge can be stored in it,

and the resistor value (1kW) sets how quickly that charge can be stored

or released.

Capacitor Charge &

Discharge

OBJECTIVE: To show how capacitors store and release

electrical charge.

Music Radio Station

OBJECTIVE: To create music and transmit it to a radio.

You need an AM radio for this project. Build the circuit shown on the

left and turn on the slide switch (S1). Place it next to your AM radio and

tune the radio frequency to where no other station is transmitting.

Then, tune the variable capacitor (CV) until your music sounds best on

the radio.

Project #115

Fading Siren

OBJECTIVE: To produce sound of a siren driving away into

the distance.

Press the press switch (S2), the alarm IC (U2) should make the sound of

an up-down siren that gets weaker with time. The fading is produced by

the charging of the 470mF capacitor (C5). After it is charged the current

stops and the sound is very weak.

To repeat this effect you must release the press switch, remove the

capacitor, and discharge it by placing it across the snaps on the bottom

bar marked A & B. Then, replace the capacitor and press the switch again.

Project #113

Replace the music IC (U1) with the alarm IC (U2), and then you will hear

a machine gun sound on the radio. You may need to re-tune the variable

capacitor (CV).

Replace the 470μF capacitor (C5) with the 100μF capacitor (C4), the siren

fades faster.

Project #114

Alarm Radio Station

Project #116

Fast Fade Siren

Project #117

Laser Gun with Limited

Shots

OBJECTIVE: To build a circuit with laser gun sounds and a

limited amount of shots.

Symphony of Sounds

OBJECTIVE: To combine sounds from the music, alarm, and

space war integrated circuits.

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

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

the full symphony of sounds that this circuit can create. Have fun!

When you press the press switch (S2), the alarm IC (U2) should start

sounding a very loud laser gun sound. The speaker (SP) will sound,

simulating a burst of laser energy. You can shoot long repeating laser

burst, or short zaps by tapping the trigger switch. But be careful, this

gun will run out of energy and you will have to wait for the energy pack

(C5) to recharge. This type of gun is more like a real life laser gun

because power would run out after a few shots due to energy drain. In

a real laser, the energy pack would have to be replaced. Here you only

have to wait a few seconds for recharge.

Project #118

Project #119 Symphony of Sounds (II)

The preceding circuit may be too loud, so replace the speaker

(SP) with the whistle chip (WC).

Project #120

Auto-Off Night-Light

OBJECTIVE: To learn about one device that is used to delay

actions in electronics.

Use the circuit from project #120 shown above.

When you rst turned on the slide switch (S1) in project

#120, the LED (D1) came on and very slowly got dimmer and

dimmer. When you turned the slide switch (S1) off and back

on after the light went out, it did NOT come on again. The

470mF capacitor (C5) was charged and everything stopped.

This time turn the slide switch off. Then press the press

switch (S2) for a moment to discharge the 470mF capacitor.

Now when you turn the slide switch back on the delay

repeats. Shorting a capacitor with a low resistance will allow

the charges on the capacitor to leave through the resistance.

In this case, the low resistance was the press switch.

Project #121

Discharging Caps

OBJECTIVE: To show how capacitor delays can be

repeated by discharging the capacitor.

Project #122

Changing Delay Time

OBJECTIVE: To show how the size of the capacitor

effects the delay time.

When you turn on the slide switch (S1) the rst time the LED (D1) will

come on and very slowly get dimmer and dimmer. If you turn the slide

switch (S1) off and back on after the light goes out it will NOT come

on again. The 470mF capacitor (C5) has charged up and the NPN

transistor amplier (Q2) can get no current at its input to turn it on.

This circuit would make a good night-light. It would allow you to get

into bed, and then it would go out. No further current is taken from the

battery so it will not drain the batteries (B1) even if left on all night.

Use the circuit from project #120 shown above.

Change the 470mF capacitor (C5) to the 100mF capacitor (C4).

Make sure the capacitor (C4) is fully discharged by pressing

the press switch (S2) before closing the on-off slide switch

(S1). When slide switch is turned on, notice how much quicker

the LED (D1) goes out. Since 100mF is approximately 5 times

smaller than 470mF, the LED will go out 5 times faster. The

bigger the capacitor the longer the delay.

In electronics, capacitors are used in every piece of equipment to

delay signal or tune circuits to a desired frequency.

Project #123 Sound Wave Magic

OBJECTIVE: To show how sound waves travel on a paper

surface.

