ARRANGEMENT FOR SIGNAL TRANSMISSION BETWEEN A TRANSMITTING STATION AND A RECEIVING STATION

摘要

A transmitting station (1) is connected to a receiving station (2) by a two-wire line (3) via which the supply current (IV) required for operating the transmitting station (1) is transferred from the receiving station (2) to the transmitting station (1). The transmitting station (1) comprises a supply circuit (13) including a voltage regulator (16) for maintaining the operating voltage of the transmitting station (1) constant and an energy store (17) for compensating current and/or voltage fluctuations. Via the two-wire line (3) an analog signal current (IS) variable between two limit values is further transferred from the transmitting station (1) to the receiving station (2), this signal current consisting of the supply current (IV) for the transmitting station (1) and a supplementary current (IE) determined by the transmitting station (1). For transfer of the communication information between the transmitting station (1) and the receiving station (2) by means of a symmetrical communication current (IK) superimposed on the signal current (IS), the communication current (IK) is superimposed on the current flowing from the two-wire line (3) into the supply circuit (13).