Block diagrams that define each principal working component of an article or installation and the component’s purpose and interconnections are developed concurrently with the design of the article, before any other type of diagram; they are used in studying the article’s structure and functioning and are referred to when the article is in actual use.
Devices with an individual physical identity, such as amplifiers, transistors, loudspeakers, and generators, are often represented by equivalent circuits for purposes of analysis. These equivalent circuits are made up of the basic passive and active elements listed above.
One means of doing analog-to-digital conversion is to use a clocked counter that feeds a digital-to-analog converter, whose output is compared with the analog signal to stop the count when the digital-to-analog output exceeds the analog signal. The counter output is then the analog-to-digital output. The comparator for such an analog-to-digital converter is similar to an open-loop operational amplifier (which changes saturation level when one of the differential input levels crosses the other). Other types of analog-to-digital converters, called flash converters, can do the conversion in a shorter time by use of parallel operations, but they are more expensive.
Circuit diagrams show connectors between components and the locations of connectors and lead-ins; such diagrams also illustrate methods of laying out, mounting, and fastening conductors, cables, and piping. Others show external connections to other articles; such diagrams are used for the installation and operation of complex units. Diagrams showing the principal parts of a complex and the interconnections between subassemblies when the complex is installed and operated are designed primarily to give a general representation of the complex. Layout diagrams show the relative spatial arrangement of components.