Improvements relating to automatic load control systems

摘要

660,681. Automatic arc furnace control systems. ELECTRIC FURNACE CO., Ltd., and SPANSWICK, J. R. Jan. 3, 1950 [Jan. 3, 1949], No. 72/49. Drawings to Specification. Class 38 (iv). In a control system for a three-phase arc furnace of the type in which the movement of each electrode is determined by balancing a quantity dependent upon arc current against a quantity dependent upon arc voltage, the quantity dependent upon arc voltage is derived through a non-linear potential divider. Hence the quantity varies substantially linearly with arc voltage for values up to that corresponding to normal symmetrical conditions, and above that remains substantially constant. The potential divider consists of a linear resistor in series with either a partially tuned circuit (a condenser in series with a self-saturating reactor) or with a self-magnetizing transductor.