COMMON MODE CHOKE

The invention relates to a common mode choke (1). The common mode choke (1) has a toroidal core (2), which is in particular magnetically permeable, and a coil. The common mode choke has at least one further coil, wherein the coil and the further coil are each arranged in the region of the toroidal core (2) in such a way that a magnetic flux passing through the coils can detect the toroidal core (2). According to the invention the toroidal core (2) surrounds a preferably cylindrical through-opening (4). For every turn of a coil each coil has at least one or only one electrical internal conductor (31-34), in particular a busbar, the internal conductor (31-34) being arranged in the through-opening (4). The internal conductors (31-34) arranged in the through-opening (4) together form a shape, preferably a cross-sectional shape, corresponding to the through-opening (4), so that together they fill the through-opening (4).