Elenco Snap Circuits® Deluxe Sound & Light Combo - Manual (Page 154)

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Method A (easy): Spread some water on the table into
puddles of different shapes, perhaps like the ones
shown here. Touch the jumper wires to points at the
ends of the puddles. Small, narrow puddles may not
produce any sound.
Method B (challenging): Use a SHARP pencil (No. 2 lead is best) and draw
shapes, such as the ones here. Draw them on a hard, flat surface. Press hard
and fill in several times until you have a thick, even layer of pencil lead. Touch
the jumper wires to points at the ends of the drawings, then move them across
the drawing to vary the sound. You may get better electrical contact if you wet
the metal with a few drops of water. Wash your hands when finished.
Method C (adult supervision and permission required): Use some double-
sided pencils if available, or VERY CAREFULLY break a pencil in half. Touch
the jumper wires to the black core of the pencil at both ends.
Build the circuit and turn on the switch (S1). Initially set the lever on the
adjustable resistor (RV) to the left, then move it later to vary the range of
sounds that can be produced. Make your parts using either the water
puddles method (A), the drawn parts method (B), or the pencil parts method
(C). Touch the metal in the jumper wires to your parts and listen to the sound.
Long, narrow shapes
have more resistance
than short, wide ones.
The black core of
pencils is graphite,
the same material
used in the resistors.
Next, place the loose ends of the jumper
wires in a cup of water, make sure the
metal parts aren’t touching each other.
The water should change the sound.
The pitch may depend on the amount of
water, so see if adding more water to the
cup changes the sound.
Now add salt to the water and stir to
dissolve it. The sound should have
higher pitch now, since
salt water has less
resistance than plain
water.
Don’t drink any water used
here.
Project 365
Color Touch Light
Build the circuit. It doesn’t do anything,
and may appear to be missing
something. It is missing something,
and that something is you.
Touch points A & B with your fingers.
The color LED (D8) may be lit. If isn’t,
then you are not making a good
enough electrical connection with the
metal. Try pressing harder on the
snaps, or wet your fingers with water
or saliva. The LED should be on now.
If it isn’t very bright, then try going into
a dimly lit room.
Make Your Own Parts Project 364
SCC-350_Manual_Part_C.qxp 7/25/14 2:11 PM Page 42