Variable inductance coil for telephone network - has fragments and sections to form network having at least one separate loop

摘要

The hybrid coil with variable inductance is designed for frequency filters for subscriber speech signals of a PCM telephone communication system, and provides the advantage of coil adjustment for altering the inductance in small steps when the magnetic core is not moved or otherwise changed. One or more of the fragments (F) and/or one or more sections (A,AN) form a network (N) of conductors, having at least one separate loop, at least during a operating phase or a mfy. phase following location of the current conducting connections (v). Adjustment of the hybrid coil is carried out by means of a laser beam in order to separate one or more of the loops (T) according to the inductance measured.