Elenco Projects PC1-PC73 User Manual

Copyright © 2005 by Elenco®Electronics, Inc. All rights reserved. No part of this book shall be reproduced by REV-B Revised 2005 753293
any means; electronic, photocopying, or otherwise without written permission from the publisher.

CI-73 - READ THIS FIRST

The CI-73 is a set of 73 Snap Circuits with special
software that allows you to “see” the electrical signals
in the circuits, just like electronics engineers do using
oscilloscopes and spectrum analyzers.

Requirements for your computer:

1. Windows

2. A working microphone input port.

®

95 or later.

INSTRUCTIONS:

1. Insert the CI-73 CD into your computer. The Snap Circuits
menu comes up automatically, with an electronic copy of this
manual. Select Run Winscope Now. Connect the plug end of
the probe to the microphone input on the back of your personal
computer.

If the Snap Circuits menu does not appear automatically: Click
<Start> - <Run> - <Browse>, then select CI-73 in your CD
drive, then select AutorunPro and click <OK>.

If Windows asks you how to open the file (or if you have
Acrobat
Acrobat®ReaderTM: Click <Start> - <Run> - <Browse>, then
select CI-73 in your CD drive, then select Acrobat®Installer
and click <OK>. Follow the instructions to install, and then re­insert the CI-73 CD into your computer.

2. Change the default settings for Winscope by selecting
<Options>. Then select <Timing> and change Sampling to
44100 and press <OK>. Then select <Options> again, then
<Colors> - <Y1 Trace> and pick a bright color like pink. Then
select <Options>, then <Save Setup> to save these settings
as your default.

®

ReaderTM3.0 or older), then you need to install

-1-

ebsite:

W

If you have any questions contact:

®

Elenco

www

.elenco

Electronics, Inc.

150 Carpenter Avenue

Wheeling, IL 60090

[phone]

.com • e-mail:

[e-mail]

Follow the instructions through project PC3 before

3.

moving on to any other circuits, since the main features
of the software are demonstrated.

WARNING:

SHOCK HAZARD - NEVER connect
the probe to AC power or a wall
electricity outlet for any reason since
serious injury or damage may result.

!

Looking at Electronic Signals using the WINSCOPE Software

Electronic engineers use specialized test equipment to “see”
electronic signals and make performance measurements. They
use an oscilloscope to look at the shape of the signal and use a
spectrum analyzer to look at its frequency content. This
equipment is specialized and usually very expensive.

The Winscope software
simulates this equipment using
your personal computer. The
PC-interface cable can be
connected across any 2 points in
your circuit to look at the signal.

WARNING:

SHOCK HAZARD - NEVER connect the probe to AC power
or a wall electricity outlet for any reason since serious injury
or damage may result.

It is usually connected to the output of a circuit, as in the circuits
shown for the CI-73. Connect the plug end of the pr

microphone input (pink plug) on the back of your personal
computer. Run the Winscope application (from the CI-73 menu).

It will come up in Hold mode looking like this:

obe to the

Click on the On-Line button to turn it on. You should now get
one of the following 2 pictures, depending on whether your
microphone input is properly turned on:

On-Line

button

Example

A

Example

B

If you get the picture shown in Example B, then your microphone
input is not properly turned on. Go to the “Turning On Your
Microphone Input” section to turn it on. There may also be other
sound card controls on your computer that you need to set.
When your input is properly configured, you will get a picture like
Example A above. Touch the red and black “alligator” clips on the
PC-interf
pattern on the Winscope screen change as you do so. You are
now ready to proceed with the first CI-73 experiment or you may
investigate the Winscope software on your own.

ace cab

le to each other and y

ou should see the r

andom

-2-

Looking at Electronic Signals using the WINSCOPE Software (continued)

You may freeze a waveform on the screen by clicking on the Hold
mode button (just to the right of the On-Line button).

Hold mode button

WARNING: Do not “save setup” in Winscope. Many of the

buttons on Winscope control features that this manual will not be
using. If you accidentally place the Winscope software into an
unknown mode, you may always close and re-start Winscope.
Doing so will reset all settings to those described in this booklet
unless you have done a “save setup”.

NOTES:

1. It is recommended that you disable or turn down the
volume to the speakers on your computer. CI-73’s use of
the microphone input port will also channel the same
signal to the speakers, and the result can be distracting.

2. It is recommended that you become familiar with the Snap
Circuits parts and assembly methods before building any
of the circuits in this manual.

Turning On Your Microphone

(For Windows®98 or XP, other Windows®versions may be
slightly different.)

