GB618247A - Improvements in or relating to electric regulating systems - Google Patents

Abstract

618,247. Automatic control systems. GENERAL ELECTRIC CO., Ltd., and DALE, S. H. March 22, 1946, No. 8888. [Classes 38 (ii) and 38 (iv)] Current and voltage.-In a regulating system, the quantity to be regulated controls the output of a rectifier and this output is balanced against the output of a further rectifier, both rectifiers being fed from the same source, variations in which are thus balanced out. Alternatively the rectifiers may be fed from distinct sources which vary in the same way. As shown, the voltage at the output of a gridcontrolled power system controls the value of a saturable choke in series with the input side of a bridge rectifier 2 feeding a resistor 16 and an adjustable choke 41 is connected in the input circuit of a second rectifier 1, the output of which feeds a resistor 15. The resistor 16 and an adjustable part of the resistor 15 are included in series so as to act in opposition in the grid circuit of an amplifier tube controlling a saturable choke 35. When the output voltage of the main rectifier varies a corresponding change occurs in the voltage across resistor 16 and consequently in the value of choke 35 and then causes a phase shift of the input to the power rectifier in such a direction as to correct the voltage variation. The arrangement may be adapted to polyphase systems and the phase-shifting arrangement may be of a rotary type instead of the static type shown. In another arrangement, Fig. 1 (not shown), control is exercised in accordance with the current flowing in a D.C. line.