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View Full Version : OT: LED based bulbs. What's your experience?



MichaelP
12-23-2011, 03:00 AM
I've decided to try those bulbs consisting of multiple LEDs and designed to be used in a regular light bulb socket. Bought a couple of different ones on eBay. Both from the more powerful variety, but with different spectrums. So far I received one with, presumably, 6500-7000K color temperature.

Gosh, what a horrible device this is! Although it's supposed to be a 1050 lumen bulb, it looks as dim as a night light. And the color is so ugly (blueish-grey) that I can hardly stand it at all (let them tell somebody else how 6500K spectrum looks: I deal with those bulbs on everyday basis). The only possible use for this garbage would be in Hollywood to light night scenes in morgue.

Is this because it's a cheap chinese crap or all of them are that bad?

Here is the one I tried: http://www.ebay.com/itm/E27-13W-110V-360-263-LED-Corn-Light-Bulb-Lamp-White-6500-7000K-/280779448806?pt=AU_Lighting_Fans&hash=item415fc261e6

Still waiting for a "warm light" one to arrive. It's supposed to be a bit more powerful, and I hope the spectrum will be, at least, tolerable.

P.S. Yes, I'm well aware of different eye sensitivity to different parts of spectrum (perception of brightness) and other related issues. I also took into consideration the difference in design (direction of light) between those corn cobs and regular luminiscent lights. And I knew it will be on a bluish side. Still I didn't expect them to produce such a totally unacceptable result.

What's your experience with those bulbs? Do you know how they connect LEDs there: in series or in parallel (which will make a night and day difference (pan intended) if one of the LEDs fail)?

darryl
12-23-2011, 03:30 AM
I've been a bit leery of those 'corn cob' type light emitting units. I've bought a couple of more normal looking ones (can't recall the manufacturer, possibly Lights of America). They use the more normal looking leds, and there are more than 60 of them standing up on a circuit board. One was warm white, the other I bought was 'bright white'. I like the warm white, and the bright is, well, brighter and less warm. Even the bright white is less blue than the white leds of the past, but the warm white was actually fairly pleasant.

I say was because I actually bought them for the leds. I've used several of them so far in some tiny keychain flashlights I was making. Needless to say, I destroyed them to remove the individual leds.

Taking a guess here- I'd say that about ten of the individual leds fired up would produce about as much light as a nightlight using a 7 watt bulb. It almost sounds like there's something really corny about your bulb-

beanbag
12-23-2011, 04:41 AM
You got crap Chinese LED's.

Buy the real stuff. Buy CREE

Disclaimer: CREE shareholder.

john hobdeclipe
12-23-2011, 08:20 PM
I tried the one on the right first. It's a Sylvania, but I don't remember the model name or the color temperature. I bought this to use in some lamps that had unvented shades that were getting too hot with an incandescent bulb. A major problem is that all of the light goes out the top, and none flows down to the bottom of the shade and to the tabletop. This seems to be the common design with these LED units. I don't know the color temperature on this one, but it is much too blue and harsh.

The one on the left is a GE. It does a somewhat better job of distributing the light, and is listed as 3000K color temperature...closer to an incandescent. It also cost a good bit more than the Sylvania...about $34.00 instead of $28.00

http://www.auldooly.com/imagehost/PC230510-11.jpg

I think the manufacturers are on the right track with these, but there is still a long ways to go. The bluish light is harsh, hard, and annoying. Hopefully as time goes by we will be able to get LEDs that more closely replicate the output of incandescent lamps.

On the other hand, they do operate at a MUCH cooler temperature, and can save a lot of money in the long run if you keep a lot of lights on all the time.

(Another problem with the Sylvania units is the the packaging was poorly done; the bulb is in a plastic clamshell within a cardboard outer wrap. The clamshell is not held together in any way, and as soon as I removed the first one from the outer pack the clamshell popped open and the bulb fell out and shattered.)

john hobdeclipe
12-23-2011, 08:31 PM
You got crap Chinese LED's.

Buy the real stuff. Buy CREE

Disclaimer: CREE shareholder.

I just looked at the CREE website. I don't see anything that can directly replace a traditional incandescent bulb and provide a nearly spherical light output.

steve45
12-23-2011, 10:05 PM
I have not tried any, in fact, I recently went out and bought a bunch of 120 W interior floodlights for my living room. I should have enough to last another 10 years or so.

