A1 Electric Light 11 A30; A2 Controlling Electricity 11 B1 - Elenco Electronics SNAP CIRCUITS XP SCXP-50 Instruction Manual

Project A1
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Placement Level
Numbers
Project A2
Use the circuit built in project A1, but replace the
100W resistor (R1) with the 1kW resistor (R2). The
circuit works the same, but the red LED (D1) will
not be as bright.
Now replace the 1kW resistor with the 10kW
resistor (R4). The LED will be dim now.
Now replace the 10kW resistor (R4) with the 100kW
resistor (R5). The 100kW has very high resistance,
so you may not see any light from the LED.
Take the circuit into a really dark room or curl your
fingers around the LED to block the surrounding
light. Now you see that the LED is on, though very
dim.
-11-
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Electric Light
Snap Circuits uses electronic blocks that snap onto a clear plastic
®
grid to build different circuits. These blocks have different colors
and numbers on them so that you can easily identify them.
Build the circuit shown on the left by placing all the parts with a
black 1 next to them on the board first. Then, assemble parts
marked with a 2. Install three (3) "AA" batteries (not included) into
the battery holder (B3) if you have not done so already.
When you turn on the slide switch (S1), current flows from the
batteries through the switch, red LED (D1), and 100W resistor (R1),
and back to the batteries. Turning on the switch completes the
circuit. When the switch is off, the current can no longer flow back
to the battery, so the red LED goes out.
The red LED is just like the ones used in electronic products
throughout your home.
Controlling Electricity
Snappy says resistors are used to control or
limit the flow of electricity in a circuit. Higher
resistor values reduce the flow of electricity in a
circuit.
In this circuit, the resistors are used to adjust the
LED brightness, to limit the current so the
batteries last longer, and to protect the LED
from being damaged by the batteries.
What is Resistance? Take your hands and rub
them together very fast. Your hands should feel
warm. The friction between your hands converts
your effort into heat. Resistance is the electrical
friction between an electric current and the
material it is flowing through.