This post was written by Keith Dawson for UBM Tech’s community Web site All LED Lighting, sponsored by Philips Lumileds. It is archived here because the All LED Lighting site has gone dark. This material is Copyright 2013-2015 by UBM Americas.

2014-01-16

LED Luminaire Design Considered Complex

An industry insider has taken a cold look at what it's like today to build up a luminaire product line using LEDs. And the complexity could be with us for a while.

The insider in question is Kevin Willmorth, whom we met a while back in the context of warm dimming. He was one of the first to call for LEDs that lower their color temperatures as they dim. Willmorth hangs his hat at the design studio Luminique and the boutique lighting manufacturer Tasca Lighting. He joined this community in the fall and has participated in some of our discussions.

On the Luminique blog, Willmorth posted a long meditation (one blogger referred to it as a rant) on the complexity inherent in designing with LEDs. The complexity stems, not from anything inherent in the technology -- which is "not any more complex than a low-voltage halogen product or fluorescent fixture" -- but from manufacturers supporting "the whim of marketing to hold a proprietary high ground."

LED makers provide no standard operating voltages, currents, package sizes, package types, or ways to present information in a data sheet. On top of these unnecessary variations, we layer "the thermal profiles of small packages, COB arrays, low- and mid-power packages and arrays, and the effect of thermal interfaces, dimming controls, and wiring issues."

Then there are changing specs. Willmorth twits LED producers (and driver makers) for modifying specs, part numbering, product lines, and just about everything else, often without warning and without any externally visible justification. "I personally spend as much as 25% of my time for customers updating, revising, and recovering from the actions of LED providers and driver producers."

It's the standards, stupid
A further source of complexity arises from the lack of standardization in LEDs and drivers, combined with the very versatility in spectrum and lumen output that LEDs offer. Especially when dealing with a product line of luminaires, it can be difficult to keep the inventory of one-off parts from ballooning unmanageably. The situation with LEDs is "significantly more complex than the conventional lamp-ballast relationships pre-dating LED technology."

Yet one more layer of complexity results from the desire for ever-growing efficacy in LED lighting and the demand that it be documented and proven. "LED products are considered with greater scrutiny than any conventionally lamped product before them," according to Willmorth. All the tests and verifications that the market now demands take time and resources, and they add complexity.

Finally, even when all this complexity is dealt with and designers give the market what it says it wants, in a way that can seem almost perverse, "sales absorption is slower than anticipated, while conventional products remain strong." There is a disconnect between what people say they want and what they will pay for; the latter seems to boil down to "retrofit light bulbs and expensive versions of commodities that have been under price pressure for decades."

Is there a way out of the complexity dilemma in a market that remains dull? Willmorth says it will take some time for rationality and standardization to settle in: "History shows that to resolve this requires decades of constant erosion of proprietary posturing, standardization, and customer acclimation." This is the price of involvement in a market in the midst of convulsive growth, innovation, and reinvention.

Read Kevin Willmorth's diatribe in its entirety. Is the situation as bad as he says? Let's hash it out in the comments.

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