What is a two -wire circuit?
The two -wire circuit is a telecommunications connection model, which uses one pair of wires capable of two -way operation for each user point, or in other words, as it sends and receives signals. This connection method is used in most consumer telephone cables that serve end users. Conversely, the connection in most of the trunk and the switching device is usually four wires, each line has separate pairs of wiring for sending and receiving signals. These four -wire systems require installation of devices such as hybrid coil or electronic converter to allow the transfer from four to two wire systems on outgoing lines. The components' impedance at both ends of the two -wire circuit must be carefully compared to avoid echoing on the line due to the current reception and transmission of signals.
Telecommunication installations are two -waysseystems that allow persons toor to communicate with the equipment at both ends of the consumer series. In general, a four -wire system consisting of two separate pairs is used in a large telephone trunk and switching devices for each line. In these installations, one pair is used to send outgoing signals and the other to receive incoming signals. The cables that run from these devices to the end user points are generally the construction of two -wire circuits and have one pair of wires for each line. This means that a single pair is used to facilitate two -way operation, allowing the reception and signal transmission.
Conversion from the four -wire replacement settings and the two -wire consumer circuit is allowed to include the converter on each line. This device allows you to convert separate outgoing and incoming signals in the device for two -way operation used in a two -wire circuit. These converters can be in older installation, be hybrid target transformers or integrated circuit (IC) and reZistor packages in newer devices. These devices also make it easier to equalize the impedance of both sides of the line.
Impedance balancing in a two -wire circuit is critically important for maintaining a good and clear signal. Impedance is a term used to describe the overall alternative (AC) resistance in terms of amplitude, voltage, current and phase relationship. If the non -user and phone or modem impedance do not match the user, the quality of the signal will be poor, with unacceptable levels of volumes and echoes. That is why most countries have strict standards that ensure consistency in tool specifications available for end users.