Oh right, about those LEDs
xiphmont.livejournal.com
xiphmont.livejournal.com
Reminds me of the ancient story of the electronics manufacturer that sourced some resistors or whatever from Japan for the first time. The spec called for max 1% bad parts or whatever. When the parts arrived, the box contained a packet with a note that said something like "Thanks for your order. We are unsure why you want 1% defective parts, but for your convenience, we have packaged them separately."
This seems to be the oldest reference: Chris Taylor, (1995) "The case for customer satisfaction", Managing Service Quality: An International Journal, Vol. 5 Iss: 1, pp.11 - 14 http://www.emeraldinsight.com/doi/abs/10.1108/09604529510081... but behind a paywall
...it is referred to for example by http://link.springer.com/chapter/10.1007/978-981-287-429-0_3... "The Effectiveness of Service Quality by Jabatan Agama Islam Wilayah Persekutuan (JAWI) Towards Customer Satisfaction"
If you are willing to buy multiple times what you need to make up for the quality issues, you can get a decent deal with the cheap Chinese ones. The ones that whined and the ones that did not whine had a fabric covering the wires at the base of the bulbs. If I had some way of knowing which eBay merchants were selling those, I would get a much better deal.
By the way, Nichia is a Japanese company.
Philips and Osram LED lamps just aren't that expensive. Cheaping out just isn't worth the hassle.
The post stated they received LEDs in excess of expectation for quality and low cost for small production run size.
They got the quality and more.
If interested, ask how.
Nichia is not only a Japanese company, but they are the inventors of the now ubiquitous GaN blue-LEDs; or at least Shuji Nakamura was working there when he invented them.
[1] Nichia is a Japanese company with US offices.
From the people I've talked to, it's impossible without being on the ground in the manufacturing center (and/or hiring a manufacturing fixer who is).
Friend, they are red.
:D
The only light more efficient than an LED is an LED that is turned off. Demand-based lighting, network controlled is the next step.
Cree already sells Power-over-Ethernet powered and controlled light fixtures to do this: http://www2.cree.com/smartcast-landing-page
Oh good, Auernheimer can wake me up in the middle of the night.
http://motherboard.vice.com/read/hacker-weev-made-thousands-...
http://news.mit.edu/2016/nanophotonic-incandescent-light-bul...
I didn't see that claim in the article, but I thought these two paragraphs were wonderfully specific:
One quantity that characterizes a lighting source is the so-called luminous efficiency, which takes into account the response of the human eye. Whereas the luminous efficiency of conventional incandescent lights is between 2 and 3 percent, that of fluorescents (including CFLs) is between 7 and 15 percent, and that of most commercial LEDs between 5 and 20 percent, the new two-stage incandescents could reach efficiencies as high as 40 percent, the team says.
The first proof-of-concept units made by the team do not yet reach that level, achieving about 6.6 percent efficiency. But even that preliminary result matches the efficiency of some of today’s CFLs and LEDs, they point out. And it is already a threefold improvement over the efficiency of today’s incandescents.
Which details in that do you question?
Yes. They say they are currently at 6% efficiency, which is better than the worst CFL's and LED's, but far from matching the best.
as theoretical efficiency of white LEDs is also around 40%
Yes, although one should probably include the power supply. I think the advantage of the incandescent approach is that there are no losses here.
I'll consider incandescents once the efficiency of commercially available ones reaches the efficiency of commercially available leds.
Sure, sounds wise. Light quality and longevity might be factors too.
But what does this have to do with the claim that the article says "LEDs are only twice as efficient as traditional bulbs"? The article can be read as claiming that the worst commercially available LED's are about 2x the efficiency of the best incandescents, and perhaps this is false, but I don't see this as reason to discount the rest of the details.
Here's earlier discussion of this approach, which includes a link to the actual paper: https://news.ycombinator.com/item?id=11771001
https://www.google.com/amp/phys.org/news/2012-03-efficiency....
