The most efficient, poweful & portable LED light source - Page 1
Forum section: electronics / projects

author: hgg
author_rank: Frequent Contributor
timestamp: April 27, 2014, 05:42:25 am
content: I don't know if you have already seen it but while I was searching for efficient light bulbs I came bythis one. The NanoLight / NanoLeaf.http://nanoleaf.me/products/nanoleafhttps://www.kickstarter.com/projects/nanoleaf/nanolight-the-worlds-most-energy-efficient-lightbuThey claim 1600 lumens (100 Watt equivalent) from 12W AC and without any heatsinking!I don't know how they do it, but If this is true, its amazing! Have you seen anything elselike that?I would like to make a DIY lantern style lamp and thinking of using this light bulb with a 12V 7Ah SLAbattery and a small 100W inverter. It will be recharged during the morning from a 500mA solar panel.With a 54mA @ 220V consumption you should have a runtime of at least 20 hours of 100wattsportable lighting! (most of the energy will be dissipated by the inverter...)The thing is that inverters are not really that efficient. Any other solutions powering this lamp?Do you thing that the bulb could be modified and be powered from DC directly?If not, any suggestions for a very efficient low power inverter?Thank you.George.

author: London Lad
author_rank: Regular Contributor
timestamp: April 27, 2014, 08:07:26 am
content: Check out Candle power forums, they have a lantern and a fixed lighting sub forum. There are much more efficient ways of doing what you describe (without the inverter) You will find a wealth of knowledge on LED lighting and drivers etchttp://www.candlepowerforums.com/vb/forum.php

author: hgg
author_rank: Frequent Contributor
timestamp: April 27, 2014, 09:09:34 am
content: Hi, yes this is probably the wrong forum...Thank you.

author: London Lad
author_rank: Regular Contributor
timestamp: April 27, 2014, 09:18:50 am
content: Oh there are some very bright people here too

author: Zero999
author_rank: Super Contributor
timestamp: April 27, 2014, 10:00:01 am
content: These sort of lamps can normally be run off DC as the mains power is rectified as soon as it enters the lamp. Buy the 120V version and hook it up to 10 12V batteries connected in series.

author: georges80
author_rank: Frequent Contributor
timestamp: April 27, 2014, 05:16:01 pm
content: I personally would stay far away from it. Just read the comments (recent ones) in the kickstarter.Given the hype on the 'sales pitch' section of kickstarter, the shipped product falls short in many areas. There's also a lot of misinformation regarding THEIR efficiency versus 'others' and other little marketing gems.I personally have some Cree brand LED 'bulbs' running in my house (3 of them) and they're well over a year old and still performing perfectly with excellent colour temperature. They are used at least 5 hours EVERY evening. The come with a 10yr warranty. UL approved etc etc. i.e. a real product... They were around $10 ea for the 60W. Cree now has 100W equivalent units out for around $25 each.The nano thing has a lot of LEDs so I'm guessing they are all in series and that would get up close to 100V total string voltage. Converting them to run 12V DC is not going to happen.A single XML2 driven at 3A will get you up in the 1200 lumen range and can be easily connected to a 12V capable constant current LED driver. There's lots of ways to get a nice light output. You could run 3 series XPG2 at lower current (higher efficiency) with a 12V LED driver that would be in the 94% efficiency range. All depends how you want to build your lantern and WHERE you want the light directed. No point shining light all over the place if you are trying to light up one area...cheers,george.

author: hgg
author_rank: Frequent Contributor
timestamp: April 27, 2014, 05:44:49 pm
content: Hello George,QuoteI've read a review by extremetech.com in which they say that the bulb has a low CRI.http://www.extremetech.com/electronics/164340-nanolight-led-bulb-strives-for-efficiency-at-any-cost-repeats-mistakes-of-the-cflThey show two photos, one of the nanoleaf and the other of the cree bulb. The nano leaf has a verystrong green tint which I really don't like in any kind of light. The review though is not convincing I thinkbecause they are comparing CRI and they don't provide in the photos a control color scaled imagefor reference. The green tint shown is very much exaggerated. Maybe someone has the bulband can confirm if it has such a strong green tint.QuoteYes I have some of them but they need a lot of power and they get really hot. I was thinking of anomnidirectional lantern that can light a room well and will last for a couple on nights from a 12V SLA.The nanoleaf emits 1600 lumens with very little heat and only 12watts. Or so they claim. But evenif the output is less, like 1200 lumens, I don't mind. If it has a green tint, then its a no go for me.Maybe I will have a look at the Cree bulbs as well.I've bought the Belkin 140 Watt inverter which has a consumption of 200mA with no load and a 90%efficiency. How can you calculate the consumption of the inverter when you apply a load of 12W likethe nanoleaf bulb? Is it different for each inverter?Thanks.

author: akis
author_rank: Frequent Contributor
timestamp: April 27, 2014, 05:56:57 pm
content: As another post above said, I had similar experience looking into a GU10 lamp (spot lights) that contained a number of white LEDs, maybe a dozen or so, there was a mini PCB with a miniature transformer and a bridge onboard, so the 240V gets rectified into DC to power the LEDs (else they would flash on and off 50 times a second).I think it's a good idea, they stay cool, have low power consumption and they should last ages.

