Why haven't filament LED bulbs taken over the market? - Page 1
Forum section: electronics / general

author: TimNJ
author_rank: Super Contributor
timestamp: January 18, 2018, 06:03:02 pm
content: As far as I can tell, filament LED bulbs seem almost like the ideal general purpose lighting technology. They meet consumer wants and needs by looking good and performing well while significantly cutting BOM size for manufacturers.The LED filaments are effectively a series string of chip-on-glass LEDs. Therefore, they can be driven at a high voltage and low current. This is basically the opposite of traditional LED bulb technology which is low voltage and high current. Because of this, BOM size is way smaller for filament LED bulbs. Usually just a bridge rectifier, driver chip, external MOSFET, a capacitor, and resistor or two. And no heatsink necessary.Philips et. al. rates them at the same expected life as traditional LED bulbs. Electronupdate did a video testing the brightness after 10k hours and the results were very good:Why then, are manufacturers still making boat loads of the "traditional" LED bulbs? Are yields for LED filaments still low? Mass manufacturing still not there yet? Find that hard to believe since I assume an incandescent production line could be retooled fairly easily for new style bulbs.Any ideas?

author: Ampera
author_rank: Super Contributor
timestamp: January 18, 2018, 06:04:48 pm
content: I haven't seen these on the market, and I agree, they do look like a home run. No clues over here, possibly something to do with capitalism?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 18, 2018, 06:29:21 pm
content: They do seem to be getting more popular, but in the days of incandescents, visible filaments weren't that common compared to pearl/diffused, as filaments cast harder shadows, so not always ideal for interior lighting.For a diffused source, conventional LEDs may be more efficient and/or cheaper.Filaments do have quite a lot of die and phosphor compared to the SMD LEDs used in conventional bulbs.

author: duak
author_rank: Super Contributor
timestamp: January 18, 2018, 06:38:12 pm
content: I bought a couple of no-name filament bulbs from the local LED lite store. The first thing that struck me was that the glass has a rubberized coating; a Good Idea for anything made of glass. The second thing is how little heat sinking there is on the LED strings. I wonder how hot the LEDs actually get? Probably not too hot if there isn't serious degradation in output luminosity. I have some 60 W GE LED bulbs that get a lot hotter - I think I measured something north of 70 C.Cheers,

author: glarsson
author_rank: Frequent Contributor
timestamp: January 18, 2018, 06:40:28 pm
content: Readily available here in Sweden in many variants. Perhaps manufacturers haven't bothered redesigning the filaments for the lower tension (120V) used in some countries?

author: TimNJ
author_rank: Super Contributor
timestamp: January 18, 2018, 06:44:47 pm
content: Maybe the cost savings in reduction of electronics BOM is made up for with more expensive(?) filaments. As mike says, they take more die space. Plus the entire string has to work or you throw it out. I assume cheap chip LEDs can be had fairly cheaply.Good point about the light quality. Though, I'm sure they could put a diffused coating on these bulbs pretty easily. For now, it seems they want everyone to know about the cool technology inside.Rubberized coating sounds tricky from a thermal perspective, but maybe not. I have a few Cree bulbs with that coating and while nice, I'm not sure why they bothered. All you have to do is safely remove the bulb from the packaging and not drop it in the 30 seconds it takes to screw it in.

author: IanB
author_rank: Super Contributor
timestamp: January 18, 2018, 06:47:52 pm
content: I like the filament bulbs and prefer to use them over other types. Some advantages are that they run cool, they have a good illumination pattern, and the light tends to be an attractive golden color. A disadvantage is they tend to be available only up to 60 W equivalent. I have not seen higher light outputs up to 100 W equivalent.I do not find the lack of a diffused globe to be a problem as the bare filaments are quite attractive and most lamps have an external shade or diffuser anyway.

author: james_s
author_rank: Super Contributor
timestamp: January 18, 2018, 06:58:19 pm
content: The filament types have been readily available here for some time now, I have a few of them in service. They are not without flaws though, the filaments create shadows of each other and you get yellow/brown fringes around objects. Typically they are also a tad less efficient than other types and have more primitive drive electronics made to fit completely in the base. They are great for decorative fixtures where the bulb is visible but otherwise I generally prefer other types.

author: phil from seattle
author_rank: Super Contributor
timestamp: January 18, 2018, 07:01:37 pm
content: I bet it's all about heat. In the standard LED line powered bulbs, the LED chips are mounted on a metal plug that connects to the base which acts as a heat sink. So, the filament bulbs need more LEDs to produce the same lumins. Frankly, I much prefer diffusers between my eyes and the LEDs. And, they are readily available in the US but are more expensive than the standard frosted edison base bulbs.

author: Nusa
author_rank: Super Contributor
timestamp: January 18, 2018, 07:17:19 pm
content: They seem to be primarily available in the lower-wattage vanity and candelabra style bulbs. In the US, at least, the incandescent version of those bulbs are still sold, which easily beat any of the alternatives on purchase price. Plus, you're going to pay extra if you need a dimmable LED, while that's a free feature on an incandescent.Also, there's simply the time factor, combined with resistance to change. I don't think any of the six 40w bulbs in my bathroom mirror fixture have burned out in the last 10 years, and I have several spares on hand if they do. Those lights only get used 10 minutes a day, and it's not worth my time or the expense of updating them. Maybe in another 10 years.In the very long run, I expect the market for replacement bulbs will largely disappear, as lighting will be so long-lasting that they're intended to last the life of the product. A current example of that would be LED lighting in new model refrigerators.

author: james_s
author_rank: Super Contributor
timestamp: January 18, 2018, 07:27:00 pm
content: I replaced every bulb in my house with LEDs years ago and I've almost forgotten what it's like to have to change bulbs. The only incandescents I have left are the oven and microwave bulbs, and a couple of lava lites which obviously need the heat of the incandescent to work. For a while I was replacing CFLs with LED as they failed but eventually I got tired of waiting for them to fail. The LEDs are so much nicer, better light, instant on, nice dimming, I was really pleased to see that tech mature and succeed.

