Elenco Snap Circuits Motion - Manual (Page 72)

Project 147 One Way Electricity
Turn on the slide switch (S1). The red/yellow bicolor LED (D10) and light
motor (M7) are on. The adjustable resistor (RV2) sets the brightness
for D10.
When you turn off the slide switch, the lights on the light motor go off
immediately, but the red/yellow LED goes out slowly. RV2 sets how
quickly the red/yellow LED goes out.
Build the circuit and turn on the slide switch (S1). A siren will sound or
a light will shine if the circuit is tilted or moved. Experiment to see which
tilt angles activate which effects.
If the circuit does not shut off when left alone, then tilt it slightly so it
turns off.
Variants: You can change the sound by removing the 1-snap and 2-
snap wires that are at point A, or by moving them to be across points A
& B. You can also replace the color LED (D8) with the red/yellow bicolor
LED (D10, oriented in either direction).
Project 148 Tilt Sound & Light
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The NPN transistor (Q2) is used here as a diode. A diode
only lets electricity flow in one direction.
When you turn off the switch, the red/yellow LED stays on
for a little while as the 100mF capacitor (C4) discharges
through it. The “diode” lets electricity flow from the batteries
to the capacitor, but blocks electricity from flowing from the
capacitor to the light motor. Without the diode the red/yellow
LED and light motor would turn off immediately after the
switch is turned off, because the low resistance of the light
motor would discharge the capacitor in an instant.
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