Radio interference filter for electronically controlled apparatus

摘要

The filter contains at least one interference equalising choke with at least one coil (L, N) on a magnetisable core (K). The coil free ends are coupled to a voltage conductor. The core of the interference equalising choke carries an extra coil (SL), which is coupled to the free ends of a protective conductor. The extra coil is set on a first rod-shaped extension on the core, or located in the cavity (2) which is formed by a bore (3) in the core. The core extension on its cavity is made or surrounded by a core material of permeability differing from that of the core part. Preferably the permeability of the extension is 2-20 times lower than the permeability of the core material.