If you don’t get any signal from the PC-interface cable then
your microphone may be disabled on your computer. To turn
it on, follow these instructions which begin by pressing the
<Start> button on the lower-left corner:

1. Select <Start> - <Programs> - <Accessories> ­<Entertainment> (or <Multimedia>) - <Volume Control>.

2. Select <Options>.

3. Select <Properties>.

4. Select <Recording> in the “Adjust Volume For” box.

PROJECTS PC1-PC3 SHOW
HOW TO USE THE MAIN
FUNCTIONS OF WINSCOPE SO
DO THEM FIRST!

-3-

5. In the “Show the Following Controls” box, check
<Microphone>.

6. Select <OK>.

7. In the “Microphone - Volume” box, check <Select> and set

olume to about 40% of max.

v

Your microphone should now be turned on.

Looking at Electronic Signals using the WINSCOPE Software (continued)

IMPORTANT NOTE: The designs for the microphone input port

vary throughout the computer industry. Hence you may get
waveforms different from those shown in your manual even
though the circuit is actually performing the same way. Here are
some types of differences:

A. The gain of your microphone input may be significantly

different from that indicated on pages 8-10 (and similarly
for the other circuits). Page 4 describes how to turn on
the microphone input and adjust its volume to about 40%
of max, you may want to adjust this volume higher or
lower so that your results better match those shown. Note
that having the volume set too high may “clip off” the top
or bottom portion of a waveform.

B. The oscilloscope waveforms shown on your display may

appear upside down (“inverted”) from those shown
throughout this document. For example the waveform
shown on the top of page 10 would look like this:

C. The shape of waveforms may appear distorted for some

circuits, due to protection circuitry that acts as a filter. For
example:

This waveform . . .

might look like this.

If this is the case then swap the connections of the red and black
clips of the Winscope probe in all circuits.

And this waveform . . . might look like this.

And this waveform . . . might look like this.

ve any questions about this.

Contact Elenco®Electronics if y

ou ha

-4-

Limitations of WINSCOPE and Its Interface

By using the microphone audio input and the flexible processing
power of the personal computer, we have created an inexpensive
and easy-to-use way of looking at electronic signals. However,
no electronic oscilloscope or spectrum analyzer ever made works
on all electronic signals, and similarly Winscope has limitations.
The projects in this booklet were written to minimize those
limitations.

Winscope can only measure changing signals (AC voltages, >20
Hz frequency) and cannot measure fixed voltages (DC voltages,
such as a battery), due to the design of the microphone input.
Fixed voltages are not very exciting to look at anyway. Slow­changing or transient signals (such as when you first turn on
power to a circuit) will be displayed in a distorted form.

Using WINSCOPE’s Full Capabilities

Winscope has 2 input channels that can be displayed at the
same time. This is commonly done by electronic engineers using
an oscilloscope, to show the relationship of one (or more) signals
to another. However, use of this requires a second microphone
input, which most computers do not have. If the sound card in

Winscope works best on signals up to about 5kHz, since its
sampling rate is limited to 44kHz. If you attempt to measure
higher frequency signals, then you will get wrong results due to
undersampling. This is a narrow range but it covers human voice
and most (but not all) music. AM and FM radio frequencies
cannot be measured. Every measurement you make will have
some amount of random “chatter” superimposed on the signal of
interest. This chatter is due to the limited sampling rate and from
the PC-interface cable picking up energy from other electronic
instruments in the vicinity (including room lights and your
computer), hence it cannot be avoided.

your computer has this then you may use all of Winscope
features for 2 channels, which include X-Y and correlate modes.
Use of these Winscope capabilities is beyond the introductory
level of this product, use the Help menu in Winscope for
information about using these features.

WARNING:

SHOCK HAZARD - NEVER connect the probe to AC power
or a wall electricity outlet for any reason since serious injury
or damage may result.

!

Exporting Graphs from WINSCOPE

To make a copy of the Winscope display screen, hold down the Alt button and press the PrtScn button on your
computer when Winscope is the active window. You can then paste it into word processing programs such as
Microsoft Word.

