Home Depot is now selling a $20 EcoSmart LED bulb — it’s dimmable, even! Margery Conner, of Electronics Design News, got one and went medieval on it to figure out what makes it tick — or in this case, glow.
I love this process of deconstructing a piece of hardware, looking up the datasheets for the components, figuring out the strengths and weaknesses of the design, etc. Here’s a bit of what she learned:
Not the usual intense light sources we’ve seen in other LED lights: These are large surface-area LEDs that make for a very pleasant diffuse light source. And the light only requires two of them to put out 429 lumens at 8.6W.
Well, I couldn’t find a manufacturer’s label, but there is an apparent part number; AM6L1, and the part looks like an LED array, meaning that, rather than a single emitter, the LED packages up several tiny LED chips in one package and covers them with a single phosphor. It’s a good choice to use such a diffused light source – no pixilation.
The e-cap (just partially visible to the right) is potential weak link and this design uses a good-quality part. Compared to other LED lights, this one has relatively little hand-soldering. As we know from Geoff Potter’s research, solder joints are the Achilles’ heel of LED lighting reliability. Going with a highly-integrated LED driver part like the LM3445 in itself gets rid of a lot of solder joints.
If you enjoy these sorts of teardown investigations, stay tuned…. We have a contest coming up to challenge you to peer under the hood of some of your gadgets and tell us what you discover. [Thanks, Tim Slagle!]
Home Depot’s $20 EcoSmart LED light: What’s inside?
More:
HOW TO – Make your own LED bulbs
18 thoughts on “EcoSmart LED light teardown”
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what’s the CRI of that bulb?
Doesn’t say. Here are the specs on the Home Depot page:
http://tinyurl.com/25dnqje
a quick google search tells me that a 60watt bulb produces about 700-800 lumens. Since this bulb produces abt 429, does that make it equivalent to about a 30w bulb? That doesn’t seem very bright to me. Am I missing something? (good possibility). But… one bulb is expected to last 46 YEARS! Wow.
At 49 lumens per watt for the LED, I’ll stick with compact fluorescents (60-70 lumens per watt). It’s encouraging that the LED makers are posting real lumen values, though – maybe they’ll finally get away from the vague, quasi-quantitative brightness and efficiency claims that have dominated their marketing hype for years.
For an objective discussion of lighting efficiency, do a web search on “luminous efficacy.” The Wikipedia article is quite good. I’d post a direct link, but the Make blog still throws me into the spammer holding cell whenever I include a URL.
The problem though is that “lumens” is a total BS unit of measure. It is the amount of light as perceived by the human eye. This is easily gamed. The human eye is more sensitive to the green part of the spectrum and therefore if the light has a spike in the green part of the spectrum, poof more lumens. This is one of the tricks used with spiral CFs to boost that lumen marketing number. It is also why they have such crappy CRIs and why mustard colored paint looks shockingly green when I turn the CFs in the kitchen on. Probably not a great light (spiral CFs) to have in a vanity either. Unless you like looking like the walking dead.
Oh and i saw that the CRI is 87, super duper sucky.
The problem is that LEDs have problems getting much beyond this, but to quantum droop effects in the gallium-indium interface – see http://www.newscientist.com/article/dn19343-making-light-work-of-led-droop.html
The answer will be not the interface gradient suggested there, but the work being done on tunnel effects in batteries, which face an identical problem delivering electrons to quantuum holes. Once that’s mastered, hopefully inside the next few months, not only will recharging a battery be as quick as refuelling a car – thereby making electric vehicles a viable option – but also the efficiency of these lights roughly double. Applying the same technology to power cables will also dispose of most of the power shed, although it will be a strong argument at the same time to revert to Tesla DC.
For the snob who thinks a CRI of 87 is “super duper sucky”, kindly point me at any other bulb with a color temperature of roughly 3000K (appropriate for in-home use) that can save this much money for me in electricity costs, without hazardous waste disposal concerns in my house, with this short of a payback period, that has a significantly BETTER CRI than 87.
I contend you can’t because it doesn’t exist. I have these bulbs, and I consider the CRI to be excellent.
All of the tech specs and EXTENSIVE independent testing results are available at the manufacturer’s website:
http://products.lsgc.com/product/difinity-a19/
Click on “files” to get the reports. This is the 40-watt bulb replacement version at $20. The 60 watt version puts out 770 lumens at the same spectral and chromacity characteristics, and consumes 13 watts instead of 8.6, and costs $30
It almost certainly does that because it has 3 of the “magic yellow circles” instead of 2, for 50% more light output at 50% more power consumed.
With a 5 year warranty, I will hit break-even due to electricity savings on the 60-watt version on any of them that I use over 4 hours per day, all before the warranty runs out. Looks like a “can’t lose” to me.
LED light consider as natural light. I have searched very deeply on this light. Even i have also made demo researched. Hope that will show as soon as possible.