One of the biggest challenges facing modern society is the conservation of energy, both at home and in the workplace. Energy efficient LEDs use as little as ten percent of the energy of conventional lighting to illuminate the same area and, coupled with fittings designed for LEDs to maximise output, are far more efficient in directing light where required.
LEDs are also rugged, durable and shock/vibration proof - much more so than alternative incandescent or fluorescent lighting – and they offer much longer life, though this will ultimately depend on the weakest link in the chain; a failing seal or electronic controller, for example.
One company that has gained a great deal of experience of LEDs over the years through its work on photoelectric sensor technology is Turck Banner, which, in addition to its sensor development activities, has its own ‘Lighting & Indicators’ division with advanced LED technology at its heart. The company now offers a comprehensive range of task lights, which provides an industrial alternative to fluorescent and halogen bulbs in enclosure, area and machine lighting, including control cabinets and panels.
Industrial LED lighting is a relatively new sector for the company and it follows on from a highly successful venture into the illuminated switches and pushbuttons market, which it has served well with high-durability products offering the highest level of sealing, including IP69K.
Despite it being a relative newcomer to the LED lighting scene, Turck Banner believes that its venture into this area could soon overtake its sensor business in volume terms, particularly as it is now actively seeking to diversify into the domestic (high-end kitchens) and leisure (boats, caravans, motor-homes) markets.
Turck Banner says its entry into the production of high-reliability, high-intensity LED lighting was born out of the more complex world of photoelectric sensing from which it has gained valuable experience in terms of encapsulation, sealing, connectors, electronic circuit and housing design – features that are just as relevant to industrial lighting fixtures as they are sensors.
Turck Banner’s WLS28-2 work light strips are a good example of the type of products that can provide bright, even and efficient LED illumination. They are suitable for use in enclosure interiors for increased visibility during component installation, maintenance and monitoring, and are also ideal for work stations with poor factory lighting.
These strips are available in low-profile, 28mm wide, rugged aluminium housings sealed to IP50 as standard, with IP67 and IP69K available as options should the application demand it. Units can be cascaded end-to-end to extend the lit area, and at just 7W per foot, they provide a particularly energy efficient alternative to fluorescent and halogen alternatives.
IDEC has introduced a new range of LED lights for challenging applications, featuring 'surface illumination technology'. Surface illumination technology provides improved light output and shadow-free target illumination. The consistency of light from the illuminated surface helps to ensure irregularities or small scratches on the target surface can be accentuated, which is particularly useful for machining operations.
The new products range from a mini version, the LF1D-C (100m x 50m x 25mm), to the larger LF1D-H (385 x 80 x 24.8mm) and -J (510 x 80 x 24.8mm) versions. These lights provide flat, no-multi shadow LED illumination with less glare, as well as offering an excellent alternative to fluorescent lights in industrial applications, including machine tool work areas. Each unit is housed within a diecast aluminium enclosure with stainless steel and reinforced glass cover providing IP67F ingress protection.
Driving LED lighting
LEDs are inherently reliable but their performance – and particularly life expectancy – will be determined by the electronic devices used to drive them. Sunpower has recently launched new DIN rail mounting units, the 40W DRA-40 and 60W DRA-60 power supply series, complete with output current adjustment. This function allows the output current to be adjusted via a 1 – 10 Vdc, variable resistance or PWM signal; in effect it provides a ‘three-in-one’ dimming function and can be used to control LED brightness effectively.
Accepting a full range 90–264Vac or 127-370Vdc input, the DRA-40 and DRA-60 ranges each comprise two models, providing 12 Vdc and 24 Vdc outputs respectively. With a working efficiency of up to 87 percent, these products can work in ambient temperatures from -30°C to +70°C using only air convection cooling. And having a width of just 40mm, they can tuck into quite tight panel spaces. Sunpower sees typical applications from machine vision inspection to LED lighting for plant cultivation systems.
Stadium Power has launched a range of competitively priced LED drivers for a wide range of indoor and outdoor use in LED based industrial and commercial lighting applications. The LDP series offers 24, 36 and 48V constant current outputs over the range 25, 40 and 60W, and an optional dimming function is available via a signal from a dimming controller with PWM/1-10Vdc control signal.
Standard features include a wide universal ac input range from 90-305Va, active power factor correction (better than 0.9), low inrush current (less than 5A), a low profile and narrow footprint for ease of installation. Optional IP67 water proofing for outdoor or harsh environmental conditions is also available.
Online distributor reichelt elektronik offers a broad range of high-quality LED switch mode adapters from the Taiwanese manufacturer MeanWell. For indoor industrial applications the LCM series with outputs of up to 60W feature a push dim function and a multi-constant current output that can be set via a DIP switch. A DALI interface is also provided, enabling integration with home automation systems.
Efficiencies of up to 91.5 percent are quoted, while simple air convection cooling enables use in ambient temperatures up to +60°C. Additionally, a connection is provided for an optional external temperature sensor, allowing temperature monitoring for active power management to maximise LED life.
For more general information about LED lighting, luminaires, controllers and the standards that apply, a good source of information and guidance can be found at the Lighting Industry Association’s website.