PROTECTING CIRCUIT FOR LIGHTNING OR THE LIKE

PURPOSE:To prevent an erroneous operation by providing two capacitors connected in series near a second gas-filled discharge element. CONSTITUTION:A high voltage to be applied among lines of an electric communication equipment 1 due to the rise in a ground potential upon discharge of a lightning surge or the like to the ground is lowered to a predetermined value or less by the operations of gas-filled discharge elements 11, 16, 17 as first, second short-circuiting elements, but an electric vibration due to a transient phenomenon caused by the impedances of the equipment 1, lines L1, L2, AC1, AC2 tends to be generated due to an abrupt change of energy fed up to the start of operation and a terminal voltage at the times of start and stop of discharge of the elements 11, 16, 17. In this case, since two series capacitors 14, 15 are provided near the elements 16, 17, the vibration can be suppressed. Or, the vibration is absorbed or converted to a harmless frequency band. Thus, it can prevent the equipment 1 from erroneously operating.