 This circuit represents a two-stage capacitively coupled amplifier. This amplifier successfully increases the size of an AC input signal without inverting its phase or adding any DC voltage at the output. The amplifying process begins with the input of an AC signal. Upon entering the amplifier, the signal passes through an initial coupling capacitor, C1, which will strip it of any DC voltage. However, entering the circuit will add a small DC value of 1.8 volts. The signal next passes through the first transistor, Q1. This process produces a larger and inverted AC signal at the collector and also adds a DC voltage of 5 volts. Before reaching the second transistor, the signal passes through another coupling capacitor, C2, which also strips away the DC voltage. However, the signal will once again pick up a low DC voltage of 1.8 at the base of the second transistor. Passing through the second transistor, Q2, yields an AC signal that is increased again and is also back in phase with the original input signal. A third and final coupling capacitor, C3, filters the amplified signal once again of any residual DC voltage, resulting in a final amplified wave output that is in phase with the original input.