Elenco Projects PC1-PC73 - Manual (Page 41)

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Project #PC28
Old-Style Typewriter PC
OBJECTIVE: To build a circuit that sounds like a typewriter.
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.
Turn the motor (snap part M1) slowly with your fingers and watch
the waveforms generated. They are very erratic and unpredictable.
A sample is shown on the upper right.
Settings
Turn on FFT mode to look at the frequency spectrum, try the
settings shown here.
You can also turn on Storage
mode to see the peaks recorded
as you turn the motor, a sample
of this is at right.
Settings Storage mode