Tap changer and vacuum interrupter for such a tap changer

A tap changer with vacuum-switching tubes for uninterrupted changeover between winding taps of a tapped transformer, wherein

• two load branches are provided for each phase to be switched,
• each load branch comprises a vacuum-switching tube acting as a main contact and mechanical switching means connectable in series therewith,
• an auxiliary current branch connectable in parallel with the corresponding load branch is provided for each phase to be switched,
• each auxiliary current branch comprises at least one switchover resistor and in series a further vacuum switching contact acting as an auxiliary contact, and
• not only the load branches, but also the auxiliary current branches of the two load branches are connectable with a common load diverter,
• the vacuum switching contact, which acts as main contact, and the mechanical switching means arranged in series therewith of the first load branch and the vacuum switching contact, which acts as auxiliary contact, of the second load branch are constructionally combined in a single vacuum-switching tube with a common housing,
• the vacuum switching contact, which acts as main contact, and the mechanical switching means arranged in series therewith of the second load branch and the vacuum switching contact, which acts as auxiliary contact, of the first load branch are combined in a further single vacuum-switching tube with a common housing and
• a respective separate hermetically sealed vacuum switching chamber is provided within the common housing for each vacuum switching contact and for each mechanical switching means.