GB341903A - Improvements in and relating to the regulation of the voltage of a power supply system or other a.c. circuit - Google Patents

Abstract

341,903. Systems depending on static transformers. FERRANTI, Ltd. and NORRIS, E. D. T., Hollinwood, Lancashire. Aug. 23, 1929, 25759. [Classes 38 (ii) and 38 (iv).] Voltage regulation of a supply circuit S1' S2 as shown in Fig. 7 is effected by moving a shortcircuited coil 4 into close magnetic association with either of the primary windings 2, 3, between which is considerable leakage reactance, of a boosting transformer, in order to vary the relative impedance of the windings 2, 3. In Fig. 7, the coil 4 is shown in close association with winding 2, the drop across which is reduced resulting in a reduced voltage in the secondary winding 7. The secondary windings 7, 8 are in opposition and " boost " and " buck " are therefore varied. As shown in Fig. 6 choking coils 5, 6 are shunted across the primary windings and a short-circuited coil 4 is brought in or out of close magnetic association with either of the choke coils which may be wound on the same core provided there is considerable leakage reactance between the coils 5, 6. The Provisional Specification describes also a means of effecting regulation by varying the relative reluctance of the magnetic circuits of the windings by arranging one of the windings around an air gap and providing a sleeve of magnetic material which is capable of movement along the core axis so as alternatively to bridge the air gap or to rest upon one end of the core adjacent to the gap.