INTERFACE CIRCUIT WITH TRANSIENT EVENT TOLERANCE

摘要

INTERFACE CIRCUIT WITH TRANSIENT EVENT TOLERANCE An interface circuit provides for coupling of communications signals between a conductor of a transmission path, and a key telephone system and provides for protection against electrical energies, as may be associated with transient electrical event occurrences along the transmission path. The interface circuit provides for coupling of some of these transient electrical energies from the transmission path conductor to an earth ground. The interface circuit includes a plurality of electrical components and a plurality of electrical conductors being fixed to either of first and second surfaces of a sheet of electrically insulating material. The electrical conductors are spaced apart from each other by at least a predetermined amount. Some of the electrical conductors connect the electrical components of the interface circuit in a workable arrangement whereby the communications signals may be coupled. First and second electrical conductors are connected to the earth ground and the transmission path conductor, and in combination are arranged to provide a coupling path for said some electrical energies. The coupling path comprises first and second terminating edge portions being arranged one within another, about an opening in the insulating sheet material. One of the first and second electrical conductors is connected to a respective one of the first and second edge portions via the opening. The terminating edge portions are spaced apart one from the other by a distance of less than the predetermined amount.