[1900k edition is in!] WTS: 1900k-5800k 5mm LED 95+ CRI

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djozz
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Alen wrote:

Blue spikes are high

These are normal blue 450nm based white leds so they have their 450nm spike which is needed as part of the visible spectrum to form the CCT/CRI, nothing extraordinary here compared to other leds, that is simply how they work. A few manufacturers recently came with new types of leds with 420nm base leds or with double dies, reducing the blue peak and filling in the cyan gap, but those are far from mainstream yet and none of the regular leds used by BLF have that.
Alen
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djozz wrote:
Alen wrote:

Blue spikes are high

These are normal blue 450nm based white leds so they have their 450nm spike which is needed as part of the visible spectrum to form the CCT/CRI, nothing extraordinary here compared to other leds, that is simply how they work. A few manufacturers recently came with new types of leds with 420nm base leds or with double dies, reducing the blue peak and filling in the cyan gap, but those are far from mainstream yet and none of the regular leds used by BLF have that.

I read about new Leds,and 420nm is near UV-A.
Marketing from bad to worse.
djozz
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Alen wrote:
djozz wrote:
Alen wrote:

Blue spikes are high

These are normal blue 450nm based white leds so they have their 450nm spike which is needed as part of the visible spectrum to form the CCT/CRI, nothing extraordinary here compared to other leds, that is simply how they work. A few manufacturers recently came with new types of leds with 420nm base leds or with double dies, reducing the blue peak and filling in the cyan gap, but those are far from mainstream yet and none of the regular leds used by BLF have that.

I read about new Leds,and 420nm is near UV-A.
Marketing from bad to worse.

So what? It is the base led, the phosfor converts almost all of it to make the rest of the spectrum. Look at the spectrum of these leds and you see that the remaining small 420nm peak is hardly higher than the 420nm level of any incandescent or day light of the same colour temperature. Which implies that you are afraid of most natural light sources too (excluding maybe camp fire light) which is not very practical in life unless you are dedicated to spend your life inside under a edison bulb at 2500K.
Alen
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djozz wrote:
Alen wrote:
djozz wrote:
Alen wrote:

Blue spikes are high

These are normal blue 450nm based white leds so they have their 450nm spike which is needed as part of the visible spectrum to form the CCT/CRI, nothing extraordinary here compared to other leds, that is simply how they work. A few manufacturers recently came with new types of leds with 420nm base leds or with double dies, reducing the blue peak and filling in the cyan gap, but those are far from mainstream yet and none of the regular leds used by BLF have that.

I read about new Leds,and 420nm is near UV-A.
Marketing from bad to worse.

So what? It is the base led, the phosfor converts almost all of it to make the rest of the spectrum. Look at the spectrum of these leds and you see that the remaining small 420nm peak is hardly higher than the 420nm level of any incandescent or day light of the same colour temperature. Which implies that you are afraid of most natural light sources too (excluding maybe camp fire light) which is not very practical in life unless you are dedicated to spend your life inside under a edison bulb at 2500K.

I wish you will test one day these 420NM Leds
from unknown brand,so we’ll know if they’re safe.
Afraid? I already take enough natural daylight,don’t need more UV-A on night
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*UVA is the least harmful type of UV
*420nm is not even UVA
*the 420nm region is a small part of these led’s spectra
*people who are frightened of blue peaks should have a look at light levels before getting afraid of a certain light source.

Quick calculation: the 5mm leds at discussion here at 20mA produce about 50 lux at 0.5M distance, which is shining a flashlight at yourself at an arm’s length. Let us assume that it is just as harmful as daylight (which is not true, it is much less harmful because it contains 0% UV, but ok) and you expose yourself directly to this flashlight for two scorching hours Evil That is equivalent to an exposure of about 3 seconds of sunlight (130 klux).

Alen
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Even worse than the amount of blue light is any source of lights that switch on suddenly in front of the eyes at night,
Like motion sensor spotlight Sick

djozz
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I guess I’m a bit insensitive Sad

Unheard
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Alen wrote:
Even worse than the amount of blue light is any source of lights that switch on suddenly in front of the eyes at night,
Like motion sensor spotlight Sick

I hate when they are brighter than my flashlight Flat Stare . At least, sensor lights should slowly (1 s) ramp up so you’ll have a chance to focus elsewhere.

djozz wrote:
I guess I’m a bit insensitive Sad

You’re blessed.

