All You Need to Know About Flickering of LED Light

The flickering of light sources as well as pulsation and stroboscopic effects cause visual disturbances and can lead to fatigue and headaches. You must, therefore, be avoided.

Fluctuations in brightness are referred to as flicker. The observer perceives them as very disturbing. These fluctuations are perceived by humans as very unpleasant at low frequencies (in extreme cases up to approx. 80 Hz). As an exception, low-frequency flicker can also trigger photosensitive epileptic seizures.

A flicker with a high frequency – i.e. outside of the visually perceptible range (e.g. at frequencies from 100 to 400 Hz) – can also have negative effects on well-being, and for example, trigger headaches. The individual feelings can be very different.

With the arrival of LEDs in general lighting, flickering has regained importance, since LEDs are less inert than halogen bulbs. Semiconductors react in the range of around 300 microseconds. When dimming the light source with pulse width modulation(PWM), the LED is periodically switched on and off completely within a short period of time. It can happen that LEDs flicker perceptibly.

In addition, cheap LEDs are often operated with very simple drivers and twice the mains frequency for cost reasons. Disruptions in the mains voltage, incorrectly functioning drivers or interactions with dimmers can also cause LEDs to flicker or produce unwanted flashes of light, even though they are switched off.

The Institute of Electrical and Electronics Engineers (IEEE) divided frequencies and degrees of modulation into basic categories. They allow conclusions to be drawn about the absence of flicker. The following applies: the higher the frequency in Hertz and the lower the degree of modulation, the better and flicker-free the product.

Research into the effects of flickering of LED light sources on the human organism is only just beginning. For safety reasons, we recommend that you always select low-flicker lighting systems. This information should be requested directly from the lighting manufacturer.

If you have any questions about the flicker of the LED lighting fixtures, welcome to contact us directly.