How Dimmer Switches Work

dimmer switch
How much do you know about light switches? Jupiterimages / Getty Images

When you're furnishing a home, light is everything. The light level in a room dictates what you can and can't do, and it has a huge effect on how you feel. You can't read very easily by a single candle, for example, and a romantic dinner for two isn't so romantic under a 1,500-watt halogen lamp.

­ ­The problem is that people need to use some rooms for multiple purposes, and these different functions call for varying amounts of light. Enter the dimmer switch, a handy electrical component that lets you adjust light levels from nearly dark to fully lit by simply turning a knob or sliding a lever.


In this article, we'll look inside one of these everyday devices to find out how it controls lamp fixtures. As it turns out, the inner workings are pretty cool -- and surprising. Modern dimmer switches work in a totally unexpected way.