what is the voltage amplifier?
Amplification means increasing the amplitude (voltage or current) of a time-varying signal by a given factor, as shown here. In this example the amplifier has a voltage gain of 3; that is at any instant v o = 3 v i {\displaystyle v_{o}=3v_{i}\,}. An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the power of a signal (a time-varying voltage or current). An amplifier functions by using electric power from a power supply to increase the amplitude of the voltage or current signal.