GB391401A - Improvements in and relating to surge indicators - Google Patents

Abstract

391,401. Protective arrangements. INTERNATIONAL GENERAL ELECTRIC CO., Inc., 120, Broadway, New York, U.S.A. -(Assignees of Allgemeine Elektricitõts- Ges. ; 2, Friedrich Karl-Ufer, Berlin.) Dec. 16, 1932, No. 35755. Convention date, Dec. 16, 1931. [Class 38 (iv).] In order to indicate the number of discharges that have taken place across a spark gap f, Fig. 1, in the earth conductor a of a lightning or surge conductor A, the gap is shunted by a condenser c in series with a choke coil d, the condenser being normally kept charged to the potential of a directcurrent source b. On the' occurrence of a discharge, the gap / is rendered conducting and allows the condenser c to discharge. After the discharge has taken place, the condenser is again charged from the source b through a resistance e and a relay g operating a counter. The choke coil d may be replaced by a resistance. In an alternative arrangement, a resistance or choke coil is inserted in the earth conductor a in place of the spark gap f, which is connected in series with the choke coil d, in the shunt circuit. In a further modification, Fig. 3, a spark gap with three electrodes i<1>, i<2>, i<3> is employed, the electrodes i<1>, i<2> being connected by a high resistance k in order to keep the surge conductor at earth potential at one side..