From backlighting computer screens and HDTVs to automobile brake and signal lights, airport message boards, large display signs, and lighting fixtures in buildings, the light-emitting diode (LED) has quietly become an integral part of our everyday lives. It has become so significant that ELECTRICAL CONTRACTOR devoted a special 39-page section, “The LED Revolution,” to the topic in July 2011.
Today, electricians and other tradespeople are carrying LED pocket flashlights and using larger portable work lights. Well-known tool-makers have added LEDs to their traditional tool product lines. Why are LEDs suddenly so popular for small work lights and flashlights?
“LEDs have become the single most popular alternative to traditional incandescent lighting,” said Rob Bresnahan of Larson Electronics Magnalight (www.magnalight.com). “Because of their size, durability and forward light projection, handheld LED lighting and small, portable LED work lights are ideally suited for electricians as well as workers in other industries.”
With the growing popularity of LED chips, prices have dropped, making LED flashlights and work lights more affordable and their benefits more attractive.
An LED, Bresnahan said, is essentially a semiconducting material that is layered on a wafer through which electricity is passed, resulting in illumination that uses as much as 25 percent less energy, yet produces the same or larger amount of light. Since they are highly visible, LEDs are popularly used in beacons and light bars.
“LEDs achieve this kind of performance due to their simple design and highly efficient nature,” Bresnahan said. “Rather than [heating] a filament to produce light, which is extremely inefficient and wastes up to 90 percent of the energy it uses to produce heat, LEDs generate light through the process of electroluminescence with much more of the energy radiated as visible light.”
LEDs are extremely efficient. They last for years, and their solid-state design means they are resistant to vibratory damage, making them durable enough to withstand abuses no incandescent lamp could survive.
In addition, heat from LED-generated light can be more efficiently dissipated than with other illuminating sources, Bresnahan said.
“If properly configured, the heat sink for an LED generally will carry heat from the LED away from the lens, while incandescent and high-intensity discharge (HID) sources, such as metal halide and mercury vapor lamps, tend to generate more heat at the lens. In high-wattage applications, LED lights eliminate the potential of high-heat contact when working in confined spaces,” he said.
For cordless personal and space lights, a battery charge—no matter what type of battery—will last longer with LEDs because power requirements are lower. However, the efficiency and durability of LEDs for personal lights would not be nearly as great without the innovation provided by modern lithium-ion batteries, a major leap forward in rechargeable battery technology, Bresnahan said.
Combining the efficiencies of LEDs with lithium-ion battery technology brings flashlights and small work lights to new levels of performance.
“Lithium-ion can retain a charge much longer than the old NiCad batteries that preceded them and when not in use, do not require special procedures for recharging,” he said. “Lithium-ion batteries do not need to be fully discharged before being recharged,” unlike NiCad batteries, and, in fact, work best when left with a small charge before being replenished. Lithium-ion batteries also have a greater charge density than other rechargeable batteries, which means they can hold a larger amount of stored energy in a smaller size. Lithium-ion batteries also can provide both low and high discharge rates depending on their design, allowing them to last twice as long as NiCad batteries. In the last 10 years, lighting and battery technology has progressed by leaps and bounds. Gone are the days of heavy D-cell batteries and fragile incandescent bulbs.”
Are there drawbacks to using LEDs for flashlights and personal lights? The cost still is higher to design and manufacture LED lighting, Bresnahan said, and because the light from LEDs is so intense, high-quality optics are needed to harness the intensity and deliver the light at a distance.
“Optics design has lagged, which can limit LED use for long-distance applications. The cost is higher, both for the design and manufacture of the LED lighting. In general, the more LEDs in a product, the more heat sink material is needed to address thermal issues. More advanced thermal management is necessary to address the cost and size of LED fixtures. Magnalight has made some advancements in this area with circuitry that monitors and controls heat, but heat sink material still is necessary.”
What’s ahead for LEDs in the personal work lighting market?
