When placed in a conventional table lamp most LED light bulbs, including this LG bulb, have a tendency to illuminate upwards. This is because of the horizontal placement of the LED emitters inside. The Philips bulbs use three vertically oriented LED panels to alleviate this concern. However, in an over the shoulder reading lamp or a task lamp, the bulb illuminates uniformly and does not throw any heat on the illuminated target.
The LG light bulb illuminates mostly upwards because of the horizontal
placement of the LED panel inside the bulb (click on image to enlarge).
The design of table lamps is meant to accommodate the Edison light bulb, which emits light in all directions. The spindle allows the electrical cord to reach the bulb and the lamp shade serves as a diffuser. The shade, being open top and bottom, allows the natural convection to take away the unwanted heat. It also enables easy replacement of the short-lived bulb. The electric table lamp has evolved over more than a century to accommodate the light bulb and is very different from its precursor luminaire, the oil lamp.
The very first electric lamps were not necessarily very effective or very popular, yet their advantages prevailed and the use of oil lamps waned. Over time, and probably rather rapidly, lamps will evolve to adapt to the peculiarities of the LED sources. When LED light sources achieve lifetimes in decades, replacing them will no longer be a concern and luminaires will take on various forms and shapes. Meanwhile, forcing LEDs to assume the Edison format is akin to forcing a square peg into a round hole.
Nevertheless, Strategies Unlimited predicts that "the global market for replacements for legacy lighting sources will grow from $2.2 billion in 2011 to $3.7 billion in 2016." Indeed, LED light bulbs provide very pleasant illumination, much more agreeable than compact fluorescent bulbs, and they will be adopted eagerly. They outlast CFLs, contain no mercury, and are instant-on. One annoying trait of CFLs is that they take a relatively long time to reach their maximum level of illumination.
LED light bulbs are complex electronic devices. The LEDs themselves are semiconductor diodes, wanting a low voltage DC supply, typically around 3 volts. Common household supply is 110V or 220V AC depending on geographic location. The LG bulb is not dimmable. More expensive models are dimmable, although newer types of dimmers may be needed. Like CFL bulbs, LED bulbs have a small circuit board stuffed inside the neck.
Watching this technology improve is fascinating. I find the attempt to make the bulb look very similar to the old incandescent bulb interesting. I'm not sure how much that helps sell the new bulb ( although we do, of course, need a compatible base ), but hopefully we'll see prices drop further and then see more adoption by consumers.
The 60W LED bulb has officially arrived. It's about time. I immediately ran out and got 3 of the Philips dimmables, even though they were still $25 each, just as a show of appreciation as an early adopter for this effort. The bulbs are fantastic, and kinda look like they came from the future, but I'll wait until the prices re-enter the atmosphere before I get any more.
$25 each if it lasts 3-5 times more than CFL, I think it is a good deal.
If heat is an issue, which piece will go away first, the power electronics or the LED? I believe it is the power electronics, isn't it?
I think that which fails first depends on the design margins. One might suspect the power electronics to be the weak link. Consider that the front end of these PCBs is an AC-DC power supply with the usual electrolytic capacitors. My bet would be that those caps are the first thing to go.
@chanj: you are correct, the power electronics components will be the ones to die first, in particular the driver.
In the LED's, there may be an accelerated decay in the chromaticity / CCT of the white light depending on the ambient temperature and the hours of use. Without these mitigating factors, it is safe assume that LED's can last 10 to 15 years!
LED light bulbs are too recent to have much data on failure modes. Electrolytic caps are indeed vulnerable to heat. This light bulb has a nice space between the back of the LED emitters and the circuit card. That should help. Most failures I have seen in CFLs circuit cards were due to sub-standard assembly, not design.
This is great. My only issue I have with the article is the notion, which I have seen expressed many times, that direct replacement of the light bulb should not be an important feature of these new LED "bulbs."
And while light bulbs did not directly replace candles or kerosene lamps nets (or whatever they were called), in the same sort of luminary, the electric lamps did closely emulate their forebears. And still do.
