Elenco Projects 1-101 - Manual (Page 35)

-34-
Project #69
OBJECTIVE: To combine effects from the space war and alarm
integrated circuits.
Build the circuit shown on the left and turn on the slide switch (S1).
Press and hold the press switch (S2) to make the lamp (L1) brighter.
Space War Siren
Quiet Water Alarm
OBJECTIVE: To sound an alarm when water is
detected.
Sometimes you want a water alarm that can be heard
but is not loud enough to be annoying or distracting,
so let's make one. We'll also put a light on it that
could be seen in a noisy room, in a real application
you could use a powerful light that would be easily
seen.
Build the circuit shown but initially leave the jumper
wires outside the cup. Turn on the slide switch (S1);
nothing happens. Place the jumper wires into a cup
of water and an alarm sounds and the light comes on.
Project #70