User manual

13
The larger 330 kΩ resistor delivers a current of approximately
0.015 mA and will thus run four years on just one battery.
Saving power pays!
6 Amplify current
The most important component of this study package is the
transistor. You should not mix up the three terminals. They
are called emitter (E), base (B) and collector (C). The emitter
connects to the negative terminal of the battery. Therefore,
the transistor’s flat side with the label should point to the left.
The experiment demonstrates the typical behavior of a tran-
sistor. When both switches are turned on, the green LED is
dimly lit, but the red one is very bright. If you turn off the
green LED with the right switch, the red LED will also go off.
The transistor acts like a switch. A small amount current
flowing through the base terminal causes a large current flow
to the collector.
Transistors are essential components in all areas of electron-
ics. They are used in radios and televisions and also in smart-
phones and computers –transistors are built-in everywhere.
That’s why it’s important to understand exactly how a transis-
tor works. The circuit diagram also shows an important basic
element of a computer, namely the AND circuit. Only if switch
1 (S1) AND switch 2 (S2) are set to ON, the red LED will turn
on. If one or both are set to off, then it will stay off. You can