Also, the "theoretical efficiency of LEDs" is a very different number than the "theoretical efficiency of white LEDs". I think when talking about white LEDs, they are assuming a monochromatic LED pumping a phosphor.
But while it's not that practical, in that it's limited to picowatts (10^-12 watts), it is interesting nonetheless. Another similarly surprising example is that the theoretical maximum efficiency of some fuel cells also exceeds 100%, for similar reasons of extracting heat from the environment.
[1] http://www.lowtechmagazine.com/2008/10/led-light-cfl-b.html
For a while the color temperature was terrible, but cheap and reliable warm phosphors have mostly fixed that.
As for private outdoor lighting, I'm not sure that less cost really affects that. People that made poor lighting choices (too much, too cool, too much spill) don't do it because it's suddenly cheap. They just paid more before. The answer to this is likely some degree of local regulation.
While LED lights have certainly allowed for new applications, that article is nearly 10 years old and the future predicted has not come to pass. There has been no wave of LED-encrusted buildings. The roads don't glow. My bookshelves and whatnot don't either.
If LEDs deliver a 10x improvement in energy use, we'll have to use 10x as much light to offset the energy gains. How likely is that?
Lots of led encrusted buildings.
I freaking love what Asia is doing with their urban environments...
I just wish that the US developers would take note.
We are building the tallest building in SF ("salesforce" tower) and its a mundane peice of shit building. Literally zero aesthetic innovation.
Lol. Give them time. Here's two examples off the top of my head, in my city: http://urbantoronto.ca/news/2015/07/aura-illuminates-downtow...
http://canderelresidential.com/files/styles/building/public/...
Speak for yourself :)
I agree, though; I use a lot more lights around the house, but they're small and very directed for their purpose. Many of them are controlled by cheap, ubiquitous PIR modules so that they're only on when needed, with absurdly low quiescent current. I use less light overall because it's only where I need it to be, and I find this to be much nicer on my eyes, and generally pleasing for the evening. The added efficiency is just a bonus on top of all that. Many are undervolted, as well, so should last a very long time; the main concern is the lifespan and quality of the power supplies.
There are those solar roadway people who are hoping to fix that. (I'm not optimistic, though. :) )
Read the same thing about four wheel drive cars, where the added safety is eaten up by drivers taking increased risks.
Interesting psychology.
And PWM lighting is annoying in a lot of ways.
Or, you can just buy a keychain or a torch made using this principle. Will provide continuous light for +10 years: http://www.kitmonster.co.uk/product_info.php/products_id/638
Which is fine for my Luminox watch, but not fine for a wizard's staff.
Also, the light is pretty weak. You can only see it in a dark environment. Again, that's fine for a watch.
Efficiency is much less important, if you also pay to heat your home.
That doesn't mean they're superior to LED, but it does change the cost/benefit to make it a little less lopsided! :-)
While, sure it makes the argument less lopsided, you'd be crazy to consider the heat output from bulbs as a benefit when replacing them with LEDs.
Don't forget, in the summer you have to pull that heat out of your house also.
Basically, what Philips Hue "White Ambiance" [1] bulbs offer. Are there any alternatives?
[1] http://www2.meethue.com/en-us/productdetail/philips-hue-whit...
Jesus.
You just missed their Black Friday sale too :(
I have a few and they work well with my other home automation stuff (broadlink IR+RF remote + Aukey RF outlets + Moteino system).
First we had terrible yellow fragile maglites that requires several large C or D cells for anything approaching reasonable brightness and battery life. I had my small maglite die at the bottom of the grand canyon, and the top of MT shasta. After trying to replace a tiny incandescent bulb in the dark in challenging conditions I decided I was switching to LEDs, no matter what the compromise was.
Similar monitors had broad spectrum CFLs that generated UV, converted it to white light with a phosphor then threw away most of the light and filtered it down to approximately R, G, and B. The resulting color accuracy was terrible.
LEDs started out expensive, not very bright, and mostly red. Migrated to different colors, I think blue was the most expensive.
