Instructions

49
Game and Knowledge in Electronics-Lab
You have already found out that your pencil
can conduct electricity well. Even a thick
line drawn with a pencil on a piece of
paper conducts some electricity. The shorter
the distance, the lower is the impedance;
similar to your potentiometer. You can use
this to build an electronic organ. You will
48
Pencil organ
need the loudspeaker and three free wires,
with which you can touch the pencil line.
The programme is started with the wire
connections A-B and C-E.
Draw a long, thin line with a pencil on a
piece of paper. It is not enough to be able
to see the line clearly. There needs to be
enough graphite on the paper so that the
individual particles touch each other.
Only then will electricity be able to flow. But
the electrical impedance is still greater than
in your variable resistor.
Touch the end of the line with one cable
and the middle of the line with the other.
You will hear a sound. Change the position
on the line and the sound will change too.
The longer the distance on your self-made
resistor, the lower the tone. If the tone seems
to be too low in general, you need to draw
the line thinker to decrease the impedance.