CIRCUIT ARRANGEMENT FOR SUPPLYING A SUBSCRIBER CONNECTION LINE

摘要

The output of a d-a converter is coupled to the subscriber line. A current measuring device measures the current flowing in the line. An a-d converter is connected to the current measuring device. A digital low pass filter is connected to the output of the a-d converter. A digital function unit is connected between the output of the filter and the input of the d-a converter. The function unit forms an output signal whose amplitude is proportional to the input according to a predetermined relationship.