LED lamps are indispensable items that play an important role in daily life, study, and work. As the most commonly used type of lamp today, LED lamps have the characteristics of no flicker or low flicker rate, which is a crucial assessment indicator. This factor not only affects users' visual comfort but also directly affects the performance and quality of lamps. Therefore, when choosing LED lamps, we must pay great attention to their flicker performance.
LED stroboscopic/flicker refers to the fluctuation of the luminous flux of an LED light source at a particular frequency. This fluctuation causes the brightness or illumination of the light source to change, thus causing a flickering phenomenon in the human eye.
The LED itself is a diode and can only pass direct current, so a power supply must be used to convert AC power into DC power (unless it is battery-powered). The response time of the LED's luminous brightness to the current is very short and changes with the current. How much electricity is passed through and how much light is emitted, so LED flicker is only related to the frequency and ripple of the output current of its driving power supply.
LED lighting products are driven by an AC-to-DC constant voltage or constant current power supply. The light source itself does not produce a flicker; whether there is a flicker depends on the LED driving power supply. Since the drivers vary greatly, the flicker performance of each LED product is also different.
Dimming is a necessary function for smart lighting products and is another cause of flicker. Flicker often intensifies further when the product is loaded with a dimming function. Especially when the dimming is dark, the fluctuation depth is relatively large.
The different flickering frequencies divide the types of flicker into visible flicker and invisible flicker.
Visible flicker: The human eye can perceive changes in brightness and darkness, and the flicker frequency is usually below 80Hz. This flicker is unacceptable for ordinary lighting or display.
Invisible flicker: The human eye cannot perceive abnormal changes in brightness and darkness, but it can be checked by other equipment. Although the human eye cannot directly perceive this flicker, it may still affect vision.
The stroboscopic effect has many effects on the human body, including headaches, eye fatigue, decreased vision, psychological stress, and potential safety issues. In particular, migraine patients are susceptible to light, and stroboscopic light may induce or aggravate migraines.
In addition, for patients with photosensitive epilepsy, stroboscopic light of a specific frequency (such as 3-70HZ) may trigger epileptic seizures.
Therefore, long-term exposure to stroboscopic light should be avoided as much as possible, especially for those sensitive to light and children in the developmental stage of vision.
Using a mobile phone camera can easily detect LED flicker. The specific operation method is as follows:
a. Open the mobile phone camera and point the camera at the LED light.
b. Adjust the shutter speed of the mobile phone camera to the fastest, usually 1/1000 second or faster.
c. Observe the flickering of the LED light in the camera.
If the number of flickers is large, it means the flicker is high;
If the number of flickers is small, the flicker is low.
2. Use a professional stroboscope detector
A professional stroboscope detector can detect LED stroboscope more accurately. The specific operation method is as follows:
a. Turn on the stroboscope detector and aim the detector at the LED light.
b. Set the detector's test frequency range and test time.
c. Start the test and observe the stroboscope data displayed on the detector.
Judge whether the stroboscope of the LED light is appropriate based on the test results.
1. It is recommended that you avoid buying uncertified, low-priced, and low-quality LED products and instead try to buy regular-brand lamps and light sources.
2. A credible product test report must be issued.
3. Choose a high-quality driver with a high power factor, preferably a constant current driver with an isolation function.
The flicker problem of LED lamps is often closely related to the design quality of the driver power supply. The driver power supply must not only provide a stable current for the LED lamp beads but also cope with changes in the grid current. Therefore, we should choose high-quality driver power supplies and lamps to ensure our health. You can visit Top Sun Lighting to choose the flicker-free LED light for your business or home.
LED flicker that is too high or too low can damage human vision. Prolonged exposure to this environment can easily lead to eye fatigue, dryness, decreased vision, and other problems. Therefore, it is essential to detect LED flicker.
The shutter speed of a mobile phone camera is breakneck and can capture the rapid flickering of LED lights. By observing the number of flickers of the LED light in the camera, you can preliminarily judge whether the flicker of the LED light is appropriate. However, this method is inaccurate and can only be used as a basis for preliminary judgment.
IEEE P1789 Standard: The IEEE P1789 standard focuses on assessing the flicker of LED lighting products. It provides guidelines for measuring flicker characteristics and setting limits to ensure that flicker does not exceed levels that could cause discomfort or health issues.
IEC 61000-3-3: This International Electrotechnical Commission (IEC) standard addresses the limitation of voltage changes, voltage fluctuations, and flicker in electrical power systems. It sets limits on the permissible flicker levels to ensure the quality of the power supply and prevent adverse effects on connected equipment.
ENERGY STAR: The ENERGY STAR program, overseen by the U.S. Environmental Protection Agency (EPA), requires flicker in LED lighting products to qualify for ENERGY STAR certification. These requirements ensure that certified products meet specific criteria for flicker performance.
CIE S 026: The International Commission on Illumination (CIE) has published CIE S 026, which provides recommendations for lighting workspaces and outdoor work areas. This document includes guidance on flicker perception thresholds and aims to minimize flicker in lighting installations.
National Regulations: Different countries may have regulations and standards related to flicker in LED lighting. These regulations often aim to protect consumers from potential health risks associated with flickering lights.
