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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® 95 or later. 2. A working microphone input port. 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.
Looking at Electronic Signals using the WINSCOPE Software Electronic engineers use specialized test equipment to electronic signals and make performance measurements. use an oscilloscope to look at the shape of the signal and spectrum analyzer to look at its frequency content. equipment is specialized and usually very expensive. “see” They use a This The Winscope software simulates this equipment using your personal computer.
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 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.
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).
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.
Project Listings Project # PC1 PC2 PC3 PC4 PC5 PC6 PC7 PC8 PC9 PC10 PC11 PC12 PC13 PC14 PC15 PC16 PC17 PC18 PC19 PC20 PC21 PC22 PC23 PC24 PC25 PC26 PC27 PC28 PC29 PC30 PC31 PC32 PC33 PC34 PC35 PC36 PC37 Description Pitch PC Screaming Fan PC Hissing Foghorn PC Light and Sounds PC Light and Sounds PC (II) Light and Sounds PC (III) Light and Sounds PC (IV) Light and Sounds PC (V) Light and Sounds PC (VI) Modulation Filtering AM Radio PC Space War PC Microphone Speaker Microphone Symphony of Sounds PC Doorbell
Project #PC1 Pitch PC OBJECTIVE: To look at the output signal from a transistor oscillator while changing the pitch of the sound. 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.
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 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.
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 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.
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. 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.
Now adjust the horizontal scale so the peaks line up with the gridlines as they did before. Horizontal scale 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: 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.
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.
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: You can also use storage mode when in FFT mode, so turn it on now. Storage mode Trigger 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.
Project #PC3 Hissing Foghorn PC 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.
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.
Project #PC4 Light & Sounds PC OBJECTIVE: To look at the output signal from a circuit that makes alarm sounds. 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.
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. 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.
Project #PC5 Light & Sounds PC (II) Project #PC6 Light & Sounds PC (III) Modify the circuit for project PC4 by connecting points X and Y on the snap diagram. Now the sound is a machine gun, it shuts off between bursts. Modify the circuit by removing the connection between X and Y and then make a connection between T and U. It makes a fire engine sound. Look at the waveform and frequency spectrum using the same settings as for project PC4, and compare them to those for the siren.
Project #PC9 Light & Sounds PC (VI) Look at the waveform in oscilloscope mode using the same settings as earlier in PC4. Replace the whistle chip with the speaker and remove the lamp. Compare the waveform you see now with that from the whistle chip. The amplitude of the waveforms are similar but yet the sound from the speaker is much louder, since the speaker is drawing more current. Build the circuit shown.
The waveform shown here is from humming into the microphone, notice how the tops of the pulses show a regular pattern of dips now. Look ahead to the Microphone project PC14 on page ??, and note the waveform shown there for humming into the microphone: If you talk into the microphone now you will get different patterns depending on what words you say, how loudly you say them, and your distance from the microphone.
You probably noticed that the width of the pulses in the pulse stream is constantly changing, that is because there is actually a second type of modulation occurring here. Press the key again and you hear a siren. A siren is not a stable tone but rather is constantly changing in frequency. Change the time scale to 0.5ms/div and observe the range of waveforms: Look back at the Light & Sounds project PC4 on page 16.
Project #PC12 AM Radio PC OBJECTIVE: To look at the output signal from an AM radio. Build the circuit shown and connect the PC-interface cable to the microphone input on your computer. Turn on the slide switch (snap part S1), tune the variable capacitor (snap part CV) to a local radio station that gives good reception, and set the adjustable resistor (snap part RV) to a comfortable volume. The integrated circuit (snap part U5) detects and amplifies the AM radio waves all around you.
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 the scale to 1:1 mode. Click on the On-Line button to activate. On-Line button 1:1 mode Click on the FFT button to look at the frequency spectrum. Set the time scale (really frequency scale in FFT mode) and amplitude scale to be as shown here.
Project #PC13 Space War PC OBJECTIVE: To look at the output signal from a circuit that makes space war sounds. 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 Time scale Set up Build the circuit shown and connect the PC-interface cable to the microphone input on your computer.
Click on the FFT button to look at the frequency spectrum for these signals. For best viewing set the amplitude and time scales (really amplitude and frequency scales in FFT mode) to be as shown here. Time scale FFT button Amplitude scale Project #PC14 Microphone OBJECTIVE: To see what your voice looks like in electrical form. Build the circuit shown and connect the PC-interface cable to the microphone input on your computer.