Build the circuit shown on the left and connect the speaker (SP) using

the two (2) jumper wires. Then, lay the speaker on a at hard surface.

Setup: Use some paper and scissors to cut out a rectangular pattern.

Use the one shown below as a guide. Use colored paper if available.

Fold at the points shown. Scotch tape the corners so the tray has no

cracks at the corners. Place the tray over the speaker and sprinkle a

small amount of white table salt in the tray. There should be enough

salt to cover the bottom with a little space between each salt grain.

Sound Magic: Turn on the circuit by turning on the slide switch (S1).

Adjust the adjustable resistor (RV) for different pitches and watch the

salt particles. Particles that bounce high are directly over the vibrating

paper and ones that do not move are in the nodes where the paper is

not vibrating. Eventually, all the salt will move to the areas that have

no vibration, and stay there. Change the position of the tray and the

material used to create different patterns due to the sound. Try sugar

and coffee creamer, for example, to see if they move differently due to

the sound waves.

Paper Tray

Salt

Sample Cut-out Pattern

Project #124

Project #126

When you turn on the slide switch (S1) the trombone should start playing.

To change the pitch of the note, simply slide the adjustable resistor (RV)

control back and forth. By turning the slide switch on and off and moving

the slider, you will be able to play a song much like a trombone player

makes music. The switch represents air going through the trombone, and

the adjustable resistor control is the same as a trombone slider bar. The

circuit may be silent at some positions of the resistor control.

When you turn on the slide switch (S1), the power amplier IC (U4)

should not oscillate. You should be able to touch point X with your

nger and hear static. If you do not hear anything, listen closely and wet

your nger that touches point X. High frequency clicks or static should

be coming from speaker (SP) indicating that the amplier is powered on

and ready to amplify signals.

The power amplier may oscillate on its own. Do not worry, this is

normal with high gain high-powered ampliers.

Trombone

OBJECTIVE: To build an electronic trombone that changes

pitch of note with slider bar.

Power Amplier

OBJECTIVE: To check stability of power amplier with open input.

Use the circuit from project #124 shown on the left, but change the 0.02μF

capacitor (C1) to a 10μF capacitor (C3). Make sure the positive (+) mark

on the capacitor is NOT on the resistor (R2) side when you snap it in.

When the slide switch (S1) is turned on, you should hear a very low

frequency oscillation. By sliding the adjustable resistor (RV) control up and

down, you should be able to make the sound of a race car engine as it’s

motor speeds up and slows down.

Use the circuit from project #126. When you place one nger on point X

and a nger from your other hand on the speaker (SP) snap that is not

connected to the battery (B1), what happens? If the amplier starts to

oscillate it is due to the fact that you just provided a feedback path to make

the amplier into an oscillator. You may even be able to change the pitch of

the oscillation by pressing harder on the snaps. This is the principle used to

make an electronic kazoo. If you practice and learn the amount of pressure

required to make each note, you may even be able to play a few songs.

Project #125

Race Car Engine

Project #127

Feedback Kazoo

Project #128

Build the circuit on the left. You’re probably wondering how it can work,

since one of the points on the NPN transistor (Q2) is unconnected. It can’t,

but there is another component that isn’t shown. That component is you.

Touch points X & Y with your ngers. The LED (D1) may be dimly lit. The

problem is your ngers aren’t making a good enough electrical contact

with the metal. Wet your ngers with water or saliva and touch the points

again. The LED should be very bright now. Think of this circuit as a touch

lamp since when you touch it, the LED lights. You may have seen such a

lamp in the store or already have one in your home.

Two-Finger Touch Lamp

OBJECTIVE: To show that your body can be used as an

electronic component.

Project #129

The touch lamps you see in stores only need to be touched by one

nger to light, not two. So let’s see if we can improve the last circuit to

only need one nger. Build the new circuit, note that near point X there

is a 2-snap wire that is only mounted on one side, swing it so the plastic

touches point X. Wet a large area of one of your ngers and touch it to

both metal contacts at point X at the same time; the LED (D2) lights. To

make it easier for one nger to touch the two contacts, touch lamps or

other touch devices will have the metal contacts interweaved as shown

below and will also be more sensitive so that you don’t have to wet your

nger to make good contact.

One-Finger Touch Lamp

OBJECTIVE: To show you how nger touch lamps work.

Project #130

Storing Electricity

OBJECTIVE: To store electricity in a capacitor.

Turn the slide switch (S1) on and connect points A & B with a 2-snap

wire. The green LED (D2) will ash and the 470mF capacitor (C5) will be

charged with electricity. The electricity is now stored in the capacitor.

