Nichia Develops 60 Lumen Per Watt White LED

mubs

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Thanks jtr. LED bulbs (at least here) are 2x - 3.5x the cost of CFLs, and the only reasons to get them is the lower power consumption and longer life. But if they fail partially or completely much sooner then expected, they're not worthwhile.
 

sechs

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I definitely sounds like an undervoltage issue. Some LED bulbs work fine down to 75 or 80 VAC, others might start to flicker at 100 VAC. Unless you can get your landlord to fix the mains power issue, which should be done anyway for a whole host of reasons having nothing to do with LED bulbs, I would just swap out the bulbs for something else. Probably nothing wrong with them, but their minimum design voltage is apparently higher than your mains voltage drops.
Unfortunately, I'm starting to agree with you. And I doubt that the landlord will do anything about it. The entire electrical network around here has problems.

After switching the sockets, the intermittent flicker is still there. I caught it flickering for about a minute, slightly less often than once a second.

Is this kind of thing made worse by overheating or long-term use?
 

jtr1962

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Is this kind of thing made worse by overheating or long-term use?
Sometimes it is because the undervoltage may cause parts to operate outside their specs. More often than not though it's more annoying than damaging. Try to look for LED bulbs which are speced for 85 VAC minimum. If they still flicker, then it's time to get your landlord or electrical company to take action because power line voltages shouldn't regularly fall that low. Even 100 VAC is considered very low. It's acceptable during brownout conditions, but not at any other time.
 

LunarMist

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Is there data that shows continuous low voltage (brownout) or are there just frequent sags?
Can you connect a data logger and use that as evidence?
 

sechs

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Data from where?

The regular supply voltage here seems to be around 110v+-5v. That's lower than other places that I've lived.
 

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Mid-tier UPSes these days have SNMP capabilities, that would allow you to log data from the wall at some frequency. This would allow you to aggregate large amounts of data and put together statistics which could compel action.
 

jtr1962

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Data from where?

The regular supply voltage here seems to be around 110v+-5v. That's lower than other places that I've lived.
That doesn't seem low enough to cause flickering. My guess is there are occasional brief sags well below that which might be causing the flickering you're seeing. Unfortunately, as Dave and Lunar already said, you would need a data logger to catch those.
 

sechs

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That doesn't seem low enough to cause flickering. My guess is there are occasional brief sags well below that which might be causing the flickering you're seeing. Unfortunately, as Dave and Lunar already said, you would need a data logger to catch those.
I have all APC RS series UPSes, and I don't think that's fancy-pants enough for voltage logging

Turns out that these Osram/Sylvania lights are dimmable. Could that actually be part of the problem?
 

sechs

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Unless the bulb *thinks* that it's being dimmed when it's not

Just a thought....
 

sechs

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For anyone keeping up on my travails, I moved both of the offending LED bulbs to my living room to live on the ceiling fan. Unsurprisingly, they flickered together, although the one bulb a couple times went full off for a couple seconds by itself. I think that it's hosed.

Since then, one of the chains broke on my ceiling fan and the property manager finagled getting the whole thing replaced. So far, only the presumably hosed bulb has shown any signs of flickering.

Current plan is to pull out one of my spare CFLs to replace the definitively dodgy bulb until I can get around to replacing it, and then keep an eye on the other and see how it goes.

Thanks to everyone for their input.
 

mubs

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The CFL has come back to the living room. Wife didn't like the harshness of the LEDs. One was too bright, another too dim. I didn't have the patience or the money to buy the Goldilocks one.
 

LunarMist

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What are the best high-output LED flashlights (3000+ lumens) with good color for nighttime panting?
It needs to have an easily replaceable battery pack and all rechargeable of course. Thanks.
 

LunarMist

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I'm sure there are now better ones, but I'm still really happy with my EagleTac

Link: http://amzn.com/B00H1IK6JY
Thanks. I'll wait until July for that.

Over the last few years the ubiquitous XM-L2 has been stuffed into most 18650 lights, even the compact ones, resulting in a wide beam that has poor usable throw.
Lately, there have been a number of XP-L lights introduced. Does anyone have any newly-designed or updated favorites?
 

