GB437118A - Improvements in and relating to control systems for alternating currents circuits - Google Patents

Abstract

437,118. Control systems for consuming devices. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London. April 26, 1934, No. 12640. Convention date, April 26, 1933. [Class 38 (iv)] A plurality of load devices such as groups of lamps 3 are supplied in parallel from A.C. mains 1, 2 through saturable chokes 4 and boosting auto-transformers 5 which compensate for volts drop due to load currents, each circuit, A, B, C being operated in sequence by controlling the saturation of the chokes 4 by windings 7 each energized in accordance with the current in a preceding circuit, rheostats 11, 10, 14, 20 being provided for varying the relative times of sequence operation of each circuit. Each of the control windings 7 is energized, preferably through a rectifier 8, in series with a saturable choke 9 paralleled by a resistance 14, and in series with a resistance 10 across the voltage of its load 3 and part of its reactor voltage 4 as by direct connection to the reactor winding or by a potentiometer connection. The saturating winding 15 of each reactor 9 is supplied in a circuit through a rectifier 16 and a voltage sensitive circuit comprising resistance 20, 21, capacity 19 and self-saturable inductance 18 from across the voltage of the load 3 in the preceding circuit, that of the first circuit A being connected across the saturable reactor 4 of the last circuit C. The arrangement produces intermittent energization of the loads 3 which are energized in sequence, the times of increase, decrease and of current in each circuit and the time interval between de-energization of each circuit being controlled by the rheostats 11, 14 and 20. Some of the control circuits 17 may be paralleled on each other to produce coincident increase of current in their load circuits. Specification 430,084 is referred to.