You can use square waves as test signals, too.
Square waves are produced by multivibrator
oscillators. Remember, you used this type of circuit
in previous projects. The name square wave comes
from the pattern produced by the signal on an
oscilloscope (shown below).
Build this circuit and you will hear the sound
produced by a square wave signal. You can vary the
pitch and the frequency of the signal by adjusting the
control. This varies the current supplied to the PNP
transistor bases.
Notes:
EXPERIMENT #124: SQUARE WAVE AUDIO OSCILLATOR
Schematic
-146-
Wiring Sequence:
o
77-75-48-27-124
o
28-81-83
o
40-107-84
o
41-106-76
o
119-42-45-80-EARPHONE
o
43-105-82
o
78-87-108-44
o
46-88
o
47-79-EARPHONE
o
121-122
Summary of Contents for EP-130
Page 11: ... 11 I ENTERTAINMENT CIRCUITS ...
Page 26: ... 26 II BASIC SEMICONDUCTOR AND COMPONENTS CIRCUITS ...
Page 36: ... 36 III LED DIGITAL DISPLAY CIRCUITS ...
Page 41: ... 41 IV A TOUR THROUGH DIGITAL CIRCUITS ...
Page 49: ... 49 V MORE ADVENTURES WITH DIGITAL CIRCUITS ...
Page 64: ... 64 VI THE WORLD OF TRANSISTOR TRANSISTOR LOGIC ...
Page 77: ... 77 VII APPLICATION CIRCUITS BASED ON THE OSCILLATOR ...
Page 88: ... 88 VIII BASIC OPERATIONAL AMPLIFIER CIRCUITS ...
Page 116: ... 116 IX MORE ADVENTURES WITH OPERATIONAL AMPLIFIERS ...
Page 129: ... 129 X COMMUNICATION CIRCUITS ...