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The input impedance or sometimes loading impedance of a circuit or electronic device is the impedance actually experienced by a signal which is connected to its input. There are many kinds of circuit An electric circuit interconnects electrical elements or electronic elements together usually to perform some useful function. ...
For example, an amplifier with 100,000 ohm input impedance looks equivalent to a 100,000 ohm resistor to the signal coming into it.
 Image File history File links A simple source and load circuit. ...
In audio systems Generally in audio and hi-fi, the input impedance of components is several times higher than the output impedance connected to them. This is called voltage bridging or impedance bridging. In this case, Audio can mean: Sound that can be heard. ...
High Fidelity is also the title of a book by Nick Hornby and a film directed by Stephen Frears, based upon Hornbys book. ...
The output impedance, source impedance, or internal impedance of an electronic device is the opposition exhibited by its output terminals to the flow of an alternating current (AC) of a particular frequency as a result of resistance, induction and capacitance. ...
For the amplifier configuration, see bridged amplifier. ...
- Zload >> Zsource
In general, this configuration will be more resistant to noise (particularly power line hum). The best circuits are created by using a voltage follower in the source with the pull-up (load) resistor at the signal receiver. A hum is a sound with a particular timbre (or sound quality), usually a monotone or with slightly varying tones, often produced by machinery in operation or by insects in flight. ...
In video and high frequency signal systems In video and other systems the impedance of inputs, transmission lines, and outputs are designed to be the same. This is known as reflectionless impedance matching or a matched connection. In this case, the impedances much be matched in order to prevent reflected waves from the signal receiver. In video circuits these reflections can cause "ghosting", where the time-delayed echo of the principle image appears as a weak and displaced image (typically to the right of the principle image). A transmission line is the material medium or structure that forms all or part of a path from one place to another for directing the transmission of energy, such as electromagnetic waves or acoustic waves. ...
Some factual claims in this article or section need to be verified. ...
- Zload = Zline = Zsource
In radio frequency power systems In circuits carrying high power it is important that the impedances be matched for several reasons. There are many kinds of circuit An electric circuit interconnects electrical elements or electronic elements together usually to perform some useful function. ...
The concept of power occurs in multiple areas. ...
- The maximum power at maximum efficiency will be transferred when the impedances are complex conjugate matched throughout the power chain, from the transmitter output, through the transmission line (which may be a balanced pair, a coaxial cable, or a waveguide), to the antenna system, which consists of an impedance matching device and the radiating element(s). For maximum power, Zload = Zsource* (where * indicates the complex conjugate)
- Failure to match impedances will create standing waves on the transmission line due to reflections. These will be periodic regions of higher than normal voltage. If this voltage exceeds the dielectric breakdown strength of the insulating material of the line then an arc will occur. This in turn can cause a reactive pulse of high voltage that can destroy the transmitter's final output stage. For reflectionless matching Zload = Zsource (no complex conjugate).
In the case of purely resistive impedances (no reactive components), the two types of impedance matching are identical. This article contains information that is not verifiable. ...
In mathematics, the complex conjugate of a complex number is given by changing the sign of the imaginary part. ...
Antenna tower of Crystal Palace transmitter, London A transmitter (sometimes abbreviated XMTR) is an electronic device which with the aid of an antenna propagates an electromagnetic signal such as radio, television, or other telecommunications. ...
A transmission line is the material medium or structure that forms all or part of a path from one place to another for directing the transmission of energy, such as electromagnetic waves or acoustic waves. ...
In biology, antenna (plural: antennae) refers to the sensing organs of several arthropods. ...
A standing wave, also known as a stationary wave, is a wave that remains in a constant position. ...
The term electrical breakdown has several similar but distinctly different meanings. ...
ARC may be: ARC (former name of Hanson Quarry Products Europe) Action Régionaliste Corse Adaptive Replacement Cache Advance Reader Copy Advanced RISC Computing Advocacy for Respect for Cyclists Affinity, Reality and Communication, the Scientology concept of understanding; see ARC (Scientology) Aging Research Centre Agricultural Research Council AIDS-related complex...
See also In electrical engineering, impedance is, loosely speaking, a measure of resistance to a sinusoidal electric current. ...
The output impedance, source impedance, or internal impedance of an electronic device is the opposition exhibited by its output terminals to the flow of an alternating current (AC) of a particular frequency as a result of resistance, induction and capacitance. ...
The damping factor in an electrical circuit gives the ratio of the impedances of two electronic devices, the load impedance (input impedance) and the source impedance (output impedance). ...
In electronics, a voltage divider or resistor divider is a design technique used to create a voltage (Vout) which is proportional to another voltage (Vin). ...
A dummy load is a completely ohmic load used mainly in radio frequency electronics. ...
External links - Calculation of the damping factor and the damping of impedance bridging
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