Elenco R-C Snap Rover® User Manual

Copyright © 2008 by Elenco®Electronics, Inc. All rights reserved. No part of this book shall be reproduced by REV-B Revised 2008 753131
any means; electronic, photocopying, or otherwise without written permission from the publisher.

-1-

Basic Troubleshooting 1

Parts List 2

How to Use It 3

About Your Snap
Circuits Parts 4

How It Works 5, 6

General Operating
Instructions 6

DO’s and DON’Ts of
Building Circuits 7

Advanced Troubleshooting 8

Project 1 9

Project 2 10

Projects 3, 4 11

Projects 5, 6 12

Projects 7, 8 13

Projects 9, 10 14

Projects 11, 12 15

Projects 13, 14 16

Projects 15, 16 17

Projects 17, 18 18

Project 19, 20 19

Projects 21-23 20

Other Snap Circuits®Products

21

Bonus Projects B1-B3 22

WARNING: SHOCK HAZARD - Never connect Snap

Circuits

®

to the electrical outlets in your home in any way!

Table of Contents

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 in the Rover body and remote control
unit.

5. Keep the wheels clean and free of lint, thread, or dirt.

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

Basic Troubleshooting

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

Advanced Troubleshooting procedure on page 8 to determine which
ones need replacing.

BATTERIES:

• Use only 1.5V AA type in the Rover body and 9V in the remote control

(not included).

• Insert batteries with correct polarity.

• Non-rechargeable batteries should not be recharged. Rechargable

batteries should only be charged under adult supervision, and should
not be recharged while in the product.

• Do not mix alkaline, standard (carbon-zinc), or rechargeable (nickel-

cadmium) batteries.

• Do not mix old and new batteries.

• Remove batteries when they are used up.

• Do not short circuit the battery terminals.

• Never throw batteries in a fire or attempt to open its outer casing.

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

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.

Warning to Snap Circuits®Owners: Do not use parts from other Snap Circuits®sets

with this kit. The Snap Rover

®

uses higher voltage which could damage those parts.

Page 22 and our website www.snapcircuits.net has approved circuits that you can use.

!

A NOTE•ABOUT•THE•FCC

The Federal Communications Commission (FCC) regulates use of the radio
frequency spectrum in the United States to prevent products from interfering with
each other.

RC Snap Rover

®

has been tested and found to comply with the limits for a Class B
digital device, pursuant to part 15 of the FCC Rules. These limits are designed to
provide reasonable protection against harmful interference in a residential
installation. RC Snap Rover

®

generates, uses and can radiate radio frequency
energy and, if not installed and used in accordance with the instructions, may cause
harmful interference to radio communications. However, there is no guarantee that
interference will not occur in a particular installation. If RC Snap Rover

®

does cause
harmful interference to radio or television reception, which can be determined by
turning RC Snap Rover®off and on, try to correct the interference by:

1. Moving RC Snap Rover®away from the receiver.

2. Contacting Elenco

®

Electronics for help by calling [phone], or e-mail

us at [e-mail].

FCC regulations for your RC•Snap Rover®require you to accept any interference
from authorized sources and that you shut down if you are causing interference with
other authorized products.

You should never modify the electrical circuit components inside your R/C Receiver
(RX1) or Remote Control transmitter as this may cause malfunctions or violate FCC
regulations for this product.

Note: If you have a more advanced model, 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 [phone] or e-mail us at:

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

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

r 1

Rover Body 6SCRB

r 2

100μF Capacitor
(non-polarized)

6SCC4N

r 1
r 1

Remote Control Unit
Antenna

6SCTX1

6SCTX1A

r 1

White LED

6SCD4

r 1

Base Grid
(11.0” x 7.7”)

6SCBG

r 1

100Ω Resistor

6SCR1

r 2

1-Snap Wire 6SC01

r 4

1KΩ Resistor

6SCR2

r 6

2-Snap Wire 6SC02

r 1

R/C Receiver

6SCRX1

r 2

3-Snap Wire 6SC03

r 1

Slide Switch 6SCS1

r 1

4-Snap Wire 6SC04

r 1

Motor Control IC 6SCU8

r 1

5-Snap Wire 6SC05

r 1

Horn 6SCW1

r 1

6-Snap Wire 6SC06

r 1
r 1

Jumper Wire (Orange)
Jumper Wire (Yellow)

6SCJ3A
6SCJ3B

r 1

7-Snap Wire 6SC07

r 1
r 1

Jumper Wire (Green)
Jumper Wire (Purple)

6SCJ3C
6SCJ3D

r 1

0.02μF Capacitor 6SCC1

r 1
r 1

Jumper Wire (Gray)
Jumper Wire (White)

6SCJ3E
6SCJ3F

7

6

5

3

2

1

C1

C4N

W1

U8

D4

-2-

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

R1

R2

4

RX1

S1

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

Note: Colors may vary

and are interchangeable.

