- What is flicker?
Strobe refers to the fluctuation of the luminous flux of the electric light source at a certain frequency. Severe flicker can create illusions for the human eye, which can lead to accidents. Different frequencies and fluctuation depths have different effects on people!
01 Visible flicker
The human eye is a very complex system, and individual differences are very large. For most people, light flicker below 80Hz can be detected, which is called visible flicker. Visible flicker is unacceptable for general lighting.
Sensitive weighting function of human eye to flicker▼
02 stroboscopic effect
The moving object is regarded as a series of still images, namely stroboscopic effect. Due to the stroboscopic effect, people will have an illusion, and it is very dangerous to regard some fast-moving equipment as slow-moving or even static.
Example of stroboscopic effect▼
Illusion of machine operation caused by stroboscopic effect▼
03 Phantom Phenomenon
When the flicker frequency is 80Hz-2kHz, and the objects in the environment remain stationary, when the human eye moves in position or direction, the stationary light source will appear as an extended light spot of the system, which is called a phantom phenomenon, such as a car taillight.
- Why does the LED flicker?
01 Caused by power driver
LED lighting products are driven by constant voltage or constant current power supply from AC to DC. Due to the wide variety of drivers, the strobe performance of each LED product is also different. In particular, some manufacturers use simpler drive circuits in order to save costs, and there will be a large stroboscopic problem.
02 Caused by LED light source
The quality of the light source is poor, the single chip is less than 1W, and the wattage of the lamp is falsely marked, which makes the chip also do not match the driver and work abnormally, resulting in stroboscopic.
- What are the effects of flicker on health?
01 Hazards to the human body
Including possible headache, increased intraocular pressure, blurred vision, distraction; neurological problems, such as photosensitive epilepsy.
02 Safety hazards
Such as optical illusions, including rotating machines, road lighting and car lights.
- How to measure flicker?
You can use the mobile phone camera function to identify whether there is stroboscopic. Turn on the camera of the mobile phone and aim it at the lighting product under test, and judge whether the product has stroboscopic by observing whether there are streaks on the screen of the mobile phone.
To assess flicker problems, professional measuring equipment can be used.
According to the requirements of the standard, the measurement of stroboscopic should use a photometric probe to collect data, and the sampling rate should be at least 2kHz or more, the faster the better.
- How to solve the stroboscopic problem?
When buying lamps, we need to try our best to choose LED lighting products from big brands, and ask the merchants to show the corresponding test reports, so as to effectively redu ce the risk of purchasing strobe lamps and protect the health of the family.
- Try to buy regular brand lamps and light sources.
- Please provide the manufacturer with a test report, such as: China Quality Certification Center (CQC) certification.
- Choose a high-quality LED driverwith high power factor, preferably a constant current drive power supply with isolation function.