That said, I was discussing this recently with a friend that had converted his living room lighting to LED and he was very pleased with it. Don't know what brand, I'll try to find out.

I have another friend that tried LED floods for outdoor use. Half the lamps that were supposed to last 7 years or more failed in less than 7 months. He had to send the failed lamps back to the manufacturer for replacement, and the color of the new ones didn't match the color of the remaining ones. He was less than pleased...

I guess this is to be expected with a government mandate.

danlb
12-24-2011, 12:36 AM
There are many problems with using "led light" as a generic term. The differences between them can be as great as the difference between a HF mini-lathe and a full blown Pacemaker. The design, the materials and engineering all make a difference.

An LED is a solid state semiconductor and as such it has the same vulnerabilities to power spikes and over heating as any other device. A typical cheap 'corncob lightbulb' simply puts enough LEDs in series that each one uses ~ 1/35 of the line voltage. If any one bulb fails open, they are all gone. If any one fails shorted, the voltage in the rest goes up and they fail quicker.

A well designed one has a usable heatsink and fins to dissipate the heat that is generated by the LED and it's power supply. The power supply is there to ensure the LED gets the proper voltage/current and to filter out spikes.

An LED that is properly cooled and run at the current that it is designed to use will last quite a while, often 11 to 15 years of constant use. But... if they are run at maximum current (often twice as bright) the life falls to months or years.

The reason that steve45's friend was not able to get lights that matched his first set's hue is that the lower cost LEDs have a lot of variation. The manufacturers save money by simply gathering all the leds from each batch that are close to the same and sell them by 'bin'. A light made from all LEDs from the same bin will be close in color. A light made from LEDs from random bins will have a lot of different shades of white, usually ranging from snowy white to blue to yellow to 'cat piss green'. Red is noticeably absent from most white LED lights.

In general, if you see 40 or more LEDs then the bulb will have unpredictable quality, color and unknown lifespan.

I only have one LED "40 watt equivalent" bulb, and I bought it as an experiment. My wife did not like that it was brighter and whiter than the one it replaced, so it has been relegated to an area that only I use. :)

Dan

danlb
12-24-2011, 12:49 AM
I just looked at the CREE website. I don't see anything that can directly replace a traditional incandescent bulb and provide a nearly spherical light output.


The nearly spherical output can be accomplished by the use of frosted bulbs and clever reflectors. An easy way to bypass the clever reflectors is to use frosted bulbs with 3 LEDS (each has a 125 degree 'beam') pointing outward from a central post. Three Cree XM-L LEDs running at only 700 ma each ( at 3.2 volts) will consume only 7 watts and output about the same light as a good 75 watt bulb (780 lumens). 700ma is the "long life" setting for that LED. If needed it can run as high as 3000ma per LED and put out 3 times the light.

Yeah, I've been into LED lighting for a decade or so.

Dan

MichaelP
12-24-2011, 02:17 AM
I only have one LED "75 watt equivalent" bulb, and I bought it as an experiment. What exactly bulb was it, Dan?

danlb
12-24-2011, 04:46 AM
What exactly bulb was it, Dan?
Darn. I mis-remembered. It was a '40 watt' equivalent by Utilitech.. (post corrected) I bought it at Lowes.

http://www.lowes.com/pd_223319-28839-LED+G2560F-WW_5003720__?productId=3407332&Ntt=Led+bulb&pl=1&currentURL=%2Fpl_4%2B5_5003720__s%3FNtt%3DLed%2Bbu lb&facetInfo=4%20-%205

I tried to replace the 40 watt "reveal' bulb that was in the lamp in the living room since it is on 8 to 12 hours a day. It made the room too bright for her. :)

Dan

Dunc
12-24-2011, 09:23 AM
I have been looking at the Philips brand of GU10 led replacement light bulbs but -so far - have called it off when I@! qqqqqqqqqqsaw the price (~$30 Cdn each).

While heavily promoted for their plus attributes - low power consumption & long life - I am interested in the light output. Specifically, is a GU10 LED's visible light output (lumens or candlepower, or whatever) anywhere near that of the 'good-old-standby' halogen?

MichaelP
12-24-2011, 10:37 AM
Thanks, Dan. I was trying to find something with the "regular" E27 socket and much more bright than a 40W equivalent. Looks like they don't have any of the same brand/construction. And it sounds like it'll cost a fortune that will totally negate its purpose (unless one is a Green Peace activist).

lakeside53
12-24-2011, 12:34 PM
I'd sure like longer life for the living room 3-way bulbs. This time of year they are on 12-15 hours a day.

danlb
12-24-2011, 12:41 PM
The economics of low wattage lights are directly tied to the price your local power company charges.

