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Balanced
In telecommunications and professional audio, a balanced line or balanced signal pair is a circuit consisting of two conductors of the same type, both of which have equal impedances along their lengths and equal impedances to ground and to other circuits. The chief advantage of the balanced line format is good rejection of common-mode noise and interference when fed to a differential device such as a transformer or differential amplifier.G. Ballou, ''Handbook for Sound Engineers'', Fifth Edition, Taylor & Francis, 2015, p. 1267–1268. As prevalent in sound recording and reproduction, balanced lines are referred to as balanced audio. Common forms of balanced line are twin-lead, used for radio frequency signals and twisted pair, used for lower frequencies. They are to be contrasted to unbalanced lines, such as coaxial cable, which is designed to have its return conductor connected to ground, or circuits whose return conductor actually is ground (see earth-return telegraph). Bal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balanced Circuit
A balanced circuit is circuitry for use with a balanced line or the balanced line itself. Balanced lines are a common method of transmitting many types of electrical communication signals between two points on two wires. In a balanced line the two signal lines are of a matched impedance to help ensure that interference induced in the line is common-mode and can be removed at the receiving end by circuitry with good common-mode rejection. To maintain the balance, circuit blocks which interface to the line, or are connected in the line, must also be balanced. Balanced lines work because the interfering noise from the surrounding environment induces equal noise voltages into both wires. By measuring the voltage difference between the two wires at the receiving end, the original signal is recovered while the noise is rejected. Any inequality in the noise induced in each wire is an imbalance and will result in the noise not being fully rejected. One requirement for balance is that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balanced Audio
Balanced audio is a method of interconnecting audio equipment using balanced interfaces. This type of connection is very important in sound recording and production because it allows the use of long cables while reducing susceptibility to external noise caused by electromagnetic interference. The balanced interface guarantees that induced noise appears as common-mode voltages at the receiver which can be rejected by a differential device. Balanced connections typically use shielded twisted-pair cable and three-conductor connectors. The connectors are usually three-pin XLR or TRS phone connectors. When used in this manner, each cable carries one channel, therefore stereo audio (for example) would require two of them. Applications Many microphones operate at low voltage levels and some with high output impedance (hi-Z), which makes long microphone cables especially susceptible to electromagnetic interference. Microphone interconnections are therefore a common application for a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balun
A balun (from "balanced to unbalanced", originally, but now dated from "balancing unit") is an electrical device that allows balanced and unbalanced lines to be interfaced without disturbing the impedance arrangement of either line. A balun can take many forms and may include devices that also transform impedances but need not do so. Sometimes, in the case of transformer baluns, they use magnetic coupling but need not do so. Common-mode chokes are also used as baluns and work by eliminating, rather than rejecting, common mode signals. Types of balun Classical transformer type In classical transformers, there are two electrically separate windings of wire coils around the transformer's core. The advantage of transformer-type over other types of balun is that the electrically separate windings for input and output allow these baluns to connect circuits whose ground-level voltages are subject to ground loops or are otherwise electrically incompatible; for that reason they ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unbalanced Circuit
In electrical engineering, an unbalanced circuit is one in which the transmission properties between the ports of the circuit are different for the two poles of each port. It is usually taken to mean that one pole of each port is bonded to a common potential (single-ended signalling) but more complex topologies are possible. This common point is commonly called ''ground'' or ''earth'' but it may well not actually be connected to electrical ground at all. Unbalanced circuits are to be contrasted to balanced circuits where the transmission paths are impedance balanced (the impedances are identical). Examples Passive filter The figure shows two versions of a simple low-pass filter, unbalanced version (A) and balanced version (B). Both circuits have exactly the same effect as filters, they have the same transfer function. However, on the unbalanced circuit, the bottom pole of the input port is connected directly to the bottom pole of the output port. Thus, the impedance betwe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unbalanced Line
In Telecommunication, telecommunications and electrical engineering in general, an unbalanced line is a pair of conductors intended to carry electrical signals, which have unequal Electrical impedance, impedances along their lengths and to Ground (electricity), ground and other circuits. Examples of unbalanced lines are coaxial cable or the historic Earth-return telegraph, earth return system invented for the telegraph, but rarely used today. Unbalanced lines are to be contrasted with balanced lines, such as twin-lead or twisted pair which use two identical conductors to maintain impedance balance throughout the line. Balanced and unbalanced lines can be interfaced using a device called a balun. The chief advantage of the unbalanced line format is cost efficiency. Multiple unbalanced lines can be provided in the same cable with one conductor per line plus a single common return conductor, typically the shielded cable, cable shielding. Likewise, multiple microstrip circuits can al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unbalanced Line
