GB515207A - Improvements relating to regulating means for electrical circuits - Google Patents

Abstract

515,207. Rectifying A.C.; phase changing; automatic regulation. HARMER, H. M. May 12, 1938, No. 14211. [Classes 38 (ii) and 38 (iv)] A load 6 is supplied through two full wave rectifiers 5, one being fed from supply terminals Vs direct or through a transformer or autotransformer; and the other through a circuit comprising a constant inductance 1 in series with a second inductance 2 in parallel with a capacity 4. The inductance 2 at voltages across it not exceeding that corresponding to the "knee-point" of its core magnetization (preferably one with a supply voltage), has a reactance numerically greater than that of the capacity 4 (so that a slight rise of this voltage causes an abrupt fall in its resistance) and the reactance of the inductance 1 is numerically equal to the reciprocal of the sum of the reciprocals of the inductances 2 and capacity 4. The inductance 2 may be substantially equal numerically to the resistance of the maximum load. This arrangement, at full load. gives substantially a two phase rectified supply to the load. The supply given by transformer 3 may be obtained from secondary windings on inductances 1 and 2 connected in series. Three phases may be derived from the arrangement by a Scott connected winding on transformers 2 and 3, or others without the transformer 3. The third harmonic may be suppressed by connecting an inductance in series with the condenser 4 to make this branch resonant to the said harmonic. The condenser 4 may in all cases be transformer coupled. Any type of rectifier may be used.