Transistor Pin Diagram. Transistor timer circuit diagram reference designators. It is interesting because using only one transistor.
Pre amplifiers circuit diagram using transistor. Pre amplifier circuit diagram using a transistor. This pin is connected internally to the collector of transistor and mostly a capacitor is connected between this terminal and ground.
Lets investigate this analogy further.
Extending the water analogy. As the voltage of the capacitor potentiometer increase the green led will turn. The common collector transistor configuration is also known as the emitter follower because the emitter voltage of this transistor follows the base terminal of the transistor. This pin has no special function what so ever.