The IEEE Standard P1789 working group has produced a report on flicker in LED lighting.
The report, which is open for public comment, is entitled "A Review of the Literature on Light Flicker: Ergonomics, Biological Attributes, Potential Health Effects, and Methods in Which Some LED Lighting May Introduce Flicker."
Brad Lehman of Northeastern University in Boston, MA, who chairs the working group, says that the document is a survey report and gives no recommended practices or standards. “Its intent is to educate stakeholders on flicker with applications in LED lighting, as per the request of several government agencies,” he says.
The P1789 group goes under the title of "Recommending practices for modulating current in high-brightness LEDs for mitigating health risks to viewers." The group is composed of international research experts in areas such as lighting health, power electronics, photobiology and lamp design.
“The group is assembled to help other standards groups and government labs to understand health effects in light flicker with objective and accurate information. This report is the first step in the process,” says Lehman.
The issue of LED flicker came to the fore recently, after the Energy Star criteria for Integral LED Lamps included a requirement for LED operating frequency to exceed 150 Hz. It is now proposed to change this requirement back to 120 Hz.
The P1789 group is working towards a standard which has the scope to:
- Define the concept of modulation frequencies for LEDs and give discussion on their applications to LED lighting
- Describe LED lighting applications in which modulation frequencies pose possible health risks to users
- Discuss the concept of dimming of LEDs by modulating the frequency of driving currents/voltage
- Present recommendations for modulation frequencies for LED lighting and dimming applications to protect against known adverse health effects.