Disconnect points A & B. Connect points B & C and there will be a ash

from the 6V lamp (L2).

The capacitor discharges through the resistor to the base of the NPN

transistor (Q2). The positive current turns on the transistor like a switch,

connecting the lamp to the negative (–) side of the batteries. The light

will go out after the capacitor discharges, because there is no more

current at the base of the transistor.

Project #131

Set the adjustable resistor (RV) to the center position. Turn the slide switch

(S1) on and the LED (D1) lights. Wave your hand over the photoresistor

(RP) and the LED turns off and on. The resistance changes as the amount

of light strikes the photoresistor. As the light decreases, the resistance

increases. The increased resistance lowers the voltage at the base of the

NPN transistor (Q2). This turns off the transistor, preventing current owing

through the LED to the negative (–) side of the battery (B1). Wave your

hand over photoresistor at different distances. The LED gets brighter the

farther away your hand is.

Motion Detector

OBJECTIVE: Build a circuit that detects motion.

Photoresistor Control

OBJECTIVE: To use a photoresistor to control the brightness of an LED.

In this circuit, the brightness of the LED (D1) depends on how much light

shines directly on the photoresistor (RP). If the photoresistor were held

next to a ashlight or other bright light, then the LED would be very bright.

The resistance of the photoresistor decreases as more light shines on it.

Photoresistors are used in applications such as streetlamps, which come

on as it gets dark due to night or a severe storm.

Project #132

Project #134

Set the adjustable resistor (RV) to the bottom position and then turn the

slide switch (S1) on. The LED (D1) will start ashing at a frequency of

0.5Hz (once every two seconds). Slowly adjust the adjustable resistor and

the LED ashes faster. As the frequency increases, the LED ashes faster.

Eventually, the LED ashes so fast, it looks like it is on all of the time.

Oscillator 0.5 - 30Hz

OBJECTIVE: To build a 0.5Hz - 30Hz oscillator that will light an LED.

Use the circuit from project #132.

Connect a single snap under the speaker (SP) and then connect it across

the LED (on level 4). Turn the slide switch (S1) on and now you can hear

the oscillator. Adjust the adjustable resistor (RV) to hear the different

frequencies. Now you can hear and see the frequencies. Note: You may

not hear sounds at all settings of the adjustable resistor.

Project #133

Sound Pulse Oscillator

Microphone Control

OBJECTIVE: To use a microphone to control the brightness of

an LED.

In this circuit, blowing on the microphone (X1) changes the LED (D1)

brightness.

The resistance of the microphone changes when you blow on it. You

can replace the microphone with one of the resistors to see what

resistor value it is closest to.

Project #136

Do not place the fan onto the motor (M1). Turn the slide switch (S1) on. The

motor rotates clockwise, and the green LED (D2) lights. When you connect

the positive (+) side of the battery (B1) to the positive (+) side of the motor,

it spins clockwise. Turn the slide switch off and press the press switch (S2).

Now the fan spins the other way and the red LED (D1) lights. The positive

(+) side of the battery is connected to the negative (–) side of the motor.

The polarity on the motor determines which way it rotates.

Now place the fan on the motor, and turn on S1 or S2 (not both). Now one

of the lamps (L1 or L2) lights as the motor spins, but the LED is dim.

The motor needs a lot of current to spin the fan, but only a little current to

spin without it. In this circuit, a lamp lights when the motor current is high,

and an LED lights when the motor current is low. The lamps also prevent a

short circuit if both switches are on.

LED Fan Rotation

Indicator

OBJECTIVE: To build an LED fan rotation indicator.

Project #135

Project #137

Build the circuit shown on the left. Place the fan onto the motor (M1).

In the circuit, the alarm IC (U2) and the music IC (U1) are connected

together. The sounds from both ICs can be played at the same time.

Press the press switch (S2). The music IC plays and the green LED

(D2) lights. Now turn on the slide switch (S1) and press the press switch

again. You should hear the sounds from both ICs playing. As the alarm

IC plays, it also drives the fan and the red LED (D1).

Sound Mixer Fan Driver

OBJECTIVE: To connect two sound ICs together to drive two

LEDs and a motor.

Project #138

Place the fan on the motor (M1). Turn on the slide switch (S1), the

motor starts spinning. As you move your hand over the photoresistor,

(RP) the motor slows. Now place a nger on top of the photoresistor

to block the light. The motor slows down. In a few seconds the motor

speeds up again.

