GB340227A - Improvements in and relating to electric transformers - Google Patents

Abstract

340,227. Transformers. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London, CLOUGH, F. H., Kilsby, near Rugby, and MAYO, C. G., 17, Alexandra Road, Rugby. June 18, 1929, Nos. 18702 and 19336. [Class 38 (ii).] In a potential transformer for use on high voltage circuits the high voltage winding 6 is formed of concentric layers of turns so arranged that the insulation between radially adjacent turns is proportional to the number of turns and therefore the voltage between them and the axial length of the layers progressively decreases as the distance from the axis increases. The high tension conductor may be connected to the outermost layer of turns, in which case the secondary winding 2 is placed next to the core, and a metallic cylinder 8 connected to the high tension line is placed over the outside of the winding in order that voltage stresses due to surges are distributed equally through the winding. For the same reason, the core is connected to the high tension line if the innermost layer is made the high voltage end, the secondary winding in this case being placed externally of the high voltage winding. Paper with oil impregnation is used for the internal insulation. The transformer may be housed in a bushing-type insulator, the winding being arranged on a straightthrough core provided with end rings serving as polepieces, the return flux path being in air. Specifications 173,606 and 145,675, [both in Class 38 (ii), Electric currents, Converting &c.], are referred to.