author: georges80
author_rank: Frequent Contributor
timestamp: April 27, 2014, 06:05:58 pm
content: Regarding heat. I would NOT believe any of their claims - it's marketing b/s on kickstarter.They draw 12W from the input (so they claim) and most of that 12W will be heat... heat is heat, doesn't matter how they try to spin their story.They don't have magic LED tech, they are using off the shelf LEDs from planet earth and their efficiency will be in the ball park of all other premium LED manufacturers.XML runs at ~10W if run at 3A input (approx 3V Vf). Its 10W will be cooler than the nano's 12W.... Heat is heat - you have to get rid of it somehow. Put an XML onto as much surface area as the nano panels and it will be cooler. The nano doesn't have some magic efficiency technology, it has surface area and no numbers to back it up. I find their kickstarter typical of most such 'projects' and very light on technical details.To determine inverter/bulb efficiency you'll need to measure it... Don't believe the 'spec' efficiency numbers. Efficiency will also depend on what kind of load the nano presents to the inverter (resistive, inductive, power factor etc). So measuring is the best option.Again, don't believe marketing b/s...Given how beautiful the Cree bulb's light output is (CRI) which mimics very well an incandescent tint, I really doubt some kickstarter project can come anywhere near in product quality. Consider that Cree makes LEDs and are still seen as one of the premium products - they can choose exactly what LED characteristic (tint etc) that want for their products and those LEDs will be cheaper for them... A lot about that nano kickstarter project and how it is present just rubs me the wrong way...cheers,george.

author: hgg
author_rank: Frequent Contributor
timestamp: April 27, 2014, 06:19:50 pm
content: They have a video showing how they are manufacturing the LEDs.Maybe they are making them with custom specifications designed for efficiency.George, do you have the model number of the Cree bulbs you are using?There are several different models and if the one you have is closer to the typical incandescentbulb temperature, I think I would give them a try. I haven't received the inverter yet but I willdo the measurements when I get it.I may buy a nanoleaf as well just to take it apart!

author: JDubU
author_rank: Frequent Contributor
timestamp: April 27, 2014, 06:39:54 pm
content: Quote from: hgg on April 27, 2014, 06:19:50 pmPMFJI.I have a bunch of the Cree LED bulbs that, I think, George is referring to.I really like them! They have a form factor and light color/quality that is the most incandescent-like that I have found.Here are a couple of links:http://www.cree.com/Lighting/Products/Indoor/Consumer/Standard-AType-Bulbshttp://www.energystar.gov/productfinder/product/certified-light-bulbs/details/2191973In my area they only cost $4.99 (USD) each at the local big box hardware store due to power company energy saver rebates.

author: hgg
author_rank: Frequent Contributor
timestamp: April 27, 2014, 06:43:58 pm
content: JDubUthank you for the info!$4.99Perfect price!

author: georges80
author_rank: Frequent Contributor
timestamp: April 27, 2014, 06:49:13 pm
content: Custom designed for efficiency - yeah, only if what you really mean is "marketing designed for efficiency of sales"Seriously, they state they buy their LEDs from a Korean company (likely Seoul semi), they don't MAKE their own LEDs... Again, they don't have some magic efficiency formula. Their 12W consumption is still 12W of mostly heat which needs sufficient surface area to dissipate.Anyhow the Cree unit I have is a 60W equivalent, 800 lumens and 9.5W (from the package I still have - in case I ever need to claim on their 10yr warranty). The model is ba19-08027omf-12de26-1u100. Here's a link from Home Depot in the US:http://www.homedepot.com/p/Cree-60W-Equivalent-Soft-White-2700K-A19-Dimmable-LED-Light-Bulb-6-Pack-BA19-08027OMF-12DE26-2U100/204084366It is a very pleasant warm white.cheers,george.

author: hgg
author_rank: Frequent Contributor
timestamp: April 27, 2014, 07:07:17 pm
content: QuoteCorrect me if I am wrong, but when you apply power to an LED some of it gets turned into light energyand the rest into heat. Now if this conversion is efficient, more power would be converted into lightand less into heat. Isn't that so? Maybe they do have a magic formula after all.Maybe that's why they get a lot of 'heat' from several sources without even one quantitative reviewand actual measurement figures.Example:http://www.allledlighting.com/author.asp?section_id=3040&doc_id=561995..."Sponsored by Philips Lumileds"...Thank you for the links! I will definitely try this one first.

author: gxti
author_rank: Frequent Contributor
timestamp: April 27, 2014, 08:15:36 pm
content: As an analogue to Poe's Law, it can be hard to differentiate between wide-eyed, naïve enthusiasm and outright shilling for a product.

author: georges80
author_rank: Frequent Contributor
timestamp: April 27, 2014, 08:17:56 pm
content: Yes, a TINY bit of the power gets turned into light. MOST of it is heat. LED efficiency is improving, but all the companies are basically in the same race. It's not like their Korean supplier has improved efficiency ahead of the rest of the main players like Cree, Nichia, Lumileds etc etc.Anyhow, you should notice I'm very skeptical of any of that nano marketing blurb... I've been in the LED driver business since the first Luxeon's hit the market, so I have quite a bit of experience behind that judgementcheers,george.

author: hgg
author_rank: Frequent Contributor
timestamp: April 27, 2014, 08:50:22 pm
content: You are probably right.I might buy both the Cree and the Nanoleaf for a proper comparison.Regards,George.

author: tjaeger
author_rank: Regular Contributor
timestamp: April 27, 2014, 09:30:32 pm
content: Black light bulbs? How stupid is that? And what's with that desk lamp anyway? Who wants to look directly at a bunch of ~100 lm LEDs?

author: mzzj
author_rank: Super Contributor
timestamp: April 28, 2014, 06:45:28 am
content: Quote from: georges80 on April 27, 2014, 08:17:56 pmNot exactly TINY amount anymore , around 40% of energy is radiated as a light. AFAIK bare Cree blue emitters had a over 50% efficiency already some time ago.Nanoleaf also makes me skeptical unless proven..