saturable control dimmer

electronics

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

July 19, 2026

Quick Summary

A saturable reactor, also known as a saturable core reactor, is an electrical component used in dimming systems. It features an AC reactor coil with a limited impedance that can be adjusted. This adjustment is achieved by using an auxiliary DC excitation coil to magnetize the reactor's magnetic core. As the DC current increases, the magnetism in the core rises, which in turn increases the core's conductivity. This allows more AC current to pass through, thereby controlling the intensity of connected lights. While an early method for dimming, saturable core dimmers are no longer in common use, having been largely replaced by more advanced electronic dimming technologies.12

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

2 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

stagecraft
Dimmers
A saturable core dimmer uses a small DC current to magnetize an iron core through which AC current flows. As the level of magnetism increases, the conductivity of the core also increases; more AC load current is thus able to pass through it, and any lights…
Read More
A saturable core dimmer uses a small DC current to magnetize an iron core through which AC current flows. As the level of magnetism increases, the conductivity of the core also increases; more AC load current is thus able to pass through it, and any lights…
Read More