Piirikaavio

Piirikaavio, Finnish for circuit diagram, is a graphical representation of an electrical circuit that shows components and their interconnections without depicting the physical layout. It is used to illustrate how a circuit functions, to analyze behavior, and to guide construction or troubleshooting. In a piirikaavio, standardized symbols represent components such as resistors, capacitors, inductors, diodes, transistors, and integrated circuits. Wires appear as lines, with junction dots indicating electrical connections. Each component generally carries a reference designator (for example R1, C2, Q1) and a value or specification (1 kΩ, 100 nF, 2N3904). Power supplies and ground are indicated, and notes may include operating voltages, tolerances, and test points.

There are related diagram types, including wiring diagrams that show the physical interconnections in a particular build, and block diagrams that depict functional relationships between subsystems. A well-made piirikaavio enables circuit designers to communicate ideas clearly, simulate behavior, create bill of materials, and support fabrication or assembly.

Standards bodies such as IEC and ANSI provide standardized symbols and conventions used in piirikaavio across industries. Software tools for creating piirikaavio-style diagrams include dedicated electronics CAD programs capable of generating nets, footprints, and documentation. The term is widely used in Finland and is often encountered in Finnish-language education and technical literature, while the English equivalent is typically called a schematic diagram or circuit diagram.