IEEE 1789:2015 pdf free download – IEEE Recommended Practices for Modulating Current in High-Brightness LEDs for Mitigating Health Risks to Viewers
1.3 How to use this document
This document is divided into eight clauses. Clause 1 provides the scope of this guide and its context withrespect to other IEEE standards and other standards that are related to the subject of flicker.(Clause 2 isreserved for future normative references.)Clause 3 lists relevant acronyms and abbreviations.Note that nonew definitions have been generated for this document;however,for the convenience of the reader,important definitions already in existence are cited in the glossary (Annex A). Clause 4 introduces theconcept of flicker and its metrics for lighting applications. Clause 5 describes how the various methodsused in the power electronic drivers for LED lights will have different effects on the light flicker that isproduced in the LED luminaire. Clause 6 gives a summary of the biological cffects of flicker that haveappeared in the literature cited in this document (see the bibliography in Annex B). Clause 7 presentsformal risk analysis for flicker in LED lighting.Clause 8 presents three recommended practices relatingflicker to moduiation depth and frequency. It should be mentioned that operating outside the low-riskrecommended practice regions presented in Clause 8 does not necessarily imply high risk. However,following the recommended practices would lead to high confidence that there is low risk of healthproblems to viewers due to flicker.This issue is further discussed in Clause 8.
This document also contains two annexes.Annex A presents basic definitions used in vision and lightingwith which a typical power electronics designer may not be familiar. Annex B is a bibliography ofmaterials cited in this document.
This document attempts to provide information to the reader(e.g., ballast designers,other standards,orcertification organizations), using the best knowledge available at the present time, on how to help mitigatethe risk of distractions and possiblce adverse bioiogical effects caused by flicker in LED lighting. Atminimum,designers may decide to use this information to help design the output filters or switchingfrequency of their driving methods for LED lamps. The authors of this document recognize，also，forexample,that it is common in the video game industry to put warning labels in their products/manuals toalert photosensitive people about their products if they believe flicker is a concern. Without the informationin this document, designers could be unaware of how their lighting design decisions may impact humanbiological responses. This document should therefore be a valuable informational resource to the entirelighting industry, LED IC driver manufacturers, LED manufacturers,and even to the broader designers ofluminaires other than LEDs (since much of what is described in this document is applicable to all types oflighting).
As the use of LED lighting proliferates in the consumer sector, it is vital for the lighting design communityand other standards organizations to determine how to best use the information in this document. Therecommended practices presented in Clause 8 describe how to help mitigate the risk of possible adversebiological effects of LED lighting.They may be, at times, conservative for specific lighting applications.This issue is thoroughly and openly discussed in Clause 8.However,following the guidelines presentedshould lead to minimal biological effects of the flicker in the LED luminaires. The recommended practicesrepresent recommended low-risk operating regions of flicker. Operating outside these recommended low-risk regions does not necessarily imply high risk,however. Instead, the purpose of the recommendedpractices is to present potentially lower risk regions that, for many LED driver approaches, are not difficultto achieve.