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 Winscope, and turn on the switch (snap part S1). On-Line button Y1 gain control Click on the FFT button to look at the frequency spectrum for these signals. Try the amplitude and time scales shown here to start, but your best settings will depend on what sounds you make, how loud you speak, and how close you are to the microphone.
mode) have nearly all of their energy at a specific frequency like for the hum. “Square” or “rectangular” looking waveforms (like in Project PC1) and most music have a series of mathematicallyrelated peaks, while “random” waveforms (like from blowing into the microphone or several people talking at the same time) have a frequency “blob” instead of distinct peaks. Project #PC15 Speaker Microphone Connect the PC-interface cable directly onto the speaker as shown; no other parts are needed here.
Project #PC16 Symphony of Sounds PC Due to the combination of sounds, the waveform is complex. Set Winscope to the settings shown, or as you prefer. Settings OBJECTIVE: To see the waveforms for a complex signal. Click on the FFT button to look at the frequency spectrum for the signal. Try the settings shown here, or as you prefer. Settings The Symphony of Sounds project combines waveforms from the Music, Alarm, and Space War integrated circuits. Build the circuit shown.
Project #PC17 Doorbell PC OBJECTIVE: To look at the output of a musical circuit. 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 slide switch (snap part S1). Try the settings shown here. When the music stops, press the press switch (part S2) and it will resume.
Project #PC18 Periodic Sounds PC 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 slide switch (snap part S1). Try the settings shown here. Settings OBJECTIVE: To look at the output of an alternately changing circuit. The oscilloscope display alternates between 2 waveforms, the one shown here and the one on the next page.
Now change to FFT mode to look at the frequency spectrums corresponding to the 2 waveforms above. Try the settings shown here. Settings Project #PC19 Lasting Doorbell PC OBJECTIVE: To look at the output of an alternately changing circuit. This is the spectrum for the oscilloscope waveform shown on the preceding page, which alternates between pulses and flat. Because of the transition between pulses and flat, the spectrum is the irregular shape shown here.
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, turn on the switch (snap part S1), and press the press switch (part S2). Try the settings shown here. Now change to FFT mode to look at the frequency spectrum as the sound fades away. Try the settings shown here.
Project #PC20 Space War Flicker PC OBJECTIVE: To continuously show the patterns created by the space war IC. Click on the On-Line button to activate, and turn on the switch (snap part S1). Set Winscope to the settings shown below. The signal from the alarm IC (snap part U2) causes the space war IC (part U3) to step through the 8 different patterns it can create. A sample waveform is shown here.
Project #PC21 Buzzing in the Dark PC OBJECTIVE: To build a circuit that buzzes. Build the circuit shown. If continuing from the previous experiment then close the Winscope program and run it again, to reset the settings. Set Winscope to the settings shown below and click on the On-Line button to activate. A sample waveform is shown here. Settings The actual waveform will vary depending on how much light is shining on the photoresistor (snap part RP).
Turn on FFT mode to look at the frequency spectrum, try the settings shown here. Settings Project #PC22 Trombone PC OBJECTIVE: To build a circuit that sounds like a trombone. Now put the 0.02mF capacitor back in place of the 0.1mF capacitor to compare its spectrum. A sample is on the left, with the same Winscope settings as above. As with the oscilloscope mode, its spectrum is weaker and more erratic.
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. At some positions there may be no sound. A sample waveform is shown here.
Project #PC23 Sound Pulse Oscillator PC 0.5ms/div scale Settings OBJECTIVE: To build a pulse oscillator. LED (D1) is on layer 1 directly beneath the speaker (SP). You can also change to the 0.5ms/div scale to take a closer look at one of the pulses, shown on the right: Turn on FFT mode to look at the frequency spectrum, try the settings shown here. Settings Build the circuit shown. If continuing from the previous experiment then close the Winscope program and run it again, to reset the settings.
Project #PC24 High Pitch Bell PC Settings OBJECTIVE: To build a high pitch bell. Turn on FFT mode to look at the frequency spectrum, try the settings shown here. Settings 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 hold down the press switch (snap part S2). Set Winscope to the settings shown on the upper right. A sample waveform is shown on the upper right.
