Schematics

Schematics, or schematic diagrams, are simplified representations of electrical, electronic, or mechanical systems that use abstract symbols to depict components and their interconnections. Unlike layout drawings, schematics emphasize function and relationships over physical location, showing how signals flow and how power is distributed.

In electronics, a schematic uses standardized symbols for components such as resistors, capacitors, inductors, diodes, transistors, and integrated circuits. Wires connect symbols to form nets; dots indicate junction points, and labels provide net names, voltages, or signal identities. Schematics can be drawn at varying levels of detail, from single-function circuits to modular hierarchies that reference subcircuits.

Standardization supports interoperability. Symbols and rules are provided by organizations such as IEC, ANSI, and IEEE, and are implemented in computer-aided design tools. Modern workflows commonly generate schematics from or into netlists, with accompanying bill of materials and test points.

Applications span electronics and electrical engineering, automotive wiring, and process control systems. Practically, a schematic communicates design intent, facilitates analysis and troubleshooting, and serves as documentation for maintenance and compliance. It is typically complemented by a schematic diagram that shows higher-level system structure, a wiring diagram or harness layout for physical wiring, and a PCB layout for component placement and routing.

Limitations include lack of geometric scale, absence of thermal or mechanical constraints, and potential ambiguity without accompanying documentation. Good practice includes modular, hierarchical designs, consistent symbol usage, clear reference designators, and complete annotations.