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I have a weird issue where different types of light bulbs are triggering some kinds of visual issues.

I found this lightbulb to be perfect. However, when I unscrewed it to read the label, it fell on the ground and broke!

What kind of lightbulb is it on the inside? Incandescent, halogen, flourescent, compact flourescent, LED, or something else? If it's LED, why are the LED rods shaped like that? And what are the keywords to find a similar bulb?

enter image description here enter image description here

There is also a small circuit board inside the bulb end that I forgot to photograph.

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  • livermoreca.gov/things-to-do/centennial-light-bulb "oldest" working lightbulb. Check out the BulbCam!!
    – Yorik
    Commented Apr 16 at 19:38
  • Whether it flashes or not is down to how cheap they have made the electronics, nothing to do with the LEDs per se. You may have to try several different brands. I have put together a small phototransistor circuit that I can read with my DMM on AC to measure flicker amplitude and quantify what I can tolerate. Many brands flicker.
    – Neil_UK
    Commented Apr 17 at 9:14

3 Answers 3

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This is a LED filament bulb. The yellow rods are actually strings of blue LEDs mounted on an insulating substrate and coated in a phosphor than converts blue light to white.

enter image description here

enter image description here

Compared to a standard lightbulb like this one:

enter image description here

Advantages:

  • It is filled with helium which transfers heat very efficiently, so it uses the whole glass bulb as cooling surface, instead of just using the base. So it overheats less in closed light fixtures.

  • Very low cost.

  • Many LEDs in series means they can be driven with high voltage which is more efficient

  • Transparent, so the light that comes out at the back of the bulb is reflected by the fixture, goes through the bulb and comes out where you need it. So you get a lot more light for the same cost and power. Standard bulbs or diffused bulbs are in the way of the reflected light, so if the bulb is mounted sideways you lose a significant fraction of the output.

Drawbacks:

  • All the electronics has to fit inside the base so it must be very small, which means a small capacitor, so some of these bulbs flicker.

  • Easy to break (it's glass)

  • Exposed mains voltage when broken

Other:

  • Light pattern is the opposite of a standard LED bulb: it emits more towards the sides, whereas the standard bulb emits more towards the top. This makes it better for some uses, worse in others. Usually for wall or ceiling fixtures it is better, because the bulb is mounted parallel to the wall or ceiling. For a pendant or desk lamp where you need the light to come out more like a spotlight, standard would be better.

Arrows indicate direction of highest light output with bulbs in the best orientation according to their type:

enter image description here

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  • if the LEDs are in series, would this mean one of them breaking will disable the entire rod? Or is that not a concern?
    – Syndic
    Commented Apr 16 at 11:02
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    @Syndic Yes. Same as pretty much all other LED bulbs.
    – bobflux
    Commented Apr 16 at 13:28
  • You might have added a bit more emphasis to the "why" in the question. The answer to that isn't physics or electronics but purely fashion: to make them look like old incandescent bulbs. No other real reason beside that. While illumination to the sides is practically true, this could have been achieved with countless other designs. This one was dictated by the supposedly fashionable retro look.
    – Gábor
    Commented Apr 16 at 13:44
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    @Gábor The reason is cost and efficiency, which is also cost. Many LEDs in series allows driving with high voltage which simplifies electronics to almost nothing. No magnetics, no heat sink, no MCPCB, no expensive thermal conductive plastic... Manufacturing cost is extremely low.
    – bobflux
    Commented Apr 16 at 14:56
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    You misunderstood my remark. :-) It was to the answer in general, not to the question of LEDs in series specifically. The reason for the whole design (transparent glass with LEDs resembling incandescent filaments and the inclusion of fake "filament holders") is obviously a market-oriented one, people wanting that retro vintage look and ready to pay a premium for it. Just as an example, it isn't important to me. I'm perfectly happy with all my LED bulbs having translucent enclosures without any filament look. All I want from them is light, nothing more. :-)
    – Gábor
    Commented Apr 16 at 15:07
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It has become trendy for marketing to call LED bulbs with retro looking glass and bases "Edison Bulbs", but in industry as the article linked to above is supporting, Edison Base bulbs are the standard for the screw is style bulbs. Their standard sizes all start with an "E" denoting Edison. Every standard screw in bulb is an Edison base bulb. Marketing departments and people who do not know anything about lighting and its history or don't care, just like calling them "edison bulbs" and they are, just one specific retro looking type. I love the retro LED bulbs. Also, they have not dominated the market for "decades" it is more accurately a century+. Radio tubes are now about 120 years old! They were made possible by light bulb technology, putting filaments,plates, and grids in evacuated glass tubes.

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    You seem to have posted a response to one of the comments above, rather than an answer to the OP's actual question. StackExchange operates in a question-and-answer format, not as a discussion forum. Commented Apr 15 at 21:44
  • @MichaelMacAskill while this answer does contain obvious responses to a comment, it also manages to answer the OP's question "What kind of lightbulb" with "Edison Bulb". Though I think this answer needs a bit of editing to be a good SE answer
    – coagmano
    Commented Apr 16 at 2:29
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    @someone Welcome to DIY SE! Please note the above comments and edit your answer to only respond to the original question
    – coagmano
    Commented Apr 16 at 2:31
  • I'm afraid this is completely wrong. In many markets, the (totally idiotic) "Vintage Style Lightbulbs" are indeed labelled "Edison style!". Because people who work in advertising - are idiots. THE IMAGE ADDED IN MY ANSWER SHOWS AN EXAMPLE of this total stupidity in product naming. Note that outside the US (Aus, UK, non-English areas) they are generally not so labelled, as nobody gives a shit about Edison outside the US, and it does not evoke "early 1900s" outside the US.
    – Fattie
    Commented Apr 16 at 21:06
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This is simply what is marketed as a "Vintage light bulb." That's all there is to it.

You can instantly find these anywhere that sells bulbs or instantly see them for sale online.

If you simply google nothing more than "light bulbs" you will see many of these (incredibly stupid) "Vintage Style" light bulbs:

enter image description here

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    they are pretty much available on the shelf in most stores that carry bulbs these days, both in name brand and generic, and in all different shapes and sizes. They aren't even labeled as vintage anymore, I know they used to be.
    – rtaft
    Commented Apr 17 at 12:18
  • right, great point.
    – Fattie
    Commented Apr 17 at 12:28

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