Wetting current supply system for pair of wires, e.g. telephone twisted pair, uses electrical switches to connect the wires to a source of current or voltage isolated from ground

摘要

Current is fed into a pair of lines via an electrical circuit with at least a voltage or a power source isolated electrically from ground. The circuit is preferably arranged so that at least a pair of lines are independently controlled in a time-wise manner, and are switched into connection with the voltage or power source whose output increases with a slow ramping function, via at least one relay.