Sign & Digital Graphics

The 2015 LED & EMC Report

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L E D & E M C • June 2015 • 17 due to the narrow space and to elimi- nate hot spots; however, with the dual beam you can normally get away with two small footprint CLM per foot where up to five might have been needed with a 120 degree CLM. Thus optics serve a real purpose when designed, manufacturers and engineered correctly. On the other hand good old 120-degree beam CLM do work fine, so do not fret if you have a large inventory of them left over of if you prefer them. Like all technology if it serves your needs and purpose then go for it. Power Options Let's talk about power on several fronts. HB LEDs provide a real advan- tage. Typically, if the "HB package"— which includes the chip (L E D ), P C B and electronics wire and housing—is designed properly all should be fine. On the other hand the easiest way to get increased lumen/brightness output is to increase the mA voltage to the p/n junction. However, if the package is not designed for the increased voltage, the requisite heat gain can cause premature failure. Understand, this failure might be years out, but in this case it will fail sooner rather than later. It begs the ques- tion: "How do you want your customers to remember you?" Watts per CLM are a direct result of the package components, in total. To understand this simply, watts while mea- sured as consumption is directly related to brightness. Thus a low watts per foot (WPF) will equate to less lumens/bright- ness per CLM and potentially the over- all impact. More and more sign shops seem to be demanding maximum CLM per power supply, even at the expense of brightness. While this seems to be driven to offer the absolute lowest costs and may be aided by our economy in general, this is not always the best solution. As an example, if the average CLM per average job is 37 feet and it only requires one 60w power supply and does not increase the need for more power in this example, then it seems you would want to go with the best brightness option you could offer. In my estimation, I see far too much emphasis on the absolute lowest material costs and a number of these types of sales will ultimately come back to cost you in the long run. Signage is still driven by impact and brightness and while every- one wants the best price, the best price is not always the best solution. This can come into to play even more when con- sidering optics because of the HB chip factor. Other Considerations One more consideration in this mar- ket is your vendor's warranty. Most LED products today in the sign industry have a five-year warranty. However, it is not the cost to warranty the replacement LED that is expensive, it is the service call, and ultimately your company's reputation, if you are in it for the long haul. In closing, these comments are very general and provide an overview of optics and related power considerations. It is my belief that we should always offer the best overall solution first and work backward if the customer demands it, but never cut the prospect short without jus- tification. SDG This channel letter module shows a wide-beam angle optic lens. This channel letter module features a more standard 120 degree SMC chip set.

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