Editing Saturable reactor

[[Image:Magnetic amplifier.svg|frame|right|In concept, the alternating current through the lamp L can be controlled by the saturation of the iron core with the direct current, regulated by variable resistor R. B- battery, G – AC source.]]

A '''saturable reactor''' in [[electrical engineering]] is a special form of [[inductor]] where the [[magnetic core]] can be deliberately [[saturation (magnetic)|saturated]] by a [[direct current|direct electric current]] in a control winding. Once saturated, the [[inductance]] of the saturable reactor drops dramatically.<ref>{{harvnb|Choudhury|2005|loc=Section 2.9.1}}</ref> This decreases inductive reactance and allows increased flow of the [[alternating current]] (AC).

==Design considerations==
Saturable reactors provide a very simple means to remotely and proportionally control the AC through a load such as an [[incandescent lamp]]; the AC current is roughly proportional to the [[direct current]] (DC) through the control winding.

The power windings, the control winding, and the core are arranged so that the control winding is well isolated from the AC power. The AC power windings are also usually configured so that they self-cancel any AC voltage that might otherwise be induced in the control winding.

Because the required inductance to achieve dimming varies with the size of the load, saturable reactors often have multiple taps, allowing a small inductance to be used with a large load or a larger inductance to be used with a smaller load. In this way, the required magnitude of the control current can be kept roughly constant, no matter what the load is.

==Obsolete technology==
Saturable reactors designed for mains (power-line) frequency are larger, heavier, and more expensive than electronic power controllers developed after the introduction of [[semiconductor electronics|semiconductor electronic components]], and have largely been replaced by [[thyristor]] [[dimmer]]s using [[TRIAC|triac]]s or [[Silicon-controlled rectifier|SCRs]].

However, as of 2015, there has been renewed interest in using these devices for control of "smart grids" with multiple current tested installations in [[California]], as well as the [[United Kingdom]].<ref name="Young-2015">Young, Marcus Aaron II, "Saturable Reactor for Power Flow Control in Electric Transmission Systems: Modeling and System Impact
Study. " PhD diss., University of Tennessee, 2015.
[https://trace.tennessee.edu/utk_graddiss/3377] Retrieved on Jun 19 2020.</ref>

== See also ==
* [[Magnetic amplifier]]
* [[Constant voltage transformer]]
* [[Transductor]]

==Citations==
{{reflist|25em}}

==References==
*{{cite book |last=Choudhury |first=D. Roy |title=Modern Control Engineering |publisher=Prentice-Hall of India |location=New Delhi |year=2005 |isbn=978-81-203-2196-0 }}

==External links==
*{{cite web |title=Saturable-core reactor |url=https://electriciantraining.tpub.com/14180/css/Saturable-Core-Reactor-152.htm |series=Neets module&nbsp;08 – Introduction to Amplifiers |id=14180 |department=Electrical engineering training series |website=tpub.com}}

[[Category:Electromagnetic components]]

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