Coils - definition
Coils - definition
A Coil is an electrical component whose primary function is to generate a magnetic field in response to the current flowing through it. It consists of a conductor - usually copper - wound spirally around a core made of magnetic material or air. Coils store energy in the form of a magnetic field, and their behaviour is described by a physical quantity called inductance, expressed in henry (H).
In AC circuits, the coil is characterised by reactance inductance, which depends on the frequency of the signal. This means that it acts as a filter to suppress high frequency components. In DC circuits, the resistance of the coil depends only on the resistance of its wire, while the inductance has no significant effect on the current flow once the stationary state is established.
The phenomenon of self-induction, i.e. the appearance of an electromotive force that counteracts the change in current, is a key feature of coils. This effect is used in interference suppression circuits, voltage converters, filters and resonant circuits. Coils can range in shape and size from microscopic SMD components to large chokes and transformers, depending on the application.
The presence of a ferromagnetic core significantly increases the inductance of the coil, enabling effective magnetic coupling in transformers. In some cases, cores with adjustable permeability or split windings are used to achieve specific dynamic parameters. Coils are also an important component of electromagnetic devices such as Relays, Solenoids and Electric Motors, where their magnetic properties are directly used to perform mechanical work.
Transfer Multisort Elektronik (TME) is one of the world’s largest global distributors of electronic components, electrotechnical parts, workshop equipment, and industrial automation. The catalog includes over 1,500,000 products from 1,300 leading manufacturers. TME’s modern logistics centers in Łódź and Rzgów (Poland), with a combined area of over 40,000 m², ship nearly 6,000 packages daily to customers in more than 150 countries.
TME also invests in the development of knowledge and skills of young engineers and electronics enthusiasts through the TME Education project, and supports the tech community by organizing the TechMasterEvent series, promoting innovation and experience exchange.
