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sixscrews
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CEO
re: Teardown: LED light shrinks size, cost with non-isolated driver
sixscrews   5/30/2013 6:25:59 AM
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Why are we stuck on screw-in replacements for Edison lamps? Yes, there are billions of Edison sockets out there that can be filled - but the future isn't written in stone. Dump the Edison screw-in replacements and think of something that works best for PN junction light emitters - what is that? I don't know but the prize goes to whoever thinks of the best solution to the new problem, not the old one.

JeffL_2
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CEO
re: Teardown: LED light shrinks size, cost with non-isolated driver
JeffL_2   5/28/2013 4:36:15 PM
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And you're surprised? I worked in that industry awhile, windmills are generally sited where there's a high probability of high sustained winds ie up on hills and at or near the end of long 480V 3PH feeders. To translate that's kind of like putting up a lightning antenna network! You quickly realize these little "surge protector diodes" don't help you A BIT, your protection devices need to actually dissipate significant amounts of power (gas tube protectors help a little). Ever try "recovering" a backplane that's suffered a near-direct strike? Keeping these things up SOUNDS easy until you actually have to do it, then you start to appreciate that it's MUCH harder than it looks!

anne-francoise.pele
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CEO
re: Teardown: LED light shrinks size, cost with non-isolated driver
anne-francoise.pele   4/12/2013 12:54:01 PM
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Click on the link below to check out the collection of Design Articles, Case Studies, Product How-To articles, Teardowns, etc... that have been published on Smart Energy Designline. Check back frequently. The list will be updated as new articles arrive. http://www.eetimes.com/design/smart-energy-design/4371743/LED-Focus

pyeatte
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Rookie
re: Teardown: LED light shrinks size, cost with non-isolated driver
pyeatte   3/23/2013 1:53:43 AM
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Perhaps LED bulb costs could come down with separate low voltage lighting circuits. A step down transformer at each room would distribute low voltage for LED lighting instead of dealing with 120VAC at each bulb.

KGround
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Rookie
re: Teardown: LED light shrinks size, cost with non-isolated driver
KGround   3/22/2013 12:55:08 PM
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A few comments ... 1) Not to be too picky, but I think it is 9 LED chips and not 6 ... 2) A large part of the power supply complexity and parts count (and much of the need for those pesky electrolytic caps) arises out of the need or desire to control power factor. To achieve an Energy Star rating the power factor must be good. This is not a requirement for UL listing as far as I know. Good power factor helps the electric company but is actually detrimental to the customer(at least in the short term) because electric meters do not measure or charge for the 'imaginary' component of power present in poor power factor equipment. 3) I do see the need, at least for the present retrofit market, to make lighting products that are backward compatible with existing fixtures, but the real future and advantage of LED lighting will be achieved with fixture and architectural designs that take maximum advantage of the desirable features of the LED source. See for example the LED 'strip lights' which are becoming widely available at reasonable cost. These are a distributed light source which is more desirable in many architectural designs, and by distributing the LEDS instead of concentrating them the heat dissipation problems go away. In my personal architectural applications I am using DC powered LEDs, which permit direct use of low voltage power source derived from solar without the inherent loss of efficiency arising from converting stored DC to AC and then back to regulated DC at the fixture. The parts count for the LED current regulator is 1 IC and no capacitors are used. But this approach requires a fully integrated design from power source through power distribution (at 12-36VDC) to LED fixture. DC designs can of course also be powered by UL listed class 2 'wall warts' allowing the choice of AC or DC power source, and providing an inexpensive and easily replaceable alternative for the short lived AC power supply.

daemlo
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Rookie
re: Teardown: LED light shrinks size, cost with non-isolated driver
daemlo   3/20/2013 6:25:06 PM
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Does anyone see a problem using electrolytic caps in this application? Forget LM80, 50,000hrs, or 50yrs - The life expectancy on the caps will dictate when you need a new bulb.

Tamza2
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Rookie
re: Teardown: LED light shrinks size, cost with non-isolated driver
Tamza2   3/11/2013 6:51:28 PM
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These little (sometimes large) caps are the bane of most power electronics; will need some alternative or a lot development for renewable energy to really kick in. As an example windmills typically have a 25 year 'warranty', but the power electronics is covered under a 'maintenance' agreement.

Tamza2
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Rookie
re: Teardown: LED light shrinks size, cost with non-isolated driver
Tamza2   3/11/2013 6:49:42 PM
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Myth of 50-year LEDS has to be nixed. Specially if additional electronics in the power circuit (such as motion-sensitive switching) spikes will shorten life of 'bulb' electronics. My CFLs last 'forever', but those with motion-sensor switching.

Tamza2
User Rank
Rookie
re: Teardown: LED light shrinks size, cost with non-isolated driver
Tamza2   3/11/2013 6:43:15 PM
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because the heat (even if a lot less) has to be essentially conducted away rather than lost by radiation.

cyclone08
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Rookie
re: Teardown: LED light shrinks size, cost with non-isolated driver
cyclone08   3/6/2013 5:10:34 PM
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This is correct - the power supply will burn out before the LEDs.

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