Induktorien

Induktorien (inductors) are passive electrical components that store energy in a magnetic field when current flows through a coil. They oppose changes in current and are characterized by inductance, L, which is measured in henries. The basic relation is V = L di/dt; the energy stored in an inductor at current I is E = 1/2 L I^2. When the current is steady, the inductor presents only its DC resistance.

Induktorien typically consist of a wire wound into one or more turns around a core made of air, ferrite, iron powder, or laminated iron. The core material and geometry determine the inductance. Increasing the number of turns, using a material with higher permeability, or shortening the magnetic path increases L. Common forms include air-core inductors, ferrite-core inductors, and powdered-iron inductors, with variants for through-hole and surface-mount layouts. Some inductors have adjustable cores to tune L.

Key specifications include inductance value, tolerance, saturation current, quality factor (Q), self-resonant frequency, and DC resistance. The inductance is sensitive to temperature and frequency, especially near the self-resonant point where the inductor behaves more like a capacitor.

Applications: inductors are used to filter signals (as parts of LC filters), store energy in switching power supplies, serve as chokes to suppress AC in DC circuits, and form resonant or impedance-matching networks. They are essential in RF circuits and power electronics.