High efficiency LED - Page 1
Forum section: electronics / beginners

author: Qrdi86
author_rank: Newbie
timestamp: November 25, 2022, 07:41:37 am
content: Hello, I have one battery lamp, where i use cheap 3W LED elements like these:https://www.ebay.com/itm/334628806453?hash=item4de96e5f35:g:DZcAAOSw4v5jc1Kq&amdata=enc%3AAQAHAAAA4IbtzG1Wmfhq7B2RrpGgQdhmd3K1AoVnW0po4xMZKFdbqvWvQUXWdnN7jeglzTnDyCSEmzOv9%2BggCw4KLe9%2Ba8AQv0DOz8LnoqgNs%2Bjie6rrQP6d7eU2%2Frah98zNyAxR6xu7j2EBWO0DNhVseQgPglAR8cFYXQsuPU0JD3mYYdVqQWJfKZUbu%2F89ArmQWFiKRL5r0NRd5u0V9LqItVrUldfn8v8cH6x%2F3TL8dyG7NXO8%2B3xUhwO%2BcSn9rJjf%2BC5pMIg2bYm3oU2XM9CRZkhVByN6efg78AO7ldgMYyGgX2pU%7Ctkp%3ABk9SR5rThtuVYQDoes anyone know how much approx lm/W these elements produce(warm white), 100lm/W is realistic? I use 200mA current this 3W elements.I found product, where is 210 lm/W E27 full lamphttps://www.electronicsweekly.com/blogs/led-luminaries/philips-goes-210-lm-w-bulbs-fanfare-done-earlier-2021-08/, here is filaments, but can i find somewhere 1-5W and single chip LED elements, which produce 200 lm/W or higher efficiency? Or what do you know highest chip efficiency LED elements and where can i buy them, thanks.

author: Terry Bites
author_rank: Super Contributor
timestamp: November 25, 2022, 09:05:38 am
content: If their figures are ture, they give P as @ 0.7A and Vf=3.4 or 2.4W@ 240lm this conveniently comes out at 100lm/W that sounds about right.You need to take viewing angle into account when designing your lamp.The wider the angle the lower the flux per unit area.

author: Qrdi86
author_rank: Newbie
timestamp: November 25, 2022, 12:49:14 pm
content: Okey, 100 lm/W is probably correct value, but where i find similary LED chips but 200lm/W efficiency like my second link, where is 210lm/W E27 pulb?

author: Siwastaja
author_rank: Super Contributor
timestamp: November 25, 2022, 02:02:53 pm
content: Quote from: Qrdi86 on November 25, 2022, 12:49:14 pmNot available to us mere mortals.Certain countries are allowed these bulbs. This is some kind of super-weird New World Order thing, given that everything else is regulated for best possible efficiency. While it is perfectly possible to make a 200 lm/W LED bulb, and reasonably inexpensive to do 150 lm/W bulbs, the actual market in our "free Western market" is from 50 - 110 lm/W, absolutely nothing above 110lm/W, no matter how much you want to pay. This applies to both fixtures and bulbs. It feels like after the "pandemic" it has got even worse, all I need are some kitchen light fixtures but I have now set a principle I will not buy anything below 90 lm/W yet it is now difficult to get fixtures even 100lm/W in Finland!You need to import them yourself from some freaking Saudi Arabia or whatever, I already forgot where you can get those forbidden LED lights, because they are actually manufactured, just not for us.Or just design and build your own lights.Regarding your question, note the Ebay LEDs are total crap. If you are lucky, they work at all. Maybe 50 lm/W, maybe 100, who knows.

author: Manul
author_rank: Super Contributor
timestamp: November 25, 2022, 02:14:07 pm
content: Open distributor web page and play with filters. They have lm/W as a filter. Example:https://www.digikey.lt/en/products/filter/led-lighting-white/124

author: Seekonk
author_rank: Super Contributor
timestamp: November 25, 2022, 02:27:55 pm
content: search Dubai LED and it can be done with almost any LED. Twice as many and half the current.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: November 25, 2022, 02:38:30 pm
content: I was a bit surprised at the over 240 lm/watt from digikey.I thought that anything over 100lm/W was quite decent.Just recently I bought a ceiling light (simple opaque round disc with white plastic diffuser) and it states it slurps 18W and delivers 2050lm.But there are quite some differences between the separate digikey LED's and a complete ceiling light. With a ceiling light you loose efficiency because of the power supply and because of the plastic diffuser which is also not completely transparent.LED color is also a significant factor. Fosfors can change the light color, but they do not increase the amount of fotons, and when you add color (and CRI = Color rendering index) to the equation it becomes fuzzy quite quickly.https://en.wikipedia.org/wiki/Luminous_efficacy

