The transistor configuration here is referred to
as the common-emitter configuration. Unlike the
emitter follower, the common emitter has voltage
gain. To figure out how this circuit works,
first set VC = 1⁄2VCC to allow for maximum swing
without clipping. Like the emitter follower,
again pick a quiescent current IQ to start with.
To set VC = 1⁄2VCC with a desired IQ, use RC, which
is found by Ohm’s law: