Protect your eyes – No flicker
Lighting Flicker and Potential Health Concerns
XineLam- Green lighting - safety, High efficiency, health, comfort

Description: The rapid development of science and technology, all kinds of colorful lighting, enrich people's nightlife; the original Star moonlight bright as day, colorful, gorgeous. However, to date, we are still difficult to find a truly green lighting products. The complete green lighting connotation contains highly efficient energy-saving, environmental protection, safety, comfort, four indicators, indispensable. However, even lighting products meet national certification standards. Even include Energy Star-certified products, there may be Invisible or Imperceptible flicker. The Invisible or Imperceptible flicker, can also affect human health, such as: The effects can range from headache to the decreased visual performance to non-specific malaise to the onset of some forms of epilepsy. (Harding and Jeavons, 1994; Wilkins,1995; Fisher et al. 2005).
View of the flicker harm to human health, so we need a detailed understanding of:

1. What is flicker, flicker harm , flicker simple identification
2. Common lighting will flicker
3. Flicker other hazards - the animals, the photographic camera
4. Flicker causes, and how to avoid the Flicker phenomenon of
5. How to choose a truly green lighting products, in line with national safety standards to comply with the Energy Star,No Invisible or Imperceptible flicker, no harmful rays
6. What is flicker

Flicker: a rapid and repeated change over time in the brightness of light. Visible Flicker: Flicker that is consciously perceivable by a human viewer. Invisible or Imperceptible Flicker: Flicker that is not consciously perceivable by a human viewer. The effects of flicker can range from decreased visual, performance to non-specific malaise to the onset of some forms of epilepsy. (Maddocks et al., 2001)，(Evans et al., 2006).
How to identify the flicker of the lamps have, the easiest way is: take out your camera or mobile phone with a camera function, close-up shots lamp light source, less than 30cm (high brightness point light source is required to use the lampshade diffusion cover), flicker the lamps will show blinds or appear regularly stripes; the no flicker lamps like a blank sheet of paper, not streaks.
The following figure is typical will produce flicker lamps photographs, looks like the blinds or escalator pedal

  
About one third of patients are sensitive to                 100/120Hz flicker
patterns even when there is no flicker,
and most are more sensitive to flicker if it is patterned            

• Common lighting will flicker

Now on the market, the vast majority of lighting have flicker, This is one of the reasons for an increase in patients with myopia. old-fashioned magnetic ballasts fluorescent tubes serious strobe; slight the Flicker phenomenon of new electronic ballasts for fluorescent lamps; high power factor PF> 0.9, single-stage PFC LED light fixtures, flicker equally serious; DC PWM dimming LED lamps strobe vary according to the frequency of the PWM dimming.
  
No flicker LED panel                             100/120Hz flicker
  
        Electronic ballasts for fluorescent tubes slight Flicker          Magnetic Ballast
  
LED tube lights     LED downlight international famous brand         LED bulb
Picture using iPhone 5 direct shooting, No PS.
Note: LED lamps use the unipolar power factor correction circuit is prone to the Flicker phenomenon of; over 5W LED lamps, and some do not use active PFC circuit, may not have the Flicker phenomenon of poor quality products, but also belong, because it does not comply with the most common safetyrequirements.

• Flicker other hazards - the animals, the photographic camera

Flicker is not only harmful to human health, but also harmful to animals, Breeding birds will have an impact (Maddocks et al, 2001), In an animal (cat), 100Hz and 120Hz modulation of light from fluorescent lamps has been shown to cause the phase-locked firing of cells in the lateral geniculate nucleus of the thalamus, part of the brain with short neural chains to the superior colliculus, a body that controls eye movements (Eysel and Burandt, 1984)
Flicker also have an impact on the shooting, poor light source, LED screen refresh frequency is not high enough, when shooting prone stripes, seriously affect the shooting

• Flicker causes, and how to avoid the Flicker phenomenon of

Flicker reasons actually very simple, mainly due to the ballast or drive power generation, we use lamps commonly used 50/60Hz AC supply, both 50Hz and 60Hz are used in different regions. The circuitry in older fluorescent lamps with  ballasts operate so as to flash the lamps at twice the supply frequency (100Hz or120Hz). Normally functioning fluorescent lighting controlled by magnetic ballasts has been associated with headaches due to the flicker produced. LEDs driven so that they flicker at a frequency twice that of the AC supply may have a depth of modulation greater than that from most fluorescent lamps. The effects of the flicker are therefore likely to be more pronounced in these cases.
How to avoid flicker, we know that, flicker AC  power supply ripple caused, greater the ripple, the Flicker phenomenon of greater; using a new type of drive circuit, such as two-stage PFC power factor correction, Increase the filter capacitor capacity, and the use of high quality capacitors, reducing ripple to eliminate the ripple , you can reduce or eliminate the Flicker phenomenon of the corrugated reduce or eliminating corrugated. Pure DC or battery-powered LED lighting products do not flicker. Installation space is limited or circuit design defects, 5 ~ 40W LED lighting market, the vast majority of serious the Flicker phenomenon of a serious impact on human health. Some inferior products may not flicker, but does not meet the requirements of the safety regulations, more low-end materials and circuit safety performance is even more worrying, its safety and reliability be more direct and serious harm to the human body, For example, do not meet the insulation requirements of the product will cause electric shock, does not comply with the EMC product will generate excess electromagnetic radiation. LED lighting lamps XineLam brand, innovative circuit design, no flicker including Invisible or Imperceptible flicker, in line with the requirements of national security regulations, safe and reliable, the international top 8,000 to 10,000 hours 105 ° C electrolytic capacitors, to ensure long life. (90% of the LED products electrolytic capacitor failure affects life, ordinary electrolysis of 1000 hours at 85 ° C)

• How to choose a truly green lighting products, in line with national safety standards to comply with the Energy Star,No Invisible or Imperceptible flicker, no harmful rays
  Green lighting includes: highly efficient energy-saving, environmental protection, safety, comfort, No Invisible or Imperceptible flicker; 5 indicators are indispensable.

Safety: meets national safety certification standards.
      (Multi-product without Hi-pot test, not meet the basic security needs, is truly inferior products).

High-efficiency and energy-saving: luminous efficiency of more than 80Lm / W with power consumption.
(Some manufacturers logo 3W products, actual LED power consumption than 3.6W power consumption, but does not contain, and the power consumption of about 20%, so this logo 3W LED products, the actual power consumption of 4.5W , superscalar 50%)
  
Environmental protection: Complies with RoHS, REACH

Comfortable: no radiation, no glare, no shadows, no noise, natural, no visible flicker (Flicker that is consciously perceivable by a human viewer)

No flicker: Invisible or Imperceptible flicker, 50/200Hz flicker. Protect your eyes – No flicker

XineLam products fully comply with the above five indicators, please purchase.
XineLam brand original article, reproduced please specify xinelam.com
Reference material: IEEE P1789