Abstract: An apparatus for measuring winding resistances of windings in a delta-connected transformer includes at least a first and a second DC current source connected each between the phase ends of a first and a second leg respectively of the primary side of the transformer and at least a third DC current source connected between two nodes of the secondary side of the transformer. Furthermore, a method for measuring a winding resistance of windings in delta-connected transformers includes the steps of applying a first and a second measuring current to each one of two corresponding legs, applying a third measuring current between two nodes of a pair of windings on the secondary side and measuring at least a winding resistance of the winding between said nodes on the secondary side of the transformer and/or the winding resistance of a leg of the primary side as soon as an inductive voltage drop in the windings substantially equals zero.

Abstract: A integrated flue support construction (2) for a Marx impulse voltage generator (2) with several generator stages (3) is disclosed. It has been known to arrange a flue (2) for flushing the air of switching spark gaps (4) separately from a support frame for the switching spark gaps (4), the impulse capacitors (5) and series and parallel resistors (7, 8). According to the invention, the flue (2) has a supporting function for the switching spark gaps (4) and individual or all electrical components (5-10) of the impulse circuit. In one embodiment the flue (2) consists of a triangular cylinder support structure (2), wherein the side walls (11) are formed by insulating plates (11), each receiving one of the electrical components, namely the switching spark gap (4), impulse capacitor (5) and resistors (7, 8).