A voltage transformer for use with high voltages. The transformer includes an insulating body in which is disposed a high-potential winding and a bushing laterally joined to the insulating body. In accord with the invention, the transformer is further provided with control electrodes in the form of conducting cylinders which are disposed concentrically with respect to the longitudinal axis of the bushing, thereby affording control of the bushing at both its ends. Moreover, in further accord with the invention, the high-potential winding is arranged adjacent to one side of the bushing so that its width extends over the control length thereof, and is comprised of subwindings which are metallically connected to the respective conducting cylinders such that a uniform voltage distribution results during the occurrence of surge voltages.
A compact valve choke that is simple to manufacture, which can, however, ensure the qualities required for all operating modes, namely the needed dielectric strength and freedom from partial discharges between components that are at different voltages. This valve-choke is achieved by having: the choke windings arranged in a supporting frame in a self-supporting manner, in relation to one leg of the choke core; the choke windings potted on all sides, and the potted block supported in the supporting frame by means of fittings; the choke core consists of two generally circular-shaped cores and is secured in the supporting frame; and the choke coil includes two primary windings wound in two layers, with an outer first winding portion and a concentric inner second winding portion as well as, a core-potential center tap roughly in the center of the windings between the first winding portion and the second winding portion.