My power is more expensive if I use more than a certain amount. It's a tiered system, like our taxes. I end up paying 1/3 of a dollar (36 cents) for every 10 hours that a 100 watt bulb runs.

The kitchen/dinning room light is on most of the day, so that bulb costs about $10 a month to run. Change to an 12 watt LED and I pay around a dollar a month for the same light. The payback for a $30 bulb is 3 months for me.

If I were to cut my electricity use to about 1/4 of my current use, the rate would be only 12 cents per KWH, so the payback gets closer to a year. If it lasts longer than an year then I'm ahead of the game.

The cost to build an LED light bulb is directly related the choice of led type and the premium involved in buying color matched LEDs. 80 low powered commercial grade LEDs are less than 10 cents each. A design using 3 high power, high output, high CRI LEDs will pay 5 to 15 dollars per LED.

I don't seem to get a long life from the compact fluorescents, and I dislike the idea that I'm throwing away an energy intensive, mercury filled light bulb instead of a nice, inert tungsten filament bulb. There was a development a few years back that created a incandescent bulb with a filament that had a tungsten lattice. It was 10 times more efficient than a standard incandescent.
http://www2.electronicproducts.com/Tungsten_lattice_increases_incandescent_bulb_effic iency-article-JULOL2-jul2002-html.aspx

danlb
12-24-2011, 01:08 PM
I have been looking at the Philips brand of GU10 led replacement light bulbs but -so far - have called it off when I@! qqqqqqqqqqsaw the price (~$30 Cdn each).

While heavily promoted for their plus attributes - low power consumption & long life - I am interested in the light output. Specifically, is a GU10 LED's visible light output (lumens or candlepower, or whatever) anywhere near that of the 'good-old-standby' halogen?

--- slightly simplified ---
The light power rating can be can be given in lumens (total light output in all directions at once) or in candlepower (how bright it is at the brightest spot at a standard distance). The candlepower can be impacted greatly by the presence and shape of reflectors or lenses.

If you look at the LUMENS rating of the good old standby halogen you will see a bit of variation, since different filament designs heat up and radiate light differently.

I found a chart at http://www.lighting.philips.com/us_en/browseliterature/download/p-8632.pdf that lists the lumens of average incandescent lights ( page 6 )
Given that 35 watt halogen, MR16 bulb with a GU10 base creates 480 lumens concentrated in a 25 degree beam, you simply need to find another bulb that makes similar light. Phillips lists a 4 watt LED in the MR16 form factor that is 10 lumens higher output than the 35 watt halogen mode.

One interesting point that some people have discovered is that they are over lighting their homes. Your eyes limit the amount of light you see. A common saying among flashlight collector's is that most people can not perceive the difference in light output until the lumens are 50% greater IF there is no direct comparison. If the brightest light in the house is 75 watt, ( 1000 lumens) then your irises open up and the room appears just as bright as if you have a 100 watt (1500 lumen ) light. The trick is to use even lighting levels.

The flip side to that last paragraph is that many older people can focus better when their iris is shut down. The depth of focus is much greater under bright lights. Oh well. :)

Dan

Evan
12-24-2011, 06:24 PM
There are several topics previously on this subject where I have posted a great deal of information about what to look for. The range in quality presently is very wide. As for "cheap Chinese crap", even Cree makes LEDs in China as well as the US. Nearly all LED "bulbs" are made in China and the variety is huge. Prices here in North America are still at the early adopter level, which is to say very high.

Prices direct from China are up to 5 times lower for the same product. There is a lot of crap out there no matter where you buy it from. Many products are made with LED seconds that don't meet specs such as unmatched colour or low output or usually both.

I have been buying and experimenting with both do it yourself lighting and pre-built just screw it in LED lighting for several years now.

A general observation is that the best buys are the lamps that use the fewest emitters to reach the stated output. Not always though. I have about 15 lamps rated at 588 lumens that use a large quantity of the 5050 surface mount device which is rated at about 15 lumens per each. The 5050 is an excellent LED with high resistance to over driving and excellent efficiency.