author: TheWelly888
author_rank: Frequent Contributor
timestamp: January 18, 2018, 07:37:51 pm
content: I have a 40W equivalent LED filament bulb in my bedside light that I bought in April 2015, it's a nice light and looks a lot nicer than the "glowing turd" shaped CFLs available! But it is not bright enough to replace my ceiling bulb which is still incandescent as I have hoarded some before the ban!I can't wait for the 100W equivalent bulb to be developed so that I can use it in the ceiling!

author: james_s
author_rank: Super Contributor
timestamp: January 18, 2018, 07:40:09 pm
content: Do you live under a rock? 100W equivalent LED bulbs have been widely available for several years. Just yesterday I was in Costco and they had 4-packs of Feit 17.5W 1600 lumen 90+ CRI LED bulbs for about $12.

author: IanB
author_rank: Super Contributor
timestamp: January 18, 2018, 07:41:08 pm
content: Quote from: james_s on January 18, 2018, 07:27:00 pmSome bulbs are hard to replace though. I have bathroom vanities with large decorative globes, and chandeliers with small decorative candles and globes, and every light is on a dimmer. I rarely run lights at full brightness as I would get blinded--my general level of room illumination is candle brightness.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 18, 2018, 07:42:14 pm
content: Quote from: TheWelly888 on January 18, 2018, 07:37:51 pmHow aboutThis

author: IanB
author_rank: Super Contributor
timestamp: January 18, 2018, 07:43:05 pm
content: Quote from: james_s on January 18, 2018, 07:40:09 pm...but not in the filament style, which is the subject of this thread.

author: james_s
author_rank: Super Contributor
timestamp: January 18, 2018, 07:43:22 pm
content: Quote from: IanB on January 18, 2018, 07:41:08 pmIt can take some searching for special application bulbs and you might not find one that looks *exactly* like the incandescent but you can get close. There is a large variety of decorative LED bulbs available now, such as the filament type covered by this thread. I have many lights on dimmers and selected LED bulbs that behave well with them.

author: james_s
author_rank: Super Contributor
timestamp: January 18, 2018, 07:46:41 pm
content: Quote from: IanB on January 18, 2018, 07:43:05 pmThe subject of the thread yes, but he didn't say he needed a filament type for that particular application. 60W equiv is the biggest filament type I've seen so far but I'm sure higher power bulbs will come.

author: IanB
author_rank: Super Contributor
timestamp: January 18, 2018, 07:48:12 pm
content: Quote from: james_s on January 18, 2018, 07:43:22 pmBut as someone else said, the original incandescent bulbs work perfectly, they look nice, they have a good CRI, they are dimmable, and they last for decades when dimmed. There is no need to replace them.

author: james_s
author_rank: Super Contributor
timestamp: January 18, 2018, 07:57:40 pm
content: Quote from: IanB on January 18, 2018, 07:48:12 pmDepends on how much use they get. Even with relatively little use the power consumption adds up, especially when dimmers are involved. When you dim an incandescent the already pitiful efficiency drops dramatically, when you dim an LED the efficiency generally rises slightly.My bedroom lamp for example used to have a 60W bulb, I would dim it down to about 1/4 apparent brightness at which point it was drawing around 40W. When I dim the 12.5W LED bulb to about the same brightness, which is older, significantly less efficient than current designs the power consumption drops to about 3W. It has made a significant reduction to my power bill. Over the life of any bulb, whether incandescent or LED, the bulk of the cost is the energy required to run it, not the cost of the bulb.

author: IanMacdonald
author_rank: Frequent Contributor
timestamp: January 18, 2018, 08:16:42 pm
content: A major problem with filament LEDs is flicker. This is not because of the filaments, but because of the need to cram the regulator into the BC or ES base of the lamp. Thus, usually no filter cap.A flickering light source can have physiological effects even if the flicker is not obvious. Try waving your hand in front, if you see a strobe effect of your fingers, it's flickering. This used to be a big problem in the days of CRT computer displays. If the display was running at the default 60Hz I would typically ask the user if they suffered headaches. The answer was often, yes. Setting to 75Hz or better usually eliminated the headaches. I would point out to some sites using old 60Hz-only displays that they were risking a compensation claim if they didn't fix this.Most LCD panels don't flicker, but there are a few that use an LED backlight which has PWM brightness control. These can be headache-causers, especially if the frequency is low enough that the eye can just detect it.Besides, as mentioned LEDs work best with a heatsink. Even if they could work without, they will last a lot longer if kept cool.

author: jmelson
author_rank: Super Contributor
timestamp: January 18, 2018, 09:00:02 pm
content: Quote from: TimNJ on January 18, 2018, 06:03:02 pmSo, there is no way to get the heat out of the LEDs. Thus, you must run them at really low current, or they will burn out in minutes.I have some LED retrofits for 48" fluorescent tubes that I made. They run at 350 mA, and have 20 LEDs in series. They provide almost as much light as TWO of the 48" tubes. With hideous old magnetic ballasts, the 2 tubes consumed 101 W from the AC mains. The string of LEDs, running on a commercial lighting power supply, draws 21 W from the mains.But, even these relatively low-power LEDs need some heat sink to keep them from deteriorating. I solder them to a strip of PC board material almost the size of one of the original tubes, and that gets the heat out.So, that is one of the big problems I see in these filament bulbs. They are great for mood or accent lighting, but NO WAY will they light up a room.Jon

author: Halcyon
author_rank: Unknown
timestamp: January 18, 2018, 09:36:13 pm
content: Quote from: TheWelly888 on January 18, 2018, 07:37:51 pm

author: IanB
author_rank: Super Contributor
timestamp: January 18, 2018, 09:36:41 pm
content: Quote from: jmelson on January 18, 2018, 09:00:02 pmOh, but they do. The output in lumens is just as good as with other designs, and the illumination pattern is better since the light is emitted in all directions rather than being focused predominantly upwards away from the base. If I use a traditional LED lamp it tends to light up the ceiling more than the room.

