Power supply for digital telephone exchange - has reserve circuit switches located behind smoothing capacitors to speed switch on

摘要

The power supply, for a digital telephone exchange, supplies reserve units and circuits that are partly or wholly switched off and brought up to full operational readiness in the shortest possible time without supplying these partly-off of wholly-off circuits with unacceptable large currents. - The power supply (Q) for the continuously-on units and circuits (K') (e.g. connection switching memories) is connected directly to the smoothing capacitors (C) that serve the partly or wholly off circuits when the latter are switched in. The switches (S1,S2) that connect in these circuits are located after the smoothing capacitors.