I've seen LED bulbs that do not arrange the LEDs in a plane, or at least they don't seem to. I have an LED candelabra based, for chandelier use, that emits light in all directions, every bit as much as a light bulb does, every bit as much as candles used to do in chandeliers.
Not saying that new types of lamps, with permanently installed LEDs, won't ALSO exist. But let's not be so happy to turn this into a racket for lamp makers, eh? Besides which, LED electronics may fail, for whatever reason, and LEDs tend to dim with use. So easy replacement will continue to be a good idea. For the customer, at least.
You are correct the added feature about the LED light bulb. As we know the Triac dimming and PFC features. The PFC is 100 % for the incandescent light bulb but when you use the Triac to dim the light, it burns the power away. LED light bulb doesn't and i can maintain PFC to reduce the E-cap which the conventional light bulbs needed.
The bottom line is improvement with the LED light bulb.
1. get rid of the E-cap and have high PFC.
2. While dimming, it saves the power,not burns away the power like the conventional light bulb.
3. there are quite a lot of protections of the circuits which doesn't exist in the conventional light bulbs. The extra protections are hidden in the LED drivers like the in-rush current limit, soft start, short circuit protection(over current), and over temperature protection..etc.
4. for the extra cost, you can have the color temperature control light bulb, to have the red LEDs to adjust the color temperature.
5. The new HV-LEDs give you higher efficacy and Lumens with less current.
I wonder what the mtbf is for the led's vs the control electronics? As mentioned before it is strange that the new bulbs are made to look like the old - what about a new socket for the led's that will fit in a base housing the electronics - then we could get away from the standard antiquated screw in base... I have started to replace them although EDN's chart had a 90% manufacturing cost drop from now until 2015 - the old early adopter costs to get it going, or wait and hope others drive the industry and thus the costs down.....
If LED bulbs really last as long as is claimed, then they're actually not more expensive in time-averaged price than CCFLs.
A few years ago, I replaced all my incandescents with CCFLs, all of which claim to have 10,000 hours life. At first I bought brand name expensive ones, but after replacing a few of those after just a year or so, I started buying the cheap no-brand made in China CCFLs, which are now only $2-$3 each. They seem to also only last a year or so, which is no worse than the expensive ones.
The no-brand LED bulbs seem to go for about $20 for a 60W equivalent light output, and they claim 25,000 hours life.
It all comes down to the claim vs. the reality.
Good stuff. The CFLs are great because they produce more light then heat -efficiency! The LEDs will produce heat but seam to have the efficiency. I found it easy to replace all of my incandesent lights with CFLs and only wish they were US made. I will try a few of the LEDs as the CFL's fail. New formats like overhead lighting or panels may come with time. Remember tube circuits and how the tubes were replaceable and now we had solid state and we no longer expect to replace active circuits.
How about we all stop using science to drive polotical agenda. This technology is wonderful, but the promises of savings to the consumer are absolute BS. see:
The savings of LEDs are very real. I recently bought several 4W GU10 100lumen/W SMD LEDs to replace 40W downlights. They cost just £6 per bulb including postage...
That means after just 833 hours they will have paid themselves back at £0.20 per kWh (yes, UK prices...). At 3 hours a day that's just over 9 months. So who cares if they last only a few years? They will have paid themselves back many times over by then.
The quoted lifetimes are PREDICTED reliability based on specific temperatures, perfect construction with no flaws, and no temperature cycling. The usual bathtub curve applies: some will fail very soon (infant mortality) due to poor construction.
If the power electronics is the weakest point, does it make sense for each household to have a low voltage DC circuit? Most consumer electronics only need low voltage DC power source anyway. That will be more energy efficient and save a lot of copper. NSF has a model house where there are USB wall plugs.
