DCcircuit

DC circuit, or direct-current circuit, is a closed path through which electric charges flow predominantly in one direction under the influence of a direct current source such as a battery or DC power supply. Components include resistors, capacitors, inductors, diodes, transistors, and interconnecting wires. The behavior of DC circuits is governed by Ohm's law and Kirchhoff's laws (KCL and KVL), which express the relationship between voltage, current, and resistance and the conservation of charge and energy in a network.

From these laws, network analysis techniques are used: series and parallel reduction for simple networks; node-voltage and mesh-current methods for complex networks; Thevenin and Norton equivalents to simplify parts of a circuit; and the superposition principle for linear circuits with independent sources. These methods allow calculation of currents and voltages throughout a circuit.

In steady state, capacitors act as open circuits and inductors act as short circuits for DC, so DC analysis often reduces to resistor networks. Transient behavior occurs when sources change; time constants determined by R and C or L and R describe how quickly the circuit responds.

Common configurations include series circuits, where the same current flows and voltages add across components, and parallel circuits, where voltages are the same and currents split among branches; many networks are combinations of these.

Applications of DC circuits span power supplies, battery-powered devices, automotive electrical systems, and a wide range of electronic circuits that require stable, unidirectional current.