Finally white LEDs started showing up in tiny AA or AAA flashlights with 50-75 lumens. About as bright as the 2xAA maglite that were huge in comparison.
Color coverage got better, life got better, efficiency started ramping up.
100-200 lumen flashlights started to become more common. 18650s that have substantially more power and a more LED friendly 3.7V started to appear.
Year or two later 400-500 lumens were common, efficiency kept increasing. Started to appear as backlights, car dash boards, brake lights, etc.
CFLs switched from wasting 95% of the light to ditching the white phosphors for a mix of RGB phosphors. The savings were twofold and multiplicative. The first was generating UV -> RGB directly with mix of RGB phosphors in the CFL. Then additionally instead of narrow notch filters that didn't pass much light they switched to very wide spectrum filters that passed most of the light. So a red pixel didn't need to be within 1% of red, but instead just block 99% of G and B. Since the RGB phosphors emitted very close to the ideal frequencies the color accuracy increased. Monitor power requirements dropped significantly.... only to be killed off by more efficient LEDs.
Things doubled again, small ish flashlights much like the 2xAA maglites except fatter. 1000 lumens hitting $50-$100 points points. Now throwing a usable light 300 Meters isn't unusual from a small hand held light. Depending on your use recharging once a month isn't unusual. 4-or 5 light levels are common, and runtimes of 1.5 hours (max light) to 100 or more hours (on low) aren't uncommon.
So now macbook pros that are extremely thin (greatly helped by very tiny LEDs for backlights) get 10 hours of battery light with 500 nit screens with wonderful color accuracy. Similarly even 55" LED screens are crazy high resolution and crazy cheap. The cost per pixel doesn't seem on that crazy different than the cost per transistor.
Sadly like Moore's law, LEDs aren't getting much better anymore. For the first time I purchased a new flashlight after 2-3 years... and the best I could find was zero % brighter 8-(.
It's not just computers that have been improving like crazy.
Personally I feel like advances in computers have been creeping along at best in the last ~five year period. Ever since Intel beat the shit out of AMD with the Bridge architectures and the x86 market became a de-facto monopoly.
Does seem like AMD has scared Intel into over drive. Seems like all price points are likely going to get significantly more cores in the next generation after stagnating for what a decade? The normal high end desktop has been quad core since way back at the Q6600 in 2007. Desktops with 8 cores/16 threads and servers with 32 cores/64 threads seems to be Intel's answer to AMD's Zen.
Here's hoping AMD delivers on promises and is competitive.
Another factor might be that the software industry is finally adapting to multi-core being the new normal. I mean sure, server software's been forking or multi-threading for ages, but I get the impression the bulk of desktop software did most of its work in a single thread until fairly recently - so having more than 2-4 cores wasn't really worth it, it would just have increased cost without making things feel that much faster for the average user.
If it were physically possible, it would have been strongly preferable to have just kept increasing clocks instead of going wider. That was a decision made out of necessity, not choice.
You see big gains from being able to multitask a little, past that it's really diminishing. All things being equal, a 2C2T or 2C4T at 6+ GHz would be strongly preferable to 4C4T or 4C8T at 4-4.5 GHz for most desktop use. The gains aren't that steep in the real world, of course. The reality is that it's more like a choice between 2C2T at 4.7 GHz (G3258, being a bit gracious here), 4C8T at 4.4 GHz (6700K) or 6C12T at 4.1 GHz (5820K). You can push all of those numbers up a little bit farther by pushing the voltage, but that's roughly the shape of things at stock-ish voltages.
I diverge from the common wisdom here, given those numbers I think the 50% increase in real cores from jumping to 6C12T justifies a 10% loss in single-thread performance for many users, especially given that they're essentially the same price. In the threaded tasks where Hyperthreading provides gains, the extra cores will really push you ahead. If you're just gaming or browsing, a 4C4T is really all you'll ever need (and realistically many people will be fine with a 2C4T or 2C2T anyway). So the 4C8T are really an awkward in-between to me, I really think it's mostly that people don't realize that the 6700K isn't "top of the line" and there's a whole other enthusiast socket out there.