Project #PC25 Tone Generator PC Turn on FFT mode to look at the frequency spectrum, try the settings shown here. Settings OBJECTIVE: To build a high frequency oscillator. 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. Set Winscope to the settings shown below. A sample waveform is shown here.
Project #PC28 Old-Style Typewriter PC Settings OBJECTIVE: To build a circuit that sounds like a typewriter. Turn on FFT mode to look at the frequency spectrum, try the settings shown here. Settings 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. Set Winscope to the settings shown on the upper right.
Project #PC29 Transistor Fading Siren PC OBJECTIVE: To build a siren that slowly fades away. This display (at the same settings) shows the siren when it has almost faded out. The waveform has become weak and sometimes erratic. Turn on FFT mode to look at the frequency spectrum, try the settings shown here. The display on the left shows the signal just after pressing the press switch and on the right shows it just before it fades out. Settings Build the circuit shown.
Project #PC31 Police Siren Amplifier PC OBJECTIVE: To show the output of an amplifier. Build the circuit shown and set Winscope to the settings shown below. The siren sound is very loud. In most cases the waveform will have flat edges on the top and bottom, indicating the voltage is too high for the microphone input stage on your computer and is being distorted. You may sometimes correct for this if you like by reducing the volume control of your microphone input (see p.
Project #PC33 Space War Amplifier PC Build the circuit shown and use the same settings as in PC31 to view the waveform. Press the switch (S2) to change the sounds and waveform. -43- Project #PC34 Adjustable Tone Generator PC Build the circuit shown, and try the settings below. Move the adjustable resistor lever to change the frequency. A sample waveform is shown here.
Try these settings to see the spectrum: Project #PC38 Adjustable FM Radio PC OBJECTIVE: To show the output of an FM Radio. Project #PC35 Adjustable Tone Generator PC (II) Modify the circuit for project PC34 by placing the 0.02mF capacitor (C1) on top of the whistle chip (WC). Look at the waveform and frequency spectrum using the same settings as for project PC34, the frequency is lower now. Project #PC36 Adjustable Tone Generator PC (III) Modify the circuit for project PC34 by placing the 0.
Project #PC39 Transistor AM Radio PC (II) Project #PC40 Playback & Record PC OBJECTIVE: To show the output of an AM Radio. OBJECTIVE: To show the waveforms for music and your voice. Turn on the switch and adjust the variable capacitor (CV) for a radio station, then adjust the loudness using the adjustable resistor (RV). Use the same Winscope settings as for project PC12 (AM radio) to view the waveform and frequency spectrum.
Use Winscope to view the waveform and frequency spectrum when playing back your recording and music. A sample music waveform is shown here. Sample music waveform Project #PC41 Power Amplifier Playing Music IC OBJECTIVE: To show how high amplification can distort music. Build the circuit shown. Turn on the slide switch (S1), you hear a beep signaling that you may begin recording. Talk into the microphone (X1) up to 8 seconds, and then turn off the slide switch (it also beeps after the 8 seconds expires).
This recorder IC circuit works the same as in project PC40 except that the power amplifer IC (U4) used here makes the sound much louder than in project PC40. If viewed with the same Winscope settings as in PC40, then the waveform appears as shown below. The output from the recorder IC has not changed, but the flat edges at the top and bottom of the waveform indicate that the higher amplification is distorting the sound.
Project #PC43 Oscillation Sounds PC You may look at a pulse close-up by changing the time scale and slightly adjusting the delay, as shown. Time scale Delay OBJECTIVE: To view the output of an oscillator circuit. You may look at the frequency spectrum on your own if desired. Project #PC44 Build the circuit and try the settings shown here. This circuit produces a series of pulses (shown below), representing when the transistor is activated.
Project #PC47 Oscillator Sounds PC OBJECTIVE: To view the output of an oscillator circuit. Project #PC48 Oscillation Sounds PC (II) Using the circuit from PC47, install the whistle chip on top of capacitor C1. Notice how the spacing between the pulses has changed. Project #PC49 Whistle Chip Sounds PC OBJECTIVE: To view the output of an oscillator circuit. Build the circuit and try the settings shown.
