Elenco Projects 102-305 - Manual (Page 45)

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Project #228 Morse Code Generator
OBJECTIVE: To make a Morse code generator and learn to
generate code.
Project #229
LED Code
Teacher
OBJECTIVE: A method of
learning the Morse code without
all the noise.
Use the circuit from project #228
shown above. Replace the
speaker with a 100
Ω resistor (R1)
so you can practice generating
the Morse code without the loud
speaker. Have someone transmit
code and watch the LED. Tell
them the letter or number after
each is generated. When you
have learned code, replace the
speaker.
OBJECTIVE: To make a ghost
like special effect from the Morse
code generator.
Project #231
LED &
Speaker
OBJECTIVE: To improve
Morse code skills and visual
recognition. OBJECTIVE: To make an
oscillator that only a dog can
hear.
Project #230
Ghost Shriek
Machine
Use the circuit from project #228
shown above, but change the 1k
Ω
resistor (R2) to a 10k Ω resistor
(R4), and 0.1 μ F capacitor (C2) to
the whistle chip (WC). While
holding the press switch (S2)
down, adjust both the adjustable
resistor (RV) and the whistle chip
for a ghost like sound. At certain
settings, sound may stop or get
very faint.
Use the circuit from project #228
shown above. Try and find a
person that already knows the
Morse code to send you a
message with both sound and
LED flashing. Try in a dark room
first so LED (D1) is easier to see.
Morse code is still used by many
amateur radio operators to send
messages around the world.
Use the circuit from project #228
shown above, but change the 1k
Ω
resistor (R2) to the 100 Ω resistor
(R1). While holding down the press
switch (S2), move the slider on the
adjustable resistor (RV) around.
When the slider is near the 100
Ω
resistor you won’t hear any sound,
but the circuit is still working. This
oscillator circuit is making sound
waves at a frequency too high for
your ears to hear. But your dog may
hear it, because dogs can hear
higher frequencies than people can.
Project #232
Dog Whistle
When you press down on the press switch (S2) you will hear a tone.
By pressing and releasing the press switch you can generate long and
short tones called Morse code. For International code, a short tone is
represented by a “+”, and a long tone by a “–”. See the chart below
for letter or number followed by code.
A + –
B – + + +
C – + – +
D – + +
E +
F + + – + G – – +
H + + + +
I + +
J + – – –
K – + –
L + – + + M – –
N – +
O – – –
P + – – +
Q – – + –
R + – + S + + +
T –
U + + –
V + + + –
W + – –
X – + + – Y – + – –
Z – – + +
1 + – – – –
2 + + – – –
3 + + + – –
4 + + + + – 5 + + + + +
6 – + + + +
7 – – + + +
8 – – – + +
9 – – – – +
0 – – – – –