Power Factor Correction & Flicker-Free LED Drivers
"Power factor" and "flicker" are the two specs that never appear on a retail box but decide whether an installation passes inspection or gives people headaches. Both are fixed at the driver stage, so here is what a buyer should actually ask for.
Power factor: why the utility cares
Power factor (PF) is the ratio of real power you use to the total power drawn from the grid. A cheap driver with PF 0.5 pulls twice the current it needs, overloading wiring and tripping the limits in commercial buildings. Many regions now require PF 0.9 or better above 5W, and EN 61000-3-2 sets harmonic limits for exactly this reason.
Flicker: why people care
LED flicker comes from ripple on the driver's DC output. Cheap drivers let ripple run 20-30%, which the eye may not catch but which cameras, sensors and some people absolutely do — it shows up as banding on video, strobing on CCTV, and eye strain in offices. Quality drivers hold ripple under 5-8% and are labelled "flicker-free".
| Symptom | Cause | Fix |
|---|---|---|
| Banding on camera / CCTV | High output ripple | Flicker-free driver, <8% ripple |
| Breaker trips under load | Low power factor | Active PFC driver, PF 0.95+ |
| Buzzing at dim | Incompatible dimming | Matched dimming standard (see dimming guide) |
Where flicker-free is non-negotiable
- Offices and schools — all-day exposure; poor drivers cause fatigue complaints.
- Retail and museums — flicker ruins product colour and photography.
- CCTV and transport hubs — banding makes plates and faces unreadable.
- Any camera-covered site — if a phone records it, specify flicker-free.
How to read a datasheet
- PF: ask for the number across the load, not just at 100%. Active PFC holds it high; passive does not.
- Ripple / flicker percentage: under 8% is "flicker-free" by the SVM metric most specifiers now use.
- THD (total harmonic distortion): lower is cleaner on the supply. Active PFC drivers sit well under the EN 61000-3-2 limit.
Every CHUGAO indoor and IP67 driver is built for PF 0.95+ and flicker-free output as standard, not as a paid option. If your market has a specific harmonic limit, tell us and we supply the test report with the batch.
What we need from you
Send the site type (office, retail, CCTV-covered), the wattage and voltage, and any local PF/harmonic limit. We will confirm a driver that passes it — and send the report before you order.
Specifying for an office or camera site?
Send the site type, wattage and any local PF/harmonic limit. We will confirm a flicker-free, high-PF driver and supply the test report.
Get a clean-driver spec