| 摘要 |
964,462. Arc rupturing in switches. ETABLISSEMENTS MERLIN & GERIN. Nov. 23, 1962 [Nov. 27, 1961], No. 44339/62. Heading H2B. In a circuit-breaker, an arc damping resistor is constituted by a film of material of high negative temperature coefficient which is exposed to the heat of the arc. In Fig. 1 the electrodes 12 of each section of an insulating plate 11 arc chute are connected through a thin layer 15 of the material. An arc loop formed between the electrodes heats the layer to conduct and is thus shunted by a low resistance. In Fig. 7, separation of the contacts 16, 17 allows the passage of hot blast gases through a conduit 32, 35, the latter being lined with a layer of the material which is heated by the gases to shunt the contacts. In Fig. 3, the initial arc between contacts 16, 17 heats a layer 23 of the material until extinguished by the blast gas. An arc is restruck on recovery of the volts between each contact and the upper and lower ends of the now conducting layer 23. Since the initial arc no longer exists the layer cools, presenting a gradually increasing resistance in series with the secondary arcs until these are finally extinguished. |