The server market's a little different of course, you can go much wider, but good single-thread performance still beats parallelism in response times. Really wide architectures like Qualcomm's 24-wide ARM server chips still have yet to really prove themselves except in throughput-oriented/latency-insensitive applications (which are the easy gimmie for slow-and-wide designs).
Another interesting observation is that, on cache-coherent systems, the maximum possible clock rate also tends to go down as soon as more than one socket is used.
> (which are the easy gimmie for slow-and-wide designs)
Nowadays they are more of an historical anecdote, but some time ago Sun created the "niagara" line of barrel processors - a technique that is a form of simultaneous multi-threading, like Hyper-Threading, just with 8-16 threads / core.
These UltraSparc T1, T2, ... processors held quite some throughput benchmarks - but were obviously not feasible and not meant for general purpose use.
Which is perfectly sensible if you think about it. No matter how fast your cache coherence mechanism is, it's slower than not sharing cache between two chips. It's fine if you are storing program code or independent data, but if you are operating on the same cache lines as another processor you have to flush the dirty lines over and possibly roll back a whole bunch of execution that might have been done there.
Sometimes this even happens when the data you are working on is different but shares a cache line (false sharing).
> Nowadays they are more of an historical anecdote, but some time ago Sun created the "niagara" line of barrel processors - a technique that is a form of simultaneous multi-threading, like Hyper-Threading, just with 8-16 threads / core.
We do a lot of contracting with a state government and I'm pretty sure they're still running these in their datacenter. It's some flavor of SPARC for sure, and I was talking to our sysadmin and he mentioned that they used a processor that I remember was a lot wider than hyperthreading, which sounds a lot like UltraSPARC.
From what my guy explained they are pretty nice in database workloads especially since they're also an Oracle DB shop. They are locked into Oracle products seriously hard and they're unwilling to contemplate moving to commodity products. Probably unable to, given their staff's skillset and in-house operating procedures. It shouldn't take a tiger team for someone to suggest restarting a misbehaving server. You get what you pay for though. The state doesn't pay much and people who have other options don't stay in that kind of work environment.
I don't know, their plans have stalled (tick tock is gone and buried), Iris is being killed and their rollouts are complete shit-shows (even ignoring Xeons, there were 9 months between the availability of the first and last Skylake mobile parts). Maybe that was intentional because there's no competition (it's not like AMD is much of an option these days) but that seems a bit odd.
Basically once intel supply catches up with demand, bugs fixed, 1 rev of silicon after production, BIOS tweaks, etc. Then intel starts pulling wafers out of the supply, adding a extra chip inside the cache for the extra GPU memory bandwidth, and starts selling the IRISs.
I'd expect the Kaby Lake Iris to be out in q1 or Q2 of 2017.
The KL roadmap reduces Iris to just some dual-core 15/28 U parts, and is adding HD-based quad-core U parts alongside that. The trend is clearly towards removing Iris.
> The new macbook pros are using Iris
These are skylake parts, and the 15" only uses HD.
> Don't forget that the IRIS parts are a half cycle behind the non-IRIS.
I'm not forgetting anything, I'm looking at the roadmap.
It just seems strange. They've been touting their Skull Canyon NUC with Iris Pro pretty heavily towards gamers and to be honest at that size, Iris Pro is exactly what I want for a lounge room gaming and 4K movie PC.
It just seems like such a shame; why kill Iris Pro when it's just actually becoming desirable?
Ideally with a higher tier version that uses HBM so the GPU is not held back by the memory bandwith.
Compare the NUC with iris 580 is $600-$700 ish. The NUC with the iris 540 is $340 and often they throw in 8GB ram for free. 580 is hardly a gaming GPU, it doesn't really run much that you can't run on the 540. Sure it's faster, but far from an AMD/Nvidia killer.