-5-

Project Listings

Project # Description Page #

PC1 Pitch PC 7
PC2 Screaming Fan PC 11
PC3 Hissing Foghorn PC 14
PC4 Light and Sounds PC 16
PC5 Light and Sounds PC (II) 18
PC6 Light and Sounds PC (III) 18
PC7 Light and Sounds PC (IV) 18
PC8 Light and Sounds PC (V) 18
PC9 Light and Sounds PC (VI) 19
PC10 Modulation 19
PC11 Filtering 21
PC12 AM Radio PC 22
PC13 Space War PC 24
PC14 Microphone 25
PC15 Speaker Microphone 27
PC16 Symphony of Sounds PC 28
PC17 Doorbell PC 29
PC18 Periodic Sounds PC 30
PC19 Lasting Doorbell PC 31
PC20 Space War Flicker PC 33
PC21 Buzzing in the Dark PC 34
PC22 Trombone PC 35
PC23 Sound Pulse Oscillator PC 37
PC24 High Pitch Bell PC 38
PC25 Tone Generator PC 39
PC26 Tone Generator PC (II) 39
PC27 Tone Generator PC (III) 39
PC28 Old-Style Typewriter PC 40
PC29 Transistor Fading Siren PC 41
PC30 Fading Doorbell PC 41
PC31 Police Siren Amplifier PC 42
PC32 Music Amplifier PC 42
PC33
PC34 Adjustable Tone Generator PC 43
PC35 Adjustable Tone Generator PC (II) 44
PC36
PC37 Adjustable Tone Generator PC (IV) 44

Space War Amplifier PC 43

Adjustable Tone Generator PC (III) 44

Project # Description Page #

PC38 Adjustable FM Radio PC 44
PC39 Transistor AM Radio PC (II) 45
PC40 Playback & Record PC 45
PC41 Power Amplifier Playing Music PC 46
PC42 Music Meter PC 47
PC43 Oscillation Sounds PC 48
PC44 Oscillation Sounds PC (II) 48
PC45 Oscillation Sounds PC (III) 48
PC46 Oscillation Sounds PC (IV) 48
PC47 Oscillator Sounds PC 49
PC48 Oscillator Sounds PC (II) 49
PC49 Whistle Chip Sounds PC 49
PC50 Whistle Chip Sounds PC (II) 50
PC51 Whistle Chip Sounds PC (III) 50
PC52 Whistle Chip Sounds PC (IV) 50
PC53 Bird Sounds PC 50
PC54 Bird Sounds PC (II) 51
PC55 Electronic Cat PC 51
PC56 Electronic Cat PC (II) 51
PC57 Electronic Cat PC (III) 51
PC58 Electronic Cat PC (IV) 51
PC59 Variable Oscillator PC 52
PC60 Variable Oscillator PC (II) 52
PC61 Variable Oscillator PC (III) 52
PC62 Variable Oscillator PC (IV) 52
PC63 Electronic Sound PC 53
PC64 Electronic Sound PC (II) 53
PC65 Siren PC 54
PC66 Drawing Resistors PC 55
PC67 Electronic Noisemaker PC 55
PC68 Electronic Noisemaker PC (II) 56
PC69 Bee PC 56
PC70
PC71 Space War Alarm Combo PC 57
PC72 Space War Music Combo PC 58
PC73

Bee PC (II) 57

Sound Mixer PC 58

-6-

Project #PC1

OBJECTIVE: To look at the output signal from a transistor oscillator while changing the pitch of the sound.

Pitch PC

-7-

You will now be introduced to the Winscope features, and thereby
become familiar with oscilloscopes and spectrum analyzers, and
see some of the most important concepts in electronics. It is
recommended that you already be familiar with the Snap Circuits
parts and assembly methods from the other manuals.

Build the circuit shown and connect the PC-interface cable to the
microphone input on your computer. Turn on the slide switch
(S1) and vary the adjustable resistor (RV). The frequency or
pitch of the sound is changed. Run the Winscope software and
be sure your microphone input is configured properly, as
described earlier.

Click on the On-Line button if Winscope is currently in Hold mode
and you should get a picture similar to this one:

On-Line

button

The waveform peak is off the top of the screen because the scope
gain (amplification) is set too high. You may adjust this gain by
moving the Y1 gain control around (try it).

Similarly, you may adjust the position of the waveform on the
screen by moving the Y1 position control around (try it).

Note that your picture may not exactly match this picture due to
variances in the microphone input gain between computers, which
is beyond software control. You may want to adjust the volume
control of your microphone input to compensate, see note A on
page 4 for more details. You may also disable 1:1 mode by clicking
on its button again and then adjust the gain using the Y1 control.

The gain and position control features just described enable
electronic engineers and technicians to “see” the amplitude
(voltage level) of a signal. By adjusting the settings on an
oscilloscope, they can look at both very large and very small
voltage waveforms.

Move the adjustable resistor control (snap part RV) and watch how
it changes the waveform on the computer screen. Now click on the

0.5ms/div button to change the time scale on the display. (The
button to the left of it is for 5ms/div, the default.) Move the
adjustable resistor control around again. You may click on the Hold
button to freeze the waveform on the screen, then click on On-Line
to re-start.

