Bright Ideas

incandescent-lightbulbOne of the Chaos Manor Advisors saw an article about a new kind of incandescent bulb that was brighter than normal bulbs.

Researchers at MIT have shown that by surrounding the filament with a special crystal structure they can bounce back the energy which is usually lost (see article here).

This seemed interesting, and brought forth a comment from Peter Glaskowsky, another CM advisor, expressed some skepticism:

Some of this story is simply false to fact, but other parts are correct.

For example, LEDs with CRI values over 90 (and up to 97) are widely available, and some of these also provide high-quality red tones (the part of “warm” that is particularly noticeable to some people).

On the other hand, it’s correct that LEDs with high CRI values are only around 14 percent efficient, as the story says, so if the MIT solution can increase this figure to 40%, that could be good.

But MIT has only achieved an efficiency level of 6.6% and these researchers haven’t even identified a theoretical basis for surpassing 20% efficiency—about where the best LEDs stand today—so they’re a long way from claiming any real advantages.

Also, the technology behind this invention looks expensive and has some limitations. First, the reflectors are made using semiconductor-like materials and processes—up to hundreds of stacked layers of exotic materials that have to be made with high precision or the product won’t work right. There’s no precedent for using these processes on highly curved surfaces, either.

Ultimately it isn’t at all clear to me that it will ever be possible for this technology to surpass the combination of cost, efficiency, and color quality offered by LEDs, which is not the conclusion invited by MIT’s press release.

I’ve seen many of these factually questionable and unjustifiably optimistic MIT press releases in the past, suggesting this is either a deliberate strategy or just a quirk of someone in their press office who really ought to find something else to do for a living. MIT does plenty of good work; there’s no need to hype it past all scientific justification.

Your CMR editor has a supply of incandescent bulbs, many bought before some sizes were outlawed by the US government (info on incandescent bulb ban here). There are several places in my house where the lights tend to be on all the time (partly due to need, partly due to laziness). Here’s my thoughts:

I have started a slow process of replacing my incandescent bulbs (and CFL’s) with LED lights (for A19 base 2700K bulbs, I got these http://amzn.to/1PsxE8h ; 6 pack for about $21.00). I have a full set of six on the light fixture above the dining table, just a few feet away from my usual spot in the living room. That light is always on, even during the day. They are 60W equivalent, and are brighter than the incandescent bulbs, and the CFL that I tried in the same fixture. And they are full-bright immediately, rather than needing the warm-up period of CFLs.

I have also started using LED bulbs in various ceiling ‘can’ fixtures (65-watt equivalent, BR30 bulbs, use 7 watts), using them as the old bulbs (incandescent and CFL) have failed. They appear to provide more light, and again do not need the warm-up period of CFLs. The 65-watt LED bulbs will eventually replace the older BR30 bulbs in the entire house, especially in the kitchen, where the slow-brighten time of CFLs is problematic.

The 65-watt BR30 bulbs were purchased from Amazon http://amzn.to/1Psxrlp , 6 for $35, with free shipping courtesy of Amazon Prime. They are ‘dimmable’.  I notice they are out of stock at the moment, but LED bulbs are available in many places. (Some local utilities are also subsidizing LED purchase.)

So far, pleased with them. I am assuming that they will be a positive effect on my electricity bill. And using the bulbs in the family room, at 7 W each instead of 65W, will allow that circuit to be powered by my generator during any power outage. (That light circuit is on the same circuit as the TV, which I plan to power during any outage with my generator.)

Advisor David Em is also an LED bulb proponent:

Last year I bought fairly inexpensive dimmable full-spectrum LED spots for the studio. I love them.

Also happen to be reading Oliver Sacks’s “Uncle Tungsten” [Amazon link ] at the moment, which has some interesting discussion of the history of light bulbs.

What do you think? Are you moving towards LED bulbs, or are you holding out with incandescent? Or are CFL’s your choice? Let us know in the comments.

10 comments on “Bright Ideas

  1. As my incandescents burn out, LEDs replace them, if their bases will fit. Lamp harps can be a problem. Thanks for clearing up the article’s errors.

    By the way, I’ve followed Jerry’s writings from his first engrossing novel. Thanks for all the imagination engendering,

    • LED are dominating the market at the moment and will dominate also in the following years. The invention is such a great that i wouldn’t be surprised if LED would be as popular from 20- to 30 years from now.

