Dimmers and various lamps

Demonstrating what happens when using different types of lamp with a traditional phase cut dimmer.

The Video

View this video on Youtube.


Traditional lamp dimmers were designed for use with incandescent filament lamps. They may work with some types of LED or even certain compact fluorescent, but in many cases there will be problems.

To work successfully the lamp must be designed for use with dimmers, otherwise dimming will be erratic or not work at all. In extreme cases the dimmer, lamp or both may be damaged.

Even when using incandescent lamps the minimum loading of the dimmer must be met - the example in the video has a minimum load of 60 watts. When used with a 25 watt incandescent lamp, the lamp flickers and even when set to full is very dim.

For dimming LED lamps, a better solution is to use a dimmer specifically designed for use with LEDs. These usually have an adjustment to set the brightness range correctly and will work with very low loads including a single LED lamp.