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Teardown: LED light shrinks size, cost with non-isolated driver

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Bert22306
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re: Teardown: LED light shrinks size, cost with non-isolated driver
Bert22306   2/23/2013 11:19:45 PM
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Wow. It takes a lot more eletronics than I would have expected, to drive these LEDs. One obvious problem is that they don't use 120 AC or 170 DC, and another must be that you need a current source to obtain predictable light output from individual LEDs. Also, a lot of filtering going on there, with chokes and caps all over the place. Hopefully, this will prevent any significant amount of RF racket from being emitted.

OleAlexander
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re: Teardown: LED light shrinks size, cost with non-isolated driver
OleAlexander   2/25/2013 8:32:12 AM
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I can't help always returning to the irony of LED bulbs; Q why are they more efficient? A because they generate much more light and much less heat. Q what is that huge ugly metal bit? A A heat sink. because it neets to get rid of so much heat. ??

Bert22306
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re: Teardown: LED light shrinks size, cost with non-isolated driver
Bert22306   2/25/2013 8:46:39 AM
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Consider the difference in operating temperature of a PN junction compared with, say, that of a white-hot thread of tungsten.

Pinestream0
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re: Teardown: LED light shrinks size, cost with non-isolated driver
Pinestream0   2/25/2013 4:42:47 PM
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Dimming is an important bulb characteristic for the US market, and is an EnergyStar requirement." This is not true!!! ENERGY STAR Lamps Draft 3 Version 1.0 Specification does NOT require dimming.

conner
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re: Teardown: LED light shrinks size, cost with non-isolated driver
conner   2/25/2013 4:49:36 PM
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You're right - I was thinking of the L-Prize requirement. This is being fixed in the article.-- Margery Conner

EVVJSK0
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re: Teardown: LED light shrinks size, cost with non-isolated driver
EVVJSK0   2/25/2013 6:12:50 PM
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It would be interesting to know an estimated cost of the electronics and if it would be possible to put all the electronics in one package (i.e. the base) that is separate from the actual LEDs and come up with something that could long-term keep the cost of replacement devices down when the LEDs finally burn out. That is, make the LED and/or Light producing part of the design replaceable, but the base resusable. It would probably require a more stable design that is not going to need to change over time so the electronics could be assured of being reusable. Lighting is one of the bigger reoccuring costs that people know are going to happen. Any way in which costs can be significantly reduced ,over the lifetime, would be a big help.

fotoguru2
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re: Teardown: LED light shrinks size, cost with non-isolated driver
fotoguru2   2/25/2013 11:24:34 PM
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I'm guessing those power supplies may burn out due to power supply spikes before those well regulated LEDs do. Or the failure of the supply is what will burn out the LEDs. Who knows? We might need replaceable power supply units for our 100 year LEDs!

Daryl Anderson
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re: Teardown: LED light shrinks size, cost with non-isolated driver
Daryl Anderson   2/26/2013 6:41:44 AM
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I went to the best buy site. From what I can tell the bulbs are 13w not 8w. What am I missing?

dleske
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re: Teardown: LED light shrinks size, cost with non-isolated driver
dleske   2/26/2013 1:32:13 PM
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It takes a lot LESS electronics to drive a LED with CC than it does for a CFL (compact fluorescent lamp) to excite a gas tube with HV/HF waveforms!

dleske
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re: Teardown: LED light shrinks size, cost with non-isolated driver
dleske   2/26/2013 1:53:56 PM
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Filament bulb: 2% of energy emitted as light, 88% as infrared, 10% as conducted heat. Filament at 2600C, glass at ~100C (regular bulb) to ~300C (halogen). Bulb operates by being hot, so heat doesn't worry it. (It can melt lamp shade though.) LED: ~20% of energy emitted as light, ~80% conducted heat. LED is very small, doesn't like being much over 100C, so needs careful design to get heat away. LED lighting can be cooler, safer and more efficient. (Some poor designs are not!)

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