author: james_s
author_rank: Super Contributor
timestamp: January 18, 2018, 10:10:47 pm
content: The light distribution was a problem early on, but a lot of engineering effort went into getting omnidirectional light and most of the decent LED bulbs on the market now have a distribution pattern pretty close to that of a standard incandescent regardless of the specific design they use.

author: helius
author_rank: Super Contributor
timestamp: January 18, 2018, 11:04:04 pm
content: The filament COB bulbs are very common and I see them everywhere, even in grocery stores. One problem is their color temperature changes significantly when dimmed, from a warm white at full power, to a greenish color below half brightness.They are also available in mini candelabra style bulbs, but unfortunately not as compact as the smallest incandescent bulbs of that type.

author: Someone
author_rank: Super Contributor
timestamp: January 18, 2018, 11:43:57 pm
content: Quote from: IanB on January 18, 2018, 09:36:41 pmWhich is one of the bigbenefitsof LED lamps, you can get directionality designed in at the source and not need a complicated reflector system to direct the light where its needed. Rather than bouncing light off the ceiling to get a diffused source in my living areas I just installed many much smaller wattage lamps around the room directly illuminating the space at greatly increased efficiency.There are "replacement" bulbs such as the originall-prizeremote phosphor lamp which try to imitate all the characteristics of an incandescent bulb. While plenty of people just see that as inefficiency of trying to shoehorn LEDs into applications which they aren't suited for, if you want omnidirectional point sources then there are better options such as the halogen lamps which are now available care of minimum efficiency standards or halide lamps which have been in commercial and industrial use for decades. But if you want to illuminate a space via the inside of your lampshade and rely on the few % transmission and scattering it provides you've already lost any effort for efficiency.

author: edavid
author_rank: Super Contributor
timestamp: January 18, 2018, 11:53:51 pm
content: Quote from: james_s on January 18, 2018, 07:40:09 pmWatch out, the Costco bulbs are 3000K "bright white". 2700K/100W can cost quite a bit more.

author: james_s
author_rank: Super Contributor
timestamp: January 19, 2018, 12:11:07 am
content: I rather like the 3000k personally, after a very short time it looks "white" and 2700k bulbs then look very yellow, that's a matter of personal preference though. 2700k 100W equivalent are readily available at hardware stores, I only have one and it's a Philips, most of the bulbs in my house are 800 lumen or less, I just don't need that much light from a single lamp.

author: tooki
author_rank: Super Contributor
timestamp: January 19, 2018, 02:18:03 am
content: Quote from: jmelson on January 18, 2018, 09:00:02 pm(Sorry, I know I’m being unnecessarily snarky, but it’s funny!) Ummm, a rectum isn’t a good source of information: your assumption is plain and simply untrue. I use two 8W LED filament bulbs as the primary lighting in my dining room. It is in no way insufficiently lit — I like it bright. They do get hot, but not really any differently from “normal” LED bulbs. The bulbs are going on 2 or 3 years old now, I think, so I don’t think the heat is bothering them. And these are ebay cheapies straight from China.

author: steve30
author_rank: Frequent Contributor
timestamp: January 19, 2018, 02:25:32 am
content: I saw some LED Filament lamps in Wilkinsons the other day which had diffused glass.

author: Halcyon
author_rank: Unknown
timestamp: January 19, 2018, 03:22:00 am
content: I useTHESEglobes in my bathrooms for accent lighting which come with a "smoked" glass appearance. I was originally going to use actual incandescent filament globes of the same style, but with an average life expectancy of 2000 hours, I decided to go with the LED version and haven't looked back. They look fantastic behind "industrial" style mesh fittings. They output a very even light all around, run cool and produce a lovely warm, flicker-free light.

author: TimNJ
author_rank: Super Contributor
timestamp: January 19, 2018, 05:12:42 am
content: To all who commented that filament bulbsarewidely available. Yes, I agree. I have purchased about dozen myself. For the 40-60W segment, I think the filament bulbs are hard to beat. That said, it still seems like like 90% of bulbs sold in this segment are traditional chip-on-heatsink LED bulbs. I guess ultimately this might come down to cost...or maybe companies want to get a return on the all the money they spent getting traditional LED bulbs on the market?For fun, I took apart one of the Philips filament LEDs I purchased. Interestingly, two of the filaments were intermittent. Shoddy connection somewhere I guess.As expected, very simple drive circuitry. The PCB uses two "Linkage" SM2082EK ICs. According to theirwebsite, you can stack these ICs for more current. That appears to be what they did here. The circuit they used is similar to the circuit I attached (minus 1 IC). There are also a few additional parts (transistors and resistors) that I'm not too certain about.Aishi is the capacitor brand of choice. Interestingly, it's a 33uF cap rated at160V. Seems a little low for 120VAC.

author: ikrase
author_rank: Regular Contributor
timestamp: January 19, 2018, 05:26:59 am
content: The only time my family ever used these, they had terribad reliability. Probably there are better ones available... somewhere.

author: Halcyon
author_rank: Unknown
timestamp: January 19, 2018, 07:40:49 am
content: Quote from: ikrase on January 19, 2018, 05:26:59 amI think doing a bit of research and sticking with the well-known brands is probably a good rule of thumb. That being said, the globes I mentioned in my previous post aren't branded, so I'm not sure who manufactures them or where they are made but they've been going strong for over 2 years now. Every light in my house is LED. I tend to stick with Philips and Mirabella, none of them have failed me. Even the Ikea stuff isn't too badly made.In the past I've usedLED Benchmarkfor a source of good information.

