Node (circuits)

In electrical engineering, a node is any region or joining point on a circuit between two circuit elements. In circuit diagrams, connections are ideal wires with zero resistance. Whether "node" refers to a single point of junction or an entire equipotential region varies by the source.

"Node" is often used, especially in mesh analysis, to mean a principal node, which is distinct from the usage defined above. A principal node is a point in a circuit diagram where three or more connections meet. Principal nodes are important points of consideration in applying Kirchhoff's circuit laws, because conservation of current means current can split or combine at these points.

When clarification is needed, a region connecting only two circuit elements is referred to as a simple node, where there is no branching of current, while a point connecting three or more elements is a principal node. The full definition uses in this article encompasses both principal and simple nodes.