Dimmer Compatibility — Avoiding Flicker & Buzz
Why your LEDs flicker, buzz, or won't dim below 30% — and how to fix it.
The Compatibility Triangle
Successful LED dimming requires compatibility between THREE components: the dimmer, the driver, and the LED module. If any pairing is incompatible, you get flicker, buzz, limited range, or pop-on behavior.
Dimmer Types & LED Compatibility
| dimmer type | led compatible | issues | best for |
|---|---|---|---|
| Leading edge (TRIAC) | Sometimes | Flicker, buzz, minimum load | Simple residential |
| Trailing edge (ELV) | Good | Smoother but check min load | Quality residential, hotel |
| 0–10V | Excellent | Needs 0-10V capable driver | Commercial, simple analog |
| DALI | Excellent | Needs DALI driver | Commercial, hospitality |
| Phase-cut (universal) | Good | Auto-detects, smoother | Retrofit residential |
Common Symptoms
**Flicker**: visible rapid on-off cycling, especially at low dim levels. Usually caused by leading-edge dimmer with incompatible driver. **Buzz**: audible hum from driver or dimmer. Caused by TRIAC switching artifacts. **Pop-on**: light jumps from off to 30% with no smooth fade. Minimum load of dimmer exceeds the LED load. **Dead travel**: dimmer slider moves but brightness doesn't change for first 20–40% of range.
The Fix
1. Check the driver manufacturer's dimmer compatibility list — most publish tested combinations. 2. For trailing-edge dimmers: ensure total LED load exceeds the dimmer's minimum load (typically 10–25W). 3. Add a 'minimum load' resistor if the total LED wattage is too low. 4. For commercial: use 0-10V or DALI dimming — these don't have phase-cut issues.