H04M1/00—Substation equipment, e.g. for use by subscribers
H04M1/738—Interface circuits for coupling substations to external telephone lines
H04M1/74—Interface circuits for coupling substations to external telephone lines with means for reducing interference; with means for reducing effects due to line faults
Poste téléphonique comportant un préamplificateur à courant porteur, un interrupteur de coupure de micro et un dispositif de signalisation de cette coupure