Project 103
Morse Code
This simple circuit can be used for communication. Press the
press switch (S2) in long and short bursts to make a pattern
of light flashes representing the dots and dashes shown in
the Morse Code table below. You can use Morse Code and
this circuit to send secret messages to some friends in the
room without others knowing what you’re saying.
If you have a strong flashlight or searchlight then you can
send messages to friends far away at night. During World
War II Navy ships sometimes communicated by flashing
Morse Code messages between ships using searchlights
(because radio transmissions might reveal their presence to
the enemy).
Years ago Indians would send messages to other tribes using
smoke signals and a special code.
Morse Code:
The forerunner of today’s telephone system
was the telegraph, which was widely used in the latter half
of the 19th century. It only had two states - on or off (that is,
transmitting or not transmitting), and could not send the
range of frequencies contained in human voices or music.
A code was developed to send information over long
distances using this system and a sequence of dots and
dashes (short or long transmit bursts). It was named Morse
Code after its inventor. It was also used extensively in the
early days of radio communications, though it isn’t in wide
use today. It is sometimes referred to in Hollywood movies,
especially Westerns. Modern fiber optics communications
systems send data across the country using similar coding
systems, but at much higher speeds.
MORSE 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 _ _ . .
Period . _ . _ . _
Comma _ _ . . _ _
Question . . _ _ . .
1 . _ _ _ _
2 . . _ _ _
3 . . . _ _
4 . . . . _
5 . . . . .
6 _ . . . .
7 _ _ . . .
8 _ _ _ . .
9 _ _ _ _ .
0 _ _ _ _ _
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