User Manual

Build the circuit and turn the slide switch (S1). Press and hold down any
green key on the keyboard (U26), and see what happens.
Project 143 Color Keyboard
Project 145 Color Keyboard (III)
-69-
Project 144 Color Keyboard (II)
Modify the preceding circuit by
adding the adjustable resistor
(RV) as shown here. Turn the
slide switch (S1). Move the lever
on the adjustable resistor around;
best effects are when it is to the
left. Press keys on the keyboard
(U26) at the same time. You will
see some cool effects.
Build the circuit and turn the slide switch (S1). Press and hold down any
green key on the keyboard (U26), and see what happens.
Project 146 Color Keyboard (IV)
Modify the preceding circuit by
adding the 100W resistor (R1) and
replacing the 1mF capacitor (C7)
with the 470mF capacitor (C5), as
shown here. Turn the slide switch
(S1) to see some cool effects.
Press any of the blue keys for
more effects. Pressing the green
keys won’t do anything.