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IEEE 1789-2015 pdf free

IEEE 1789-2015 pdf free.IEEE Recommended Practices for Modulating Current in High-Brightness U EDs for Mitigating Health Risks to Viewers.
This document is divided into eight clauses. Clause I provides the scope of this guide and its context with respect to other IEEE standards and other standards thai arc related to the subject of flicker. (Clause 2 is reserved for future nonnative references.) Clause 3 lists relevant acronyms and abbreviations. Note that no new 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 the concept of flicker and its metrics for lighting applications. Clause 5 describes how the various methods used in the power electronic drivers for LEL) lights will have different effects on the light flicker that is produced in the LED luminaire. Clause 6 gives a summary of the biological elkcts of flicker that have appeared in the literature cited in this document (see the bibliography in Annex B). Clause 7 presents formal risk analysis for flicker in LED lighting. Clause 8 presents three recommended practices relating flicker to modulation depth and frequency. Ii should be mentioned that operating outside the low-risk recommended 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 health problems 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 lighting with which a typical power electronics designer may not be familiar. Annex H is a bibliography of materials cited in this document.
This document attempts to provide information to the reader (e.g.. ballast designers, other standards, or certification organizations). using the best knowledge available at the present lime, on how to help mitigate the risk of distractions and possible adverse biological effects caused by flicker in LED lighting. At minimum, designers may decide to use this information to help design the output filters or switching frequency of their driving methods for LE[) lamps. The authors of this document recognize. also, for example. that it is common in the video game industry to put warning labels in their productsimanuals to alert photosensitive people about their products if they believe flicker is a concern. Without the information in this document, designers could be unaware of how their lighting design decisions may impact human biological responses. This document should therefore be a valuable informational resource to the entire lighting industry. LED IC driver manufacturers, LED manufacturers, and even to the broader designers of luminaires other than LEDs since much of what is described in this document is applicable to all types of lighting).
As the use of LED lighting proliferates in the consumer sector, it is vital for the lighting design community and other standards organizations to determine how to best use the information in this document. The recommended practices presented in Clause 8 describe how to help mitigate the risk of possible adverse biological 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 presented should lead to minimal biological eflcis of the flicker in the LED luminaires. The recommended practices represent 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 recommended practices is to present potentially lower risk regions that, for many LED driver approaches, are not difficult to achieve.
One of the strengths of this document is that Clause 7 adapts a rigorous risk assessment framework formally used by government agencies and consumer protection agencies for product safety evaluation.This risk assessment follows the method developed by the Eurosafe Working Group on Risk Assessment(Rider et al. 11190]) and is similar in form to the SCENIIIR “Scientific opinion on light sensitivity” [1195].This formal analysis procedure is able to separate the discussions on severity of the biological effect,probability of occurrence, and confidence level of the scientific data on which the conclusions are based. This approach was adopted so that areas that have limited experimental data can be discussed openly within the lighting community. In fact, an additional purpose of this document is to urge industry and research laboratories to continue to critically evaluate data from research and from field cxpcricnce and make additional recommendations when supported by data. The risk analysis discussion in Clause 7 should allow research entities to identify areas of valuable research topics that could further the understanding of the human biological effects of light flicker.
The purpose of this subclause is to assist the reader in applying the recommendations of this document to particular cases of interest in LED lighting. LEDs as a light source do not inherently flicker. Nevertheless. when coupled with their driving electronics, some (but not all) LED lighting products will exhibit more pronounced flicker than current fluorescent and incandescent lamps, even as high as high-pressure sodium (UPS) lamps. This study was undertaken to collect what is known about potential undesirable health eflcts of flicker especially urgent because government and industry studies project that LED lighting products will account for as much as 50% of the lighting market by the year 2020,
It is important to mention that, when dctcrmining the most suitable light source tr a specific application. flicker is only one condition that must be considered, along with factors such as luminous intensity and color metrics, power factor, electromagnetic fields of the driver circuitry, audio noise of chokes. total harmonic distortion metrics, reliability and life metrics, energy saving, cost, lighting application. etc. The scope of this document, though, is to emphasize flicker performance. It is beyond the scope of IEEE Std 1789 to explain many of these other design aspects, but they may also be important in making lighting decisions.
This document provides recommended practices that can help mitigate the risk of possible adverse biological effects of flicker in LED lighting. The recommended practices are suitable for all LED lighting in general illumination. In other words, this document does not separate the discussion into different lighting applications and then create recommended practices for each of the lighting application circumstances. The reasons for this approach are extensively discussed in Clause 7 and Clause 8. However, it could be the next step for other organizations to develop lighting-application-specific recommended practices. This may be within the scope of other certification and standards groups. such as CIE, lEA 4E Solid State Lighting group. ISO TC 274, ENERGY STAR, CALIPER. etc. A logical next step would be for these bodies to use this IEEE document to help develop particular standards that may include lightingspecific applications, weighing such matters as adaptation luminance, color, tasks. etc. The end of Clause 8 further clarifies this idea and urges the lighting community to continue to expand guidelines for flicker in LED lighting.IEEE 1789 pdf download.

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