GB696262A - Improvements in and relating to voltage regulators - Google Patents

Abstract

696,262. Transformers. BRITISH THOMSON-HOUSTON CO., Ltd. Oct. 10, 1951 [Oct. 14, 1950], No. 23579/51. Class 38 (ii). In a voltage regulator having on the same core 30 a winding 3 connected in parallel with the load L and a tapped winding 4 in series with the load, the layers of turns of the latter between the tappings are distributed between two or more cylindrical groups 32, 33 in such an arrangement that when the regulator is operating at less than maximum buck or boost, so that less than the whole series winding is being used, the cooling is adequate to permit the load current to be proportionately increased. In the regulator of Fig. 1 the voltage may be regulated from 100 per cent boost with switch 6 on contact R and contacts 18, 19 of switch 5 on tap 17 to a 100 buck by rotating contacts 18, 19 twice in a counterclockwise direction and operating switch 6 from R to L when contacts 18, 19 were on contact N. Fig. 4 shows the nine tap sections 21-29 distributed in such a way between two groups 32, 33 separated by air space 34, that when contacts 18, 19 engage taps 13 for 50 per cent boost the sections 21, 22, 23, 24 through which the load current flows are all on the outsides of the windings with maximum heat dissipation, while with contacts 18, 19 on. tap 14 for 50 per cent buck, the load current flows through section 26, 27, 28, 29 which are below the outer sections in good but less effective heat dissipating conditions. Section 25 in the worst position is not in use during 50 per cent buck or boost. Heat dissipation needs are greater during boost than during buck when the load current is usually lighter and the shunt current is not increased, but is reduced by the shunt current. In modifications the layers may comprise more than one intertap section, Fig. 5 (not shown), or the groups may comprise two (or three) layers only, Fig. 6 (not shown). Alternatively the the full range may be provided by selectively operating the tapped winding between conditions of 100 per cent voltage boost and zero, 100 per cent buck and zero and the like for other percentages, Fig. 7 (not shown).