bifilar

Bifilar is an adjective meaning composed of two filaments or threads. The term derives from Latin bi- meaning two and filum meaning thread. In technical contexts, bifilar describes arrangements that use two parallel filaments or conductors, often in a precisely controlled geometry.

In electrical engineering, a bifilar winding refers to a coil made from two parallel conductors wound together around a core. The close pairing promotes strong magnetic coupling between the conductors, enabling compact, high-performance transformers and inductors. Depending on the connection, a bifilar winding can function as a transformer by providing mutual inductance between the two conductors or as a common-mode choke when the two conductors carry currents that share the same path. In the latter case, the arrangement presents a high impedance to common-mode signals while allowing differential signals to pass with minimal interference. Bifilar windings have been used in radio frequency components, precision inductors, and other passive devices where tight coupling and compact form factors are desirable.

Beyond electronics, bifilar also appears in mechanics. A bifilar suspension uses two parallel filaments to support a body, reducing friction and enabling more precise rotational measurements. A related setup, the bifilar pendulum, employs two parallels to determine an object's moment of inertia and related gravitational effects. In both contexts, the dual-filament configuration is chosen to improve balance, symmetry, or measurement accuracy.

In summary, bifilar denotes a two-filament arrangement found in both electrical components and precision mechanical systems, valued for its coupling, symmetry, and stability.