-3-

Install six “AA” batteries (not included) into the bottom of the Rover
body and one 9V•battery (not included) into the remote control unit.
Install the antenna into the remote control unit by screwing it in.

The R/C Snap Rover Kit 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, LED 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 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.

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

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

A large clear plastic base grid is included with this kit to keep the
circuit blocks together, it fits on top of the Rover body. You will see
evenly spaced posts that the different blocks snap into, these keep
your circuit together. The base has rows labeled A-G and columns
labeled 1-10.

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

Jumper wires are used to connect your circuits to the batteries and
motors in the Rover body. Snap them on as shown in the projects.
The colors are interchangeable, so it doesn’t matter which color
you use.

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

How To Use It

2

Warning to Snap Circuits owners: Do not use parts from other
Snap Circuits

®

sets with this kit unless directed to do so. The Snap

Rover

®

uses higher voltage which could damage those parts. Page
22 and our website www.snapcircuits.net has approved circuits
that you can use.

3

4

5

6

7

S1

Front of Rover

Antenna

Remote

control

–

(Part designs are subject to change without notice).

Note: If you have a more advanced Model, there is additional information in
your other project manual(s).

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 white, orange, yellow, green, gray, and purple

jumper wires make flexible

connections for times when using the snap wires would be difficult. They also
are used to make connections off the base grid. The different colored wires all
work the same way, and are interchangeable.

The

batteries (in the Rover body) 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 flows.

The

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

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

Resistors, such as the

100Ω resistor (R1) and 1KΩ resistor (R2), “resist” the

flow of electricity and are used to control or limit the electricity in a circuit.
Increasing circuit resistance reduces the flow of electricity.

The

LED (D4) is a light emitting diode, and may be thought of as a special

one-way light bulb. In the “forward” direction (indicated by the “arrow” in the
symbol) electricity flows if the voltage exceeds a turn-on threshold (about 3V);
brightness then increases. A high current will burn out the LED, so the current
must be limited by other components in the circuit. LEDs block electricity in
the “reverse” direction.

The

0.02μF (C1) and 100μF (C4N) 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 filtering and delay
circuits. Large values have a “+” marking that should always be connected to
the higher voltage.

The

horn (W1) converts electricity into sound by making mechanical

vibrations. These vibrations create variations in air pressure which travel
across the room. You “hear” sound when your ears feel these air pressure
variations.

The

R/C Receiver (RX1) is a complex module containing a radio receiver

circuit, a specialized radio decoder integrated circuit, and other supporting

components. It includes resistors, capacitors, inductors, and transistors that

are always needed together. This was done to simplify the connections you

need to make, otherwise this circuitry would not fit on the base grid. A

description for this module is given here for those interested, see project #1

for a connection example:

The

Motor Control (U8) module contains 16 transistors and resistors that are

usually needed to control the motors. A description for this module is given

here for those interested, see project 1 for a connection example:

The

motors (in the Rover body) convert elecricity into mechanical motion.

Electricity is closely related to magnetism, and an electric current flowing in a

wire has a magnetic field similar to that of a very, very tiny magnet. Inside the

motor is a coil of wire with many loops wrapped around metal plates. If a large

electric current flows through the loops, it will turn ordinary metal into a

magnet. The motor shell also has a magnet on it.•When electricity flows

through the coil, it magnetizes the metal plates and they repel from the

magnet on the motor shell - spinning the shaft. A small gear is on the end of

the shaft and spins with it.

