Elenco Circuit Maker Skill Builder 125 - Manual (Page 45)

Project #84 Two-way Light Switch
Project #85 Electron Warehouse
Notice that a capacitor is not very
efficient at storing electricity - compare
how long the 470mF capacitor kept the
LED lit with how your batteries run all
of your projects! That is because a
capacitor stores electrical energy while
a battery stores chemical energy.
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Build the circuit on the left. Note that two of the 2-snaps are left
unconnected on one end because they will be used as switches in this
project. If you connect the free ends of each of these 2-snaps both to
the “high bar” or positions B in the figure or both to the “low bar” or
positions A in the figure, the LED (D1) lights up. But if you connect the
free end of one of the 2-snaps to the “high bar” and the free end of the
other 2-snap to the “low bar”, then the LED does not light up.
Build the circuit, then connect points B & C (use a 2-snap wire) for a
moment. Nothing appears to happen, but you just filled up the 470mF
capacitor (C5) with electricity. Now disconnect B & C and instead touch
a connection between A & B. The red LED (D1) will be lit and then go
out after a few seconds as the electricity you stored in it is discharged
through the LED and resistor (R2).
CM-125_Manual_031514.qxp_CM-125_Manual_031514 4/2/14 12:20 PM Page 45