author: Qrdi86
author_rank: Newbie
timestamp: November 25, 2022, 03:11:16 pm
content: Thanks for that digikey link, i found this onehttps://media.digikey.com/pdf/Data%20Sheets/Osram%20PDFs/GW_Q9LR31.EM_Ver1.0_2-9-22.pdf200lm/W, when i use it 45mA and 22,08V, then it was 1W power. This voltage is suitable, but i look datasheet and connector pins and cooling looks hard my DIY project. How much this 200lm/W LED chip generate heat, when i use this 1W input electrical power?

author: Doctorandus_P
author_rank: Super Contributor
timestamp: November 25, 2022, 03:51:25 pm
content: On the wikipedia link I posted before you can see an example of a LED which has 172lm/W and a luminous efficiency of 25%. That would mean that for a 200lm/W LED about 60% to 70% of the energy input is turned into heat.A LED with 100% efficiency would generate 683 lumen/Watt and have monochromatic green light with a wavelength of 555nm.

author: DavidKo
author_rank: Frequent Contributor
timestamp: November 30, 2022, 06:15:23 am
content: I think that you can forget these numbers in datasheet, they are more or less informative. The light flux defined in datasheet is usually measured with 25ms pulse (10ms in case of GW_Q9LR31.EM, so even more optimistic). It means in cold state. LEDs light flux degrade with temperature like hell in first minute and the hardest thing is to keep the LED chip cool enough to get reasonable lifetime of the LED. With xxW LEDs you need to care how to get LED cooled. Every thermal resistivity counts.In case that you want to take things seriously, these hundred lm LEDs need to have special PCB designs (vias to decrease PCB resistivity around LED) or use IMS (copper or alluminium) to meet lifetime expectancy of the final product at specified surrounding temperature and power. When the LED chip (not the case, which have thermal resistivity) reaches 150°C, the LED lifetime will be hundreds to thousands of hours.

author: Psi
author_rank: Super Contributor
timestamp: November 30, 2022, 06:44:40 am
content: Ya, be careful with lumens per watt and temperature.Sometimes it will only do x lumens per watt if you run it at like -20 deg C

author: james_s
author_rank: Super Contributor
timestamp: November 30, 2022, 07:00:49 am
content: Quote from: Doctorandus_P on November 25, 2022, 03:51:25 pmI'm not sure that's true, efficiency is not wavelength dependent, it is just the ratio of useful output to wasted energy. A 100% efficient LED would produce no heat, the wavelength could be anything you want. 555nm would appear brightest to the eye but if what you actually wanted was orange or blue light the efficiency would be terrible.Regarding the original topic, LED efficiency typically falls pretty significantly as drive current increases, so to maximize efficiency you need to add more LED dies and run them at lower current. I don't know off hand how linear the relationship between current and efficiency is.

author: DavidKo
author_rank: Frequent Contributor
timestamp: November 30, 2022, 07:09:00 am
content: In Osram case you can be sure they will meet the 190-290 lm as specified in datasheet (measured with 10ms pulse).Currently the realistic value is around 250-300lm/chip from LED likeOSLON Compact PL- FR4, one or two LEDs close to each another, thermal vias, good heatsink.

author: Berni
author_rank: Super Contributor
timestamp: November 30, 2022, 08:07:10 am
content: At least you get reasonable lumen numbersMost Chinese flashlights out there give lumen numbers that might be advertised a 'little' higher than reality

author: mikerj
author_rank: Super Contributor
timestamp: November 30, 2022, 11:06:08 am
content: Quote from: Siwastaja on November 25, 2022, 02:02:53 pmThe ultra high efficiency lamps have been available in the UK for a while, I'd be surprised if they couldn't be obtained in Europe? I bought some a month or so ago in the UK, they are pretty expensive as you might expect but I'm pretty optimistic that the life will be good as they run so cool. The 40W equivalent lamp consumes just 2.4W, and to me seems far brighter than the old 40W incandescent glow worms.https://www.lighting.philips.co.uk/consumer/ultra-efficient

author: Twoflower
author_rank: Frequent Contributor
timestamp: November 30, 2022, 12:06:44 pm
content: The high efficiency bulbs from Philips are available quiet some time, not just in UK. And they use a different way to drive the LEDs compared to the 'Dubai Lamps'. On paper they even have a slightly higher lm/W. There is a discussion about the Dubai and non-Dubai version:https://www.eevblog.com/forum/chat/the-dubai-lamp/msg4126000/#msg4126000.