I believe the issue with running DC is in the math. Joule's Law and Ohm's Law state P = I^2 x R = V x I. For transmission, higher voltage means lower current means less loss in the wire while allows for a smaller gauge wire. I believe this is why there was a (albeit failed) push a while ago to increase car power rails from 12V to 42V. Running a low voltage DC bus in a house may lead to heavier gauge, more expensive wiring. Everyone, feel free to correct me if I am wrong.
Math has nothing to do with it. The electrical code requires a certain size wire. If you have a kitchen circuit with a refrigerator, toaster and coffee maker, you need a 20 amp circuit with #12 wire. If you have 24 watts of LEDs in your kitchen (that's pretty bright) and run them off a 12 V bus, you can use #18 wire with less insulation.
In my experience with CFLs, lifetime is much, much longer than with incandescent bulbs, although I don't use CFLs in the refrigerator or in the oven.
I've found that in fixtures where incandescent bulbs were very short-lived, i.e. two lamps in particular, CFLs also fail sooner than normal, for whatever reason. But my sample size is too small to say that for sure yet. And in this involves CFLs with the small candelabra base, which most likely means that cooling of the electronics is inadequate. (I've changed the socket of one lamp to regular Edison, but still have some candelabra-to-Edison CFLs, with adpater, to use up. And these adapters look terrible for heat dissipation.)
In fixtures that use the regular Edison base, 60W or 40W equivalent CFLs, they soldier on for many years. Way longer than incandescents.
I'm sure that in time, the failure modes will be taken into consideration. Also, for oven or refrigerator use, it seems really trivial to use glass fibers to bring the light into the unfriendly environments, and locate the light source where the climate is more temperate. Otherwise, you're looking at hardening like for automobile engine electronics.
I love incandescant bulbs. The light can't be beat. I buy them now and I'll keep buying them until I can't. And then I'll probably go black-market if the lumo-fascists ever get their way. The last time I bought a four pack they cost me around a buck. Can you beleive that? What a deal!
And with the money I save I buy modest bottles of wine like nobodies business. Next time I'll raise my glass to all suckers.
Drivers for the LEDs need better design for the long life of the LEDs. Today there are LED Lamps and LED fixtures available from many different manufactures, but in most of the cased due to poor designs of the drivers, driver fails before the life of LED. This makes the LED lamps costlier than CFLs.
seems the best way around this is to have a DC circuit running around (eg for the whole ceiling of one room) with a single higher quality controller unit that is readily serviceable/replaceable without buying replacement bulbs. This unit can then support dimming etc quite easily (dimming LEDs themselves is relatively easy using simple digital PWM)
The problem is all being caused by fitting LED bulbs into existing 120-240v AC fixtures
Separating the LEDs from the power conversion & control would greatly increase the repairability, an spreading them out can increase the reliability. Designers can cool them better. 12 volts is a common standard, and you can use less insulation.
I'm not seeing anything particularly revolutionary in this "me-too" snow cone design. The GE 62180 A-19 "40W" 430 lumen (9W actually) is a far superior optical design and produces more even dispersion than the "top firing" model shown here. I have reviews of several LED retrofits here: http://www.proaudiodesignforum.com/forum/php/viewtopic.php?f=11&t=408
LG's $10 dollar pricing is highly competitive. The LED used will be a 10 watts capacity which is made to work at 7.5 watts to get the optimum light output and life.The cost of 10 watt white LED of good make will be around $5 and the rest part electronics, enclosure, profit, manufacturing cost all put together is $5.That is why i felt it is priced rightly. Soon this market also will be captured by LG and may be Samsung also.Other companies watch out.
I treat claims of bulb lifetimes as highly suspect. I have used Quartz-Halide lamps that 'promise' 2000 hours that are failing after a few hundred, certainly no longer than the tungstan incandescents that they claim to replace!
LEDs seem to have one major benefit over CFLs - at least they switch-on at full brightness. So far they seem to have one significant drawback; they just don't have illuminating capability of the bulbs they purport to replace, whatever the figues say!
