Why are the LEDs blinking? Flickering light effect in LED luminaires

We divide the flickering of light into visible and invisible, consciously perceived by the observer and involuntarily influencing human well-being and health. The effect itself depends on the power supply systems, the quality of current and voltage in the network and the types of luminaire control solutions. Unfortunately, the problem concerns all light sources, both traditional light bulbs and energy-saving LED systems. We can feel the side effects even after a few seconds of exposure to light or after long-term use of a defective source.

Health Impact

A long stay in a room where the light frequency is higher than 70 Hz may affect our health and malaise. Installing electromagnetic ballasts in the system reduces the risk of complications. However, we must remember that with the passage of time, the quality of the emitted light deteriorates, and thus its frequency decreases. In addition to frequency, the flicker effect is also influenced by the waveform and the amount of modulation.

The following parameters are used to investigate the effects of flicker:

  • Flicker Percent - determines the cyclical variation of the light amplitude, we can calculate it in this way: Flicker Percent ≤ 0.0333 * flicker frequency [HZ], it results from the fact that the flicker frequency above 3000 Hz meets the safety requirements.
  • Flicker Index - includes a percentage of flicker, waveform shape, and duty cycle, the factor should be in the range of 0 - 0.1.

Strobe effect

In addition to the pulsation of light, there may also be a change in the perception of the visual perception of different frequencies of the light source, the so-called strobe effect. It causes the impression of stopping, slowing down, poses a threat to human health and life. The SVM parameter allows to determine the strobe effect, it is assumed that the SVM value of ≤ 0.4 significantly reduces the possibility of this phenomenon occurring.

Light ripple and LED light

Light emitting diodes are much more sensitive than traditional light sources. At the moment of a power surge in the electric network, a flickering effect may occur, to prevent it, protective filters are used in the power supplies. When buying LED bulbs, it is worth paying special attention to their quality. Obtaining the highest quality light source will reduce the risk of flickering. The cause of this phenomenon may also be a faulty electrical installation, so it is worth checking it in case of any problems with the LEDs.

Lighting has a huge impact on our health and well-being. During the day, countless sources of artificial light illuminate our work and leisure places. It is worth paying attention to and investing in luminaires with high lighting parameters that will reduce the risk of flickering or stroboscopic effects.


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