So the iris pro might die, but I expect the iris line to continue.
Certainly the popularity of the iris based mac pro will help. Hell I wish more of the skylake iris's were easy to get. I've been hoping for an Iris 550 based NUC or similar system for a quiet desktop. I've yet to find one.
The MSRP difference between the 6820HQ (2.7/3.6, HD 530) and 6870HQ (2.7/3.6, Pro 580) is 12%: http://ark.intel.com/compare/88970,93340
The former is $378, the latter is $434.
What an end user can buy is a NUC, the iris 580 is something like $650 list, $575 street. The Iris 540 version is $400 list, and around $340 (but often with a "free" 8GB ram.
Iris seems generally a failure on the desktop, but seems fairly popular in mini pc's and laptops. Apparently the NUC was one of the few success stories in pc desktops for the last year or two.
I wonder how long before bits of linux are running on the GPU? Once the process of porting to GPU more and more code will run there.
There is little reason to waste them (and compromise efficiency) for Linux or any other OS.
Depends which spec you are looking at. While not much has happend with flops/core, flops/Watt has improved dramatically in the low energy space.
This has kept the server space rolling over a bit, which is somewhat nice, it's also helped laptop battery life immensely. There's not as much need for true desktops, but I imagine the nuc-class will continue to improve over the next few years.
It just depends on your needs... Also, the GTX 1080 is impressive to say the least, and still a bit under-powered in gaming at 4K (which is what is now pushing that space). Encoding to h.265 is still really intensive as well.
The use cases where more power is needed are eroding, but there are still a few, and the use cases where the power usage needs to be lower still are many.
Lots of cores is all very well, but a lot of applications still can't utilise them that well.
The last time computing hardware felt exciting was late 90s, or early 00s when there were half a dozen graphics players, SPARC, PowerPC, 680x0 and the odd strange idea like NeXT, transputers and BeBOXes.
That we care more about the case, the interfaces and the coloured LEDs says we're firmly past the innovation era.
Right, which is the real issue I think. It's not that we can't make faster computers, it's that we've run out of good software use cases, just like the limiting factor on how good videogames look is no longer how good the engine and rendering are but rather how good the artists can make the textures and models.
There is still innovation going on - intel's recent hardware transactional memory support is very exciting - but for the most part we simply already have more CPU capability than we know what to do with.
Proper credit: Maciej's observation, not mine: http://idlewords.com/talks/web_design_first_100_years.htm
I love that you can date a lot of electronics by the colour of the LEDs (anyone still own an alarm clock with a red display?). As soon as a new colour was possible/cheap enough the last 'hot' colour was dropped quick-smart.
Finding a new one with LEDs in any color other than blue was essentially impossible. Which was especially infuriating because I specifically wanted to avoid adding more sleep-disrupting blue light to my bedroom.
The clock display was backlit by orange LEDs and seemed even less noticeable than the classic red LED display you mention.
The phrase to search for is "Philips wake up light", on Amazon or whatnot. They make a few models, but the prices start around $60.
Seems to keep time fine, nothing turns on randomly, etc. Not cheap though.
https://www.amazon.com/Lighten-39-95-Uses-Your-Lamp/dp/B00AX...
The time settings were much better than the Philips, which had sort of an awful UX. Also, you can have a longer ramp up, which better approximates a real sunrise.
For the lamp, I used a 3 bulb floor lamp, with Satco halogen lightbulbs (the kind that, for ~70 watts, replace a 100 watt incandescent). It's a higher watt draw, but I'm only running it for an hour or so each morning.
So I put some window tint on it. I picked up some samples with different transmissivity from the local shop that did my car, and mixed & matched until I got what I wanted, then applied them.
I'm not sure it's a feature, since the apartment is rented and I'll probably need to pay for the repair, but I dropped it on the floor, and it has left a fairly obvious dent.
http://www.braun-clocks.com/clocks/digital/bnc015-rc-digital...
Tungsten is for oven lamps, specialist use and little else.
