PowerSource

Do you have a good topic for a technical paper for the 2010 “Designing with LEDs” Workshop to be held March 17 at the Santa Clara Convention Center? We’re looking for papers on power control, thermal management, optics, and lighting control and networking. If so, please fire off an abstract summarizing your paper in 300 words or less and send it along with author information (name, title, company, and contact information) to me at mconner@reedbusiness.com. Deadline to submit is December 4.

The LED Workshop, which is the only event of its kind to focus on the HB LED drive and control electronics as well as thermal management, will be a great place to see and discuss the latest advances in this booming technology, and to network with fellow designers and developers. For more in...Read More

Reader Jim K left a comment on Monday’s post, “Micro-inverters offer one solution for optimizing solar efficiency,” asking for a list of micro-inverter companies. As mentioned, Enphase is the only one that I know of that’s shipping product, but here’s a list of companies which have made announcements at least of their intention to sell micro-inverters:

• ·         Accurate Solar
• ·        

The lead-in to this post is here: Micro-inverters offer one solution for optimizing solar efficiency.

Probably the most well-known micro-inverter company is Enphase, which sells a 200W inverter for about $200 or about $1/W. This compares with a 3kW string inverter for about $2,000 or about $0.66/W.  Enphase suggests that the additional $.33/W is compensated for by the lowered installation labor and investment costs.

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Power-generating installations of solar photovoltaic panels are changing. Rather than the massive solar farms of the past10-20 years, smaller residential and industrial roof-top installations are gaining favor. These small-scale installations have different characteristics from the solar farms with their acres of arrays of solar panels that all face in the same direction and receive the same amount of sunlight. Solar farms have no obstacles such as neighbors’ trees or utility poles to shade a panel, causing a panel-to-panel variation in power output. On the other hand, residential and industrial installations have some features in common with solar farms: They are subject to dirt and require washing at regular intervals, and have panels that age at slightly different rates, causing variations in panel outputs.

S...Read More

When I saw the headline over at Make magazine, “Eternal flame replaced by LEDs,” I thought I understood immediately what the article would be about. Some monument somewhere which previously had a natural gas flame was “lowering its carbon footprint” by switching to LEDs. Not exactly.

It seems the memorial, located in the Ukraine, was erected after WWII to commemorate the many, many who died there. Natural gas was one of the plentiful commodities under the USSR regime, and for 50 years there was no trouble getting the flame illuminated with its own natural gas line. However, when things started to fall apart in the USSR several years ago, the free natural gas stopped, and it was to...Read More

Cree is inviting folks to submit their photos of lousy lighting. Each month Cree will give away 5 of Cree’s LED-based  LR6 recessed downlights to some lucky winner. Lest you think that’s not a very big give-away, look at the lights’ current price: $98 ea.

Doug Leeper mentioned a while ago that he had bought a Cree LR6 and wa...Read More

In general, batteries are good at storing energy and not so good at charging or discharging rapidly. Supercaps, on the other hand, are excellent at fast charging/discharging, but not so good at storing energy over a period of days or months. Ideally, for energy storage and delivery for the next generation of electric vehicles, you need both characteristics. After all, it takes just 5 minutes to gas (or diesel) up a conventional car. The 4 – 10 hours it takes to re-charge today’s batteries is a sticking point for EVs of the future.

The redox battery (which is shorthand for reduction-oxidation flow battery) offers a novel solution to the problem of charging times: Replace the discharged electrolyte ...Read More

Lest anyone thought the LED-lit, bubble-themed arena design of the Beijing Sports Cube was a fluke, here’s the winning design for the 2014 Winter Olympic Games in Russia. There are very few details on the design itself, other than, “…the exterior shell of the stadium involves a translucent, crystalline skin which engages with the surrounding landscape during the day, and is illuminated at night.” Sounds like the same infinitely changeable LED-based lighting approach of the Water Cube, and its 496,000 Cree XLamp LEDs in red, green and blue.

Via designboom.

