| 摘要 |
1,105,290. Automatic control systems. WIENER SCHWACHSTROMWERKE G. m. b. H. Sept. 2, 1965 [Sept. 8, 1964], No.37558/65. Heading G3R. The movement of each electrode in an arc furnace 1 is controlled by a controller 10 in dependence upon actual arc voltage and arc current, the input to the controller being derived from a voltage divider 8, 9; a signal proportional to arc current is applied to resistor 8 by way of a current transformer 3, a rheostat 4 and a rectifier 6; a signal proportional to the voltage applied to the electrode is derived from a potentiometer 5 and a rectifier 7 and is applied to resistor 9 so that it opposes the signal on resistor 8, the second signal being modified by a further signal developed across a resistor 14. This further signal, which represents the volt-drop in the electrode supply conductors &c. is derived from the current signal circuit by way of an adjustable resistor 11, a transformer 12 and a rectifier 13, and opposes the signal from rectifier 7 so that the voltage applied to resistor 9 is representative only of the actual voltage across the arc. The controller 10 operates a positioning motor or a hydraulic drive for adjusting the electrode. The current sensing circuit also includes a capacitor 15 which compensates for the inductance of the supply conductor connected to the electrode. |
