Light-emitting diodes (LEDs) have become so prominent in so short a time that new standards and specifications are emerging faster than most engineers can gain familiarity with them. Prime among those are standards involving overcurrent and overvoltage protection from such organizations as the International Electrotechnical Commission (IEC), the Institute of Electrical and Electronics Engineers (IEEE), Underwriters Laboratories (UL), and the US Department of Energy's Municipal Solid State Street Lighting Consortium (MSSSLC), among others.
Experts say that most designers have a rudimentary understanding of the technical protection requirements for LED-based systems, but often need to be schooled on the details.
"Engineers know surge immunity," Usha Patel, director of the Latin American sales and segment marketing for Littelfuse Inc., told Design News. "They know they have to protect against lightning. They know they have to protect against inductive spikes. But there are areas where they still need to be educated."
The need to know involves many factors. Without protection, overvoltages and inductive spikes can damage sensitive electronics. And lack of understanding can cost money up front.
Patel, who has been involved with a DOE task force and other organizations on the creation of the specifications, suggests engineers familiarize themselves with the following standards:
Overcurrent protection for LED bulbs.UL 8750 addresses protection against the risk of shock and fire.
Overcurrent protection for LED luminaires. Key standards addressing the issue of overcurrent at the luminaire include UL 1598 and UL 1993, as well as UL 1310 and UL 8750.
Overvoltage protection for LED bulbs. Energy Star standards based on IEEE C62.41.2-2002 deal directly with surge suppression at LED bulbs. Outside the US, IEC61000-4-5 is the surge immunity specification for LED lighting.
Overvoltage protection for LED luminaires. DOE standards based on IEEE C62.41.2-2002 deal with surge immunity requirements for outdoor LED lighting.
Well, I won't go so far as to say that they are a racket, but....... they are not a non-profit organization. They have a bad reputation because of their poor customer service, yet if you pay them extra money for expedited testing you can still get the testing you need completed on schedule.
Some engineer colleagues of mine say that UL is a racket. They have toured some of their facilities, and found their practices and testing areas to be very unprofessional and ineffective. Once a company set out to protect consumers, now is just a company to absorb as much money as they can.
After hearing the stories, I have to pause and question any UL standard.
Festo's BionicKangaroo combines pneumatic and electrical drive technology, plus very precise controls and condition monitoring. Like a real kangaroo, the BionicKangaroo robot harvests the kinetic energy of each takeoff and immediately uses it to power the next jump.
Design News and Digi-Key presents: Creating & Testing Your First RTOS Application Using MQX, a crash course that will look at defining a project, selecting a target processor, blocking code, defining tasks, completing code, and debugging.
These are the toys that inspired budding engineers to try out sublime designs, create miniature structures, and experiment with bizarre contraptions using sets that could be torn down and reconstructed over and over.
PowerStream is deploying the microgrid at its headquarters to demonstrate how people can generate and distribute their own energy and make their homes and businesses more sustainable through renewables.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.