User Manual

Use either of the two preceding
circuits, but reverse the connection
to the programmable fan (M8). The
fan still spins, but it does not
display any messages.
Project 90
Slow-Fast
Fan
!
WARNING: Moving parts. Do not
touch the fan while it is spinning.
Project 91 Different Sounds
Build the circuit as shown and turn the slide
switch (S1) on. Press the A, B, and C buttons on
the selector (S8) to make different sounds.
-40-
Turn on the slide switch (S1). The
programmable fan (M8) spins and may slowly
display messages. Push the press switch (S2)
to speed up the fan and slowly display
messages.
Add a blue jumper wire
across points A & B. Now it
is a little faster when S2 is
not pressed, and messages
on it are brighter.
Project 89
Not So
Slow-Fast
Word Fan
Project 88 Slow-Fast Word Fan
This change bypasses Q2,
so there is less voltage drop
and a smaller “speed bump”.
When connected as shown
in this circuit, the Q1 & Q2
transistors act as a “speed
bump” to reduce the voltage
to the programmable fan,
slowing it down and making
the messages it can display
dim or off. Pressing S2
bypasses this speed bump
so the fan spins at full speed
and its message circuit can
operate properly.