Now I'd like to be able to buy 10 year life household bulbs that last and preserve something resembling a colour temp. A set of LED daylight bulbs I bought 2 years ago are down to 1/2-2/3 original brightness and all except one are spread around the "warm white" territory.
By 10k hours they'll be down to nightlights. Realistically they'll have been replaced long before.
Half the desk lights on Amazon, including expensive brands like Luxo, are using LED to mean fixed "expensive manufacturer replacement part", rather than bulb.
I'm hoping for a continuation in solar and a breakthrough in batteries so we can tip away from fossil at similar rate.
If you want to see across parks, tops of distant trees, flag down helicopters, etc then get an 18650 based light.
Fenix is a good place to start, but there's many companies that made good lights. Even $50-$60 buys a hell of a light .
yes. Which is why to this day so many "cool" accessories insist on blue LEDs as a power indicator making them completely useless whenever too much light would actually be harmful to the experience (like the Playstation Power LED, or any other power LED on devices you have in your bedroom).
The blue LEDs feel so incredibly bright compared to all other LED types to the point where they become very distracting.
Blue light isn't cool any more (I would argue that it never was in the first place). Stop adding blue LEDs to all your devices. Please.
http://www.cree.com/~/media/Files/Cree/LED%20Components%20an...
Changing this will take years. Perhaps premium brands will start making red power LEDs hip again, and we will enter a period of red LEDs (again). On the other hand, violet power LEDs might become fashionable, so count your blessings.
I was amused that the HTPC computer case I chose had a small slider just below the blue power indicator; you can slide it to the right, and the blue is no longer visible.
https://www.amazon.com/LightDims-Original-Strength-Electroni...
"Hide your indicator lights" really isn't reasonable, but marker or masking tape would be good candidates for blocking 80%+ of the light.
[0]: a Dell tower PC, a MBP with power button on the keyboard that is backlit like any other key, and a Dell monitor
[1]: two other models of Dell monitor
I just double checked to make sure, no LED control on this monitor :(
Or in this case specifically, maybe it's time to rethink whether you really need a power LED on your monitor as it will be undoubtedly obvious whether a monitor is in-fact powered or not by just looking at it.
Will it? Is the screen dark because it's off (janitor bumped it at night), because my laptop didn't wake up when I docked it, or because I forgot to plug the cable back in after fooling with an SBC on that monitor yesterday?
The power light makes the state of the monitor obvious, and so does an image displaying on it. The light's useful for the edge cases when there isn't an image being displayed.
Red/off, green/on (stop/go) has a much, much deeper symbolic link and would be easy to adopt and be understood - no matter how entrenched blue LED symbolism has, or will, become.
edit: sorry, did not see 'electrical' in your post. What device has luminosity to shine through e*tape? My electric toothbrush can illuminate entire bathroom, hall and most of my attached bedroom. 1 strip cured it.
When blue LEDs were first available in sample quantities, the R&D Lab in which I worked ordered a few 5mm blues for £35 each - no free samples available!
And as an aside, having a light that turns on to tell you when a product is off/asleep is just offensively bad design.
The other colors later followed suit - the brightness you now get with a few mA is amazing when you know the old LEDs.
Do LED bulbs fix that and work with stock power systems in a car?
No, scuba diving. Tech divers who operate at extreme depths or in overhead environments need powerful flashlights. They need to be reliable and redundant, because you really don't want to be stuck in a cave system or a shipwreck with no source of light.
HID was the gold standard of dive lighting for many years. The thermal issues that accompany HID lighting practically disappear underwater, because you're floating about in the world's biggest watercooling system.
As gaius said, LEDs suddenly overtook HID lighting a few years ago. The brightness, light quality and beam shape of LED lights matched HID, at which point the changeover was inevitable. LEDs don't explode if you drop them on the dive boat, they turn on instantly, they have consistent color temperature and they're efficient and easily dimmable. HID and HMI still have a role in underwater photography, but it's a shrinking niche.
