GB654116A - Improvements in voltage regulator - Google Patents

Abstract

654,116. Automatic and current control systems. SORENSEN & CO., Inc. Feb. 20, 1948, No. 5108. Convention date, April 17, 1946. [Class 38 (iv)] An A.C. voltage or current regulator comprises an auto-transformer, the input to which is varied by a saturable reactor controlled by the amplified output of a bridge circuit, one arm of the bridge being a tungsten filament diode, the filament current being varied in accordance with the output voltage or current. In a voltage regulator, Fig. 3, the auto-transformer 46 is in series with a saturable reactor 37 across the input terminals 21, 22, the output being taken from terminals 31, 32. The D.C. winding of reactor 37 is controlled by an amplifier valve 35 supplied with D.C. by a rectifier 40 and winding on transformer 24 fed from the output terminals. A voltage is applied to the control grid of valve 35 whenever the bridge, consisting of resistors 10, 11, 12 and the diode 13, is unbalanced. A high D.C. voltage derived from transformer 24 and rectifier 33 is applied across the imput corners of the bridge, the balance of which is determined by the impedance of diode 13 in turn determined by the filament current provided by a transformer 51, the primary of which is connected in series with resistors 29 and 39 across the output terminals 31, 32. Resistor 39 is for datum setting. Resistor 29 applies a voltage component proportional to input voltage becuase it is in series with the supply to the primary of transformer 24 the load on which varies according to the D.C. excitation of reactor 37 and this varies with the input voltage to the regulator. A transformer 61 in series opposition to transformer 51 applies a component proportional to the output current through a shunt 57, to obtain level compounding. A condenser 49 across bridge resistor 11 prevents hunting. In a modification, Fig. 5 (not shown), the diode filament is supplied by three transformers in series, the third transformer supplying a voltage proportional to the input voltage. In another embodiment, Fig. 4 (not shown), output current is stabilized by supplying the diode filament from the secondary of a current transformer in the output line and also by an opposing voltage proportional to output voltage to stabilize the regulator. The transformer supplying the auxiliary D.C. circuits is supplied from the input terminals instead of the output.