“LEDs are the future,” Bresnahan said. “For lighting efficiency, LEDs now rival or surpass almost every other form of lighting. They can match most forms of lighting in output and intensity with few notable exceptions, such as high-intensity discharge lamps. Their lifespan is many times that of all other forms of lighting, and they have an inherent durability that is unmatched. On a broader scale, LEDs offer the potential to reduce, by extreme margins, the cost of energy usage in large-scale applications in the industrial and commercial sectors.
“Over the next five years, we can expect rapid increases in the lumen-to-watt ratio. To some degree, the ceiling of progress will be thermal management. If there are significant improvements in a lightweight, cost-effective thermal management material, the improvement could be exponential. That translates into very high-powered, long-lasting personal work lighting at prices that may rival today’s HID lighting.
“Personally, I believe LED lighting will take the path of computer processors and memory capacity with people upgrading consistently, not because the current light they have has failed, but because the newer LED lighting products offer so many more benefits for the price,” Bresnahan said.
Spotlight on Personal LED Work Lights
Bosch’s (www.boschtools.com) 12-volt (V) Max lithium-ion LED flashlight delivers 50 to 60 lumens of light in a compact size that is easy to carry in tool belt, bucket or pocket. It is designed to operate with Bosch 10.8V or 12V Max lithium-ion batteries, which provide more than 7 hours continuous run time on one charge.
The Designers Edge’s (www.designersedge.com) Eco Zone rechargeable work light uses 180 50,000-hour-rated LEDs with high output mirror reflector producing 1,600 lumen output. Durable polymeric housing is cool to touch and suitable for indoor and outdoor use. The on/off switch is weatherproof.
Dewalt’s (www.dewalt.com) 12V Max LED work light produces 130 lumens output. It is powered by a 12V Max lithium-ion battery pack that quick charges in 40 minutes and has no memory and virtually no self discharge. The head rotates 360 degrees and pivots. A powerful magnet provides hands-free use and a kickstand enables hands-free multiple placements.
Greenlee (www.greenlee.com) has a new line of LED flashlights that features 50,000-hour life and digitally regulated beam for constant brightness. The FL2D comes with two brightness settings to extend battery life. It has an aircraft-grade anodized aluminum casing of antiroll feature design.
Gyros’ (www.gyrostools.com) Magnalite Pro cordless, rechargeable 36-LED work lamp is powered by a rechargeable 7.2V lithium-ion battery, which operates 6 hours per charge. Output is 1,100 lumens. The cool-to-the-touch ABS body has a magnetized bottom with a head with a 120-degree pivot range.
Husky’s (www.homedepot.com) 180 LED portable work light has 180 super-bright LEDs producing 100,000 hours of light. The durable lightweight polymeric housing remains cool to the touch during operation and is mounted on a sturdy stand. The weatherproof dual-level switch has a power-saver mode. The light operates on one charge for 4 hours.
Klein Tools’ (www.kleintools.com) Recoil LED Grip-It 90-degree LED flashlight provides 10,000 hours of 21-lumen test light output with 100 percent of light focused forward in a white collimated beam. It has a rugged ABS body with stainless-steel clip for hands-free operation and a durable polycarbonate lens.
Magnalight’s (www.magnalight.com) RL-85-10W1 LED pistol-grip spotlight is rugged and effective. It produces 800 lumens and generates a light beam approximately 800 feet long by 175 feet wide. The light contains a single 10-watt LED rated at 120,000 hours of operational life. It operates for 41/2 hours on a single 90-minute charge of its integrated lithium-ion battery pack.
Milwaukee’s (www.milwaukeetool.com) M18 lithium-ion LED cordless work light has a sealed aluminum head that rotates 135 degrees to allow the 160 lumen LED beam to be directed at the work area. An integrated hook allows for hands-free use.
GRIFFIN, a construction and tools writer from Oklahoma City, can be reached at email@example.com.