Hold

button

0.5ms/div button

Now click on the 1:1 button to set the gain to x1 and disable the
Y1 controls. You should now have a picture similar to this one:

1:1 button

Y1 position

control

Y1 gain

control

With the time scale at 0.5ms/div and the adjustable resistor set for
middle position, you should now have a picture similar to this one.

Your picture may appear different due to variations in the
microphone input designs between computers. Although this is
beyond software control, in some cases you may be able to
compensate e

xternally. See notes B and C on page 4 for details.

-8-

Notice that the waveform seems to be randomly dancing across the
screen, making it hard to study. We can fix this. Click on the
“trigger positive level” button and make sure the trigger bar is
in the position shown here. Notice that a small “-” appears on the
left of the display as you do so.

“Trigger positive level button

“-”

Trigger bar

Now its time to look at your electronic signal in a different way. The
oscilloscope features you have been using show you voltage
(amplitude) vs. time, now you will see voltage vs. frequency.
Engineers use expensive instruments called spectrum analyzers to
do this, but Winscope uses a mathematical transformation called
an FFT to do this. Set the Y1 gain control back to its default
position for now. Click on the 5ms/div button to display a wider
range, then click on the FFT button. Your display should be similar
to this:

5ms/div button FFT button

Y1 gain

control

default

position

The small slash “-” represents the trigger voltage, when the signal
reaches this voltage level it activates the display. This makes it
easy to observe a stream of pulses like you have now, and also to
record a single (non-repeating) pulse.

Move the adjustable resistor control (snap part RV) and watch how
it changes the waveform on the computer screen. Now you can
see how changing the adjustable resistor changes the time
between the pulses, which changes the tone of the sound you
hear.

The waveform you see here is the voltage across the speaker, the
peaks of the pulses occur when the transistors turn on and provide
current to the speaker. Changing the amplitude of the peaks
changes the loudness of the sound, changing their separation
changes the tone or “pitch” of the sound. The time scale and
trigger control features just described enable electronic engineers
and technicians to see the relationship betw

m on their oscilloscope

or

ef

v

a

w

.

een par

ts of a

-9-

You are seeing the frequency spectrum of your signal, up to 22kHz.
Notice that most of the energy is at the low frequencies (below
7kHz), and there is very little as you go higher.

The 1:1 gain mode does not apply to the FFT screen, so move the
Y1 gain control down to here so you can see the peak energy at
the low frequencies.

Y1 gain

control

level

Move the adjustable resistor control (snap part RV) and watch how
it changes the frequencies on the display.

Set the adjustable resistor control (snap part RV) to mid-range. In
addition to the 5ms/div and 0.5ms/div settings for the horizontal
scale, there is also a variable setting. See if you can set it so that
all the signal peaks line up with the grid lines, as shown.

Now you can see that the tone you hear is actually a range of
related frequencies combined together. The first peak is
considered to be the main signal (and it is usually but not always
the highest), the energy at all the other peaks determine the
waveform of the signal you see on an oscilloscope.

Now modify your circuit by placing the 0.1mF capacitor (C2) on top
of the 0.02mF capacitor (C1). By increasing circuit capacitance,
you lower the oscillation frequency and your display should now
look something like this:

Variable

setting

Frequency

As you can see, all the peaks are equally spaced in frequency.
Move your computer mouse directly over the first peak, the
software displays the frequency you are pointing at. Move the
mouse to the other peaks and you see they are multiples of the first
frequency

.

-10-

Now adjust the horizontal scale so the peaks line up with the
gridlines as they did before.

Horizontal scale

Notice that all the peaks went down in frequency by a
corresponding amount and many changed in amplitude, that is why
your ears hear a different sound. Notice also that in this case the
left-most frequency peak no longer is the highest in voltage (your
results may vary).

Now you can click on the FFT box to return to oscilloscope mode
and look at the waveform with the 0.1mF capacitor in the circuit. You
can observe it with the same settings as before for comparison, but
these settings usually work best:

-11-

Project #PC2

WARNING: Moving parts. Do not touch the fan or

!

motor during operation.

WARNING: Do not lean over the motor.

!

Screaming Fan PC

OBJECTIVE: To demonstrate storage mode.

Build the circuit shown. If continuing from the previous experiment
then close the Winscope program and run it again, to reset the
settings. Click on the On-Line button to activate, and turn on the
switch (snap part S1). Set Winscope to the settings shown below,
and move the lever on the adjustable resistor (snap part RV)
around to change the waveform and the sound. A sample
waveform is shown here, but the pattern and shape of the pulses
depends on the adjustable resistor setting.

