Editing Network analysis (electrical circuits) (section)

==Definitions==
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|'''[[Electronic component|Component]]'''||A device with two or more [[terminal (electronics)|terminal]]s into which, or out of which, current may flow.
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|'''[[Node (circuits)|Node]]'''||A point at which terminals of more than two components are joined.  A conductor with a substantially zero resistance is considered to be a node for the purpose of analysis.
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|'''Branch'''||The component(s) joining two nodes.
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|'''[[Mesh analysis|Mesh]]'''||A group of branches within a network joined so as to form a complete loop such that there is no other loop inside it.
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|'''[[Port (circuit theory)|Port]]'''||Two terminals where the current into one is identical to the current out of the other.
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|'''[[Electrical circuit|Circuit]]'''||A current from one terminal of a [[generator (circuit theory)|generator]], through load component(s) and back into the other terminal.  A circuit is, in this sense, a one-port network and is a trivial case to analyse.  If there is any connection to any other circuits then a non-trivial network has been formed and at least two ports must exist.  Often, "circuit" and "network" are used interchangeably, but many analysts reserve "network" to mean an idealised model consisting of ideal components.<ref>{{cite journal |author=Belevitch V |title=Summary of the history of circuit theory |journal=Proceedings of the IRE |volume=50 |issue=5 |pages=849 |date=May 1962 |doi=10.1109/JRPROC.1962.288301  |s2cid=51666316 |author-link=Vitold Belevitch }} cites {{cite journal |title=IRE Standards on Circuits: Definitions of Terms for Linear Passive Reciprocal Time Invariant Networks, 1960 |journal=Proceedings of the IRE |volume=48 |issue=9 |pages=1609 |date=September 1960  |doi=10.1109/JRPROC.1960.287676 }}to justify this definition.<br />[[Sidney Darlington]] {{cite journal |author=Darlington S  |title=A history of network synthesis and filter theory for circuits composed of resistors, inductors, and capacitors |journal= IEEE Transactions on Circuits and Systems|volume=31 |issue=1 |pages=4 |year=1984 |doi= 10.1109/TCS.1984.1085415}}<br />follows Belevitch but notes there are now also many colloquial uses of "network".</ref>
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|'''[[Transfer function]]'''||The relationship of the currents and/or voltages between two ports.  Most often, an input port and an output port are discussed and the transfer function is described as gain or attenuation.
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|'''Component transfer function'''||For a two-terminal component (i.e. one-port component), the current and voltage are taken as the input and output and the transfer function will have units of impedance or admittance (it is usually a matter of arbitrary convenience whether voltage or current is considered the input). A three (or more) terminal component effectively has two (or more) ports and the transfer function cannot be expressed as a single impedance. The usual approach is to express the transfer function as a matrix of parameters. These parameters can be impedances, but there is a large number of other approaches (see [[two-port network]]).
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