| 摘要 |
914,467. Arc-rupturing in switches. BROWN, BOVERI & CIE A.G. June 29, 1960 [June 30, 1959], No. 22732/60. Class 38 (5). [Also in Group XL (b)] In a circuit-breaker comprising a power interrupter and a seriesdisconnecting switch 5, a photo-sensitive resistor connected in parallel with the interrupter contacts 2 has its resistance value reduced directly or indirectly in response to the light radiation of the arc drawn between the contacts 2 when opened. Thus the arc is shunted by a low resistance which persists for a short interval to reduce the rate of rise of the recovery voltage. After the arc has been extinguished, the resistor reverts to its high - resistance value to reduce the residual current before the disconnecting switch is opened. In Fig. 1 the resistor 1 is housed in the interrupter chamber 3 so as to be directly exposed to the light radiation of the arc, the resistor being protected by a transparent tube 4. In Fig. 2, a photoelectric cell 6 in the chamber 3 produces a voltage when subjected to the light radiation of the arc. This voltage controls an amplifier 7 which supplies a light source 8 acting on the resistor 9. The resistor is of a light-sensitive single or multi-crystalline semi-conductor material such as silicon. |