author: tszaboo
author_rank: Super Contributor
timestamp: January 19, 2018, 08:04:27 am
content: I also bought some of these in E14 sockets. They blinked. There was a visible stroboscopic effect when you moved around the light. So they went to the trashcan.I guess you dont have the space for a proper cap in that size.

author: Kleinstein
author_rank: Super Contributor
timestamp: January 19, 2018, 08:09:28 am
content: Quote from: TimNJ on January 19, 2018, 05:12:42 amFrom the circuit shown the cap is directly in parallel to the LEDs. So it will not see the full voltage, but only the LEDs voltage. So the voltage rating is not a problem. However directly at the LEDs the effectiveness of the cap is also limited.

author: kalel
author_rank: Frequent Contributor
timestamp: January 19, 2018, 08:17:40 am
content: They look really good. However, looking at them is more blinding comparing to a standard, diffused LED. That could be one downside. And I guess that if you buy a diffused glass filament lamp, you could as well buy a standard LED bulb that is cheaper. All can be blinding to look at, but diffused is better versus a single spot or filament.They are widely available from China (as well as the filaments themselves), and BigClive has videos of quite a few types.As for flickering, I only have seen live a very small one (3-5w - not sure exactly) and it does not show any visible flickering to my eyes. I did not test with a camera though.

author: jonovid
author_rank: Super Contributor
timestamp: January 19, 2018, 08:19:10 am
content: in the video, only one bulb is run, looks like non stop.proper way to test it is to implement switch on/off automatics that will simulate daily usage. not just to run it non stop.using more than one bulb.

author: kalel
author_rank: Frequent Contributor
timestamp: January 19, 2018, 08:28:16 am
content: Quote from: jonovid on January 19, 2018, 08:19:10 amDo you think that turning on would produce additional stress to some components (e.g. capacitors)?

author: jonovid
author_rank: Super Contributor
timestamp: January 19, 2018, 08:52:02 am
content: Quote from: kalel on January 19, 2018, 08:28:16 ambest scientific methods will simulate daily usage. 8 or 10 minuteoff timeneed only simulate daily usage.example thermal cycling inside the glass envelope, no matter how small this is.

author: hayatepilot
author_rank: Frequent Contributor
timestamp: January 19, 2018, 09:00:03 am
content: Quote from: IanB on January 18, 2018, 07:43:05 pmThere you go:https://www.philips.co.uk/c-p/8718696742396/led-bulb100W equivalent 1500Lumen 2700K

author: kalel
author_rank: Frequent Contributor
timestamp: January 19, 2018, 09:16:39 am
content: Do the Philips bulbs show a significantly higher quality than similar non-branded ones?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 19, 2018, 10:05:03 am
content: Quote from: kalel on January 19, 2018, 08:28:16 amShouldn't do - there may be some thermal cycling effects but reliablity will usually boil dowm to how hot the PSU componants get

author: ovnr
author_rank: Frequent Contributor
timestamp: January 19, 2018, 11:05:58 am
content: I'm happy they haven't taken over the market. Worse efficiency, plus the flicker. Ihateflickery light sources, and I'd never buy a lamp that I knew had said issue - and I've thrown out a number of brand new bulbs that fail the flicker test.

author: amyk
author_rank: Super Contributor
timestamp: January 19, 2018, 11:08:44 am
content: Quote from: kalel on January 19, 2018, 08:28:16 amIf they use capacitive droppers (which a lot of them do, due to the space constraints), then the inrush limiting resistor will be subjected to additional stress depending on when in the waveform it's switched on.

author: hayatepilot
author_rank: Frequent Contributor
timestamp: January 19, 2018, 12:00:51 pm
content: Quote from: ovnr on January 19, 2018, 11:05:58 amI don't know about the flickering (to me they look identical to normal LED bulbs) but the efficiency of filament LED bulb is certainlyBETTERor equal to normal LEDs.This is because they don't need to step down the voltage much to drive the LEDs, which leads to a more efficient power supply in the bulb.

author: ovnr
author_rank: Frequent Contributor
timestamp: January 19, 2018, 01:25:11 pm
content: Quote from: hayatepilot on January 19, 2018, 12:00:51 pmThey have capacitive droppers. Not exactly a paragon of efficiency. Plus the LED chips used are undoubtedly from the cheapo bin at the market.I get filament-style lamps for when you have visible bulbs, or want the radiation pattern of an incandescent bulb. For anything else? Nah.

author: Richard Crowley
author_rank: Super Contributor
timestamp: January 19, 2018, 01:33:08 pm
content: Quote from: TheWelly888 on January 18, 2018, 07:37:51 pmYesterday, I bought a box of five 100W equivalent LED bulbs for $10Around 40% if the price was subsidized to encourage replacement of incandescent home lighting.

author: kalel
author_rank: Frequent Contributor
timestamp: January 19, 2018, 01:56:44 pm
content: Quote from: Richard Crowley on January 19, 2018, 01:33:08 pmThat's a great price. Are they 12-15W? Different manufacturers have different opinions on what 100W equiv is.

author: TimNJ
author_rank: Super Contributor
timestamp: January 19, 2018, 05:05:37 pm
content: Quote from: kalel on January 19, 2018, 09:16:39 amI'm not entirely convinced they're much different than any of the no name bulbs. Aishi cap and Chinese driver IC. Doubt that any of the no name bulbs are much different. Does Philips even manufacture the filaments? You'd think theywouldproduce their own to reduce unit cost, but maybe not.Only thing you might get with buying Philips (or other big names) is more thorough life testing of the product before pushing it out on the market. Maybe increased quality control? (Ironically, one of the six bulbs I bought was defective.)

