GB1298884A - Auto-transformers or controllable reactance coils - Google Patents

Abstract

1298884 Transformers and inductors; transformer tap-changers K SCHMID 10 April 1970 [15 April 1969] 17254/70 Headings H1N and HIT Current tapping equipment for an autotransformer or choke includes a former 1 carrying a wire winding 8a, 8b with which cooperates a tapping member rolling across the bared turns of the winding. The tapping roller is provided with insulated current collecting segments 3a, 3b, around its circumference. The turns of said winding are pitched to conform with the pitch of the segments, the evennumbered and odd-numbered segments respectively each being connected in a group and the two groups being interconnected by a current-limiting reactor 5 having a centre tap. The winding consists of flat, insulated wire wound edgewise 10 into a helical slot pitched to conform with the pitch of the segments. The turns may be held in rack-like or rake-like supporting bars extending in the direction of the winding axis. The tapping roller comprises two similar axially interfitting, cup-shaped halves (11) (Fig. 4, not shown) having deeply slotted sides in such a manner that the teeth (3a) between the slots (3b<SP>1</SP>) of one half engage the slots of the other half with the interposition of an insulation and form the current collecting segments. The transfer of current is effected by a multi-contact bush on the tapping roller to a pivot or half shaft received into said bush. Each segment is provided with a V-section trough 9. The tapping roller is loaded by at least one spring (17), (Fig. 3, not shown), which urges the roller against the turns. Current tapping equipment of this type may be used for a polyphase transformer or a polyphase reactance coil, in which a plurality of tapping rollers (2), (Fig. 7, not shown), are mounted in a common carrier on a slide which is movable parallel to the axes of the co-operating windings.