  2. My house is nearly five years old. I replaced the first wave of failed incandescents with CFLs, now I am putting in LED. The main trick is to find 2700 K LEDs and avoid the harsh blue white glare of “hotter” emitters.
    My latest was to replace a regular tubular fluorescent with a “drop-in” LED. The first generation of LEDs required rewiring the fluorescent fixture, but these don’t. They cost twice as much, of course.

  3. I too stocked up (modestly, as poverty can have a strong moderating effect on any purchases — if anyone asks, Social Security is neither social, nor secure), I also, at a time when I was making good money, stocked up on CFL tubes and electronic ballasts. I bought them on ebay — I was able to buy 4-pin CFL tubes in a variety of outputs, ranging from 7W to over 20W (the latter are blindingly bright), at prices far below wholesale. The real windfall was a box with probably 15 pounds or so of electronic ballasts.

    After studying the circuitry, I was able to do some tweaking. The ballasts were officially designed for two four pin tubes, IIRC something like 10 to 12 watts each.

    Four pin tubes have two heaters, one at each end. The ballast puts out a low voltage at each coil, to warm it up to help toss the electrons off, into the tube.

    My experiments were successful — I was able to use the ballasts to power one 20/25W tube, by “bridging” the two outputs.

    I was also able to use two-pin tubes (I had a number of them as well as the 4-pin variety). Two-pin CFL tubes have an integral starter (a small capacitor, and a small tube with mercury in it, which starts out “closed” so as to bridge the two heaters, until they warm up, and the light flickers to life, at which point the bimetal contact in the mercury tube heats up too — and opens, allowing the high voltage to illuminate the light).

    That starter is the biggest failure mode in two-pin tubes.

    My first experiment was to remove the starter — and in so doing, “liberate” the two “bridged” heater wires, converting the two-pin tube to a four-pin tube.

    But I had another “bright idea’ — I tried using these tubes (both four pin, and “gelded” two-pin) as “instant-on” tubes (after reading the specs on the output voltage of the ballast). They worked perfectly! Less wiring, and better results!

    I rigged up a “light panel” with an array of 20W tubes, in ersatz two-wire/instant on mode, and it put out a hellacious amount of light.

    My plan was to put up a hydroponic tomato garden in the spare room, but when my health took a turn, the plan slid to the back burner. (I’ve been sort of obsessed with the idea after reading an article in the local electric co-op’s magazine, about a local tomato farmer, who put up a hydroponic greenhouse — he said he got better yield from one acre (it may even have been less than an acre) of hydroponic greenhouse tomatoes than he was able to get from TEN acres of “dirt”-grown tomatoes. I love vine ripened tomatoes. I hate the picked-green/shelf-ripened tasteless tomatoes found in the stores (not to mention the obscene prices).

    I digress a tad.

    My wife picked up a sack of 9.5W LEDs at the hardware store (touted as 60W equivalent), for $2,99 each. I was not expecting to be much thrilled with the output, but when we screwed them into the ceiling fan, I was blown away by how bright they were! IMO that “60W equivalent” is a ridiculously conservative rating, If they were sold as 100W equivalent, I think I’d have been satisfied that the figure was accurate.

    They seen to have similar color temperature as tungsten bubs. The bubble-pak says they are “Soft White 3000K” as well as dimmable.

    I would expect that the efficiency of this type “bulb” to continue increasing in the near future.

    That said, should I ever manage to put up my garden, I do plan on sticking with the 20W CFL tubes (or even higher wattage), I don’t know if they’re more efficient than the LEDs, or if it’s just sheer brute force, but I can’t imagine how many LEDs I’d need to duplicate the amount of light that grid of “big” CFL tubes emits.

    BTW, the biggest problem I had with those CFL tubes was finding sockets for them, Apparently they’re a contractor-only part, and damn hard to find. Took a few years of ebay searching before I was able to glom onto a sack of ’em. Prior to that, I drilled holes in the bases and screw-mounted them. Crude, but effective. (To make matters even more frustrating, there are a large number of different sockets for the things — apparently “based” (pun not intended… or maybe it was) on wattage. The different wattage tubes are “keyed” so as to prevent inserting into the “wrong” socket. Dremel to the rescue. That soft plastic in the base quickly yielded to my cutting bit, and the tubes I had fit into the sockets I had.)

