 coaxial cable. Only a limited number of ratios (such as 1:9,1:4,1:2) can be achieved with this technique. The cores of such transformers help performance at the lower frequency end of the band. This style of transformer is frequently used as an impedance matching balun to convert from 300 ohm balanced to 75 ohm unbalanced in FM receivers.
Uses of transformers Edit
- Electric power transmission over long distances. The simplicity, reliability, and economy of conversion of voltages by stationary transformers was the principal factor in the selection of alternating current power transmission (see War of Currents)
- High-voltage direct-current HVDC power transmission systems
- Large, specially constructed power transformers are used for electric arc furnaces used in steelmaking.
- Rotating transformers are designed so that one winding turns while the other remains stationary. A common use was the video head system as used in VHS and Beta video tape players. These can pass power or radio signals from a stationary mounting to a rotating mechanism, or radar antenna.
- Sliding transformers can pass power or signals from a stationary mounting to a moving part such as a machine tool head. See linear variable differential transformer,
- Some rotary transformers are precisely constructed in order to measure distances or angles. Usually they have a single primary and two or more secondaries, and electronic circuits measure the different amplitudes of the currents in the secondaries. See synchro and resolver.
- Small transformers are often used to isolate and link different parts of radio receivers and audio amplifiers, converting high current low voltage circuits to low current high voltage, or vice versa. See electronics and impedance matching. See also isolation transformer and repeating coil.
- Balanced-to-unbalanced conversion. A special type of transformer called a balun is used in radio and audio circuits to convert between balanced circuits and unbalanced transmission lines such as antenna downleads. A balanced line is one in which the two conductors (signal and return) have the same impedance to ground: twisted pair and "balanced twin" are examples. Unbalanced lines include coaxial cables and strip-line traces on printed circuit boards. A similar use is for connecting the "single ended" input stages of an amplifier to the high-powered "push-pull" output stage.
- Main : Distributed generation, Electronic power supply, Electronics, Inductor, Pickup, Electrical network, Electricity distribution, Wet transformer, List of electronics topics
- Circuits: Ballast, Clamp meter, Repeating coil, Inverter (electrical), Ignition system, Electricity generation, Linear variable differential transformer, Neon signage, Regulator, Electrical substation, Switched-mode power supply, Technological applications of superconductivity, Tesla coil, Transducer
- Electromagnetism: Alternating current, Electric power, Electric power transmission, Electromagnetic induction, Equivalent series resistance, High-voltage direct current, Impedance matching, Inductive coupling, Potential difference, Skin effect, Leakage inductance, Superconductivity
- People: Ottó Bláthy, Miksa Déri, John Ambrose Fleming, Otto A. Knopp, William Stanley, Nikola Tesla, Milan Vidmar, George Westinghouse, Károly Zipernowsky
- Other: DI unit, Polychlorinated biphenyl, Stafford, Timeline of invention, War of Currents, World Columbian Exposition
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