author: coppice
author_rank: Super Contributor
timestamp: January 19, 2018, 05:16:27 pm
content: Has anyone tried measuring the temperature of the LEDs in these filament style lamps? These things used to be low consumption decorative devices. Now they are making bulbs that consume 10W or more there's quite a lot of heat to remove, and apparently only poor heat conduction paths to remove it.

author: IanB
author_rank: Super Contributor
timestamp: January 19, 2018, 05:25:41 pm
content: On the flicker question and design of the bulbs, there must be some differences between brands and sources because my samples of filament bulbs do not have any observable flicker. I have waved my hands and fingers across them and the light is continuous.On the heat generation and heat removal, I do not think there is much of a thermal problem. There are thin filaments suspended in free air, allowing heat to be removed by convection and radiation over quite a large surface area. If you think how hard it is to heat up a wire suspended in free air you can get a feel for the cooling efficiency of the arrangement. If I put my hand on top of the glass bulb after the lamp has been on for a while it does not get especially hot.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 19, 2018, 05:32:17 pm
content: Quote from: coppice on January 19, 2018, 05:16:27 pmI just got some loose filaments. rated 0.9W 60-65W, 10mA. Obviously these figures are not self-consistent.At 10mA, Vf =56V, 560mW, surface temp reaches 60 deg.C when vertical in free airat 16mA ~900mw, Vf=57V, 78 deg.This is measured with a small thermocouple in contact with the side.Surface area is approx 85mm^2

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 19, 2018, 05:34:50 pm
content: Here's a datsheet for some osram filamentshttp://docs-europe.electrocomponents.com/webdocs/1603/0900766b81603b8c.pdf

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 19, 2018, 05:39:32 pm
content: BTW the one I had started flashing on & off at 40mA / 140 deg. C !

author: coppice
author_rank: Super Contributor
timestamp: January 19, 2018, 05:55:49 pm
content: Quote from: mikeselectricstuff on January 19, 2018, 05:32:17 pmThat's kinda what I was expecting. So, you put a bunch of those close together, massively reduce airflow with a small sealed enclosure, and make that enclosure of a material with poor thermal conduction. Those LEDs are going to get rather toasty.

author: Richard Crowley
author_rank: Super Contributor
timestamp: January 19, 2018, 06:15:10 pm
content: Quote from: kalel on January 19, 2018, 01:56:44 pmFEIT brand, 15W

author: TimNJ
author_rank: Super Contributor
timestamp: January 19, 2018, 06:35:43 pm
content: Quote from: IanB on January 19, 2018, 05:25:41 pmNot sure if it's been mentioned, but some filament bulbs are filled with an inert gas like helium which facilitates better heat transfer from the filament to the glass globe.

author: james_s
author_rank: Super Contributor
timestamp: January 19, 2018, 06:38:43 pm
content: At one point I read about a prototype LED filament bulb that was filled with helium due to the high thermal conductivity of that gas. That was one of the first filament style LED bulbs I ever heard of so I don't know if that technique is used in the bulbs available now.

author: TimNJ
author_rank: Super Contributor
timestamp: January 19, 2018, 06:43:57 pm
content: Quote from: james_s on January 19, 2018, 06:38:43 pmI see. Plus, that sounds like it would require a somewhat more advanced/expensive manufacturing process. Don't think the Philips bulb I took apart yesterday had an air tight seal though it did have this weird crumbly, yellow, glassy adhesive around the base.

author: james_s
author_rank: Super Contributor
timestamp: January 19, 2018, 06:46:50 pm
content: Apparently it used the same manufacturing process as traditional incandescent lamps, replacing the argon/nitrogen gas fill with helium and the tungsten filament with LED filaments, the reuse of existing production lines was touted as one of the advantages. Of course if one could dispense with the airtight bulb and gas fill entirely that would be even simpler.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: January 19, 2018, 07:15:20 pm
content: So now we know what limits the life of these things. How long for the helium to escape. It is slippery stuff.

author: james_s
author_rank: Super Contributor
timestamp: January 19, 2018, 07:19:19 pm
content: Well we don't even know if the helium filled tech went anywhere, but slippery as it is, I don't think helium can diffuse through hermetically sealed glass. I have decades old hard-seal HeNe laser tubes that still work just fine. The old soft seal type would fail though as helium diffused through the epoxy attaching the mirrors.

author: TimNJ
author_rank: Super Contributor
timestamp: January 19, 2018, 07:26:59 pm
content: Quote from: james_s on January 19, 2018, 06:46:50 pmThought the same thing initially but then thought the electronics in the base might make it tricky, but probably not.What do you mean by gas fill it entirely?

author: james_s
author_rank: Super Contributor
timestamp: January 19, 2018, 07:50:43 pm
content: I meant dispense with the airtight bulb, which also means eliminate the gas fill because the bulb is not sealed anyway. Bulb is just filled with atmospheric air, should be cheaper and simpler than any special fill.One thing that helps with these is they use a large number of LED chips run at a much lower current than the power LEDs in most LED bulbs. That should in theory result in higher efficiency and less heat.

author: hayatepilot
author_rank: Frequent Contributor
timestamp: January 19, 2018, 08:50:38 pm
content: Quote from: james_s on January 19, 2018, 07:50:43 pmApparently it doesn't help just in theory. Just look at that datasheet that mikeselectricstuff posted above:172lm/w efficiency at 2700k!That is insane

author: jmelson
author_rank: Super Contributor
timestamp: January 19, 2018, 08:55:03 pm
content: Quote from: TimNJ on January 19, 2018, 06:35:43 pmHmm, I kind of doubt it. First, Helium has gotten quite expensive, lately. Second, thin plastic shells glued together will not hold Helium in for more than 15 minutes. It passes through glass pretty easily, too.Jon

author: james_s
author_rank: Super Contributor
timestamp: January 19, 2018, 09:16:36 pm
content: Quote from: jmelson on January 19, 2018, 08:55:03 pmNo it doesn't pass through glass easily. As I already mentioned I have helium-neon laser tubes that are made of glass and decades old that still contain their helium. It certainly would not stay inside a plastic bulb though.This is the bulb I was thinking ofhttp://lamptech.co.uk/Spec%20Sheets/LEDi%20Philips%20470A60IF827-E27%20Midpower-in-Glass.htmMy memory was wrong of it being a filament type, it appears to be more conventional.

