LED modules sit at the confluence of numerous technologies (MAGAZINE)

Oct. 21, 2011
Synergistic electronic, optical and lighting technologies are revolutionizing LED luminaires, says DAN McGOWAN, an Engineering Manager with Molex Inc.
Today’s advanced LED lighting technologies can deliver the sustainability, scalability, and design flexibility that OEMs need to help them engineer competitive solutions for residential, commercial and industrial markets for solid-state lighting (SSL). However, despite many advantages, there are challenges intrinsic to LED technologies. For example, while LEDs run significantly cooler than incandescent lamps, without proper thermal management their effective service life can be shortened considerably due to heat build-up within the LED junction. Conversely, with proper thermal management in place, LED fixtures can last an impressive 50,000 hours at 70 percent lumen maintenance under normal usage.

LED emitters typically have been soldered to PCBs and assembled into integrated fixtures, without a mechanism to replace a failed LED or update the LED. This assembly approach poses several challenges to the fixture manufacturer, being closer to an electronics assembly than a typical lighting fixture. Even well-established fixture manufacturers can struggle with light sources that are actually electronic components requiring a secure connection to an electronic circuit. Successfully soldered designs still leave solder joints vulnerable to stress during handling. A cold solder joint can result in scrapping a high-cost LED array.

In effect, the LED lighting industry converged into the electronic-component space, requiring different expertise that did not yet exist. As a result, LED product development was initially slow, because the industry was rightly cautious about investing heavily in fixtures that could not be easily assembled, repaired or upgraded. Fixture manufacturers accustomed to traditional lighting have consistently demanded LED modules that more closely emulate traditional lighting.

To address these practical design issues and needs, some manufacturers have combined their electrical, thermal and optical expertise with in-house design and manufacturing capabilities. The resultant modular LED-lighting solutions introduced onto the market follow a familiar model long used by distributors, who are now able to broaden their portfolios beyond traditional light sources to include LED sources. Advances in electronic technologies are for the first time making LED luminaires practical and affordable for mass production.

One LED-lighting modular assembly that was recently introduced to the market uses a two-piece design that emulates a traditional lighting socket, to deliver an easy and familiar installation experience. The assembly consists of a socket or lamp holder that is permanently fastened into the luminaire. The light module inserts into the socket with a push to make the electrical connections, followed by an intuitive quarter-turn to lock the module in place.

This type of modular assembly allows for different flood-beam patterns that enable precision effects for a wide variety of lighting applications, and users can readily alter the beam angle, temperature or light output without removing or replacing the luminaire. Simply switching out the module (with an easy turn) can lend an entirely new look and feel to a lighting installation design.

With such simple LED-lighting modular designs, interior- and exterior-luminaire manufacturers can achieve LED-based products that require effortless installation, interchangeability and upgradeability. The simple plug-and-play modular solution allows manufacturers to adopt SSL into their luminaires, with a flexible path forward at a low price point. Luminaire designers can also use these types of modular designs to develop products in which the LED source can be easily replaced and upgraded, and do so at price points that offer short payback periods for SSL installations.

Potential applications can include down lights, task or accent lights, spot and track lights, troffers and interior-area lighting, retail and display lighting, hospitality lighting, architectural lighting, decorative lighting, and even museum lighting. Support for the industry standardization of module interconnect technology will help to ensure long-term design opportunities, while protecting the development investment of fixture OEMs and their customers.

As LED adoption progresses, the integration of lighting control systems with network devices will likely play an integral role in energy-cost reduction, allowing end-users greater flexibility and control over their environment. Intelligent lighting controls are already making jobs easier, while lowering the carbon footprint. New commercial, industrial and residential buildings are incorporating local-area networks directly into lighting systems to monitor maintenance requirements, determine occupancy, and offer daylight controls and light dimming systems – yet a few more simple and effective ways for OEMs to harness electronic technology to drive down LED power consumption.