Not only did LEDs make it cheaper and easier for us to get lights, the cost is so low that there's a huge increase in the number of people riding after dark. This is a really great thing, since having more people out in the woods after dark makes it overall safer, more welcoming, etc.
The best LEDs are now remarkably close to the theoretical maximum luminous efficacy. We're now bottlenecked by batteries and the limits of sanity.
Specialist diving companies will happily sell you a 60w, 6300 lumen flashlight. It's not a big market, but it exists. To run a light like that you need a massive external battery pack tethered with an umbilical, because it'll eat through the entire capacity of an 18650 cell in under 10 minutes. That's no problem for divers, because a properly designed battery pack is close to neutrally buoyant; it's a major inconvenience for people on the surface.
1000 lumens is Good Enough for 99% of users of handheld flashlights. There really aren't that many people who need to throw a beam for half a kilometre or light up a football stadium with a flashlight.
Do you have any pointers/references where I could read up on this? I'm designing home lighting with power leds and finding that despite all the hype, it's quite difficult to beat the efficiency of TL5 HE fluorescent tubes with LEDs. I also noticed that while the output in lm/W has been increasing, it seems to increase very slowly these last few years.
There's room for improvement, but nothing revolutionary. Cree had a prototype device achieving 303 lm/W in 2014, but it isn't currently commercially viable. Lower efficiency LEDs still make up a large proportion of the market for simple reasons of cost.
https://arxiv.org/pdf/1309.7039.pdf https://www.nichia.co.jp/specification/products/led/NF2W757G... http://www.cree.com/~/media/Files/Cree/LED%20Components%20an... http://www.cree.com/News-and-Events/Cree-News/Press-Releases...
And for most people, a product that can do that is substantially worse than one that can't. If you want a flashlight to play tag, walk the dog, or wander your house in a power outage, you probably can't use a dive-strength light.
We're finally hitting the point where even modest, internal-battery flashlights can be so powerful that they're painful to look at, and for most people you don't want to go any brighter than that.
None of mine have both a way of getting full power fast /and/ deterministically turning it on on the lowest setting.
(Except for the one that only has 'very bright' and where I first wondered why there is no rebound when I turn it on.)
While I haven't made any formal measurements, the result is several times brighter than the old bulb, and of course the batteries last many, many times longer. Recommended.
The flashlights are cheap stuff from China, $10 or thereabouts. The cells are about half that price. The charger is about same price as a flashlight.
The damn things are blindingly bright. The whole family has a 18650 flashlight on their bikes, and I always get comments from people when I'm biking through the neighborhood. Oh, and the devices are tiny, the barrel is just big enough to contain the Lithium cell.
In terms of amount of light, I'm not even sure I want something better. Seriously, they beat the pants off the antiquated Maglite candles in every way.
The current regulator inside is not resistive, it's a switched regulator with a frequency in the audible range. If it's very quiet in the room and you press the barrel to your cheekbone, you can hear a very faint whine from the regulator.
Please make sure the beam is directed if you do this. I've seen many people riding around with lights that are quite blinding to oncoming traffic, especially on dark roads. Sometimes just pointing regular flashlights down can solve this, but not always.
The US hasn't caught on yet, but countries like Germany have mercifully begun to regulate this.
As part of my public duty I switch my 1000 lumen flashlight into flash mode which often causes audible complaints. It does seem to get my point across.
5 Years ago I replaced all my light bulbs with LEDs, but it was not easy.
First I had to find a brand that didn't sell this clinically white light emitting crap and then I had to buy 3 times as much as I needed and send 2/3 back because not all emitted the same color.
The dimmer ones were made in China, but the brightest ones were made in Germany.
That said, some people are absolutely insane when it comes to color temps. I learned this the hard way helping friends covert to LED - the pickiness is something I never knew existed and gave me a new appreciation for how much people care about "their" version of light.
By the way, wouldn't it be feasible to just mix red and blue, either discrete or in RGB packages?