Line-powered, automatic changeover circuit which connects a main or secondary connection line to the terminals, in particular telephone stations

摘要

The invention relates to a line-powered, automatic changeover circuit with which n terminals SpStn are connected to a connection line La/Lb, in which known loop detections, setting and resetting circuits are used in conjunction with electronic switching elements and modules in order to carry out the required functions quickly and reliably while excluding complicated relay arrangements and strictly complying with the regulations governing connection to a main or secondary connection line.