WaveformOn-Line

button

Winscope has a mode that can display multiple scans at the same
time, called Storage mode. Set the adjustable resistor lever to a
low-middle position, place Winscope in this mode, and watch the
results.

Without Storage Mode

Storage

mode

With Stora

ge Mode

-12-

What you see here is the effect of timing variations on the trigger
used for synchronization. Turn off the trigger and you will see how
much variation there is without using the trigger:

Trigger

You can also use storage mode when in FFT mode, so turn it on
now.

Storage mode

You can use Storage mode on any of the other circuit waveforms if
desired.

Now turn off storage mode and turn on FFT mode to look at the
frequency spectrum, try the settings shown here.

Settings

ving the adjustab

Mo

le resistor le

ver will change the spectrum

shown.

-13-

In this way you can show the peak energy achieved at each
frequency. But this is only useful on a stable waveform, so if you
move the adjustable resistor lever now the signal will fill the screen
as the peaks move across the display.

Most oscilloscopes and spectrum analyzers have a storage mode
like this of some form.

Project #PC3

OBJECTIVE: To demonstrate wait mode with multiple colors.

Build the circuit shown. If continuing from the previous experiment
then close the Winscope program and run it again, to reset the
settings. Click on the On-Line button to activate, and turn on the
switch (snap part S1). Set Winscope to the settings shown on the
right, and move the lever on the adjustable resistor (snap part RV)
around to change the waveform and the sound. At some positions
there may be no sound. A sample waveform is shown here, but the
pattern and shape of the pulses depends on the adjustable resistor
setting.

Hissing Foghor n PC

On-Line

button

Settings

-14-

Place Winscope in Wait mode by clicking on the button for it, then
slowly press the On-Line button several times. Now turn off the
slide switch (snap part S1) and press On-Line again. Then turn the
switch back on. You see that in Wait mode Winscope scans
(“waits”) until it sees a waveform that exceeds the trigger level you
set, then stops. With a strong signal it will make one scan and then
stop, whereas if no signal is present it keeps scanning until it finds
one. You could use this to sense when someone has turned on the
circuit.

Now your display should look something like this:

Storage mode

On-Line

button

Wait

mode

You can change the color of the waveform: select <Options>, then
select <Colors>, then select <Y1 Trace>. Now select the color you
like and click <OK>.

Now we will combine the wait and storage modes to display several
waveforms that this circuit can create. You should have the circuit
on with the adjustable resistor at mid-range and Winscope in Wait
mode. Now turn on Storage mode. Now change the color of the
Y1 trace. Move the adjustable resistor control lever a little, then
press On-Line once to record another waveform. Now change the
color of Y1 again. Move the resistance control again and press On­Line once. Change the Y1 color, adjust the resistance and press
On-Line. Change the Y1 color, adjust the resistance and press On-

eral more times if you like. Note that at some

Line

Do this se

.

v
resistance settings there may be no waveform to trigger on, move
the resistance control until it does.

-15-

Now you see the range of waveforms this circuit can create, all at
the same time. Engineers often do this to compare signals during
analysis.

You can use Wait mode and different colors like this on the other
circuits if you like.

Now turn off storage mode and turn on FFT mode to look at the
frequency spectrum, try the

settings shown here. Wait mode does

not apply in FFT mode, so it has no effect here. Moving the
adjustable resistor lever will change the spectrum shown.

Settings

Project #PC4

OBJECTIVE: To look at the output signal from a circuit that makes alarm sounds.

Light & Sounds PC

Build the circuit and connect the Winscope PC-interface cable as
shown, the cable should still be connected to the microphone input
on your computer.

-16-

If continuing from the previous experiment then close the Winscope
program and run it again, to reset the settings. Then use the mouse
to set it up as shown here, and turn on the switch (snap part S1).
Click on the On-Line button to activate.

On-Line

button

Set up

Click on the FFT button to look at the frequency spectrum.
Also set the amplitude and time scales (really amplitude and
frequency scales in FFT mode) to be as shown here.

Time scales

Amplitude

FFT button

You should see a waveform similar to that shown here, but it will be
constantly changing. This is because the siren sound you hear is
not a continuous tone but instead is constantly changing. Note the
differences in the waveshape for this circuit compared to the circuit
in Project PC1.

Your picture may appear different due to variations in the
microphone input designs between computers. See the notes on
page 4 for details.

-17-

You should see a fuzzy spectrum similar to that shown here, but it
will be constantly changing. This is because the siren sound you
hear is not a continuous tone but instead is constantly changing
frequency, and it spends more time at some frequencies than at
others. Note the differences in the spectrum for this circuit
compared to the circuit in Project PC1.