Smile, you cannot kill them all.

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Unheard wrote:
Alen wrote:
Even worse than the amount of blue light is any source of lights that switch on suddenly in front of the eyes at night,
Like motion sensor spotlight Sick

I hate when they are brighter than my flashlight Flat Stare . At least, sensor lights should slowly (1 s) ramp up so you’ll have a chance to focus elsewhere.

djozz wrote:
I guess I’m a bit insensitive Sad

You’re blessed.

I liked when swiched on ,CFL bulb increased bright gradually was pleasant near bed
but they took too long time to arrive at max.
Does there are a sort of fast auto dimmer (1-2sec.) on modern Led bulbs
Or similar to put on wall box for inca. lights?
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Never seen a bulb that does this. I’d buy it if it has as additionaly three mode UI.

If you find an external box, let us know.

Smile, you cannot kill them all.

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There is a thread dedicated to the blue light topic that would be a better place for a detailed continuation of this tangent.

As a couple brief comments, though: I second djozz’s observation that the spike shown is very typical. For example, in the top part of image here is a spectrum of a 4500K Nichia 219B (from Maukka’s Fireflies ROT66 review) of the same color temperature. It’s very similar in the location and relative scale of the peaks and valleys:

https://i.imgur.com/g2HKhcQ.png

I’ll leave off my other thoughts on the topic, and simply note that based on the research I’ve read: if in doubt, there’s certainly no harm in erring towards lower light levels as the first priority, lower color temperatures as the next priority, and high CRI as a final priority to reduce blue light exposure. However, I have not seen research that indicates the typical narrow spike is worse than the more spectrally distributed but similar total energy of blue emission in an idealized black body.

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Got the 32K-CEX today. What a nice surprise they are very rosy. Love it.

Left: C01, right: Tube.

Thus far, closest to the Yuji. Tried all LEDs in the pack, tints do not vary much, which is also very good.

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Posted this on reddit a week ago or two, but here's what's in my collection. In the case you're wondering about it, yes, all the emitters in the picture here are at least R9050/R9080.

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Hi rngwn, what is your standard shipping method? It looks like ePacket is currently the only option for Australia – is it a reasonable cost?

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skinny_tie wrote:
Hi rngwn, what is your standard shipping method? It looks like ePacket is currently the only option for Australia – is it a reasonable cost?

The same to U.S. and Canana, $10. Not the cheapest, but fairly reasonable.

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How about direct driving these at 3.2V with a LiFePO4? Are we talking instant death, or a decent but reduced lifespan?

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HareLantern wrote:
How about direct driving these at 3.2V with a LiFePO4? Are we talking instant death, or a decent but reduced lifespan?

LiFePo cells start off at 3.6V fully charged, that will push enough current through these leds to kill them (see the current/output/voltage graph in the OP)
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djozz wrote:
HareLantern wrote:
How about direct driving these at 3.2V with a LiFePO4? Are we talking instant death, or a decent but reduced lifespan?
LiFePo cells start off at 3.6V fully charged, that will push enough current through these leds to kill them (see the current/output/voltage graph in the OP)

Could I put a resistor in series with the battery to bring down the current? My shaky understanding of Ohm’s Law is thinking that about 150ohms would be about right?

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HareLantern wrote:
djozz wrote:
HareLantern wrote:
How about direct driving these at 3.2V with a LiFePO4? Are we talking instant death, or a decent but reduced lifespan?
LiFePo cells start off at 3.6V fully charged, that will push enough current through these leds to kill them (see the current/output/voltage graph in the OP)

Could I put a resistor in series with the battery to bring down the current? My shaky understanding of Ohm’s Law is thinking that about 150ohms would be about right?

22 Ohms would do just fine. With fresh cell, it will drive the emitter at 45mA and less as the battery are being used up. Still, if you can afford to do it, a buck converter or at least a linear regulator is recommended to keep the LED drive current constant.

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rngwn wrote:
HareLantern wrote:
djozz wrote:
HareLantern wrote:
How about direct driving these at 3.2V with a LiFePO4? Are we talking instant death, or a decent but reduced lifespan?
LiFePo cells start off at 3.6V fully charged, that will push enough current through these leds to kill them (see the current/output/voltage graph in the OP)

Could I put a resistor in series with the battery to bring down the current? My shaky understanding of Ohm’s Law is thinking that about 150ohms would be about right?

