Protecting against transients in a communication system

摘要

A system is disclosed for transmitting alternating current power and communication signals between a first location and a second location via a communication path which includes at least one inductive load (5) and at least one switching means (13) for switching power to said at least one load on and off. The system includes control means (25) adapted for controlling said at least one switching means so that, in response to switching off said power, a direct current is applied to said at least one inductive load and, in response to actuation of said at least one switching means to switch said power on, said power is switched on during a phase of the power which results in a magnetisation of said at least one inductive load opposite to that resulting from said direct current.