EXPERIMENT 62
Morse telegraph
Before the internet or telephone, people
sent messages by Morse code through
wires running between cities and conti-
nents. After radio technology was invented
those message were sent wirelessly around
the world.
Would you like to build a Morse telegraph
to render dots and dashes audible? With a
little dexterity, you can certainly build this
kind of device. You already know the Morse
code symbols from page 15.
HERE’S HOW
Assemble two circuits supplied with elec-
tricity from the battery case. One, shown in
figure 1, will power the motor and contain
the two-way switch and two I-connectors.
The other will supply current to the horse-
shoe electromagnet, and it will have a
push button so you can switch the current
on and off.
Again, attach the metal prong fastener
strip to the hanger device so that it can
swing freely, but without slipping, at a
height of about three centimeters (figure 2).
Tape the horseshoe electromagnet to the
battery case so it’s at just the right height
(figure 3).
Continued on the next page…
Electromagnetism
61
1
2
3
TIP!
If you can get a few
meters of dual-cable wire
from an electronics or
hardware store, you may
be able to figure out how
to install this system
between two different
rooms in your house.
Содержание Electricity and Magnetism 620417
Страница 1: ...TITELSEITE U1 EXPERIMENT MANUAL ...
Страница 68: ......