author: Siwastaja
author_rank: Super Contributor
timestamp: November 30, 2022, 12:39:28 pm
content: Quote from: mikerj on November 30, 2022, 11:06:08 amPhilips even has a Finnish website with the same marketing info about those high efficiency bulbs, yet when you click "where to buy" you get the listing of all the usual Finnish stores that sell Philips products.But none of them actually stock these high efficiency bulbs. It seems you can't get them in EU, just vaporware. It is possible some store somewhere sells them, but I have no idea how to search because I only get bait&switch. "Buy ultra efficient LED bulbs here" "oh here are standard 100lm/W bulbs for you".UK is of course different due to Brexit. I'm not surprised at all if you can get them.

author: tunk
author_rank: Super Contributor
timestamp: November 30, 2022, 12:56:31 pm
content: Quote from: Siwastaja on November 30, 2022, 12:39:28 pmDustinhome.fi claims to have a few of some modelsin stock, and others "shipping within 3-4 days".

author: DavidKo
author_rank: Frequent Contributor
timestamp: November 30, 2022, 12:56:47 pm
content: That is odd. I Czechia seems to be available (cca 10EUR for 4W pc.).AlzaDatartEven some new one

author: Siwastaja
author_rank: Super Contributor
timestamp: November 30, 2022, 01:07:31 pm
content: Quote from: tunk on November 30, 2022, 12:56:31 pmNeverheard, thanks.From the local ones, apparently Verkkokauppa.com also carries these bulbs, just "out of stock" and maybe available by end of February 2023.In any case, it's clearly a web order thing. I have went through all the big markets (Bauhaus etc.) with large lighting and bulb departments and absolutely nothing above 120lm/W. This is surprising because components to manufacture bulbs >150lm/W have been available for over a decade, and it is not excessively expensive to do so. Yet the whole market is saturated with only 90-110 lm/W products almost if someone was actually controlling the market. It's nice Philips now sells some 200lm/W stuff even outside of Dubai, but I would like to see this becoming a normal thing, from multiple manufacturers, in all well-equipped stores.

author: deadlylover
author_rank: Frequent Contributor
timestamp: November 30, 2022, 01:40:34 pm
content: The CREE XP-L2 will get in the 200lm/W region for a single chip high power LED depending on the flux bin. Very popular in output focused flashlights so shouldn't be too hard to source.But it's 2022 and do you really need that much efficiency at the expense of everything else? It will have crappy CRI.These days the hot new LED in the flashlight enthusiast world that balances output/efficiency/CRI is the Nichia 519A (while having a decent tint). 90CRI (R9 >80) and say 120lm/W is more reasonable.Other choices would be the Osram SST-20, Samsung LH351D. As always it depends on the flux, CRI, CCT bins but they would have no trouble performing close to 200lm/W at lower drive levels for their more efficient models.You can find them on Convoy's Aliexpress store in low quantities even mounted to a copper MCPCB already.

author: bingo600
author_rank: Super Contributor
timestamp: November 30, 2022, 06:19:21 pm
content: I see them in several places.Tip : Search for the EAN number & Country8719514435599 site:.de

author: stefan_o
author_rank: Regular Contributor
timestamp: April 05, 2023, 10:57:26 pm
content: Just in case somebody is finding this topic. High-efficiency (>200 lm/W) standard retro-fit E27 LED lamps are commonly available (in Germany) and not overly expensive (<10€), this shop has it's own category for high-efficiency light bulbs, there not special/custom-made lamps, but standard Osram/Philips lamps, you can buy them at many places (probably even slightly cheaper):https://de.elv.com/technik-fuer-ihr-zuhause/beleuchtung/hocheffiziente-led-lampen-eek-a/