(–)

(+)

R/C Receiver:

(+) - power from batteries
(–) - power return to batteries
RBUT - right button function (active low)
LBUT - left button function (active low)
BYP1 - low frequency bypass
BYP2 - high frequency bypass
RF - right forward output (active high)
RB - right backward output (active high)
LF - left forward output (active high)
LB - left backward output (active high)
ABC switch - selects radio channel

Motor Control:

(+) - power from batteries
(–) - power return to batteries
RF - right forward control input
RB - right backward control input
LF - left forward control input
LB - left backward control input
R+ - right forward motor drive
R – - right backward motor drive
L+ - left forward motor drive
L – - left backward motor drive

-4-

About Your Snap Circuits®Parts

LF

BYP1

BYP2

LB

RF

RB

LBUT

RBUT

!

Only connect

this part as

shown in the

projects!

Only connect

this part as

shown in the

projects!

Warning to Snap Circuits®owners: Do not use parts from other Snap Circuits®sets with this kit. The Snap Rover®uses higher

voltage which could damage those parts. Page 22 and our website www.snapcircuits.net has approved circuits that you can use.

(–)

(+)

L–

RF

RB

L+

R–

R+

LF

LB

!

!

Rover Rear:

(+) - power from batteries
(–) - power return to batteries
L+ - left forward motor drive
L – - left backward motor drive
R+ - right forward motor drive
R – - right backward motor drive
N1, N2 - not used

(+)

(–)

R–

L+

R+

L–

Rover Rear

N1

N2

-5-

Remote Control Transmitter:

When the levers in the Remote Control Unit are pushed, electrical
contacts are made connecting the 9V battery power to the transmitter,
indicating which commands the user wants sent to the Rover.
Forwards/Backwards commands for each set of wheels and two extra
functions are controlled by different levers or buttons. Each of these use
a different set of electrical contacts which encode a sequence of
electrical pulses; the pulse sequence depends on which command(s) are
being sent. The spacing between the sequences represents which
channel setting (A-B-C) the remote control is on. This allows three units
to use the same operating frequency in the same room at the same time
without interfering with each other. An electrical circuit that is tuned to a
frequency of 27 MHz creates a signal that is sent to the antenna when
the pulses are active. The antenna converts this electrical energy into
radio energy, creating a stream of radio energy bursts, which travel
through the air and are picked up by, and understood by, the radio
receiver in the car. The frequency of 27 MHz was selected for your Rover
with the approval of the FCC (the US government) to minimize radio
interference between this product and all other electrical products.

Radio Receiver:

The Rover antenna collects radio energy and converts it back into
electrical energy. If the Rover is turned on, then the radio receiver in the
Rover is continuously monitoring the radio energy from its antenna. The
receiver is basically a filter which is tuned to amplify any energy around
27 MHz and block energy the antenna picks up outside this region. If the
Remote Control Transmitter is sending commands, then its radio signal

will be picked up by the receiver and converted back into the original
pulse sequence. Decoding circuitry then determines which commands
were sent by examining the pulses in the sequence. Signals are then
sent to motors that drive the wheels to execute the commands, or the
other R/C Receiver outputs to control other functions. Commands sent to
other receivers using a different channel setting (A-B-C) are ignored.

Characteristics of Radio Reception:

Many factors affect the ability of the Rover to receive commands from its
Remote Control Transmitter. A weak battery in the Transmitter will result
in a weaker transmitted signal; if the battery is very weak then the
Transmitter may not function at all. The Transmitter’s ability to convert
electrical energy to radio energy is best when its antenna is fully
extended and degrades as the antenna length is reduced. The same
thing also applies to the Rover antenna’s ability to convert the radio
signal back into electrical energy for the receiver. The Transmitter’s
antenna transmits energy in all directions so as the range between it and
the Rover is increased, less energy is received at the Rover. When
operated with strong batteries and in an open area, the range will be at
least 25 ft. Obstacles such as walls, furniture, and trees will degrade the
radio signal’s ability to travel through air and reduce the operating range,
but will never block it completely. In some cases more radio energy may
travel from the Transmitter to the Rover by going around obstacles than
by going through them. In the Rover, weak batteries will reduce power to
the motor and degrade the receiver’s ability to filter, amplify, and decode
commands from the Transmitter.

