Symmetrical injection of signals e.g. for testing ADSL, by using two transformers so that voltages are superimposed in opposite directions on both sides of symmetrical line

摘要

Voltages are additively superimposed in opposite directions on both sides of a symmetrical line. The voltage injection is performed using two transformers, whose secondary windings are connected lengthwise in both lines, and whose primary windings are connected in parallel, forming the connections for a supply source. The winding direction is selected so that the injected voltages are oriented in opposite directions.