Why haven't filament LED bulbs taken over the market?

[helius]

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.

[Someone]

They are great for mood or accent lighting, but NO WAY will they light up a room.

Oh, 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.

Which is one of the big benefits of 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 original l-prize remote 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.

[edavid]

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.

Watch out, the Costco bulbs are 3000K "bright white".  2700K/100W can cost quite a bit more.

[james_s]

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.

[tooki]

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.

(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.

[steve30]

I saw some LED Filament lamps in Wilkinsons the other day which had diffused glass.

[Halcyon]

I use THESE globes 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.

[TimNJ]

To all who commented that filament bulbs are widely 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 their website, 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 at 160V. Seems a little low for 120VAC.

[ikrase]

The only time my family ever used these, they had terribad reliability. Probably there are better ones available... somewhere.

[Halcyon]

The only time my family ever used these, they had terribad reliability. Probably there are better ones available... somewhere.

I 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 used LED Benchmark for a source of good information.

[tszaboo]

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.

[Kleinstein]

....
Aishi is the capacitor brand of choice. Interestingly, it's a 33uF cap rated at 160V. Seems a little low for 120VAC.

From 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.

[kalel]

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.

[jonovid]

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.

[kalel]

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.

Do you think that turning on would produce additional stress to some components (e.g. capacitors)?

[jonovid]

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.

Do you think that turning on would produce additional stress to some components (e.g. capacitors)?

best scientific methods will simulate daily usage.  8 or 10 minute off time need only simulate daily usage.
example thermal cycling inside the glass envelope, no matter how small this is.

[hayatepilot]

Do you live under a rock? 100W equivalent LED bulbs have been widely available for several years.

...but not in the filament style, which is the subject of this thread.

There you go: 


https://www.philips.co.uk/c-p/8718696742396/led-bulb

100W equivalent 1500Lumen 2700K

[kalel]

Do the Philips bulbs show a significantly higher quality than similar non-branded ones?

[mikeselectricstuff]

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.

Do you think that turning on would produce additional stress to some components (e.g. capacitors)?

Shouldn't do - there may be some thermal cycling effects but reliablity will usually boil dowm to how hot the PSU componants get

[ovnr]

I'm happy they haven't taken over the market. Worse efficiency, plus the flicker. I hate flickery 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.

[amyk]

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.

Do you think that turning on would produce additional stress to some components (e.g. capacitors)?

If 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.

[hayatepilot]

I'm happy they haven't taken over the market. Worse efficiency, plus the flicker. I hate flickery 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.

I don't know about the flickering (to me they look identical to normal LED bulbs) but the efficiency of filament LED bulb is certainly BETTER or 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.

[ovnr]

I'm happy they haven't taken over the market. Worse efficiency, plus the flicker. I hate flickery 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.

I don't know about the flickering (to me they look identical to normal LED bulbs) but the efficiency of filament LED bulb is certainly BETTER or 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.

They 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.

[Richard Crowley]

I can't wait for the 100W equivalent bulb to be developed so that I can use it in the ceiling!

Yesterday, I bought a box of five 100W equivalent LED bulbs for $10
Around 40% if the price was subsidized to encourage replacement of incandescent home lighting.

[kalel]

I can't wait for the 100W equivalent bulb to be developed so that I can use it in the ceiling!

Yesterday, I bought a box of five 100W equivalent LED bulbs for $10
Around 40% if the price was subsidized to encourage replacement of incandescent home lighting.

That's a great price. Are they 12-15W? Different manufacturers have different opinions on what 100W equiv is.