author: tooki
author_rank: Super Contributor
timestamp: January 20, 2018, 04:18:16 am
content: Quote from: jmelson on January 19, 2018, 08:55:03 pmThey're not plastic shells, never mind glued. They're traditional glass bulbs. As james_s just explained a few posts above yours, part of the impetus of designing the LED filaments was that it allows all the existing incandescent bulb manufacturing equipment and processes to be repurposed with only minimal alteration.Quote from: james_s on January 19, 2018, 06:46:50 pm

author: coppice
author_rank: Super Contributor
timestamp: January 20, 2018, 03:58:03 pm
content: Quote from: james_s on January 19, 2018, 09:16:36 pmThey don't mention why there is 20% oxygen with the helium. Does anyone know?

author: IanB
author_rank: Super Contributor
timestamp: January 20, 2018, 05:06:02 pm
content: Quote from: coppice on January 20, 2018, 03:58:03 pmAs far as I know, commercial helium is supplied that way because people love to breathe it in and play with squeaky voices. If the helium was 100% pure then people would tend to die of asphyxiation, which is bad for business. So they mix oxygen with it to make it equivalent to air so it is safe to breathe.

author: HighVoltage
author_rank: Super Contributor
timestamp: January 20, 2018, 05:21:12 pm
content: Filament LED bulbs have been available in Germany for at least two years.They are called "LED-Leuchtfaden" here.And I have been using them about that long and so far no failure.

author: james_s
author_rank: Super Contributor
timestamp: January 21, 2018, 02:23:16 am
content: I was out today so I bought a couple new types of LED filament bulbs to play with, both are Ecosmart brand from Home Depot and both claim 800 lumens. One is a 6.5W clear bulb in a compact envelope the size of a standard appliance bulb, if the ratings are believed that's a very impressive 123 lm/W. The other is a more conventional A19 size, inside frosted so it looks exactly like an ordinary incandescent bulb, it's 7.5W so slightly less efficient, likely owing to the diffuse coating. Both have a reasonably nice 2700k light, CRI is nothing spectacular, probably around 80. They run cool and put out a lot of light, and to a casual observer they look incandescent, they even dim quite nicely on a dimmer.There is one fatal flat though for me that will restrict these to specific uses, they flicker. My other half can't see the flicker at all but it's very visible to me, especially if I scan my eyes across the room looking from one thing to another or move my hand. I suspect it's unavoidable unless we have some kind of breakthrough in compact capacitors in high enough ratings that will fit down inside the base. That right there is probably why they remain somewhat of a niche product.

author: IanB
author_rank: Super Contributor
timestamp: January 21, 2018, 03:03:37 am
content: See if you can find the Ecosmart brand. They don't seem to have any flicker. (6.5 W, 810 lumens)

author: kalel
author_rank: Frequent Contributor
timestamp: January 21, 2018, 07:51:39 am
content: Is it possible that some of us are better at seeing the flicker than others?The ones I have seen so far do not flicker at all. The only time I saw visible flicker was from a Chinese night light that had a half-wave rectifier and an inadequate capacitor. But that's quite obvious, low frequency flicker. However, I can see monitor flickering on those that show some.I can also see the "power on" RED LED flicker on some devices when moving my eyes across (or the finger thing, or seeing through the corner of the eye). However, whatever I try I don't see it on the filament bulbs (I did not see a high sample amount though).I could try to see the flicker through a phone camera, but I'm not sure how representative that is. Cameras have their own refresh rate, so it will depend on whether or not the light is "in sync".

author: Kjelt
author_rank: Super Contributor
timestamp: January 21, 2018, 02:35:57 pm
content: I personally don't like these bulbs.The only application where I like them is in that golden glass colored retro big bulbs for 1930s retro applications.For new LED lighting I never would choose:- HV (110-230V) leds- E27 bulb replacements (GU10 is ok'ish).I don't get it if you really really want a lightbulb with its orange glow when dimmed than buy a lightbulb not a ledreplacement.Or better get in the led century: design your lighting conditions with multiple different lightsources and choose the settings (scenes) for the application, meaning if you have a dinnertable where you study and also like to eat in a romantic atmosphere you need more different lightsources with different colortemperatures and lumens to choose from. With for instance the modern tunable white color led bulbs you can do anything your creativity can imagine.These filaments is like when in the late 19th century they designed automobiles to replace the horses, they would have put an engine in an iron horse and let it run with four robotised legs instead of integrating it in the carriage. This is so....... not getting what led could do, or just unable to change and stick to what you knew.Take a look at modern light led fixtures, they are pieces of art and have a magnificent lighting pattern.Yes you have to replace them after 25 years unless you are an electronic engineer and can replace the ledsThrow out your old E27 fixtures (unless they are design and worth considerable amount of money) and join the new century of lighting

author: kalel
author_rank: Frequent Contributor
timestamp: January 21, 2018, 02:49:57 pm
content: As replacement bulbs are relatively cheap, I'm not sure that expensive fixtures (unless they are cheap too) are more economical. If they really last 15 years, maybe so, but I assume it's not always the case.