22 Ohms would do just fine. With fresh cell, it will drive the emitter at 45mA and less as the battery are being used up. Still, if you can afford to do it, a buck converter or at least a linear regulator is recommended to keep the LED drive current constant.

Thanks, I’m a complete noob with all this. I’m going to get some C01s to play with, but I also have some old 2AA minimag hosts, and some plastic AA dummy cells that would take a resistor soldered across the inside really easily.

Unless you can suggest any kind of buck converter with a diameter less than 14mm that I could just put in series? Maximum simplicity is the idea here..

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HareLantern wrote:
djozz wrote:
HareLantern wrote:
How about direct driving these at 3.2V with a LiFePO4? Are we talking instant death, or a decent but reduced lifespan?
LiFePo cells start off at 3.6V fully charged, that will push enough current through these leds to kill them (see the current/output/voltage graph in the OP)

Could I put a resistor in series with the battery to bring down the current? My shaky understanding of Ohm’s Law is thinking that about 150ohms would be about right?


Sure, for the low currents that 5mm leds need, a resistor in series is a perfect way to regulate the current (for high power leds you needs more fancy ways of regulation if you want to maintain more or less constant output). 150 Ohm seems rather high, but you can experiment, you may end up with 10 Ohms or less.
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djozz wrote:
HareLantern wrote:
How about direct driving these at 3.2V with a LiFePO4? Are we talking instant death, or a decent but reduced lifespan?
LiFePo cells start off at 3.6V fully charged, that will push enough current through these leds to kill them (see the current/output/voltage graph in the OP)

I’ll bet they can be safely used direct drive on two Eneloop or any 2 NiMH or NiCad cells, or two primary 1.5V cells of choice, like button cells or alkaline (but not 2 Energizer Lithium), also probably fine direct drive with a single primary CR123A or any size 3V primary.

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Just got mine today, 3400k and 4500k. Ordinary shipping took 13 days to the UK. Well packaged, ESD bags. All good.

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PM sent

Attempting to build a Convoy of Convoys.

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nocturne wrote:
djozz wrote:
HareLantern wrote:
How about direct driving these at 3.2V with a LiFePO4? Are we talking instant death, or a decent but reduced lifespan?
LiFePo cells start off at 3.6V fully charged, that will push enough current through these leds to kill them (see the current/output/voltage graph in the OP)

I’ll bet they can be safely used direct drive on two Eneloop or any 2 NiMH or NiCad cells, or two primary 1.5V cells of choice, like button cells or alkaline (but not 2 Energizer Lithium), also probably fine direct drive with a single primary CR123A or any size 3V primary.

So far I have had not trouble using Yuji 5mm LED’s direct driven from 2 x AA alkalines or 1 x CR2032 lithium coin cells.

rngwn’s LED’s are even more robust than the Yuji’s, and I also have several of them in 3xLR44 button cell lights.

Voltage drop under load for all of these options seems to keep the output pretty reasonable.

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Who is the manufacturer of “rngwn’s LED’s?” If they have been named, I missed it. It doesn’t matter to me, but it would be easier to refer to them with the name of the manufacturer, rather than, “these LEDs” and “those LEDs rngwn found” or some arcane code that is effectively meaningless because no one knows what it means. One thing Yuji really has going for it…. easy as hell to know what someone is talking about when they mention “Yuji.” Just a thought.

Unheard
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It’s likely Sophia. But since rngwn found them, have djozz tested them, stocked them and gave them a good naming scheme, I’ll stick to the terms he coined.

Smile, you cannot kill them all.

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Unheard wrote:
It’s likely Sophia. But since rngwn found them, have djozz tested them, stocked them and gave them a good naming scheme, I’ll stick to the terms he coined.


This 2$ keychain would be nice for these 5mm Leds if only mounted a real battery and circuit board,
also solar panel is not connect on board according reviews. And why 3 Leds?

https://a.aliexpress.com/_BOKgr7

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A coin cell and contacts welded to it is utter crap imo. Probably no rechargable battery (3V) due to cost, so the panel wasn’t connected.

Smile, you cannot kill them all.

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Unheard wrote:
A coin cell and contacts welded to it is utter crap imo. Probably no rechargable battery (3V) due to cost, so the panel wasn’t connected.

Maybe there is a good one? Idea was not bad
This 2014… have panel connected but still not circuit and you have to press hold button on,boring
https://m.youtube.com/watch?v=cq9VZbQXSZ0
I

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