Patent ID: 6320119
Filing Date: 2001-11-20
Classification: H02G

Abstract:
An air terminal including a curved conductive surface capacitively spaced from a permanent grounded upper central rod, said curved conductive surface having shape and size to optimize the formation of surface corona and streamer only when the median field strength is sufficient to support streamer to propagation of a leader, the curved surface being insulated from said central grounded rod, with an annular air gap there between which acts as a spark gap, an electronic circuit joining the curved conductive surface to ground and, in conjunction with the calculation of the capacitive leader coupling according to the dimension of the conductive surface, and having a value such that in a rising electric field of between 10.sup.8 Vm.sup.-1 s.sup.-1 and 3.times.10.sup.9 Vm.sup.-1 s.sup.-1 the terminal will allow triggering of an arc at the annular air gap, but at lower rates of rise of electric field prevent such a triggering arc.