LINE SURGE PROTECTION DEVICE FOR TELEPHONE LINES

摘要

LINE SURGE PROTECTION DEVICE FOR TELEPHONE LINES A line voltage surge protection device for telephone systems which normally include means for grounding excessive currents caused by strokes of lightning and the like. The device includes a gaseous discharge element which becomes conductive when the voltage in the line being protected momentarily exceeds a predetermined value to conduct current to a source of ground potential. A temperature sensitive element which operates upon the presence of a prolonged current serves to short the gaseous discharge element whereby the surge sensitive element includes means resiliently biasing the gaseous element for movement in a direction serving to short the same. A soldered retaining means opposes such movement, and heat developed in a coil in series with the line to be protected melts the solder permitting the shorting action to occur.