A row of humps or a filled rectangle in a wire, marking an inductor.
Also known as: Coil symbol, Choke symbol, Humps symbol, Inductance symbol
An inductor is drawn as a series of humps in North American practice — a picture of a coil of wire — and as a filled rectangle under IEC practice. Like the resistor, the same component has two current and incompatible drawings.
Marks an inductor: a coil that stores energy in a magnetic field and opposes changes in the current through it.
Contexts: Electrical equipment
Is drawn in its common form as a picture of the component — a series of three or four semicircular humps standing for the turns of a coil.
Contexts: Electrical equipment
Appears under IEC practice as a plain filled rectangle instead, which carries no visual resemblance to a coil and is not interchangeable with the humped form.
As with the resistor, these are two conventions in simultaneous use rather than a symbol and its variant.
Contexts: Electrical equipment
Gains one or two parallel lines drawn alongside the coil where the inductor has a ferrite or iron core, which changes its behaviour substantially.
Contexts: Electrical equipment
Three or four semicircular humps in a row along a straight horizontal line, all bulging the same way, like a flattened coil seen from the side.
Both are passive components whose ANSI and IEC drawings diverge in the same way.