The fan will not move on most settings of the resistor, because the

resistance is too high to overcome friction in the motor. If the fan does

not move at any resistor setting, then replace your batteries.

Start-Stop Delay

OBJECTIVE: To start and stop a motor with light.

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 #139

AM Radio with

Transistors

OBJECTIVE: To build a complete, working AM radio with

transistor output.

When you turn on the slide switch (S1), the integrated circuit (U5)

should amplify and detect the AM radio waves. Tune the variable

capacitor (CV) to the desirable station. Set the adjustable resistor (RV)

for the best sound. The two transistors (Q1 & Q2) drive the speaker

(SP) to complete the radio. The radio will not be very loud.

Note: 5-snap wire is connected

from base grid locations G3 to G7.

Delayed Action Lamp

OBJECTIVE: To build a lamp that stays on for a while.

Turn on the slide switch (S1) and press the press switch (S2). The

lamps (L1 & L2) turn on slowly, but stay on for a while after you release

the press switch.

Project #140

Replace the lamp (L1) with the motor (M1), positive (+) side up. Be sure

to put on the fan. Turn on the slide switch (S1) and press the press switch

(S2). The fan turns on slowly but stays on for a while after you release the

press switch.

Project 141

Delayed Action Fan

Lasting Doorbell

OBJECTIVE: To build a doorbell that stays on for a while.

Build the circuit at left, note that there is a 4-snap wire on layer 1 that is

not connected to a 3-snap wire that runs over it on layer 3. Turn on the

slide switch (S1), then press and release the press switch (S2). There is

a doorbell sound that slowly fades away.

When the press switch is pressed, the transistors are supplied with

current for oscillation. At the same time, the 100mF capacitor (C4)

is being charged. When the press switch is released, the capacitor

discharges and keeps the oscillation going for a while.

Project #144

Place the fan on the motor (M1) and turn off the slide switch (S1).

Press the press switch (S2) and listen to the motor.

As the motor shaft spins around it connects/ disconnects several sets

of electrical contacts. As these contacts are switched, an electrical

disturbance is created, which the speaker converts into sound.

Turn on the slide switch and push the press switch again. The fan

spins just as fast, but the sound is not as loud. Capacitors, like the

470mF capacitor (C5), are often used to lter out undesired electrical

disturbances. If you replace C5 with one of the other capacitors in your

set then the sound will not be changed as much.

Quieting a Motor

OBJECTIVE: To show how capacitors can lter out electrical

disturbances.

Project #142

WARNING: Moving parts. Do not touch the fan or

motor during operation. Do not lean over the motor.

Place the 10μF capacitor (C3) on top of the whistle chip (WC). Press and

release the press switch (S2). It makes a clicking sound that repeats for a while.

Project #143

Lasting Clicking

Project #147

Build the circuit and turn it on, you hear a high-frequency sound.

Tone Generator

OBJECTIVE: To build a high-frequency oscillator.

Watch Light

OBJECTIVE: To build a lamp that stays on for a while.

Turn on the switch and press the press switch (S2). The lamp stays on

for a few seconds after you release the press switch.

A miniature version of a circuit like this might be in your wristwatch -

when you press a light button on the watch to read the time in the dark,

a light comes on but automatically turns off after a few seconds to avoid

draining the battery.

Project #145

Replace the lamp (L1) with the motor (M1, positive (+) side up), be sure

to put on the fan. Turn on the switch and press the press switch (S2). The

fan stays on for a while after you release the press switch. This could have

a longer delay and be near your bed, to turn off after you fall asleep.

Place the 0.02μF capacitor (C1) on top of the whistle chip (WC) in the

preceding circuit, you hear a middle-frequency sound. Why? The whistle chip

is used here as a capacitor and by placing the 0.02μF on top (in parallel) we

have increased the capacitance, and doing so lowers the frequency.

Next, replace the 0.02μF capacitor (C1) and the whistle chip (WC) with the

larger 0.1μF capacitor (C2). You now hear a low frequency sound, due to yet

more capacitance.

Now replace the 0.1μF (C2) with the much larger 10μF capacitor (C3), (orient

with the positive (+) side towards the left); the circuit just clicks about once a

second. There isn’t a constant tone anymore due to other transistor properties.

You need a different type of circuit to create very low frequency tones.

Project #146 Delayed Bedside Fan

Project #148 Tone Generator (II)

Project #149 Tone Generator (III)

Project #150 Tone Generator (IV)

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Elenco SC-300 Snap Circuits 300-in-1 Electronics Kit

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