dimmers

A dimmer is an electrical device or control that adjusts the brightness of a light by varying the power delivered to the lamp. Dimmed lighting can create ambience, conserve energy, and extend bulb life in homes, offices, and public spaces.

Most modern dimmers are solid-state devices that cut the AC waveform in a process called phase-cutting. The two common types are leading-edge dimmers, which use a triac to start conduction partway through each cycle, and trailing-edge dimmers, which switch at the end of the cycle. In practice, leading-edge dimmers are common for incandescent and halogen lamps, while trailing-edge dimmers are often preferred for electronic transformers and many LED drivers.

Compatibility matters. Incandescent and halogen lamps dim well with many dimmers, but LEDs and some CFLs require matched combinations and may have a minimum load, flicker, or limited dimming range. Dimmable LEDs exist but should specify both the LED driver and the dimmer type. Some bulbs are not dimmable at all. The dimmer’s performance is influenced by the load type, the driver design, and the dimmer’s control curve, soft-start features, and maximum or minimum brightness.

Safety and installation: dimmers are typically installed in wall switches or lighting control panels. They should be used on circuits rated for the load and installed according to electrical codes. Improper use can cause overheating, buzzing, or fire risk; seek a qualified electrician for installation or repair.