Schwingspule

Schwingspule is a term found in historical German technical literature for an electrical coil that participates in oscillatory circuits. In many texts it is used interchangeably with Schwingungspule or similar variants, and design descriptions typically treat it as an inductor that forms or helps sustain electrical oscillations.

Function and role

A Schwingspule is used to generate or maintain AC oscillations when combined with capacitive elements in a resonant circuit. In an LC tank, the coil provides inductance L that, together with a capacitor C, sets the resonant frequency f ≈ 1/(2π√LC). In oscillator circuits, such as Hartley or Colpitts configurations, the coil may also provide feedback or couple energy between stages through mutual inductance with other windings.

Construction and tuning

Schwingspulen are usually wound from enamelled copper wire on a bobbin and may include an adjustable magnetic core (air, ferrite, or laminated material) to alter inductance. They can be single-winding inductors or multi-winding transformers used to transfer energy between stages or to adjust feedback levels. Tuning is typically achieved by changing the core position, winding configuration, or adding/removing taps.

Applications and context

Historically, Schwingspulen were central components in early radio receive and transmit equipment, signal generators, and laboratory oscillators. In modern German-language terminology the term is largely historical; contemporary usage more often employs Induktors, Spulen, or Induktivität, with explicit references to their role in circuits rather than a distinct name for oscillatory coils.

See also: Schwingkreis, Induktivität, Spule, Kondensator.