author: Kjelt
author_rank: Super Contributor
timestamp: January 21, 2018, 03:25:44 pm
content: If "economical" was the only parameter in a lighting decision everyone would buy the very cold white 6500K industrial lamps with a 150Lm/W efficacy.I visit people that have modern design leather couches/chairs and cabinets costing thousands of $ , but their lighting fixtures are from the Ikea kind of stores. I can't resist asking why they didn't buy their furniture from the Ikea to match the lighting

author: CatalinaWOW
author_rank: Super Contributor
timestamp: January 21, 2018, 07:47:30 pm
content: When you buy your lighting with style in mind there is no way you can predict a 25 year life. Style changes much more quickly than that. Depending on where you are and how conscious of these things you are things can be horribly outdated in less than a decade.

author: james_s
author_rank: Super Contributor
timestamp: January 21, 2018, 08:48:01 pm
content: Quote from: IanB on January 21, 2018, 03:03:37 amThe ones I got are Ecosmart, I was looking at some other lamps when I said Commercial Electric originally.A lot of people can't see the flicker but I can, I've had people tell me I'm making it up but I'm certainly not, I wish I couldn't see it. I remember back in the day seeing people use CRT monitors set to 60Hz refresh rate and it was like looking into a strobe light, multiple people looked at it and asked me "what flicker?" Some people's eyes must respond more slowly, or their brain is better at tuning it out.

author: james_s
author_rank: Super Contributor
timestamp: January 21, 2018, 08:53:31 pm
content: Quote from: kalel on January 21, 2018, 02:49:57 pmMy house was built in the 1970s so I try to have mostly period correct vintage light fixtures. When I bought the place somebody had tried to update it by putting in some hideous cheap modern looking light fixtures that looked completely out of place. I hate the "Home Depot remodel" look that is so common around here, I don't give a rat's ass about fashion fads, I just want everything to look roughly the same era.

author: glarsson
author_rank: Frequent Contributor
timestamp: January 21, 2018, 09:01:02 pm
content: Quote from: Kjelt on January 21, 2018, 02:35:57 pmWe can't buy traditional lightbulbs any more. The only options that will fit are LED, CFL or halogen.

author: Gyro
author_rank: Super Contributor
timestamp: January 21, 2018, 09:06:22 pm
content: Haha, hard to think of '70s as period vintage, you guys always did have a distorted sense of historyActually, looking back, I suppose it it a fair while ago.

author: james_s
author_rank: Super Contributor
timestamp: January 21, 2018, 09:10:19 pm
content: Quote from: Gyro on January 21, 2018, 09:06:22 pmThe 1970s are as long ago now as the 1940s were when I was born. Time flies.A lot of the "vintage" computers and video games I'm interested in are from the 80s, that's quite a long time ago now too.

author: Gyro
author_rank: Super Contributor
timestamp: January 21, 2018, 09:13:28 pm
content: QuoteScarily so, and accelerating!

author: Kjelt
author_rank: Super Contributor
timestamp: January 21, 2018, 09:20:10 pm
content: Quote from: glarsson on January 21, 2018, 09:01:02 pmThe halogen lightbulb replacements have identical behaviour in color as traditional lightbulbs when dimming.It is correct that >100W bulbs will no longer be available but that is hardly the bulb you would dim for "mood" light, what many are complaining about.

author: james_s
author_rank: Super Contributor
timestamp: January 21, 2018, 09:24:04 pm
content: Halogen bulbs are rapidly vanishing here too outside of a few compact quartz capsule types and decorative lamps. The market was never very big for halogen retrofits for standard incandescent, the small improvement in efficiency is not worth the high cost of the lamps, LED bulbs are significantly cheaper now and far more efficient.

author: Kjelt
author_rank: Super Contributor
timestamp: January 21, 2018, 09:27:24 pm
content: I forgot to mention that some manufacturers are already integrating red(dish) leds in their led bulbs that start to imitate the warmer mood lighting when dimming.It will never be perfect eg infinite steps like with a traditional bulb but over time it will come close.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 21, 2018, 09:31:55 pm
content: Quote from: Kjelt on January 21, 2018, 09:27:24 pmCitizen make a COB device with red LEDs integrated, which gets warmer at lower currents. Obviously you can't PWM dim it..

author: glarsson
author_rank: Frequent Contributor
timestamp: January 21, 2018, 09:55:40 pm
content: Quote from: Kjelt on January 21, 2018, 09:20:10 pm"will no longer be available"? It is 2018 and 100W bulbs were phased out in the EU in 2009!Timeline:2009: Clear 100W bulbs and all frosted bulbs phased out.2010: Clear 75W bulbs phased out.2010: Clear 60W bulbs phased out.2010: Clear 50, 25 and 15W bulbs phased out.2018: Halogen bulbs (energy class C-D) phased out.

author: tszaboo
author_rank: Super Contributor
timestamp: January 22, 2018, 11:33:05 am
content: Quote from: kalel on January 21, 2018, 07:51:39 amDefinitely. I get sick from a bright flickering light, while others just stand there, and have no idea what I'm talking about. There was a lot of research for VR, and they concluded, that 90Hzmostof the people did not experience sickness. But you are able to detect an LED if it is only on for 1 ms. Human perception is weird.I think it also changes with age, because people with BMWs and Teslas actively blind you every single night you drive.

author: james_s
author_rank: Super Contributor
timestamp: January 22, 2018, 07:55:55 pm
content: Those PWM modulated LED tail lights are awful, the flicker is pronounced and extremely distracting. I'm not sure why either, it would have been trivial to use a higher PWM frequency.

author: tooki
author_rank: Super Contributor
timestamp: January 22, 2018, 11:20:58 pm
content: For those of you looking for info on led lighting flicker, the magic google phrase is the “flicker fusion threshold”. And it turns out that to completely eliminate it even in worst case scenarios (small point light sources heavily dimmed [low duty cycle] while saccading at full speed), it takes a PWM frequency of about 3KHz IIRC. I’ve got another post on here somewhere going into more detail.

