TRIAC dimming chops the AC line waveform to reduce power, the same phase-cut method used by classic wall dimmers. It is common in residential retrofits.
| Aspect | Detail |
|---|---|
| Method | Phase-cut on the line voltage |
| Forward phase | Leading edge, older dimmers |
| Reverse phase | Trailing edge, better for LED |
| Needs | Dimmable driver + compatible dimmer |
| Watch for | Flicker, buzz, min-load issues |
Compatibility is everything
TRIAC was designed for resistive incandescent loads. LEDs draw far less, so a mismatched dimmer can flicker, buzz, or fail to dim smoothly at the low end.
Trailing-edge (reverse phase) dimmers generally work better with LED drivers than older leading-edge units.
Check the compatibility list. Manufacturers publish tested dimmer-driver pairings. Using a listed combination is the surest way to avoid flicker and dropout.
See the 0-10V Dimming Guide and the Control Protocol Comparison.