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Community and Q&A

LED Filament bulbs

Aaron Birkland | Posted in Green Products and Materials on

Does anybody have any experience with these new so-called LED filament bulbs?

It’s an unusual design, featuring thin LED “filaments” composed of about 25+ tiny LEDs mounted in series on a metal or glass substrate, then encased in phosphorous-impregnated silicone. A high DC voltage (> 70V) is placed across these “filaments”, which are suspended in a clear bulb with electrodes in a manner nearly identical to incandescents. A simple power supply fits inside the screw base. It appears that the heat dissipation qualities of the filaments and power supply are good. Efficacy seems to be typically >100 lm/w.

To me, it appears to be an attractive and creative design that actually looks like it can succeed as drop-in replacement for incandescents in terms of looks and quality of light (i.e. radiation pattern).

Here are some videos I found that tear them down and explain how they work.

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  1. gozags | | #1

    I have been making my own light fixtures the last couple weeks and have delved into those new LED Edison style bulbs a bit. A showroom in town has a large display of these (forget the brands, sorry). They were going over the benefits/caveats with me. The first series had the led components being fairly obvious - like tiny yellow straws encased in glass. The newer ones look better off. The light looked the same to me. They said people love them - but they were also $30+ per (they sell fixtures that cost thousands, so perhaps there is a buyer for $35 bulbs).

    The newer ones were between $10-$20. Looking online myself, they seem like a cool product. Give you that old times look but w/ new tech.

    Of all places, Etsy had people selling them. For as low as $13 per but I haven't picked any up myself.

  2. Aaron Birkland | | #2

    Wow, $30. Apparently, there are several sellers on eBay that ship directly from China, with a 6W plane Jane bulb going for about $7.50, with free shipping. I doubt those are UL listed, though :)

  3. gozags | | #3

    Yah - seemed expensive to me as well. Though these were the first on the market and you could pick from a variety of bulb and filament looks/shapes. Like everything, the price comes down.

    More expensive one there, but attractive.

  4. Aaron Birkland | | #4

    Yeah, these look like they would offer fantastic artistic potential. Those cage bulbs would seem to look convincing at a distance.

    Regarding price, the man in this video suggests that the price was initially quite high as well, until the design became widely copied and improved upon:
    (it contains a fascinating description of their construction, as well as a demo of soldering these things together, including an accidentally bent one)

  5. gozags | | #5

    I ended up getting these for a project. They work and look great. No humming or 'flashing' while dimming on a basic resistor type Lutron dimmer and they work even better on a digital dimmer. My analogue dimmer does this 'soft rise' thing instead of instant on and the bulb sort of springs to life on a delay, but nothing distracting. Regular bulbs did a little of a delay on that switch as well.

    The comparable regular bulb are 3k hrs and $5 a year. These are 27 year $.50 a year bulbs. No contest.

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