Elenco Circuit Maker Sound Plus 200 - Manual (Page 41)

Project #81
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Project #80 Storing Electricity
Here is a combination with two transistors. This combination increases
the amplifying power. By changing the resistance, the current at the base
of the transistor is also changed. With this amplifying ability of the
combination, there is a greater change of current to the 4.5V lamp (L4).
This changes the brightness.
Turn the slide switch (S1) on and connect points A & B with a 2-snap
wire. The red LED (D1) will flash and the 100mF capacitor (C4) will be
charged with electricity. The electricity is now stored in the capacitor.
Disconnect points A & B. Connect points B & C and there will be a flash
from the 4.5V lamp (L4).
Lamp Brightness
Control
The capacitor discharges through the resistor to the
base of the NPN transistor (Q2). The positive current
turns on the transistor like a switch, connecting the
lamp to the negative (–) side of the batteries. The
light will go out after the capacitor discharges,
because there is no more current at the base of the
transistor.
CM-200_Manual_031914.qxp_CM-200_Manual_031914 4/2/14 12:04 PM Page 41