Schematic

A schematic is a diagram that uses abstract symbols to represent the components and interconnections of a system, focusing on function and relationships rather than physical layout. In electronics, a schematic diagram shows electronic components as standardized symbols connected by wires or nets to illustrate how a circuit operates.

Symbols and conventions are central to schematics. Components are represented by internationally or industry standardized symbols (for example, resistors, capacitors, inductors, diodes, and transistors), each with a reference designator such as R1, C2, or Q1. Wires indicate electrical connections, while ground and power rails are shown with specific symbols. Schematics may use buses and net labels to group related signals and to manage complex designs. They are often created with computer-aided design (CAD) tools and can be hierarchical, spanning multiple sheets.

Purpose and use vary by field. In electronics, schematics aid circuit design, analysis, testing, and documentation, and they serve as the basis for simulation and for generating wiring or printed circuit board layouts. They emphasize symbol-level behavior and signal flow rather than physical arrangement.

Reading a schematic involves tracing nets from power to signal paths, using reference designators to locate components, and understanding the function of each symbol. Limitations include the fact that schematics are not to scale and may omit mechanical constraints or layout considerations. They are typically complemented by layout drawings, bill of materials, and experimental validation.