GB326572A - Improvements in and relating to variable electric condensers - Google Patents

Abstract

326,572. Standard Telephones & Cables, Ltd., and Scaife, F. N. Dec. 20, 1928. Condensers of the differential type, suitable for measuring the capacity unbalance between or within the quods of a cable, are so arranged that measurements of more than one order of magnitude may be made, such as measurement of large capacity differences with moderate accuracy, and of small differences with higher accuracy. In the exploded view diagrammatic shown in Fig. 1, the moving quadrantshaped-plates 1 co-operate with two sets 3, 4 of fixed plates, and in the position shown, as well as in the position in which they are displaced 180‹, the capacity of two parts constituting the differential condenser will be the same. Some of the plates are cut away to form sets of quadrant-shaped plates 3<1>, 4', so that when the plates 1 are rotated from the position shown, only a small change of capacity takes place, whereas when they are rotated from the diametrically-opposite neutral position, a larger change takes place. The scale in the latter arrangement is coarser, and readings are less accurate, than in the former arrangement. In a constructional form, Fig. 4, two sets of fixed triangular plates 3, 4 have located between them the two sets of triangular plates 3', 4<1>, which are only half the area of the plates 3, 4, these being all mounted on pillars 11 between end plates 8, 9 in a casing 12. The end of the spindle 2, projecting from the casing 12 has a calibrated dial 13 visible through two windows in the cover plate 17 of the box 15.