Transistor Amplifier – Emitter Follower
This a Emitter Follower circuit. This circuit is also called The common collector junction transistor amplifier. This amplifier has little voltage gain, less than one, because the emitter voltage is forced to drop about 0.6V below the base. This circuit is used for impedance matching and power or current gain. Here is the schematic diagram of the circuit:
The signal source work easy because the output impedance is much lower than the input impedance. it could happen because the emitter current is 100 times larger than base current. This circuit can buffer the signal source from that low impedance. Beside that, The output impedance of this circuit match the low impedance load.