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Here’s another entry into the e-book reader market, following on the heels reports that Barnes & Noble would also be fielding their own Kindle-killer. This most recent entry is from LG Display, and its twist is that it comes with a solar cell to boost outdoor reading time.  LG says, "Exposure to sunlight for about four to five hours would extend the running time of the e-book’s battery by a day without the need for additional charging. This would allow longer outdoor use of the e-book and lessens worries about battery discharging."

LG’s interest in thin-film solar cells is that it us...Read More

In the rush to embrace LEDs as the Great Hope for energy-efficient lighting, it’s easy to forget that LEDs themselves are only part of the design equation: The power control electronics are vital components in ensuring both power efficiency and thermal performance for lighting.

We’re having the lunchtime panel discussion that features many of the significant players in LED power management ICs**. I’d like to lead off with some questions that will both spark a good discussion among the panelists, as well as take advantage of the wide variety of experience and design approaches represented on the panel. For example, a softball question might be, “When designing a triac-dimmable LED light, what are the most important features the driver IC should have?” Or, “Are there any gotchas in driving the LED that will affect the life of the LED or ...Read More

In spite of their high lighting efficiency, the cost of high-brightness (HB) LEDs for commodity applications is not low enough yet to compete head-on with older forms of lighting such as incandescent and high-intensity discharge (HID). However, certain applications can justify paying a premium for high-efficiency, long life, ruggedness, and light-color temperature control, and these applications are the sweet spot for HB LEDs.

Here’s a good example (pictured in the brochure below): Solar-powered outdoor lighting for off-grid applications. This Solar Vision Pole’s lamp post is especially novel, because rather than use a standard rigid solar panel that requires additional bracing for wind shear (and can attract the attention of scavenging thieves), the pole itself is wrapped with a flexible solar panel that ...Read More

Philips Electronics has become the first company to submit an entry for the L Prize competition, which is sponsored by the Department of Energy and seeks an LED replacement for the common 80W incandescent light bulb. In addition to bragging rights, the winner will get a significant chunk of the $10M prize fund.

Required metrics for the 60-Watt incandescent LED replacement, as laid out by DOE, include:

• Efficacy of more than 90 lumens per watt, which exceeds the efficiency of all incandescent and most compact fluorescent sources today, which range from 10 to 60 lumens per watt
• Energy consumption of less than 10 watts as compared to a 60 Watt incandescent.
• Output of more than 90

We now have two OSRAM development kits to give away at the free “Designing with LEDs” workshop in Chicago on October 6. The kits aren’t just a handful of LEDs – they  include a power supply board, an ac adapter, a plastic lens, and heat-sink-mounted versions of OSRAM’s OSTAR Lighting, Observation, and Headlamp devices, which target general lighting, projection, and automotive applications.

The workshop features a keynote by LED visionary Cary Eskow, panel discussions with both LED and power IC manufacturers, technical papers, and three hands-on workshops. As you can see, it’s a lot to pack in one day. It’s free, but attendance is limited so click on over and register now.

September 1^st marked the beginning of the phase-out of the incandescent bulb in European Union countries. Intrepid reporters at the British newspaper, the Telegraph, decided not to trust the packaging information on CFLs claiming the enclosed 12W CFL had the equivalent light output of a 60W incandescent. The Telegraph reported that, when measured with a hand-held light meter placed half a meter away from the test light bulb in an otherwise-darkened room, that a frosted 60W measured 101 lux, while a 11W CFL made by General Electric and handed out free to a local utility’s customers measured only 79 lux.

(...Read More

[Are you interested in learning about the latest in designing with HB LEDs? Sign up now for EDN's free "Designing with LEDs Workshop", Oct. 6 in Chicago.]

Last April at Milan Design Week Philips unveiled its OLED-based Lumiblade lighting which it claimed would be the first OLED lighting to reach the mass market. The designs unveiled at Milan were mostly small, lamp-sized devices that did an excellent job of showing off OLEDs’ potential to provide diffused, wide-area lighting, as opposed to the point-source lighting you get from traditional lighting sources.

Philips has announced ...Read More