In Telecommunication, telecommunications and electrical engineering in general, an unbalanced line is a pair of conductors intended to carry electrical signals, which have unequal Electrical impedance, impedances along their lengths and to Ground (electricity), ground and other circuits. Examples of unbalanced lines are coaxial cable or the historic Earth-return telegraph, earth return system invented for the telegraph, but rarely used today. Unbalanced lines are to be contrasted with balanced lines, such as twin-lead or twisted pair which use two identical conductors to maintain impedance balance throughout the line. Balanced and unbalanced lines can be interfaced using a device called a balun. The chief advantage of the unbalanced line format is cost efficiency. Multiple unbalanced lines can be provided in the same cable with one conductor per line plus a single common return conductor, typically the shielded cable, cable shielding. Likewise, multiple microstrip circuits can al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Differential Signaling
Differential signalling is a method for electrically transmitting information using two complementary signals. The technique sends the same electrical signal as a differential pair of signals, each in its own conductor. The pair of conductors can be wires in a twisted-pair or ribbon cable or traces on a printed circuit board. Electrically, the two conductors carry voltage signals which are equal in magnitude, but of opposite polarity. The receiving circuit responds to the difference between the two signals, which results in a signal with a magnitude twice as large. The symmetrical signals of differential signalling may be referred to as ''balanced'', but this term is more appropriately applied to balanced circuits and balanced lines which reject common-mode interference when fed into a differential receiver. Differential signalling does not make a line balanced, nor does noise rejection in balanced circuits require differential signalling. Differential signalling is to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Differential Signalling
Differential signalling is a method for electrically transmitting information using two complementary signals. The technique sends the same electrical signal as a differential pair of signals, each in its own conductor. The pair of conductors can be wires in a twisted-pair or ribbon cable or traces on a printed circuit board. Electrically, the two conductors carry voltage signals which are equal in magnitude, but of opposite polarity. The receiving circuit responds to the difference between the two signals, which results in a signal with a magnitude twice as large. The symmetrical signals of differential signalling may be referred to as ''balanced'', but this term is more appropriately applied to balanced circuits and balanced lines which reject common-mode interference when fed into a differential receiver. Differential signalling does not make a line balanced, nor does noise rejection in balanced circuits require differential signalling. Differential signalling is to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Twin Lead
Twin-lead cable is a two-conductor flat cable used as a balanced transmission line to carry radio frequency (RF) signals. It is constructed of two stranded or solid copper or copper-clad steel wires, held a precise distance apart by a plastic (usually polyethylene) ribbon. The uniform spacing of the wires is the key to the cable's function as a transmission line; any abrupt changes in spacing would reflect some of the signal back toward the source. The plastic also covers and insulates the wires. It is available with several different values of characteristic impedance, the most common type is 300 ohm. Twin lead is mainly used as an antenna feedline at shortwave and VHF frequencies, to connect radio receivers and transmitters to their antennas. It can have significantly lower signal loss than miniature flexible coaxial cable, the main alternative type of feedline at these frequencies; for example, type RG-58 coaxial cable loses 6.6 dB per 100 m at 30 MHz, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Twin-lead
Twin-lead cable is a two-conductor flat cable used as a balanced transmission line to carry radio frequency (RF) signals. It is constructed of two stranded or solid copper or copper-clad steel wires, held a precise distance apart by a plastic (usually polyethylene) ribbon. The uniform spacing of the wires is the key to the cable's function as a transmission line; any abrupt changes in spacing would reflect some of the signal back toward the source. The plastic also covers and insulates the wires. It is available with several different values of characteristic impedance, the most common type is 300 ohm. Twin lead is mainly used as an antenna feedline at shortwave and VHF frequencies, to connect radio receivers and transmitters to their antennas. It can have significantly lower signal loss than miniature flexible coaxial cable, the main alternative type of feedline at these frequencies; for example, type RG-58 coaxial cable loses 6.6 dB per 100 m at 30 MHz, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star Quad Cable
Star-quad cable is a four-conductor cable that has a special quadrupole geometry which provides magnetic immunity when used in a balanced line. Four conductors are used to carry the two legs of the balanced line. All four conductors must be an equal distance from a common point (usually the center of a cable). The four conductors are arranged in a four-pointed star (forming a square). Opposite points of the star are connected together at each end of the cable to form each leg of the balanced circuit. Star quad cables often use filler elements to hold the conductor centers in a symmetric four-point arrangement about the cable axis. All points of the star must lie at equal distances from the center of the star. When opposite points are connected together they act as if they are one conductor located at the center of the star. This configuration places the geometric center of each of the two legs of the balanced circuit in the center of the star. To a magnetic field, both legs of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Twisted Pair
Twisted pair cabling is a type of wiring used for communications in which two conductors of a single circuit are twisted together for the purposes of improving electromagnetic compatibility. Compared to a single conductor or an untwisted balanced pair, a twisted pair reduces electromagnetic radiation from the pair and crosstalk between neighboring pairs and improves rejection of external electromagnetic interference. It was invented by Alexander Graham Bell. For additional noise immunity, twisted-pair cabling may be shielded. Cable with shielding is known as shielded twisted pair (STP) and without as unshielded twisted pair (UTP). Explanation A twisted pair can be used as a balanced line, which as part of a balanced circuit can greatly reduce the effect of noise currents induced on the line by coupling of electric or magnetic fields. The idea is that the currents induced in each of the two wires are very nearly equal. The twisting ensures that the two wires are on ave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
