Schematic
Encyclopedia
A schematic diagram represents the elements of a system
using abstract, graphic symbol
s rather than realistic pictures. A schematic usually omits all details that are not relevant to the information the schematic is intended to convey, and may add unrealistic elements that aid comprehension. For example, a subway map intended for riders may represent a subway station with a dot; the dot doesn't resemble the actual station at all but gives the viewer information without unnecessary visual clutter. A schematic diagram of a chemical process uses symbols to represent the vessels, piping, valves, pumps, and other equipment of the system, emphasizing their interconnection paths and suppressing physical details. In an electronic circuit diagram
, the layout of the symbols may not resemble the layout in the physical circuit. In the schematic diagram, the symbolic elements are arranged to be more easily interpreted by the viewer.
A semi-schematic diagram combines some of the abstraction of a purely schematic diagram with other elements displayed as realistically as possible, for various reasons. It is a compromise between a purely abstract diagram (e.g. the schematic of the Washington Metro) and an exclusively realistic representation (e.g. the corresponding aerial view of Washington).
software is often used.
In electronic design automation
, until the 1980s schematics were virtually the only formal representation for circuits. More recently, with the progress of computer technology, other representations were introduced and specialized computer languages were developed, since with the explosive growth of the complexity of electronic circuits, traditional schematics are becoming less practical. For example, hardware description language
s are indispensable for modern digital circuit
design.
Schematics for electronic circuits are prepared by designers using EDA (Electronic Design Automation
) tools called schematic capture
tools or schematic entry tools. These tools go beyond simple drawing of devices and connections. Usually they are integrated into the whole IC design flow and linked to other EDA tools for verification and simulation of the circuit under design.
In electric power systems design, a schematic drawing called a one-line diagram
is frequently used to represent substations
, distribution systems or even whole electrical power grids. These diagrams simplify and compress the details that would be repeated on each phase of a three-phase
system, showing only one element instead of three. Electrical diagrams for switchgear often have common device functions designate by standard function numbers
.
System
System is a set of interacting or interdependent components forming an integrated whole....
using abstract, graphic symbol
Symbol
A symbol is something which represents an idea, a physical entity or a process but is distinct from it. The purpose of a symbol is to communicate meaning. For example, a red octagon may be a symbol for "STOP". On a map, a picture of a tent might represent a campsite. Numerals are symbols for...
s rather than realistic pictures. A schematic usually omits all details that are not relevant to the information the schematic is intended to convey, and may add unrealistic elements that aid comprehension. For example, a subway map intended for riders may represent a subway station with a dot; the dot doesn't resemble the actual station at all but gives the viewer information without unnecessary visual clutter. A schematic diagram of a chemical process uses symbols to represent the vessels, piping, valves, pumps, and other equipment of the system, emphasizing their interconnection paths and suppressing physical details. In an electronic circuit diagram
Circuit diagram
A circuit diagram is a simplified conventional graphical representation of an electrical circuit...
, the layout of the symbols may not resemble the layout in the physical circuit. In the schematic diagram, the symbolic elements are arranged to be more easily interpreted by the viewer.
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A semi-schematic diagram combines some of the abstraction of a purely schematic diagram with other elements displayed as realistically as possible, for various reasons. It is a compromise between a purely abstract diagram (e.g. the schematic of the Washington Metro) and an exclusively realistic representation (e.g. the corresponding aerial view of Washington).
Electrical and electronic industry
In the electrical industry, a schematic diagram is often used to describe the design of equipment. Schematic diagrams are often used for the maintenance and repair of electronic and electromechanical systems. Original schematics were done by hand, using standardized templates or pre-printed adhesive symbols, but today Electrical CADElectrical CAD
Electrical CAD refers to software packages that allow an electrical engineer to create and manage electrical schematics. Advanced packages will not only manage electrical schematics, but also integrate functionalities such as cabinet and panel lay-outs and terminal management.The benefit of using...
software is often used.
