Elenco Snap Circuits® Deluxe Sound & Light Combo - Manual (Page 55)

Project 62 Brightness Control
Project 63
Resistors
Project 64 Resistors & LEDs
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 adjustable resistor is 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.
The adjustable resistor can be set for as low as 200W, or as high as
50,000W (50kW).
The R1 resistor (100W) will have
little effect, since it will be
dominated by the adjustable
resistor. Resistor R5 (100kW) is a
high resistance, which greatly
restricts the flow of electricity, so
the LED will be very dim or off.
Resistor R3 (5.1kW) will be in
between those.
Vary the brightness of the color LED (D8)
using the 500kW adjustable resistor (RV3).
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Build the circuit and turn on the slide switch (S1). Move the lever on the adjustable
resistor (RV) to vary the brightness of the light from the white LED (D6). If desired,
you may place any of the LED attachments (tower, egg, or fiber optic tree) on the LED.
Use the circuit built in project
62, but replace the 3-snap
with one of the yellow
resistors in this set (R1, R3, or
R5). Observe how each
changes the LED brightness
at different settings for the
adjustable resistor.
Use the circuits from projects 62 and 63, but replace the white
LED (D6) with the red LED (D1) or color LED (D8). Vary the
adjustable resistor lever and change the yellow resistors to see
how the light varies with each LED.
Project 65 Big Brightness
Adjuster
The 500kW adjustable resistor
(RV3) can be set for as low as
200W, or as high as 500,000W
(500kW), so the color LED will
only light on a small portion of
RV3’s range.
SCC-350_Manual_Part_A.qxp 7/25/14 2:40 PM Page 55