EIM Lab-OnThe-Go Manual page 23

Prepare Components and Tools CH 3
The electrical symbol presented below shows that BJTs are three terminal
devices: (B) stands for Base, (C) stands for Collector and (E) stands for
Emitter. The NPN, or N-type transistor has an arrow pointing outward from
the base, while the PNP, or P-type transistor has an arrow pointing inward
towards the base.
A BJT can be used as a current-controlled switch in a DC circuit. The
Collector-Emitter side of a BJT can function as a channel through which a
larger current can pass, while the Base can be thought of as a valve that
controls the current flow through this channel. By controlling the current
flowing into the Base, the amount of current flowing through the Collector-
Emitter channel can be controlled.
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