Class A Power Amplifier
Great strengthening AC signals can be calculated with an AC signal circuit analysis theory. In an AC circuit analysis of all components of the capacitor C connected brief and the imaginary connecting the VCC to ground. With In this way a series of images 1-18 can be assembled into such picture 1-20. Resistors Ra and Rc is connected to GND and all short-circuited capacitor.
Typical class A amplifier, all output signals to work on active region. Amplifier type class A is called as a reinforcement that has fidelitas a high level. Provided the signal is still working in the active region, form the output signal will exactly match the input signal. But class A amplifier has low efficiency of approximately only 25% – 50%. It’s none other since the point Q is at point A, so that although there is no input signal (or when the input signal = 0 Vac) transistors to keep working in the active region with a constant bias current. Transistor is always active (ON) so that most of the sources of supply wasted power into heat. Since this is class A transistor amplifier should be augmented with extra cooling like heatsinks are more large.