Flicker in LEDs Explained
What Is Flicker?
Flicker refers to rapid, periodic fluctuations in the brightness of a light source. In LED light sources, flicker can occur when the LED driver does not cleanly convert the alternating voltage from the mains into a constant direct voltage. The result is rapid light-dark cycles that the eye perceives either consciously or subconsciously.
Why Is Flicker a Problem?
Visible flicker (below approximately 80 Hz) is perceived as disturbing and can cause headaches, fatigue or discomfort in sensitive individuals. Even invisible flicker above the conscious perception threshold can have a negative impact on well-being and concentration – this is known as phantom flicker or the stroboscopic effect.
The stroboscopic effect is particularly noticeable with moving objects: rotating parts can appear stationary or to be running in reverse, which poses a safety risk in industrial environments.
How Is Flicker Measured?
- Flicker Percentage (%): Indicates the amplitude of the brightness fluctuation. 0 % means no flicker; 100 % means the light source oscillates between full brightness and darkness.
- Flicker Index: Additionally takes the waveform into account and is more meaningful than the percentage value alone.
- SVM (Stroboscopic Visibility Measure): Assesses the stroboscopic effect. An SVM value of 0.4 or below is considered non-critical.
Which Light Sources Are Flicker-Free?
Premium LED light sources and luminaires with high-quality LED drivers generally produce virtually flicker-free light. Inexpensive drivers without adequate voltage smoothing are the most common cause of flicker. When purchasing, look for specifications such as "flicker-free" or low SVM values.
Frequently Asked Questions (FAQ)
Why does my LED lamp flicker?
Common causes include an unsuitable dimmer, a low-quality LED driver or too low a load on the dimmer. Defective light sources can also cause flicker.
Are all LED lamps flicker-free?
No. The quality of the LED driver is the decisive factor in flicker behaviour. Premium brand products generally offer flicker-free light.
Can flicker be harmful to health?
Prolonged exposure to flicker can contribute to fatigue, headaches and difficulty concentrating. Particularly sensitive individuals or people with epilepsy may be more severely affected.
In Summary:
Flicker-free light is an important quality feature of modern LED lighting. High-quality LED drivers ensure constant, steady light without disruptive brightness fluctuations. At Leuchtenland.com you will find exclusively light sources and luminaires from renowned manufacturers that place great emphasis on high light quality – including low-flicker technology.