Drive 12 LEDs with one I/O line
Date: Feb 4, 2010 | Author: Charaf Laissoub, Maisons Alfort, France; Edited by Martin Rowe and Fran Granville | EDN
Use a binary counter to generate LED-lighting codes. + read more.
Innovative packaging improves LEDs’ light output, lifetime, and reliability
Date: Jan 7, 2010 | Author: By Margery Conner, Technical Editor | EDN
HB-LED packaging design continues to advance, contributing almost as much to performance as the LED chip itself. + read more.
LED flasher checks fiber-optic strands
Date: Jan 7, 2010 | Author: Edwin A Mack, Port Republic, NJ; Edited by Martin Rowe and Fran Granville | EDN
Send visible light through strands to check for breaks. + read more.
Gadget Freak Case #156: Flip on Your Car's Lights and Sirens!
Date: Jan 1, 2010 | Author: Design News Staff | Design News
John Graham's Pinewood Derby cars simulate a two-tone police siren. Book ‘em, Danno! + read more.
7W LED bulb spills its guts, lives to light another day
Feb 8 2010 10:49AM | Comments (6)
I saw an product announcement a couple of months ago from TESS, a Taiwanese manufacturing company, for a 7W LED bulb that, at 560 lumens (lm), can serve as a replacement for a 40W incandescent bulb which typically produces 500 lm. TESS has received UL approval for the light and can begin selling it in the US. It expects the lights to sell for about $22.
I asked for a sample, and TESS obligingly sent along two versions of the light, one in cool while (5000K) and one in warm white (2700K). (The warm white produces 450 lm.) These bulbs are not direct replacements for 40W incandescent because they are non-dimmable. (More on that later.)
I put the warm white... + read more
Cree breaks 200 lm/W barrier, demos 208 lm/W in lab
Feb 5 2010 9:40AM | Comments (8)
Cree announced this week that it broke the 200 lumens/Watt barrier with an industry-best efficacy of 208 lumens per watt for a single white power LED. The device has a correlated color temperature of 4579 K. The tests were conducted under standard LED test conditions at a drive current of 350 mA at room temperature.
This is R&D performance, not a production device. In the past, Cree has said that it generally takes Cree only about 12 months before a lab-level LED is commercialized.
Last mongth, Cree announced 186 lm/W in the lab at 4577 K.
[Via ... + read more
UPDATE: Cree’s MPL EasyWhite LED packs 24 chips into tiny package, obsoletes binning
Feb 2 2010 12:00AM | Comments (4)
With Cree’s announcement today of its XLamp MPL EasyWhite LED the company moves another step forward on its quest to eliminate “binning” from the vocabulary of LED lighting application designers.
The XLamp MPL Easy White can provide as much as 1500 lm at 250mA. This is a best-case number with a pulsed, rather than a constantly-on drive current, but with proper drive electronics and heat sinking, the LED can deliver the light output for a 3000 K, 75-Watt equivalent BR-30 light bulb, while consuming 78% less power than a traditional halogen bulb. (This performance meets the efficacy/lumen requirements for integral LED lamps as defined by the Energy Star... + read more
REFERENCE GUIDE: Nuventix LED Bulb Design
Ideal for LED applications running off 12V or 24V rails, this 4-layer board has input voltage and ground as the 2 internal planes. LM3429 LED driver converts 9 to 36 VDC input to a 700 mA constant current output designed to operate a load of 3 to 4 series LEDs.Works with Nuventix SynJet module to cool the LED luminaire/bulb replacement for MR16 or PAR20/25/30/38 form factors. + view resource.
WEBCAST: Light Sensors and their Role in LED Lighting
Intelligent lighting control systems for LED-based illumination rely on an ambient light sensor, power control circuitry, and a microcontroller. Hear our expert panel discuss selecting the right light sensor for the app, designing the control circuitry, choosing the appropriate microcontroller, and more. + view resource.
WHITEPAPER: Thermal Management for Solid-State Lighting
A common challenge solid-state lighting designers have to address is controlling the thermal environment. National's thermal management solutions address this issue with a portfolio of temperature sensors that complement National’s high-brightness LED drivers. + view resource.
