Electro-slag smelter - with cold start control system and electrode feed servo loop

摘要

To prevent overshoot and hunting of the electrode setting servo system and to maintain quick response, hence high efficiency, after the initial start up phase, the superimposed error pulses picked off from either the applied voltage or current to the furnace are amplified, filtered, integrated and compared with a fixed, adjustable, reference voltage, the comparator output being fed back into the input amplifier in opposite polarity to the basic d.c. pick off signal, and the output of the amplifier used as control parameter for the servo motor drive to the electrode feed.