Low voltage two wire to four wire telephone circuit converter apparatus

摘要

A low voltage two wire to four wire telephone circuit converter apparatus utilizing a series pair of amplifiers to provide a transmit data out signal that is referenced to analog ground. A pair of amplifiers in parallel to receive a receive data in signal which is referenced to analog ground and apply it to the telephone unit. A signal adapter converts the telephone ring signal to a constant one level for transmission over a digital channel in a fiber optic link.