| 摘要 |
1,059,783. Automatic position control of furnace electrodes. W. C. HERAEUS G. m. b. H. April 28, 1964 [May 24, 1963], No.17628/64. Heading G3R. A vacuum arc furnace 1 comprising a consumable electrode 4 has the electrode 4 positioned relatively to the melt by a motor 13 which is responsive to the amplitude and frequency of pulses which occur in the voltage across the arc, the amplitude and frequency of the pulses being dependent on the spacing between the electrode and the melt. The arc voltage is applied, by way of terminals 15 to a filter circuit 16, 17 and to a further filter circuit 18, 19 which also serves as an attentuator. The pulses occurring in the arc are then integrated by a circuit 25, 26 and applied to the control grid of an amplifying tube 27 which forms a bridge circuit with resistors 29, 30, 31 the output of which bridge controls the electrode positioning motor 13 by way of a controller 14. In a further embodiment the signal circuit comprises a transformer and a rectifier but omits the amplifying tube. |
