A tapchanger for a regulating transformer includes a rotatable combined diverter switch tap selector, of which the fixed contacts are arranged in a circular row and are mounted at equal free distances from each other and at least one fixed contact extends over a larger arc of a circle than the other contacts and in which a set of switching contacts mounted for rotation about the axis of the circular row and cooperating with the fixed contacts is adapted to be rotated, for the changeover operation between at least one pair of adjacent fixed contacts, through a greater angle than for the changeover operation between the other pairs of adjacent fixed contacts.