Abstract: In a current limiter for limiting currents in case of a fault including an additional device comprising an additional electric valve connected in series and being conductive in the same direction as the associated main valve, two series-connected valve branches arranged in opposition bypass two series connected current limiting inductors and both additional valves are bypassed by a similar passively complex connection for limiting current in the case of a fault, wherein the current limiter is not noticeable during normal operation, but, in the event of a fault, effectively limits the short circuit to a predetermined extent.

Abstract: In a current limiter for limiting currents in case of a fault including an additional device comprising an additional electric valve connected in series and being conductive in the same direction as the associated main valve, two series-connected valve branches arranged in opposition bypass two series connected current limiting inductors and both additional valves are bypassed by a similar passively complex connection for limiting current in the case of a fault, wherein the current limiter is not noticeable during normal operation, but, in the event of a fault, effectively limits the short circuit to a predetermined extent.

Abstract: In a current limiter with electric valves for limiting a short circuit in an electric power supply, wherein two throttles are connected in series and in a parallel path with two series-connected valves, which are disposed in opposition to each other and the two parallel paths are interconnected by a connection extending between the common potential point of the valves and that of the throttles, the valves are semi-controlled valves, which, for the operation of the current limiter, are activated by an external control whereby the valves are converted from a conductive to a blocking state in which they remain so that the current limiter automatically limits the current upon the occurrence of a fault current exceeding a predetermined current threshold.

Abstract: In a production system included in a power modulator for the protection of a load connected to the power modulator, comprising a charging system, a power impulse former, a control arrangement and a pulse transformer with a first protection circuit in the form of a crowbar circuit connected to the input side and the load connected to the output side of the pulse transformer, a second protection circuit is connected to the output side of the pulse transformer between the low potential and the ground potential connections thereof wherein the second protection circuit includes a controlled switch with a resistor arranged in parallel therewith.

Abstract: An arcuate shaped magnetic system is housed in a fixed cryostat within a rotating drum. A slurry containing magnetizable particles is charged into an operating area defined by the magnetic system at the lower part of the drum and magnetic particles adhering to the drum are removed as the drum rotates the same to a discharge location. The cryostat has an outer wall which conforms to the shape of the drum and houses a sector-shaped refrigeration tank. The refrigeration tank has an arcuate wall section conforming to the shapes of the cryostat wall and the drum and is positioned in close proximity to the outer cryostat wall only in the operating area in order to minimize inward heat transfer.

Abstract: A magnetic separator, in particular a drum separator, includes a magnetic system having a plurality of magnets. Each of the magnets produces an open field directed toward a separation zone which, in a drum separator, extends axially of the drum outside of the surface of the drum. The magnets may include conductive coils, preferably superconducting coils, which are traversed in the same direction by current and which include an iron-free core. The average center-to-center spacing of the coils is a maximum of 25 times the spacing between the coils and the separating zone and is preferably in the range of 15:1 to 10:1. The coils are elliptical and have major and minor axes which decrease from the outermost coil winding to the innermost coil winding, with the distances between the windings being greater along the major axes than along the minor axes.This is a continuation of application Ser. No. 843,737, filed Oct. 19, 1977, now abandoned.