A four-wire terminating set (4WTS) is a balanced transformer used to perform a conversion between four-wire and two-wire operation in telecommunication systems.
For example, a 4-wire circuit may, by means of a 4-wire terminating set, be connected to a 2-wire telephone set. Also, a pair of 4-wire terminating sets may be used to introduce an intermediate 4-wire circuit into a 2-wire circuit, in which loop repeaters may be situated to amplify signals in each direction without positive feedback and oscillation.
The 4WTS differs from a simple hybrid coil in being equipped to adjust its impedance to maximize return loss.
Four-wire terminating sets were largely supplanted by resistance hybrids in the late 20th century.
Famous quotes containing the words terminating and/or set:
“For, rightly, every man is a channel through which heaven floweth, and, whilst I fancied I was criticising him, I was censuring or rather terminating my own soul.”
—Ralph Waldo Emerson (1803–1882)
“They roused him with muffins—they roused him with ice—
They roused him with mustard and cress—
They roused him with jam and judicious advice—
They set him conundrums to guess.”
—Lewis Carroll [Charles Lutwidge Dodgson] (1832–1898)