    I know I’ve droned on, but hopefully some of this will be of use to someone. If not, well, sorry ’bout that. 😉

  4. I’d like to move towards LED lights except for 2 main issues.

    1. Price. I have a lot of lights in the house and even at a few bucks per bulb, it would cost a LOT to swap over. And swapping one at a time looks bad especially in an area where there are a lot of bulbs and buying them one or two at a time will result in different brands being installed in the same area so the light just won’t be consistent.

    2. Immature tech? I got an LED recessed bathroom light advertised as dimmable, and I have it on a dimmer that was advertised as “works with LED lighting”, probably due to working correctly with lower wattage draws. The problem is that the LED light buzzes fairly loudly if it isn’t at full brightness. The dimmer doesn’t buzz, it is the light bulb that makes the noise. My hearing is good enough that a house full of buzzing bulbs would drive me insane.

    So… When the prices drop to the point where it wouldn’t cost a few hundred bucks to swap over without the house looking weird, and when the tech is mature enough that I don’t have to worry so much about which exact brand won’t buzz or otherwise act poorly, I’ll probably swap over. In the meantime, I have a spare box of cheap incandescent bulbs for places that need full light instantly, and a couple of boxes of cheap CFLs for everywhere else.

    Another concern that isn’t critical but is still something I’d rather not have to be concerned with, is that LEDs can overheat if not cooled properly and that can reduce light output or cause them to degrade over time. I don’t think I’ve seen a real industry standard emerge for how to fit a reasonably compact heatsink and/or fan that will fit into 99% of existing light fixtures without overheating or causing other problems, and that makes shopping for an LED bulb a bit more work than it should be in my opinion. One LED bulb I have purchased didn’t fit in its intended fixture and got pretty darn hot in the fixture it ended up in. I don’t know if that was a unique experience to just that brand or not.

    If we have to have a new industry standard for bulb size/shape and sockets, then so be it. Just get on with it and in the meantime figure out a reasonable standard for LED bulbs that will still fit in regular fixtures without overheating.

  5. All incandescents were replaced with CFLs long ago. Now I am changing them to LEDs.

    I’ve noticed some LEDs are troublesome. I have had 6 Crees so far go into eternal blink mode, where they flash on and off about twice a second forever. Don’t know why that is. I assume a problem in the support circuitry. Odd because Cree supplied the actual diodes for a lot of other vendors.

    At any rate, I am not using Crees any more. They were worth about two years and they should be worth a lot more than that.

  6. On heat sinks and roasted diodes…

    I had a cheap headlamp, bought from DX for something like eight or nine bucks. Horrifically bright, but two drawbacks: It had a lens in front, which could be focused from a very bright, very small spot, to a very bright, but not much bigger spot. It was never a big enough light cone to illuminate the entire area in front of me (i.e., on m desk or workbench). The second drawback was the power supply. It ran on three AAA cells, and it ran the into the ground in nothing flat. I was constantly swapping batteries between the battery compartment and the battery charger.

    I solved the first problem by unscrewing the lens, exposing the bare Cree LED, which was bright enough to nicely illuminate the entire are in front of me. In fact, it was bright enough to illuminate an entire room (night, lights out, fully dark). It did not light up the room to daylight equivalent, but it was more than enough light to see what I was doing. Very impressive for a bare LED.

    I solved the battery issue by attaching a Lithium Ion battery, I forget the number, 16180 or something like that. It had an attached charger module (I broke open the plastic case which contained the battery, a charger, and a boost module which provided USB output. The thing was originally a micro-Ipod booster, I bought a bunch of them on Woot a few years ago for a few bucks a piece. Handy for USB in/out,)

    The battery was nominally something like 4.2V, not quite as much as the nominal 4.5 from the three AAA cells, but much more current, and it powered the light nicely — I could not see any difference in brightness, and it was much easier to use. It ran a lot longer than the AAA cells, and I could charge it by simply plugging in a USB cable — even while I was using it. I put it all together with the engineer’s best friend: duct tape.

    Then, after several months of use, it stopped working. Examination revealed that the solder attaching the LED to its substrate had become “not soldered” anymore. I surmised this was similar to the problem reported with Xbox chips, where the chip’s heat caused the solder to melt.

    I did not have a wave solder tank or anything of that sort, but I was able to solder a jumper to an exposed contact on the LED, and it worked again — for a few minutes.