Do not judge LED lighting based on a single experience with one or even just a few examples of the products. This is a new field for consumers and there are people taking advantage of consumers because few people know what to look for. It will sort itself out in the next few years as the public becomes more aware of what to look for and some brand vs quality reputations develop.

I have cut my electric bill in half over the last 4 years in large part by using LED lighting. I have also thrown out various bulbs because they didn't work well or didn't last. I now have good, reliable LED lighting in much of our house and it is very cheap to run. The savings have easily already paid for even the mistakes as well as the ones in service. My electric bill is stable at around $53 per month and we have electric water heat, electric clothes dryer, a fridge and very large freezer and a 1.5 hp well pump not to mention some 24/7 computer loads as well as shop machinery and welding.

This is how our living room looks on about 50 watts of LED lighting.

http://ixian.ca/pics9/ledlroom.jpg

This our bi-monthly electricity consumption the last four years.

http://ixian.ca/pics9/electricity.gif

The electricity consumption reduction isn't due just to LED lighting but I would say it is responsible for about a 20% reduction by itself.

I also have LEDs for both shops, garage and downstairs with about 5000 lumens in the garage. I also use about 4000 lumens for out door yard lighting for the fenced portion the dog runs in and a couple of others for the driveway area and back door. We have no incandescents and only a few fluorescents still in use. For the same lumens rating an LED lamp produces much greater light on the work area than a fluorescent because the light is much better directed.

PaulT
12-24-2011, 06:54 PM
Evan, can you post a LED light brand name in the standard screw in format that has worked well for you?

In particular, I need some "short" bulbs to use in standard screw in sockets in the crawl space above the office space at my shop.

Anybody that crawls up their now runs a good risk of hitting their head on the screw in bulbs, I'm used to hearing the "pop" and "oh ****" combination anytime someone goes up there to store or retreive something.

I saw several different brands of LED based ones at Lowes that were shorter than a traditional bulb, but at $30. a pop I don't want to buy any without some pretty positive recommendations. I'm hoping to get at least as much light as a 40 watt old style bulb if possible.

Thanks,

Paul T.

barts
12-24-2011, 07:01 PM
The local Costco offers small candelabra base LED bulbs; I'm trying these in our outdoor light fixtures... so far, they're working quite well. They're about 3000K color temperature, and of course are instant on - much better than the CFLs we were using. Our power here in the SF Bay area is quite expensive, so not avoiding 6 x 25W incandescents is nice - these are often on for 8 hours in the winter months. The porch lights are R30 LED floods, again instant on instead of a minute or more at 32F.

What some clever soul needs to do is use some RGB emitters in addition to the bright 3000K ones, so as these lights are dimmed they could shift to warmer colors like incandescents do....

- Bart

darryl
12-24-2011, 08:49 PM
That sounds like a good idea. You could run them all at maximum, then drop the intensity of one or two to give you the tone you want. For lighting purposes you would want basically a warm white, but the potential is sure there for mood lighting, etc.

I have some RGB leds- 'problem' is they are also an IC, giving a random fluctuating pattern of color- think Halloween or Christmas tree light.

Evan
12-24-2011, 09:43 PM
3000K is already warm white, sunlight is 6000 Kelvin. My wife and I really like the daylight white at 5000 to 6000 K. It really seems to help combat S.A.D. because it resembles sunlight.


Evan, can you post a LED light brand name in the standard screw in format that has worked well for you?

A few weeks ago I bought a couple of very stubby standard base LED bulbs at Walmart that are about 40 watt equivalent. They cost 10 bucks. I don't recall the brand on the package but Walmart has all sorts of these in different shapes and sizes. There were some big differences in lumens per dollar and these were by far the best buy. They have very even light and are bright enough to make an excellent reading light or task light. They are the best buy I have seen so far for local retail pricing, no sale or rebates. They seem well made too.

This is all I can say about the brand.

http://ixian.ca/pics9/globe_led.jpg

PaulT
12-25-2011, 03:26 PM
Evan, thanks for the tip, those look very short and could work well for me, I'll give one a shot.

Paul T.

Dunc
12-26-2011, 11:29 AM
I have found a cfl in a flat package at HD. It contains the familiar spiral - I guess - but it is wound in a flat, instead of a vertical spiral and has an integrated protective cover. Not cheap but beats the spiral cfs that seem to break off at the base if viewed cross-eyed.

Went on the website but unable to find it. In our local store (Ottawa, Canada) it is stocked among the light switches, plugs, etc and not the lamp fixtures.