GB267929A - Improvements in and relating to electric discharge devices - Google Patents

Abstract

267,929. British Thomson-Houston Co., Ltd., (Assignees of Peek, F. W.). March 17, 1926, [Convention date]. Void [Published under Sect. 91 of the Acts]. Protective arrangements for discharging excessive potentials. The spark-over voltage of a discharge gap is reduced on the occurrence of excess voltage such as may be due to a surge or lightning. A series of electrodes or a conducting surface is arranged in the sphere of influence of one of the electrodes constituting a gap bridging two conductors, one of which is to be protected. The capacity element so formed is connected to the gap electrode or to the conductor with which it is associated through an impedance and under normal conditions acts to raise the spark over voltage, its effect ceasing under voltages of high frequency with the result of lowering the spark-over voltages. The impedance may be inductance or resistance and in one form comprises inductance and capacity in series. The Figures show :-Fig. 1, a ring of electrodes of which 9 is the gap electrode opposed to a plate 11; Fig. 2, two rings of electrodes of which 21, 22 form the gap; Fig. 3, gap electrodes 33, 34 associated with spheres 31, 32; Fig. 4, hemispheres 38, 39, 41, 42 of which 38, 41 form the gap; Fig. 5, gap electrodes each associated with an umbrella plate 50 or 51. In the modification according to Fig 6 the capacity element 67 is inserted in the path of the discharge.