|5544197||Cutover apparatus and methods for switching a signal between two transmission media|
A system and methods are provided for switching a signal from a first transmission media having a characteristic impedance to a second transmission media. The system includes a driver for driving a signal, the driver having a driver input having a high im...
|4076961||Automatic switching unit for data communications network|
An automatic switching unit for connection to a modem at a remote site in a data communications network. The switching unit normally connects the modem to a primary data transmission path. If the primary path malfunctions, a central site operator can tele...
|3962623||Direct current transmission with two parallel circuits|
A direct current transmission system includes two separate parallel transmission circuits each including convertors. The transmission circuits are bipolar. One pole of one of the circuits is provided with pole reversing switches for the convertors of that...