Manual

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42. Heart LED
Build the circuit, press the switch (62), the alarm
(78) will start in a low volume, while the LED (69)
turns on. Reverse the direction of the LED (69) and
the heart will not light and the alarm will not sound.
LEDs stand for Light Emitting Diodes, and diodes
are made of semiconductor material that only allows
signicant current to ow in one direction.
43. Morse Code Revisited
Build the circuit, hold the press switch (61), the
alarm (78) will start in a low volume, while the LED
(69) turns on. Release the press switch (61), then
the alarm (78) and the LED (69) will turn off at the
same time.
Try tapping in the Morse code below. This stands
for S.O.S, or Save Our Souls. If you ever hear this
sound then it means someone is in danger and
calling for help.
S O S
lll – – – lll