In electronic design automation
Electronic design automation
Electronic design automation is a category of software tools for designing electronic systems such as printed circuit boards and integrated circuits...
, until the 1980s schematics were virtually the only formal representation for circuits. More recently, with the progress of computer technology, other representations were introduced and specialized computer languages were developed, since with the explosive growth of the complexity of electronic circuits, traditional schematics are becoming less practical. For example, hardware description language
Hardware description language
In electronics, a hardware description language or HDL is any language from a class of computer languages, specification languages, or modeling languages for formal description and design of electronic circuits, and most-commonly, digital logic...
s are indispensable for modern digital circuit
Digital circuit
Digital electronics represent signals by discrete bands of analog levels, rather than by a continuous range. All levels within a band represent the same signal state...
design.
Schematics for electronic circuits are prepared by designers using EDA (Electronic Design Automation
Electronic design automation
Electronic design automation is a category of software tools for designing electronic systems such as printed circuit boards and integrated circuits...
) tools called schematic capture
Schematic capture
Schematic capture or schematic entry is a step in the design cycle of electronic design automation at which the electronic diagram, or electronic schematic of the designed electronic circuit is created by a designer...
tools or schematic entry tools. These tools go beyond simple drawing of devices and connections. Usually they are integrated into the whole IC design flow and linked to other EDA tools for verification and simulation of the circuit under design.
In electric power systems design, a schematic drawing called a one-line diagram
One-line diagram
In power engineering, a one-line diagram or single-line diagram is a simplified notation for representing a three-phase power system. The one-line diagram has its largest application in power flow studies. Electrical elements such as circuit breakers, transformers, capacitors, bus bars, and...
is frequently used to represent substations
Electrical substation
A substation is a part of an electrical generation, transmission, and distribution system. Substations transform voltage from high to low, or the reverse, or perform any of several other important functions...
, distribution systems or even whole electrical power grids. These diagrams simplify and compress the details that would be repeated on each phase of a three-phase
Three-phase
In electrical engineering, three-phase electric power systems have at least three conductors carrying voltage waveforms that are radians offset in time...
system, showing only one element instead of three. Electrical diagrams for switchgear often have common device functions designate by standard function numbers
ANSI Device Numbers
In the design of electrical power systems, the ANSI Standard Device Numbers denote what features a protective device supports . These types of devices protect electrical systems and components from damage when an unwanted event occurs, such as an electrical fault...
.
Schematics in repair manuals
Schematic diagrams are used extensively in repair manuals to help users understand the interconnections of parts, and to provide graphical instruction to assist in taking apart and rebuilding mechanical assemblies. Many automotive and motorcycle repair manuals devote a significant number of pages to schematic diagrams.See also
- Energy Systems LanguageEnergy Systems LanguageThe Energy Systems Language , also referred to as Energese, Energy Circuit Language and Generic Systems Symbols, was developed by the ecologist Howard T. Odum and colleagues in the 1950s during studies of the tropical forests funded by the United States Atomic Energy Commission...
- ChartChartA chart is a graphical representation of data, in which "the data is represented by symbols, such as bars in a bar chart, lines in a line chart, or slices in a pie chart"...
- DiagramDiagramA diagram is a two-dimensional geometric symbolic representation of information according to some visualization technique. Sometimes, the technique uses a three-dimensional visualization which is then projected onto the two-dimensional surface...
- Straight-line diagramStraight-line diagramA straight-line diagram is a diagram of a road where the road is shown as a straight line. Such diagrams are usually produced by a highway department, and display features along the road, including bridges and intersecting roads...
- Topological mapTopological mapIn cartography and geology, a topological map is one that has been simplified so that only vital information remains and unnecessary detail has been removed. These maps lack scale, and distance and direction are subject to change and variation, but the relationship between points is maintained...
- Transit map
External links
- WebEE Schematics and Projects Many Circuits and Electronic Projects.
- Discover Circuits Large collection of electronic circuit schematics.
- FSM Directory Provides many circuit schematics for repair professionals.