Okay, so if I’m reading all this correctly, they’re phosphor-coated filaments?
Filaments have plenty of thermal inertia that only rather drastic fluctuations should be noticeable. The driver must exhibit some pretty serious fluctuations/dropouts to visibly register. Yeah, I’d say definitely work on that.
People used to grex about “pre-flash” when flicking on moonlight/firefly mode on some lights. Having visible stutter on a lightbulb would be a pretty serious glitch.
@jon_slider It’s unclear why you think I don’t understand this discussion. I can confirm that this is a very rare issue with the US bulbs. We’ve sold 10s of thousands with mostly happy customers. Like I said, we only see visible changes in places with power that’s too noisy.
Maukka was literally the first person to test the first batch we ever shipped to Europe. It’s good to know upfront if we have a potential issue with this batch.
We will keep testing to see if it’s an isolated case or a widespread case with the European version. The prototype did not have this issue, so we are doing an investigation to see what changed from test to production.
@Lightbringer They are LED “filaments.” Similar concept to regular discrete LEDs except shaped differently, plus our custom phosphor. The stability of light output is mostly due to the driver circuit as the diodes themselves can fluctuate very rapidly to changes in input.
Europeans (EU countries + UK only): interested in helping me do a test of my bulb? I’ll send you a free Bedtime Bulb if you don’t mind helping me out with a small experiment.
I want to see if the issue that Maukka had is replicable in other regions of Europe. All I would need you to do is to screw in the bulb, observe it for a few minutes, and see if the light is constant or not. You’re free to do whatever you want with the bulb after the test.
If you are interested, please send me a private message with your name and shipping address. Also specify if you prefer the B22 Bayonet base instead of the E27 screw.
Okay, so when you say “filament” it’s more a form-factor (similar to COB LEDs but on a string vs on a board), and not a heated filament as in incandescent bulbs.
I was curious what kind of phosphor would be thermally excited to produce light… that’s what threw me by use of the term “filament”.
So it would in fact be subject to flicker, etc., if the driver passed through voltage variations (hiccoughs) in the mains supply.
Find a source of the “underling blue LED chip” and start mixing up phosphors.
I recall when the original single-phosphor “office white” fluorescents got driven out by “triple phosphor” high color rendering fluorescent tubes.
Triple phosphor lamps had another advantage, as some phosphors have a long decay time so kept puttiing out light when the AC power 60 cycle went through its zero point or the AC power flickered briefly.
Not aware of any consumer-level retailers. Maybe talk to Yuji. They can do some low-volume LED finished goods and they mix custom phosphors. Perhaps they could sell the phosphors but I can’t guarantee it.
Even a few grams can be pretty pricey though. A little goes a long way!
This is a cool page just to learn about the contribution of various phosphor materials: LED phosphors | YUJILEDS
Yes. It was phosphor on Yuji store 2 years ago. But now I can not find it in their store. It was really expensive. You do not need it, just believe me.
I know, right? I discovered from mixing bulbs that 3500K is the sweet spot.
You can do this too by using both 3000K and 4000K in the same fixture. The biggest downside is that the fixture looks odd when you look at it. If only one bulb type could achieve 3500K…
It’s definitely possible as there are a number of 3500K LEDs, especially those with high CRI and/or “human-centric” SPDs. So it could become a thing. We are listening!
I am eagerly waiting for this to happen :partying_face:
For this, I could imagine 2000 lumens ceiling bulb version as well, and maybe 1300 and 800 lumens for smaller spaces to be illuminated.
Additionally, many of the 95-ish CRI LED light sources still have a mild to moderate gap in the cyan part of the spectrum. If a phosphorus compound set could be tuned to diminish this gap, that would be awesome.
I hope it happens too, I like the bedtime bulb focus on quality. If they made a 3500K bulb with good CRI I would pay good for that.
Unfortunately making bulbs better CRI and brighter at the same time isn’t going to happen with current tech. The more you fiddle with the spectrum, the less efficient the bulb becomes. That makes it run hotter and dimmer.
Hyperikon’s Amazon page is filled with pictures of lights that have melted components or nearly burnt bases, so I would assume “quality” is the direction they would be going for given the price range and niche of this bulb.
Interesting, must be a different product listing or they “cleaned up” their reviews like so many products on Amazon do.
I really wanted to pick some up a few months ago but the first couple pages of reviews I saw were all negative with many pics of discolored/melted bases.
On the other hand maybe they have improved their heat sinks?