Posts Tagged ‘SSL’

There remains an issue of flicker and its issues that has been drawn out by a lack of action on the part of our standards and professional organizations. The topic of flicker has been turned into years of discussion, consternation, regurgitation of old information, tests to prove what has already been known for years, and avoidance of conflict. One of my best selling products from the Lumenique Product Center is the Flicker Machine, as simple device for visually detecting and confirming that visible flicker exists within a space or from a source, indicating there is a desire of individuals to know more. I presented a bit on this device and its use here some time ago.

This little spinning wheel tells the story. If you see banding and colorful rainbows, the lights are a flickerin'

This little spinning wheel tells the story. If you see banding and colorful rainbows, the lights are a flickerin’

I have invested my personal time exploring this topic, including membership in the IEEE 1789 committee addressing the risks of flicker, presentations at DOE and other conferences, working with various manufacturers on their line voltage, non-driver products, and personal testing, experimentation and actively living with and under AC LED products.  After more than 6 years of this, one simple question surfaced for me.

If DC and high frequency (>2,000Hz) PWM driven constant current LED solutions produce no visible flicker, why consider a source with greater flicker presence? (more…)

In my previous entries regarding the Cree LR6, I’ve noted the good and bad sides of the product in some detail. I’ve noted my dissatisfaction with the brightness of the diffuser, which has caused me to first apply plastic trim rings to add a little cutoff, then later, to simply not turn them on. Dimming performance over the years has been disappointing as well. No dimmer I have found has dimmed them satisfactorily, most cause them to flicker. The latest from Lutron, designed specifically for LED/CFL sources, did not fix the issues, so I simply gave up. Rather than remove these expensive retrofits ($65.00+ each), I chose to do what many of us do when caught in a  quandary – stopped using them at all. Estimating these were not used more than an average of 1 hour a day for the last 4 years, total operating time is less than 1,500 hours. I’ll give them 2,000hrs, assuming that when they were first put in place, I used them more than I did as we grew tired of their glare and flickering under dimmer control. (more…)

For anyone interested in saying hello in person, to knock ideas around, or just tell me what you think of things, meeting up at a conference is ideal. Since I try to bring original content to each venue, the time it takes to put a presentation together is enough that I usually limit the number of presentations to 3-5 a year. This year is about over, but I do have 3 more to go on the schedule, for anyone interested. (more…)

In a recent article published in Architectural SSL on the topic of blue light content of LEDs, I attempted to present the discussion of blue light from the perspective of those raising concerns about blue light hazards against known and practical objective knowledge on the topic. The article covered the gambit of concerns, from retinal damage concerns to melatonin levels in occupants, from both sides of the argument, as there are those who dismiss this as a non-issue out of hand. The article also forwarded two conclusive suggestions. First: The research on this specific topic, as it relates specifically to LED light sources, is a little thin. Second: For those concerned about blue light content, selecting LEDs of a lower CCT and higher CRI delivered the lowest blue light content. Whether or not this is the best choice for visual acuity was not the subject of the article, nor was it suggested as the best solution overall. There is a great deal of research supporting the concept of high CCT light for enhancing human visual performance. Much of this was completed under light sources other than LEDs, so there is no caveat included that states anywhere that blue light content of LEDs is at acceptable levels, or of no concern. (more…)

After reviewing a range of different metering choices in actual use, I compiled a summary of findings, as well as my own personal subjective ratings of features and overall utility as a lighting professional. This chart is the collection of all findings in a simple comparison table for those who find this useful (like me): (more…)

This is the Lighting Passport Flagship set. Includes case and accessories in a neat package.

This is the Lighting Passport Flagship set. Includes case and accessories in a neat package.

I first saw this device at Light+Build Frankfurt last fall. I was impressed enough to find one added to my collection of tools. The Asensetek Lighting Passport is a unique product in several ways. First, it is essentially a meter head (where the cost is), coupled to an iOS or Android device that does all the computational and display work. The lighting head has a nifty slide action receptor cover, so there is nothing to come off or get lost in a bag or pocket. The measurement range is as broad as any of the other spectrometers tested here, plus some. Not only does it produce the expected spectral power distribution, CRI, CCT, CIE 1931 and 1976 coordinates and illumunance in lux and Fc, it also delivers CQS values. (more…)

We have now entered the modern era, where meters are available with a dazzling array of features, at a fraction of the cost once commanded. In this case, the UPRtek MK350S, available also in a lesser featured, and lower cost MK350N version, produces amazingly beautiful results with little pain in the wallet or the head from learning to use it. You may find this also sold under other brand names, such as AIBC, or sold through outlets such as Allied and Ikan. I first saw the MK350S at Light+Build in Frankfurt. A customer of mine also saw them, and was so impressed, he purchased one and has allowed me some time to play with it and in preparation of building up a test lab for his company. (more…)