Encoding

Circuitry

27 MHz

Signal

Filter/

Amplifier

Filter/

Amplifier

Decoding

Circuitry

L-F
L-B
R-F
R-B

Pulse Sequence,
depends on which
command(s) are being
sent and channel used

Sequence
of Radio
Frequency
Pulses

Pulse Sequence,
depends on which
command(s) were sent
and channel used

128-1

Gear Ratio

Left

Wheels

Left

Motor

128-1

Gear Ratio

Right

Wheels

Right

Motor

How It Works

LBUT
RBUT

Control For Two
Other Functions

BLOCK DIAGRAM

HOW•IT•WORKS

General Operating Instructions

-6-

Wheel shaft

Motor gear

Spins 128 times

faster than wheels

How It Works (continued)

Rover Drive Mechanism:

The small gear on the Motor drives a larger gear, which drives a
larger gear, which drives two larger gears (one on each side), which
drive larger gears. The last, largest gears are fixed on shafts that are
attached to the front and back wheels, making them move. Note that
interlocking gears spin in opposite directions. Also notice that in the
sets of interlocking gears between the Motor and the gears on the
wheel shafts, the number of “teeth” is increased each time (40-8, 44­8, 64-44, and 64-20), for 128:1 gear ratio overall. This means the
Motor must rotate 128 times to rotate the wheels once. The reason for
this is that if the Motor were to drive the wheels directly then the
Rover would be so fast that it would be impossible to control. Using
the gears to reduce the speed also makes the wheels move with
much greater force, preventing the Rover from getting stuck in rough
terrain and allowing it to carry heavy loads uphill.

Build the circuit for projects 1 or 2. Set the channel switches on the
remote control unit and R/C Receiver module (RX1) to the same
setting (A, B, or C). Place the Rover on a flat, open area, turn the
ON/OFF switch on the remote control unit and the slide switch (S1) to
ON, and extend the antenna on the Remote Control.

Push both levers forward to make Snap Rover

®

go forward.
Push both levers backward to go backward.
Push the left lever backward and the right lever forward to turn left.
Push the left lever forward and the right lever backward to turn
right.

The buttons on the remote control unit are used to control sounds or
lights (or other special functions) as described in the projects.

Never

operate Snap Rover®in the street.

Never drive your Rover in rain, snow, mud, sand, dirt, or on a wet
floor, as damage may result.

GEARS

Right control

lever

Left control

lever

Power switch

Power ON indicator LED

Antenna

Channel selector switch

Left function

button

Right function button

-7-

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, motor, integrated circuit, etc.), and wiring paths between them
and back.

You must be careful not to create “short circuits” (very low­resistance paths across the batteries, see examples below) as this will
damage components

and/or quickly drain your batteries. Only connect the

ICs using configurations given in the projects, incorrectly doing so may
damage them. Elenco®Electronics is not responsible for parts

damaged due to incorrect wiring.

Here are some important guidelines:

ALWAYS

USE EYE PROTECTION WHEN EXPERIMENTING ON
YOUR OWN.

ALWAYS

include at least one component that will limit the current
through a circuit, such as a resistor, motor, horn, or the RX1
and U8 modules (which must be connected properly).

ALWAYS

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

ALWAYS

disconnect your batteries immediately and check your wiring if
something appears to be getting hot.

ALWAYS

check your wiring before turning on a circuit.

ALWAYS

connect the RX1 and U8 modules using configurations given in
the projects or as per the connection descriptions for the parts.

NEVER

connect to an electrical outlet in your home in any way.

NEVER

leave a circuit unattended when it is turned on.

Note: If you have a more advanced model, there are additional
guidelines in your other project manual(s).

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.

WARNING: SHOCK HAZARD - Never connect Snap Circuits®to

the electrical outlets in your home in any way!

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

You are encouraged to tell us about new circuits you create. Upon review,
we will post them with your name in a special section on our website. If
we use them in future manual revisions, we will send you a copy of the
manual so you can show your family and friends. Send your suggestions

to Elenco

®

Electronics.

CAUTION: Do not mix alkaline, standard (carbon-zinc), or

rechargeable (nickel-cadmium) batteries.

!

DO’s and DON’Ts of Building Circuits

Placing a jumper
wire directly across
the battery snaps is
a SHORT CIRCUIT.

When the 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!

Warning to Snap Circuits®owners: Do not use parts from

other Snap Circuits®sets with this kit except for the circuits
on page 22. The Snap Rover®uses higher voltage which
could damage those parts. Our website www.snapcircuits.net
also has approved circuits that you can use.

!

!

!

NEVER

DO!

NEVER DO!

NEVER

DO!

(+)

(–)

(+)
(–)

!

NEVER

DO!

ROVER•REAR

!