    At that point, I gave up, and moved the battery to the other headlamp (I had two of them).

    It too worked for a few months, and then all of a sudden, grew very dim. Examination revealed that the yellow filter in front of the LED (which fluoresces to convert the blue/UV light from the LED to white light) was no longer yellow. It was brown. Apparently the LED had thrown off enough heat to roast the filter.

    Clearly, there was insufficient heatsink provided.

    I ordered two more of the headlamps. When they arrived, I opened the LED housing, and filled the area with heatsink compound. I also removed the two screws that attached the LED “disc”, so that I could press some of the goo beneath it and the housing, and then replaced the screws.

    I put it all back together, and rigged up my battery to it, and powered it up. It seemed to do the trick. The heatsink (cast aluminum with miniscule “fins” protruding around it) never got beyond “warm stage” — meanwhile, the other one, which I had not “gooed up” would become too hot to touch after a few minutes of operation.

    Moving along…

    Those “60 Watt equivalent” bulbs I mentioned earlier have fairly hefty heatsinks. The entire thing has a form factor roughly equivalent to a tungsten light bulb. The globe portion is made of translucent plastic, and around its base there are fins from the heatsink, which encircles the base of the light, right down to the screw-in part.

    They have been on 24/7 for the past few weeks. The heatsink is “very” warm, i.e., it’s not too hot to touch, but if you wrap your hand around it, you will want to let go after about 15-20 seconds. There have been no noticeable problems — no flickering, no dimming, and I am confident that there is sufficient heatsinking.

  7. I was an early adopter of CFLs, back when some used mechanical starters (they also weren’t very compact). Most of the early CFLs lasted a fairly long time, but in the past several years, they’ve been cost-reduced (cheapified) to the point of decreased reliability. (I had an 18W Osram that lasted about 12 years every evening, but the modern day 13W bulbs are good for about 2 years, and that’s in a well ventilated fixture.

    As a result, once LEDs started to get affordable, we started with floor and table lamps, and then the hard-to-replace fixtures. We’re now completly converted in the house, I think. Our local power company is offering a subsidy, and we’ve been stocking up at Costco when we make the trek to the store.

    I lost a lot of CFLs to vibration, especially when I replaced the roof on the house. One light was supposed to be a worklight for my home shop, and it lasted a minute or two from the vibration. When I get to it, I’ll try an LED in that function.

    The only real downside is some RF interference from some bulbs. I have a couple of floods above the bathroom sinks, and turning them on destroys the signal to my weather radio. We have a similar, but lesser problem from a spot above the kitchen sink. Haven’t seen this issue on any other lamps, so YMMV.

    I still have CFLs in the shop/barn, but as they die, I will replace them with LEDs. We donated a quantity of unused stock CFLs to the local mission/shelter, and they were as happy to get them as we were to get rid of them. Win-win.

  8. Getting a buzz on^H^H^H off…

    In no particular order (that I know of), there are two main categories of CFL lights, which for lack of a better (or known — to me) term, I will call “consumer grade” and “contractor grade.” Be aware that there is naturally some overlap, rarely accruing to the consumer’s benefit.

    The archetypical consumer CFL is the “Made in China” bulb, with a spiral tube and an Edison base, with integral electronic ballast.

    In my experience these are often, if not generally poorly engineered, and poorly constructed, with hilariously optimistic MTBF numbers. If they don’t go dark at the ends before the under-engineered ballast (made of shoddy components) fails, then the ballast will fail first. Place your bets, folks. Heads they win, tails you lose.

    If that “Part 15” (or other “relevant part(s)” are mentioned, it should be taken with a kilograin of salt). Snap and Crackle will come over your radio, as a coded message: “Brace for, ‘Pop!”

    Contractor Grade CFL tubes are a two-part affair: the tube, and the ballast. Older (and perhaps still, for low-end ballasts) are of the “traditional” magnetic variety. They tend to be fairly RF-friendly until they fail, and when they fail, they may take out your tubes too, not to mention waking up your smoke detectors.

    Electronic ballasts are really little more than rebadged switching power supplies, which chop your 69 Hz. house current into high frequency juice which is then fed into a compact (ferrite toroid, IIRC — it’s been a decade or so since I’ve spelunked one) transformer, and then rectified, with something to the high side of 500VDC (possibly even VAC — I plead age, and years) coming out the other end.