Build the circuit and try the settings shown. You may try other settings to zoom in or look at the frequency spectrum. Settings Project #PC53 Bird Sounds PC OBJECTIVE: To view the output of an oscillator circuit. Project #PC50 Whistle Chip Sounds PC (II) Connect the whistle chip (with the PC-interface cable still connected across it) across points B & C. The circuit oscillates in short intervals. Project #PC51 Build the circuit and try the settings shown.
Project #PC54 Bird Sounds PC (II) Replace the 100mF capacitor (C4) with the 10mF capacitor (C3). The frequency of the oscillator is the same as before (and so the pulses look the same), but the oscillator activates in shorter intervals (so the bursts of pulses are shorter but closer together). You could use the 470mF capacitor to increase the oscillation interval. Project #PC55 Electronic Cat PC OBJECTIVE: To view the output of an oscillator circuit. Build the circuit and try the settings shown.
Project #PC59 Variable Oscillator PC Build the circuit and try the settings shown. Move the adjustable resistor lever to change the pitch of the sound and pulse separation in the waveform. Settings OBJECTIVE: To view the output of an oscillator circuit. Project #PC60 Variable Oscillator PC (II) Connect the whistle chip across points A & B, then B & C, then D & E and observe how the waveform changes as the sound changes.
Project #PC63 Electronic Sound PC OBJECTIVE: To view the output of an oscillator circuit. Build the circuit and try the settings shown. Press the press switch to lower the frequency of the signal by increasing the capacitance in the oscillator. You can replace the 0.1mF capacitor C2 with the 10mF capacitor C3 (“+” on the right) to further lower the frequency of the tone. You may try other settings to zoom in or look at the frequency spectrum.
Project #PC65 Siren PC Note: Although the amplitude of the pulses appears to be varying across the screen (the wider time scale shown below shows this better), this is an illusion caused by the way Winscope measures the signal. The amplitude of the pulses is not really varying. OBJECTIVE: To view the output of a fading siren circuit. Build the circuit and try the settings shown. Flip on the slide switch and press the press switch for a few seconds and release.
Project #PC66 Drawing Resistors PC OBJECTIVE: To draw your own resistors. Project #PC67 Electronic Noisemaker PC OBJECTIVE: To view the output of an oscillator circuit. Use the circuit from the Drawing Resistors project #516, but connect the PC-interface cable across the speaker. Use a pencil to draw the shapes shown in projects #516-518, as per the directions given in those projects.
Project #PC69 Bee PC Sample frequency spectrum: Settings OBJECTIVE: To view the output of an oscillator circuit. Sample waveform: Settings You can replace the 0.1mF capacitor C2 with the 10mF capacitor C3 (“+” on the right) to change the sound. Project #PC68 Electronic Noisemaker PC (II) Replace the 10KW resistor R4 with the 100KW resistor R5. Now you change the frequency by changing the resistance in the oscillator.
Build the circuit and press the press switch a few times, you hear cute sounds like a bumble bee. Use Winscope to see how the waveform fades away after you release the switch, and try storage mode as shown here. Time scale Settings Storage mode You may replace the 0.02mF capacitor C1 with 0.1mF capacitor C2 or 10mF capacitor C3 (“+” on the right) to change the sound, but you may want to change the time scale.
Project #PC72 Space War Music Combo PC Project #PC73 Sound Mixer PC OBJECTIVE: To view the output of the combined outputs from the space war and music integrated circuits. OBJECTIVE: To view the output of the music and alarm integrated circuits. Build the circuit and try the settings shown. Turn it on, press the press switch (S2) several times, and wave your hand over the photoresistor (RP) to view all the sound combinations. Compare the waveform and spectrum to the alarm IC combo circuit.
IMPORTANT NOTICE Disclaimer Information Oscilloscope for Windows95® or newer, version 2.51. OSCILLOSCOPE IS SUPPLIED TO YOU AS IS, AND IN NO CASE IS THE AUTHOR OF THIS PROGRAM RESPONSIBLE FOR PERSONAL INJURY, HARDWARE AND/OR DATA DAMAGE, PROPERTY DAMAGE OR PROFIT LOSS ARISING FROM USE OR INABILITY TO USE THIS SOFTWARE. THERE IS NO GUARANTEE IMPLIED OR OTHERWISE TO THE FITNESS OF THIS OSCILLOSCOPE PROGRAM FOR ANY PARTICULAR PURPOSE. THIS SOFTWARE IS NOT INTENDED FOR INDUSTRIAL OR COMMERCIAL USE.
