Control circuit for arc furnace electrodes - moves electrode towards melt in response to DC control signals derived from current and voltage values

摘要

The control circuit moves an arc furnace electrodes down towards the melt. It measures the current and voltage in the phase lines leading to the electrodes and converts the measured values into proportional direct voltages. The direct current voltage is directly amplified in an amplifier. The direct voltage is multiplied by the output of a function generator, whose input is proportional to the furnace transformer secondary voltage, and then applied to the amplifier. The amplifier gain is made inversely proportional to this secondary voltage.