LunarMist

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The site is working today for some reason. The main light head especially looks rather small, so it will be floody. I'd call that a Jack of the trades, but master of nothing except the recharging glow in the dark.
That is interesting, but I can't help but think that it would be brighter with an LED at low power.
 

jtr1962

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That is interesting, but I can't help but think that it would be brighter with an LED at low power.
That was my initial thought but then I'm thinking LED drivers often end up horribly inefficient at very low drive currents. And the LED themselves lose efficiency below a certain drive current, typically around 5% of rated current. Because of these factors, if you try to extend battery life 60 fold via dimming you might end up with only 1/500th of full light output, not 1/60th. The approach they're using may well be superior.
 

LunarMist

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That was my initial thought but then I'm thinking LED drivers often end up horribly inefficient at very low drive currents. And the LED themselves lose efficiency below a certain drive current, typically around 5% of rated current. Because of these factors, if you try to extend battery life 60 fold via dimming you might end up with only 1/500th of full light output, not 1/60th. The approach they're using may well be superior.
I'd prefer a regular 800-1000 lumen 18650-based light with the pulse mode and a glow in the dark cap that fits over the front for that purpose.
 

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LunarMist

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It seems I have completely sidetracked the comments of the Kickstarter campaign by asking a number of some simple questions about the light that should be easily answered, yet haven't been. I will be cancelling my "pledge" if they're not answered satisfactorily before the end.
Yeah, that's rather ridiculous. I get the feeling the product is nowhere near being finalized, but I suppose the Kickstand programs are often like that.
Is that Tang associated with the manufacturer or just being a Richard?
 

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Yeah, that's rather ridiculous. I get the feeling the product is nowhere near being finalized, but I suppose the Kickstand programs are often like that.
Well, a few people have reviewed the prototype on YouTube, so either the prototype is not really representative of the finished product and the design is still up in the air, or they intentionally don't want to get specific.

Is that Tang associated with the manufacturer or just being a Richard?
I suspect the latter.
 

LunarMist

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I think the MH20GT will be my next light.
 
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jtr1962

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In an interesting development consistent with this thread's original theme, Cree has released the XP-G3. Datasheet. Note the S5 bin (172 lumens @ 350mA and 85°C). And this isn't vaporware. These parts are actually available. Efficiency of the top bin would be 180 lm/W @ 85°C and 190 lm/W @ 25°C. If you want to look at CRI 90 LEDs, even there you have the R3 bin (122 to 129 lumens @ 350 mA and 85°C) available which equates to an efficiency in excess of 125 lm/W.

We've come amazingly far in the nearly 13 years since this thread was started. 60 lm/W existed only the lab. Production LEDs were only at 20 to 30 lm/W. Nowadays 100 to 160 lm/W is pretty common, depending upon CCT and CRI.
 

Stereodude

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Well, a few people have reviewed the prototype on YouTube, so either the prototype is not really representative of the finished product and the design is still up in the air, or they intentionally don't want to get specific.
The creator said: "...I'm still waiting on the answers to your questions from my engineering team. I apologize it is taking so long. Just remember we have a 100% satisfaction guarantee on all our products."

That was yesterday around noon. I canceled my pledge this morning. I don't expect answers will be forthcoming in the next 5 hours and I'm going to be busy this morning and not glued to the internet monitoring it.
 

Stereodude

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So I am a bit surprised... They did answer the questions, and I'm glad I got out. 64Hz PWM? Really?!?!? The user can't swap Li-Ion cells in the holder. They're only using a 2.4Ah battery which mean's it's probably not really Li-Ion, but one of the safer Lithium chemistries (or they got really cheap cells). The lens is plastic with no AR coating...

All in all, they made a lot of odd designs criteria that pretty much no serious flashlight user would expect or accept.
 

LunarMist

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So I am a bit surprised... They did answer the questions, and I'm glad I got out. 64Hz PWM? Really?!?!? The user can't swap Li-Ion cells in the holder. They're only using a 2.4Ah battery which mean's it's probably not really Li-Ion, but one of the safer Lithium chemistries (or they got really cheap cells). The lens is plastic with no AR coating...

