Elenco Circuit Maker Sound Plus 200 - Manual (Page 22)

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Project #29
Place the 3-snap as shown and turn the switch (S1) on. There should
be no sound since the 3-snap is not touching point A or B. Now rotate
the 3-snap to points A or B and the speaker sounds.
Today most device use electric switches. Until the early 1970s,
mechanical switches were used as channel selectors on television and
other electronic equipment.
Build the circuit shown. Pretend the 2-snap wire marked fuse in the
drawing on the left is a device that will open the circuit if too much current
is taken from the battery. With the slide switch (S1) turned on, remove
the 2-snap wire marked fuse and notice how the lamp (L4) shuts off. Until
the fuse is replaced, the open circuit path protects the electronic parts.
If fuses did not exist, many parts could get hot and even start fires.
Replace the 2-snap wire and the lamp should light again.
Some fuses contain special wires that break when too much current
flows, and need to be replaced after they activate. Other fuses can be
reset by flipping a switch.
Many electronic products in your home have a fuse that will open when
too much current is drawn. Can you name some?
The Fuse Project #28
Actual fuse - if too much current flows then the
wire inside melts to break the circuit.
Sound by
Rotary Switch
CM-200_Manual_031914.qxp_CM-200_Manual_031914 4/2/14 12:04 PM Page 22