"So far they seem to have one significant drawback; [LEDs] just don't have illuminating capability of the bulbs they purport to replace, whatever the figures say!"
As someone that has lived with almost total residential LED lighting every day for the last year I just haven't found that to be the case. (The only tungsten lamps in the entire house are in the stove vent hood.) You do have to pick your lamps and dimmers carefully and avoid the really cheap top-firing product. My under counter LED lamps run fully-dimmed almost continuously. I don't think I could stand running them at full brightness without shades. Most of the time my PAR and MR-16s are dimmed.
I've found that for a 12x12 room, a cluster of four of the GE62180 430 lumens in an overhead is about the equivalent of two conventional 75W incandescents. The former is 36W PF ~0.9 vs 150W PF 1.0. The LEDs look far cleaner and produce a fraction of the waste heat with attendant air conditioning load.
Ever tried to read laser-marked SMT ICs? Much easier with LEDs and I don't know why. Just better contrast.
For whatever reason LED lamps attract less bugs.
Go to Home Depot or Lowes and buy the cheapest LED you can find. You will be completely disappointed. There are (were?) quite a lot of losers and a few gems.
I've had good luck with GE A-series, Sylvania Osram PAR and MR-16, Philips A-series and Utilitech A-series. I prefer the 3000K but the 2700K Philips ambient light is gorgeous giving that Thomas Kinkade look.
There have been cases where electronic capacitors in the small MR16/GU5.3 LED bulbs have failed after prolonged use where there was an increase in heat due to the use of electronic transformers and poor convection cooling.
My reading shows that the life time of various capacitors at 45°C ranges from 32,000 hours to greater than 15 years for long life ones, e.g., NAZV series. However, at 85°C the general purpose capacitor, e.g., NACE series is rated at 2,000 hours and the long life 40,000 hours, and others in the range of 6,000 to 32,000 hours, less than the life of the LED. We have measured heat sink surface temperatures of up to 72°C using compatible electronic transformers so capacitor life is probably a significant issue with heat being the real killer for caps.
I have seen no studies as yet comparing the performance of MR16 with constant voltage driver vs. GU10 with integrated driver, which would be interesting. My theory is the GU10 LED form factor will have a shorter life span than the MR16/GU5.3 due to greater componentry and additional heat, supporting the use of independent constant voltage drivers.
Does anyone know the temperature of the circuitry in a GU10 or A19/E27 LED bulb? don@ www.liteonled.com
"Does anyone know the temperature of the circuitry in a GU10 or A19/E27 LED bulb?"
I don't know the internal temperature but the hottest "60W" A-19 I've used is the Philips. The external heat sink temperature is about 122 deg F with a 73 deg ambient.
Though the life of electrolytics at the elevated temperatures in an LED are a concern, my greater concern are the life of the electrolytics in a SmartMeter. Last summer, 105-110 deg ambient temps were the norm here in Texas. The meters are "designed for 20+ year life." (Landis-Gyr spec sheet.) That's 175,200 hours in temps ranging from 15-110 deg F 24/7/365 x 20.
The "fixture" (such as the lamp base) could have the power conversion circuit (from wall 120/240VAC) and the "bulb" could be primarily the LED's + diffuser. The packaging often wouldn't be as tight physically and there could be one power conversion circuit for several "bulbs". The LED bulbs could be replaced or potentially the lamp base's electronic module could be modular and replaceable. I don't see why the power circuit would be very expensive, especially given the possibility of much more packaging freedom.
We should get a teardown of the driver and PFC or whatever else they use to understand this aspect better.
There is one aspect of LED lamps that uniquely sets them apart - No RF interference. For a long time now, RF interference (particularly in the VHF / UHF range) from fluorescent lamps is well known. LED for the first time offers a clean source without this interference. It is major plus for many outdoor public areas. In addition, it would be a major plus even for business offices where public safety personnel are needed (such as EMS, Fire etc).
I'm not so sure about that. I installed a no-name in my garage door opener and while the light is on it blocks the remote signal. I've also tried three of the major manuf. and 2 had some interference, one had little to no affect with the remote.
