Cívky

Cívky (singular cívka) is a Czech term for a coil or spool. It denotes a wound form designed to contain or guide material, such as wire or thread. In electrical engineering, cívka commonly refers to an inductor—a wound conductor arranged to generate a magnetic field and to store energy. In textiles and sewing, a cívka, or bobbin, is a spool on which thread or yarn is wound for feeding into weaving or sewing machines.

In electronics, a coil consists of a conductor wound into turns around a core. Inductance depends on the number of turns, the cross-sectional area, the length of the winding, and the magnetic permeability of the core. Coils can be air‑core or ferrite/ferromagnetic‑core, which affects inductance and the quality factor. Common shapes include solenoids and toroids; surface‑mount inductors are used in compact circuits. Coils are essential in transformers, filters, chokes, RF circuits, and power electronics, where they store energy and shape signals. Design considerations include current handling, thermal dissipation, and magnetic saturation.

In textiles, cívky are spools or bobbins that hold thread or yarn during spinning, weaving, or sewing. They come in various sizes and materials, chosen to minimize friction and ensure smooth unwinding. Traditional cívky were carved from wood; modern versions are typically plastic or metal. In both contexts, cívky play a foundational role in enabling controlled winding, storage, and transfer of flexible materials.