Functional diagrams showing the processes that occur within an article and within individual components are used in studying the functional capabilities of the article, as well as in installation, adjustment, control, and repair work.
Electric circuit theory includes the study of all aspects of electric circuits, including analysis, design, and application. In electric circuit theory the fundamental quantities are the potential differences (voltages) in volts between various points, the electric currents in amperes flowing in the several paths, and the parameters in ohms or mhos which describe the passive elements. Other important circuit quantities such as power, energy, and time constants may be calculated from the fundamental variables. For a discussion of these parameters.
Often, though, they are used for other purposes, such as to route signals in logic circuits. Transistors can be considered the workhorses of modern electronic circuits, and consequently many types of transistors have been developed, among which the most widely used are the bipolar junction transistor (BJT), the junction field-effect transistor (JFET), and the metal oxide silicon field-effect transistor (MOSFET).
Circuit diagrams can be classified into four types: schematic diagrams, wiring diagrams, basic diagrams, and design diagrams. Schematic diagrams depict the functional components of an electric circuit and their interconnections. Wiring diagrams (for connections and junctions) show the arrangement of circuit components and of connecting wires.