I have no problem at all with retaining the standard Edison base. For one thing, it means that using LED bulbs does not mandate buying all new light fixtures for the entire house. Hardly something to ignore.
For another, it means that when you change the LED bulb, which on average should be several years, the electronics are trivially easily changed along with the bulb. Without having to go through an INEVITABLY more complicated procedure, should the electronics, part of the lamp fixture itself, go bad.
Besides, it wouldn't be all that hard to have the LED part of the bulb be a separate piece from the Edison base which houses the electronics. Snap the LED glass part onto the Edison base. Assuming the electronics are good enought to last way longer than the LED. That still makes the system fully backward compatible AND totally user serviceable.
Parenthetically, I'm not saying that everyone prefers a system that is fully backward compatible and totally user serviceable. We could create a whole new industry of previously unnecessary lamp maintenance shops, to artifically improve employment opportunities.
All lighting has advantages.
No lighting technology can "replace" another.
LEDs are ideal in sheet or panel form,
Fluorescents in long tube form.
As with this warm fixed color temp incandescent copying Philips LED bulb,
they are compromised as politically pushed replacements for simple incandescent bulbs
- with particular difficulties to achieve omnidirectional and broad spectrum and, not least, bright 100W+ equivalent lighting in the small bulb format.
The Deception behind the Light Bulb Switchover
13 points, referenced
About that Philips LED bulb, its quality issues, and issues over how
it won the US Govmt prize...
The poor quality of the bulb on testing and how competition rules were skirted - as referenced with competition rules, patents, lobbying
finance records, the prize committee's own lab test review document
and publicly less known designated lab test reports released on Freedom of Information requests.
Incandescent bulbs have gotten a bad rap. OK, they're not especially efficient in making visible light. BUT there's is more to the problem set than producing lumens. In North America the vast majority of the population lives north of 30 degrees north latitude which means there is a significant seasonal change in hours of daylight. ALso, obviously there is a strong correlation between shorter days and lower temperatures - meaning that a residence requiring both heat and light simultaneously is to be expected. When I turned on the 100W incandescent on my nightstand this morning not only did I receive illumination but heat - as it was 9F outside any heat produced by the incandescent bulb was a welcome addition - and heat that my furnace then did not have to produce. While this little "space heater" may not be quite as efficient as my natural gas furnace in heating my house NOT A SINGLE JOULE WAS WASTED! Now the same can be said for the lesser amount of heat produced by any other electrically powered lamp - like LED. However, incandescent bulbs are cheap to make and are easily and safely recycled. OK so what happens on a warm July morning or evening? Well unless I'm getting up before 5am or VERY cloudy there will be ample natural light - and even at night, it's usually well past 8pm before I need to turn on interior lighting. Sure, the heat generated by my incandescent will indeed be wasted then, but only during this fairly limited span of the calendar. My back-of-the-envelope calculation shows that when you include the visible and infra-red light given off by an incandescent 100W bulb it's only at a ~15% disadvantage in total system efficiency compared to a similar amount of lumens produced by a MUCH more expensive LED bulb. BTW - I design LED lamps (commercial T-8s, etc) so I am no novice to solid state illumination.
Dude, a good heat pump is 300% efficient (it doesn't create heat, it just moves it around, and thus). Even if your lightbulb is 100% efficient (heat + light), which it isn't, you're way behind the competition.
LEDs are far too expensive considering all the things that could go wrong over an expected multi-year life. How often do incandescents break due to accidents, problems with fixture etc???
Expect a very conservative ramp in these products - i.e., only new construction where builder puts them in and subsequent home owner pays the price without much consultation.
I too am concerned about the lifetime.
I am afraid that we are going to get the same failure to meet reliability claims that we had with CCFLs: Six years ago I replaced most of the lamps in my home with CCFLs that came with a 6-year warranty (or was it 9?). In about a year half had died. Unfortunately I had lost my receipt and could not claim replacements.
