Elenco Snap Circuits SOUND &reg - Manual (Page 53)

Project 81 LED Keyboard Control Project 82
LED
Keyboard
Control (II)
Project 83
Photo LED
Keyboard
Control
Use the project 81 circuit, but replace
the 5.1k
W resistor (R3) with the
photoresistor (RP). Wave your hand
over the photoresistor or adjust the
room lighting to vary the amount of
light shining on the photoresistor, and
listen to the sounds. You can also
press keys on the keyboard (U26) to
add more sounds.
Build the circuit, and turn on the slide
switch (S1). You hear a sound pattern
that is synchronized with the color LED
(D8) flashing. You can press keys on the
keyboard (U26) to change the sound.
Use the preceding circuit, but
remove the 5.1k
W resistor
(R3). Now there is only sound
when you press keys on the
keyboard, and the sounds for
some keys are different.
Modify the project 81 circuit to match
this one. Turn on the slide switch (S1)
and move the lever on the adjustable
resistor (RV) to vary the sounds. You
can also press keys on the keyboard
(U26) to add more sounds.
Project 84 Adjustable
LED Keyboard
Control
The color LED turns off briefly when it
changes colors. Here the color LED
controls the keyboard through the
transistor (Q2), so when the color LED
turns off, the keyboard sound is also
turned off. This produces the sound
effects you hear.
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