| 摘要 |
398,252. Transformers; phase changing. BRITISH POWER RAILWAY SIGNAL CO., Ltd., Windsor Works, Slough, GLENN, S. L., 3, Central Buildings, Westminster, TINSLEY, H., and GALL, D. C., (trading as TINSLEY & CO.), Werndee Hall, South Norwood, London. Dec. 8, 1932, No. 34146/31. [Class 38 (ii).] In an alternating-current track circuit railway signalling system employing two-element relays with the phase of the track current set to such a position that the phase change which occurs on shunting by the train reduces or reverses the relay torque, the phase setting is obtained by superimposing upon a current in phase with the mains supply a current whose phase is in quadrature therewith, the respective E.M.F.'s being suitably proportioned. A transformer device for this purpose comprises two primary windings, one 3 directly connected to the mains, and the other 4 connected through a reactance such as a condenser 5. The secondary windings 8, 9 are connected in series to supply the track section 6, 7 and the track element 14 of the two-element relay 15. The transformer 3, 8 gives an in-phase E.M.F. and the transformer 4, 9 a quadrature E.M.F. and by suitable tappings the magnitudes of these E.M.F.'s are adjusted to give the required phase setting to the track current. The fluxes from the two primary windings may act on a common secondary. Specifications 278,831, [Class 38 (ii), Electric currents, Converting &c.], 385,666, and 393,939, [both in Group XXX], are referred to. |
