LED Lighting for Industrial Environments Reduces Cost, Improves Safety



Installing energy-efficient lighting in industrial environments can do more than reduce costs; it also can improve safety in industrial areas, such as warehouses and production/manufacturing floors, by providing uniform lighting where it is needed. LED manufacturers continue to develop new technologies and techniques that deliver smaller sizes and higher performance in industrial packages. In many cases, the new LED designs also offer higher brightness that reduce the number of LEDs required for a fixture, all translating into lower total costs, again while improving worker safety.

One of the latest white LEDs from Toshiba America Electronic Components Inc. (TAEC) makes it easier for designers of all types of applications to transition to LED technology. TAEC has extended its LETERAS family of white LEDs to include the ultra-compact TL1L3 series available with an industrial standard 3535 (3.5 mm x 3.5 mm) lens package (Figure 1). The height (including the lens) measures 2.42 mm.

What’s interesting about these white LEDs is that they are produced on gallium nitride-on-silicon (GaN-on-Si) technology, which allows the GaN LEDs to be produced on 200 mm wafers, compared to competitive high-performance white LEDs typically fabricated on sapphire substrates using either 100 or 200 mm wafers. The key advantage for industrial LED lighting and general-purpose manufacturers is lower cost. In addition, the integrated lenses make them suitable for a variety of applications, including security lighting, road lights, LED bulbs, and downlights.


Figure 1: Toshiba’s LETERAS TL1L3 series of white LEDs is available in an industrial-standard 3535 (3.5 mm x 3.5 mm) lens package. (Courtesy of Toshiba)

Despite the small size, the 1.0 W white LEDs deliver up to 145 lumens (typ), depending on the correlated-color temperature (CCT), according to Toshiba. The TL1L3 LED series, consisting of seven devices, offer color temperatures from 2700 K to 6500 K. The LEDs also deliver natural-looking lighting with a minimum color-rendering index (Ra) rating of up to 80. Other key specs include an operating temperature range of -40°C to 100°C, maximum power dissipation of 3.4 W, and very-low typical-thermal-resistance Rthj-s from LED junction to solder point of 5°C/W.

Also addressing 3535 packaging and cost issues, Philips Lumileds’ LUXEON 3535 2D (Figure 2) offers up to 140 lumens per watt (lm/W) efficacy for cool-white light at 4000 K with a minimum-coloring-rendering index (CRI) of 80 for a variety of indoor and outdoor applications. This device combines two LED chips in the package to achieve part-count reduction, reducing the cost of designing diffuse industrial lamps, retrofit lights, as well as consumer downlights. Package dimensions are 3.4 mm x 3.5 mm with a height of 0.8 mm.

The new design reduces LED count in retrofit lamps by fifty percent, according to Philips Lumileds. For example, a 5 W PAR20 lamp can be designed with only four LEDs and a 40 W A19 lamp can be designed with only six LEDs, down from fourteen LEDs, according to the company.


Figure 2: Philips Lumileds’ LUXEON 3535 2D offers up to 140 lumens per watt (lm/W) efficacy for cool-white light at 4000 K. (Courtesy of Philips Lumileds)

In addition to the cost savings, the big advantages here are the high lumens with high efficacy along with the fewer chips required per lighting fixture. These mid-power LEDs operate at 0.5 – 1 W, delivering up to 130 lumens in the 3535 form-factor. Typical luminous flux ranges from 65 to 70 lm. The LUXEON 3535 2D is rated at 100 mA but can be driven up to a maximum of 200 mA. The LUXEON 3535 2D supports ENERGY STAR certification requirements up to 25,000 hours at 85°C and 150 mA. These cost-effective devices provide good uniformity along with low-heat management.

Philips Lumileds also offers the LUXEON M LEDs for industrial, indoor, and outdoor applications, which are optimized for low cost or high efficiency. Like the 3535 2D series, it can reduce LED count in retrofit lamps by 50 percent, but is designed for high-lumen applications. The LUXEON M offers a high-lumen output of more than 1100 lumens with a minimum CRI of 70. Typical voltage is 11.2 V. This design does two things: lowers system cost and improves system performance with the use of efficient off-the-shelf drivers.

Delivering uniform intensity and color, the LUXEON M (Figure 3) is available in three different correlated color temperatures – 3000 K, 4000 K, and 5700 K, and delivers more than 1100 lumens with a minimum CRI of 70. Every LUXEON M is hot tested and specified at 85°C and delivers “Freedom From Binning,” delivering color consistency within a single 3- or 5-step MacAdam ellipse. The series exceeds Energy Star lumen-maintenance requirements.


Figure 3: For high-lumen requirements, Philips Lumileds offers the LUXEON M LEDs for industrial, indoor, and outdoor applications, offering lower-system complexity and overall-solution costs thanks to its light output and efficacy. (Courtesy of Philips Lumileds)

Lower-overall-solution costs are achieved via the light output and efficacy. The LEDs drive down system complexity by eliminating emitters and associated assembly costs. Source uniformity allows optical engineers to create crisp shadow-less beams, tight-beam angles and tight ratios of luminance, according to Philips Lumileds.

Also combining high light output and efficacy is Cree’s XLamp XP-G2 LED, built on its SC³ technology. This device improved upon the previous versions with twenty percent more lumens per watt and 2.5 times the lumens-per-dollar, which translates into a system-cost reduction of fifty-seven percent, according to Cree. Optimized for directional, high-lumen applications, the XP-G2 LEDs (Figure 4) can be used in a variety of indoor and outdoor applications, including low- and high-bay lighting, street, and area lighting. They also can be used in PAR replacement lamps.


Figure 4: Cree’s XLamp XP-G2 LED enables designers to use fewer LEDs to achieve the same brightness at a lower cost or increase performance at the same LED count and power. (Courtesy of Cree)

The higher-performance XP-G2 means designs can use fewer LEDs, which translates into less optics and a smaller printed circuit board, thus lowering system costs. The XP-G2 LEDs offer up to 142 lumens per watt at 350 mA, 85°C or 155 lumens per watt at 350 mA, 25°C in warm white (3000 K). This means lighting manufacturers can use fewer LEDs to achieve the same brightness at a lower system cost or increase performance levels using the same LED count and power.

The XP-G2 family is available in white, outdoor white, and 80-, 85-, and 90-CRI white, and are binned at 85°C. The LEDs are housed in a 3.45 mm x 3.45 mm package size.

Summary

Key to driving adoption in a host of industrial-lighting applications is lower costs through energy efficiency, which LEDs can provide without a doubt, and lowering overall systems costs. Many of the latest LED designs and processes from leading LED manufacturers have been delivering on the latter issue over the past year. These range from the use of GaN-on-Si technology on 200 mm wafers to lower manufacturing costs to improving the light output and efficacy of LEDs that helps reduce the number of LEDs required for a design.

For more information about the parts discussed in this article, use the links provided to access product pages on the Hotenda website.

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