| 摘要 |
A certain amount of DC supply current derivable from a subscriber's line (VL, GROUND) is used for powering at respective regulated voltages a plurality of functional circuits (A,B...) of an equipment connectable to the line. A sensible energy saving can be achieved by splitting the valuable current among the functional circuits, on account of their priority rank, by using at least a differential pair of current delivering transistors (P2,P3). A special circuit monitors the actual current of absorption of the functional circuit of highest rank (A) and produces a control signal that is used for modifying the drive conditions of the current delivering transistors. The current waste caused by sinking a design maximum current through a dissipative shunt voltage regulator of each functional circuit as done in the prior art circuits, is prevented and all the current exceeding the actual absorption needs of the highest rank functional circuit may be distributed to the other functional circuits without waste. This same principle may be advantageously applied also to functional circuits of lesser and lesser rank of priority for maximizing the saving. <IMAGE> |
