Introduction to engineering systems
A simple practical processing system is shown in Figure 43.1 comprising an input, an output and an energy source, together with unwanted inputs and outputs that may, or may not, be present.
A typical public address system is shown in Figure 43.2.Amicrophone is used as an input transducer to collect acoustic energy in the form of sound pressure waves and convert this into electrical energy in the form of small voltages and currents. The signal from the microphone is then amplified by means of an electronic circuit containing transistors and/or integrated circuits before it is applied to a loudspeaker. This output transducer converts the electrical energy supplied to it back into acoustic energy.