    The main difference between a “plain” switching PS and an”Electronic Ballast” is the provision for low-voltage to feed the heaters (unless it’s an “instant-on” type). This is accomplished by a pair of taps in the secondary that peel off a few volts at higher current (the “light” voltage is quite low current).

    And as I mentioned earlier, it’s possible to use a “heater type” ballast as an “instant-on” ballast — even with “heater-type” tubes — providing the output voltage is high enough to start the bulbs sans heated filaments (i.e., using the filaments strictly as electrodes).

    The difference between a “contractor grade” ballast and a “consumer grade” model will become apparent the instant you pop the lid off of two of them. The contractor grade ballast will have sufficient heatsinking, RF shielding, and a much higher component count — and will be obviously better built, and designed.

    The label plate legend will state things like RF compliance and Power Factor, and unlike the consumer bulbs, can be taken at face value.

    Contractors like to install these things — often in other-than-readily-accessible locations — and get paid. They don’t like to get called in for can’t-bill re-do’s. So these things tend to be reliable.

    The tubes tend to be much better made too, and have a better lifespan.

    They don’t have a screw-in Edison base. Instead, they have a square plastic snap-in base.Easy to install, and easy to replace, when they eventually fail. Since the ballast is not integral, it doesn’t need to be replaced at the same time, even if it’s still good (he laughs). And since the ballasts are built like Sherman Tanks, they don’t tend to fail.

    Overlap: I have some bastard-ballasts: Edison screw-in base at one end, square plastic snap-in socket at the other. Bigger and heavier than the typical consumer grade integral “spiral bulb” — because they contain a simple magnetic ballast. Lower tech, cheaper (at least, cheaper when they were made, and I doubt they are still in production; most likely, they were made before the advent of the cheap “Redi-Fail” integral consumer bulb’s cheap electronics), so, they’re apt to be longer-lived (and the snap-in socket means you can replace the tube and keep using the ballast).

    I don’t know of any other way to easily retrofit contractor-grade CFL lighting into existing Edison-base sockets. Maybe there is, I just don’t know of any (and I don’t really keep up on these things).

    Executive Summary: Contractor Grade CFL/Electronic ballast gear is very, very good stuff. Consumer Grade “Spiral bulb”/integral ballast gear is very, very bad. The market, such as it is, mitigates against “the consumer” availing himself of the former, while pummeling him with a crapucopia of the latter. If you like to tinker, and are at least halfway good at it (and have a life-long history of avoiding self-electrocution), Ebay may still be your friend.

    As to LEDs, they too seem to have inexpensive switching supplies — at least the one I sacrificed to my curiosity. It had a small PCB with the PS, and number of LEDs — I think there were three rows of them (they’re in other room, it’s late, I’m lazy, hey, sue me), and as I recall, they were “wired” in series. Something like 36 volts or thereabouts. (I had originally nurtured the hope that I’d be able to easily convert them to run off of low volt DC supply, for things like nice bright camping lanterns and so forth, but this was not to be the case — unless I can find those smallish supplies I bought from Woot many years ago, which contain a number of AA nicads, and a 30W 110VAC inverter, with a pair of USB power outlets too; these ought to easily power one or two of these bulbs for a decent period of time, or three, for a less than decent period of time.)

    If any of this is of any use to anyone, good. Better yet, I think I’ve run out of things to say on the matter. 🙂

  9. I worked for a large aerospace company supporting NASA for a long time, One of our projects was LED lights for the Space Station. Some of the main lessons learned:
    – burn in LEDs as they have infant mortality problems, as you have likely seen with some cheap arrays used as tail lights and stop signals
    – heat sinks and heat transfer are very hard for dense arrays, but are very necessary.
    – white LEDs can have very different color output curves.

    About 10 years ago, I participated in a joint R&D conference with another major tech company, one outside the aerospace area. They did a pitch on white LED technology, One prediction: LEDs would start to displace incandescent and other lighting technologies about now. The major sticking point was getting manufacturing yields of white LEDs up – most white LEDs are in effect a mini fluorescent light, being made up of a UV emitter covered with phosphors.

    I have started replacing the lamps here with LEDs as the bulbs fail. I have LEDs in all the floods and spots in our kitchen and love the lighting. As soon as the CFL floods in the yard fail, I’ll be putting LEDs there.One thing I haven’t found are cheap 3-way LEDs.

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