Schematic diagrams define the components of the article that constitute a complete set and the interconnections between components; they usually give a detailed representation of the working principle of the article and may serve as a basis for developing other design documents, such as electrical installation blueprints and specification sheets.
If a system has two or more input variables and two or more output variables, simultaneous equations for the output variables can be written. In general, when the number of inputs and outputs is large, the simultaneous equations are written in matrix form.
Transistors are basic to the operation of electronic circuits. Bipolar transistors have three terminals, designated as the base B, the collector C, and the emitter E. These terminals connect to two diode junctions, B-C and B-E, these forming back-to-back diodes. The B-E junction is often forward-biased, in which case its voltage is about 0.7 V, while the B-C junction is reverse-biased for linear operation.
A board whose surfaces have printed current conductors with contact areas, which are used to connect components mounted on the boards according to the circuit diagram of a functional subassembly for electric or radio apparatus, and also have plated circuit holes and nonplated mounting holes. There are about 200 methods for making printed circuit boards; among the most important are the photochemical, photoelectrochemical, and offset-electrochemical methods. The methods differ in the means of producing the conductive coating or the form in which the pattern of the printed conductors is realized.