GB166548A - - Google Patents

Abstract

166,548. Soc. d'Electro-Chimie et d'Electro-Metallurgie. July 15, 1920, [Convention date]. Regulating transformers.- The current obtained from a single-phase or polyphase supply is regulated by connecting a pair of transformers T<1>, T<2> in series across each phase, the primary or secondary or both windings of the transformers being provided with tappings connected to contacts a<1>- - d<1> and a<2> - - d<2> of a switch c. The movable contact-arm of the switch carries brushes f<1>, f<2> of a width greater than the distance between successive contacts, and the brushes are arranged to change contact alternately on the two transformers. A form of switch suitable for high-tension circuits is shown in Figs. 5 and 6. The two series of fixed contacts are separated by an insulating-scrsen l and are arranged to form a cylindrical surface engaged by the curved brushes f<1>, f<2>, carried by a spindle g rotated by a hand-wheel through gearing. Each contact is provided with anti-arc horns m. The spindle g carries a cam having oppositelyarranged stops j<1>, j<2>, between which are a number of teeth adapted to engage rollers i carried by spring-connected pivoted arms n in order to give a definite step-by-step motion to the contact brushes and to make it impossible for them to stop between two contacts. In a modified construction for low-tension circuits, Fig. 7, the two series of contacts are arranged concentrically, and the spindle g carries a slidable arm h controlled by a spring k and provided with rollers i co-operating with a fixed cam j to define the successive steps of the switching-movement.