Circuit arrangement for power supply devices in telecommunications systems, in particular telephone switching systems

摘要

Two voltage sources with equally high voltage individually and separately supply two voltage sinks assigned individually to them in fault-free normal operation via first diodes. Each voltage sink is additionally connected via second diodes to the respective unassigned voltage source and is supplied by the latter if the respective assigned voltage source fails. Two changeover switches individually controlled by each of the voltage sources bypass the first diodes in fault-free normal operation. If one of the voltage sources fails due to a fault, the relevant changeover switch enables the relevant first diode and short-circuits the relevant second diode. The voltage drop which occurs on the diodes when current flows in the forward direction and which is greater than the tolerance range of the supplied voltages, decouples the two voltage sources even during their fault-free parallel operation. If one voltage source fails, voltage supply is taken over without interruption by the other voltage source for the voltage sink assigned to the former voltage source, the operating voltage concerned being reduced by the amount of the diode voltage drop only during the changeover switch response time.