ABSTRACT
This chapter deals with sinusoidal waveforms. There are several important power relationships in designing an output stage. Both the average and peak power dissipated in the output devices must be considered when determining their type and number. The average power dissipated controls the heat-sink design. In most amplifier types the power dissipation varies strongly with output signal amplitude as it goes from zero to maximum, so it presents as a graph of dissipation against the fraction of the available rail-to-rail output swing that is, the output voltage fraction. For a resistive load the peak power is fixed and easily calculable. With a reactive load the peak power excursions are less easy to determine but highly important because they are increased by the changed voltage/phase relationships in the output device. Power dissipations are plotted against the input voltage fraction. Peak powers are taken at 0.95 of full output, average power at whatever output fraction gives maximum dissipation.