author: Someone
author_rank: Super Contributor
timestamp: January 23, 2018, 01:40:56 am
content: Quote from: kalel on January 21, 2018, 07:51:39 amAs above from tooki there is a wide range of variation from person to person, typical "most people won't see it" depends on many factors and how the source is viewed. Your vision field has varying sensitivities to flicker across it, typically much more sensitive in the peripheral vision. I'll expand on it below but relative motion is also important in flicker perception, for LED lamps viewing in the peripheral vision while turning your head or walking quickly can cause the effect but stopping or looking at it the flicker disappears. For a diffuse light in full field view the upper limit is around 90Hz in extreme cases and 60Hz is not far above average.Quote from: NANDBlog on January 22, 2018, 11:33:05 amThis research around spatial orientation and motion sickness is less about flicker and more to do with the typical movement speeds of the scene. You don't get motion sickness walking around in a stroboscopic environment but the moving reference of the VR display confuses the brain and does cause motion sickness, pick any threshold and if you move your head/body faster the display rate needs to increase.Quote from: james_s on January 22, 2018, 07:55:55 pmSpeed is the key here. The relative motion of the lights in your frame can be very high and/or the pulses can become discontinuous which is extremely distracting. This has been a problem with bicycle lights for a long time as many countries allow flashing/strobing and the only requirement is static visibility at a certain distance, not accurate location in motion. To save power the typical bicycle light uses an extremely short duty cycle with obvious dark periods and on the road it appears as a dot jumping around and is extremely hard to estimate the heading of the vehicle.

author: Nusa
author_rank: Super Contributor
timestamp: January 23, 2018, 02:12:46 am
content: QuoteTo be fair, for the bicycle rider the most important objective is to be seen AT ALL. A strobe is FAR more effective for that than a steady light. The good ones are even effective in daylight conditions.

author: Zero999
author_rank: Super Contributor
timestamp: January 23, 2018, 10:29:03 am
content: In my experience, the duty cycle is also important for flicker, with lower duty cycle being more noticeable.Speaking as a cyclist, I think being able to see is as or more important than being seen. I've had accidents because the lights I was using weren't bright enough.To answer the original question. LED filament bulbs are great, but not everyone wants something that has the same appearance and lighting pattern as an incandescent lamp. Flicker wise, not all LED filament bulbs are equal: some are better/worse than others.

author: TheWelly888
author_rank: Frequent Contributor
timestamp: February 06, 2018, 11:39:22 am
content: Quote from: hayatepilot on January 19, 2018, 09:00:03 amUnfortunately not yet available - Amazon has the bulb on their website but out of stock with no known delivery date. Hope they become available before Christmas(Which Christmas?)

author: hayatepilot
author_rank: Frequent Contributor
timestamp: February 06, 2018, 12:10:52 pm
content: Quote from: TheWelly888 on February 06, 2018, 11:39:22 amWhere I live they are in stock at the local retailers...And the german amazon site has them in stock too.Maybe they are only available in 220V

author: tooki
author_rank: Super Contributor
timestamp: February 06, 2018, 02:27:55 pm
content: Quote from: hayatepilot on February 06, 2018, 12:10:52 pmWhich ones?

author: hayatepilot
author_rank: Frequent Contributor
timestamp: February 06, 2018, 03:19:25 pm
content: @tookiThose in the links...

author: mrflibble
author_rank: Super Contributor
timestamp: February 06, 2018, 03:27:28 pm
content: Quote from: Gyro on January 21, 2018, 09:13:28 pmIndeed, time for a different universe!

author: tooki
author_rank: Super Contributor
timestamp: February 07, 2018, 09:21:17 pm
content: Quote from: hayatepilot on February 06, 2018, 03:19:25 pmOops sorry, I meant which retailers.

author: hayatepilot
author_rank: Frequent Contributor
timestamp: February 07, 2018, 11:15:45 pm
content: Quote from: tooki on February 07, 2018, 09:21:17 pmOhHornbach, Conrad, Lumimart, digitec/Galaxus, Brack, Siroop etc...

author: Cathreenh
author_rank: Newbie
timestamp: September 14, 2019, 01:24:43 pm
content: Do the company bulbs shows higher quality than similar non-branded ones

author: dnwheeler
author_rank: Regular Contributor
timestamp: September 17, 2019, 04:34:05 pm
content: This is a fairly old topic, but recently (end of July), the University of California Santa Barbara started suing major retailers for patent violation on their filament style bulbs:https://www.cnn.com/2019/07/31/business/light-bulb-lawsuit-amazon/index.html

author: Nusa
author_rank: Super Contributor
timestamp: September 17, 2019, 05:54:16 pm
content: Quote from: dnwheeler on September 17, 2019, 04:34:05 pmhttps://www.eevblog.com/forum/chat/uc-santa-barbara-sues-walmart-amazon-and-others-over-led-lightbulbs/

author: tooki
author_rank: Super Contributor
timestamp: October 21, 2019, 11:06:06 am
content: In all fairness, in the almost two years since this thread was started, filament LED bulbs have become extremely common. You can find them at IKEA, wal-mart, and any grocery store, sold by big name lighting vendors like Philips and Osram. The only reason anyone would be unfamiliar with them is if they haven’t had to buy a light bulb in the past year (which, admittedly, is a lot of people, especially if they already bought LED bulbs a few years ago, and thus have no need for replacements yet.)

author: james_s
author_rank: Super Contributor
timestamp: October 21, 2019, 03:12:28 pm
content: It's been years since I've actually needed to buy a lightbulb, although I buy them occasionally to play with when I see an interesting new type on the shelves. At this point I've replaced several bulbs not because they failed but because they were technologically obsolete and a new one offered better efficiency or other desired characteristics.