Now these LED lights are claiming 25000 hour lifetimes. I wonder? I am most concerned about the 330uf capacitor I see on the photo. Most electrolytic caps have a lifetime spec of only a few thousand hours at 85 degrees C. I did a quick search and found only one with a lifetime spec of 18000 hours, and it was large and expensive - not the one in the photo.
I would like to see the teardown include the make and spec of the cap in question, as well as other components likely to be problematic. Also I would like to see some actual temperature measurements - wire up the device with thermocouples in strategic locations, and run it in a hot environment for a while. Just like we test every new product we build.
My experience with CCFLs has been that they have a life span either dramatically less than an incandescent or, about the same. I read that the CCFLs were designed to operated in an open fixture with the base down and that the rated life-span was dependent upon adhering to those operating conditions.
How ridiculous is it to sell a product that only operates on a specific set of conditions that are not in place more often than they are. I don't have a single light fixture in my house were the bulb isn't either enclosed or mounted base up. I could get 500,000 miles out of my car with little or no wear and tear if I'd only put it on a trailer and tow it everywhere.
When I look at the workmanship on the circuit boards shown in this article, I can't help but expect that we'll be seeing the same thing with LED bulbs due to poorly made power supplies.
There are some interesting points in time in this article but I don’t know if I see all of them center to heart. There is some validity but I will take hold opinion until I look into it further. Good article , thanks and we want more!
I hope it will be a good device, thanks to your post.
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They may be good to some who want to save the earth however I equate this new LED technology to governments starting a war without an army.
Things have not been thought out on operating a 1.2 volt LED off of high voltage inverters and unfortunately industry jumped on the bandwagon without any guidance at all from the FCC as to requirements on real world reduction of RFI emissions from the inverters.
In fact from what I am measuring it appears that the FCC will allow any incidental RFI radiator as long as it is of the so called Green technology or a new start up technology.
Don't get me wrong I have no problem with conserving but when a poor thought out technology creates an after effect that no one wants to address then that's where my concerns are.
Presently being an RF engineer I am faced with numerous Radio Frequency Interference, RFI, issues to avionics transceivers in aircraft and Public safety radios in ground based vehicles and it appears to only be the tip of the iceberg on what is to come by poor inverter/power supply designs.
So while KRagh says there may not be an RFI problem from the LED itself, it is the entire LED lighting assembly from the LEDS to the power supply that needs to be evaluated and this is where the flaw in the design is.
From my measurements on CREE and Panasonic household LED fixtures which were used in an RF emissions testing screen room and in an aircraft hanger along with similar findings recently observed in public safety Strobe lamps as used in Police and fire vehicles and in Avionics wing Tip Green and Red LED strobe lights of airplanes.
It is the inverters which are of such poor unfiltered designs that they in fact create more RF problems in the HF thru lower UHF region as opposed to the older incandescent cousins previously used which had no such problems.
Unfortunately the range of RFI emissions that these new LED assemblies emit falls within the frequency ranges used in avionics and other mission critical radio systems.
The whole idea of running LED lights with sophisticated switching power supplies so they are screw-in compatible with standard bulbs is poorly conceived. This just causes excessive consumption of raw materials by an overly complicated design that invariably leads to premature failure not related to the LED's themselves.
When tube fluorescence's were introduced, no one complained about having to switch to new light fixtures. So why not also with LED lights?
Light fixtures for LED's could have a small step-down transformer built in, like a doorbell transformer, that would last a lifetime. Then the LED bulbs would only need to run on low voltage, eliminating the costly power supply that needs to work on 120 AC and be able to resist lightning surges.
This is so obvious I's surprised no major company is pursuing it. Changing the light fixture is a do-it-yourself project for most homeowners, so I don't think it would be opposed by the public looking to upgrade lighting in the family home.
The result would be a better, safer, and lower cost design with much better reliability. How do we tell our non-technical lawmakers they are going down the wrong path?