All in all, they made a lot of odd designs criteria that pretty much no serious flashlight user would expect or accept.
Why can't the Li-ion batteries be swapped? Are they not 1860? 64Hz seems slow and perhaps will cause the seizures or embolism. :)
 

LunarMist

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In an interesting development consistent with this thread's original theme, Cree has released the XP-G3. Datasheet. Note the S5 bin (172 lumens @ 350mA and 85°C). And this isn't vaporware. These parts are actually available. Efficiency of the top bin would be 180 lm/W @ 85°C and 190 lm/W @ 25°C. If you want to look at CRI 90 LEDs, even there you have the R3 bin (122 to 129 lumens @ 350 mA and 85°C) available which equates to an efficiency in excess of 125 lm/W.

We've come amazingly far in the nearly 13 years since this thread was started. 60 lm/W existed only the lab. Production LEDs were only at 20 to 30 lm/W. Nowadays 100 to 160 lm/W is pretty common, depending upon CCT and CRI.
Arrgh. I suppose there will always be something new.
 

Stereodude

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Why can't the Li-ion batteries be swapped? Are they not 1860? 64Hz seems slow and perhaps will cause the seizures or embolism. :)
It sounds like they've decided to make the 18650 a sealed "pack" with a micro USB port for charging it instead of making it an 18650 holder with charging circuit. As a result you can't swap the 18650 cell. It probably a good decision for people who aren't familiar with 18650 cells, the different types of them, etc. Which, quite frankly, is probably most of their customers.

I had a light with a PWM around 60Hz. It was unusable IMO. Since you can wave the light around, PWM can be very problematic if it's not something close to 1kHz (or higher).
 

LunarMist

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I just received the MH20GT. I had the older MH20, but the beam was rather wide. The GT is quite bright and reasonably concentrated (33,000 cd) for such a small light (<140g w/18650). Mainly this will be for travel where the USB charging is also a major advantage.

I'm using the Olight 3400mAH battery if that makes any difference. The Nitecore battery bundled with it is only 2300.
 

LunarMist

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It sounds like they've decided to make the 18650 a sealed "pack" with a micro USB port for charging it instead of making it an 18650 holder with charging circuit. As a result you can't swap the 18650 cell. It probably a good decision for people who aren't familiar with 18650 cells, the different types of them, etc. Which, quite frankly, is probably most of their customers.

I had a light with a PWM around 60Hz. It was unusable IMO. Since you can wave the light around, PWM can be very problematic if it's not something close to 1kHz (or higher).
It sucks to remove the battery every time and also have lower capacity. I'd rather use a regular 18650 and a single-cell XTAR USB charger in that case.
 

Stereodude

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I just received the MH20GT. I had the older MH20, but the beam was rather wide. The GT is quite bright and reasonably concentrated (33,000 cd) for such a small light (<140g w/18650). Mainly this will be for travel where the USB charging is also a major advantage.

I'm using the Olight 3400mAH battery if that makes any difference. The Nitecore battery bundled with it is only 2300.
That looks pretty nice. Do they have a version of it that's neutral white?
 

LunarMist

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That looks pretty nice. Do they have a version of it that's neutral white?
The color of mine is slightly yellow on the white ceiling, though not terrible like some lights.
The CRI is probably not very high. I doubt there are any options in that type of light.
 

Stereodude

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The color of mine is slightly yellow on the white ceiling, though not terrible like some lights.
The CRI is probably not very high. I doubt there are any options in that type of light.
I've stopped buying 6500k lights. Neutral white or bust.
 

Stereodude

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Well I looked around and could not find any as good for my travel needs.
I really like my neutral Eagletac GX30A3D. I took it to Asia with me in January. I didn't really need it or use it, but I had it just in case. It also allowed me to get acquainted with the luggage x-ray person at the airport when I was leaving too. :razz:
 

LunarMist

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Their website shows the 3400 mAH with this flashlight? :scratch:
My time is very short and the only one I could receive this weekend was the bare light with a store bundle of several items including the 2300 Nitecore.
I have numerous 18650 batteries, but the highest capacity are the Eagletec and Olight 3400mAH. Eagletec does not make contact in some lights, but I think it also works in the MH20 series.
 
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