An oscillating inductor has a symmetrical double-E core, which has two geometrically identical core windows, a cuboid center limb and two cuboid outer limbs. The double-E core is designed such that a longitudinal cross sectional area of the center limb is greater than 90 mm2, with a longitudinal cross section being regarded as a cross section which would separate the double-E core into two single E-cores, and the cross section being at right angles to the longitudinal cross section such that the double-E can be identified in the cross section, with the double-E core being located in a component volume of less than 26.5 mm×26.5 mm×15 mm (width×depth×height).