Rain sensor
YOU WILL NEED
+ your humidity detector
+ and additional household
items: blotting paper, tape,
scissors
HERE’S HOW
1. Cut a piece of blotting paper about
5 x 10 cm in size and tape it to the
outside sill of a window in your
room.
2. Insert the bare ends of the long
wires A and B of the humidity
detector into the blotting paper
strip. Now you just have to wait for
a good rain.
When it starts to rain, the blotting
paper soaks up water and your
electronic circuit reacts to the
moisture — the green LED
lights up.
When the rain stops, the blotting
paper dries again, and the red LED
comes on.
C
WHAT’S HAPPENING?
EXPERIMENT 2
18
Содержание Electronics
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