Electrical symbols represent or identify a primary electrical device in a circuit diagram and are standardized internationally by the IEEE standard, IEEE Std 315-1975. Basic electrical devices identified by symbols include wires, switches, power sources and wave generators. Other electrical components are grounding, resistors, variable resistors and capacitors.
Standard electrical and electronic symbols are used to represent conductors or wires conducting electrical current. Symbols also represent a live connection between two conductors, where a dot shows a junction point.
Switches are indicated as either push button normally open or normally closed, the spst, spdt, dpst or dpdt switch. There are distinct symbols for sources including AC, DC, constant current, controlled current and controlled voltage sources. Other types of power supply symbols include the single, multicell battery source.
Wave generator symbols represent the sinusoidal, pulse and triangular wave generators. Ground symbols are used to indicate normal, signal and chassis grounding. Standard electrical symbols are used to indicate the position of fixed and variable resistors in a circuitry diagram.
Electrical symbols also indicate the position of nonpolarized, polarized, electrolytic, fixed-through and variable capacitors. Other symbols exist for standard, iron core, ferrite core, center tapped and other types of inductors used in a circuit.