Some LED bulbs...

[glire]

Here are some pictures from a dual "spider" Ikea fixture holding different E14 bulbs:
1x E14 18x5mm LED (less than 1W ?),
2x E14 compact fl (Ikea, 7W rated),
1x E14 3x1W Cree LED (warm white),
1x E14 3x1W Cree LED (cold white),
1x E14 incan bulb (40W rated).

The E14 18x5mm LED is bluish which is quite common.
The cold white 3x1W is greenish, I don't like it much (yet).

Here are pictures of several bulbs. top-bottom, left-right:
E27 PAR38 12x1W Cree LED (this is HUGE, weight is 670g),
E27 PAR30 7x1W Cree LED (weight is 285g),
GU10 halogen 35W,
E14 3x1W Cree LED,
GU10 3x1W Cree LED,
E14 18x5mm LED

I opened some bulbs to see them inside and also because I had some doubts about build quality (after seeing the LED die through the reflectors): dirty soldering (done by hand ?), most LED domes are broken/moved resulting in "air bulbs" inside the gel (blurry die resulting in brightness loss). I still can't believe it...
Heat dissipation seems also not very good. I noticed a loss of about 10% of brightness when bulbs are hot (using a lux meter).

The cold Cree LEDs seem from an older generation, the die is different from all Cree XRE LEDs I purchased elsewhere recently. The warm Cree LEDs seem to be XRE (they have 4 leads attached to the die).

In brief, I'm disapointed.
Poor manufacturing, *huge* price, brightness comparable to low wattage incans only (in the 20-50W range)... Making LED bulbs for replacement seems a big challenge.
A common cfl 11W is still the best solution to replace a basic 60W incan.

I was thinking some weeks/months ago LEDs will be the future of light. I have serious doubts now. Please prove me I'm wrong

 

[CM]

...I was thinking some weeks/months ago LEDs will be the future of light. I have serious doubts now. Please prove me I'm wrong

They will be the light of the future. What you have are examples of people's ignorance about what LED's require (good attention to thermal management) Newer LED's are designed to have low thermal resistance and are designed for higher die operating temperatures which translate to better performance with less than optimum heatsinking.

From the picture, I see them using multiple high power LED's in a small fixture. Multiple (low efficiency older generation) LED's generate a lot of heat and compounding this fact with a small form factor means that the entire mass will thermally saturate rapidly. With today's LED's outputting about 100 lumens/watt, you won't need as many emitters which in turn make cooling an easier problem to solve. LED's are approaching performance that make them suitable for general purpose lighting. They will get there. It will not be overnight.

 

[MGett]

If anybody remembers this thread in one year I'll bet you'll be truly surprised at all that happens in 2008. LEDs made some pretty impressive advancements in 2007 and we'll see more advances in LED tech this year... as well as lower prices for last year's highest tech.

I'm really excited about LEDs in 2008.

need my shades.

Thanks for this thread by the way... I've bought so many LED products to test them out that I'm weary... I appreciate the testing on the CREE bulbs.

 

[made in china]

In brief, I'm disapointed.
Poor manufacturing, *huge* price, brightness comparable to low wattage incans only (in the 20-50W range)... Making LED bulbs for replacement seems a big challenge.
A common cfl 11W is still the best solution to replace a basic 60W incan.

I was thinking some weeks/months ago LEDs will be the future of light. I have serious doubts now. Please prove me I'm wrong

Where are these LED units manufactured? Therein you will find the cause of the problems you found.

 

[Stromberg]

I was thinking some weeks/months ago LEDs will be the future of light. I have serious doubts now. Please prove me I'm wrong

Well, I have used power leds to illuminate some of my rooms for years, so in that respect, you are wrong.

I think that power leds ARE the future of light but only if they are used properly. This means that at least thermal management is taken seriously and possible secondary optics is done by quality parts.

I have also checked few led household bulbs(GU10, E27) and I think that it's big mistake to jam power leds and all of their possible electronics in so small space.
Other thing is that why they even should? Why should leds have to mimic incans or cfl's when there is so much better possibilities? There should be lots of light manufacturers by now who are designing innovative led specific household lights.
For example think how little space the actual led require: few square millimeters and good thermal path to larger heat sink that can also be the body of the light! And all of the additional electronics can be placed in other place if necessary.

Ps. You can read my "investigations" from one GU10 bulb from here:
http://www.candlepowerforums.com/vb/showthread.php?t=175271

 

[LukeA]

Where are these LED units manufactured? Therein you will find the cause of the problems you found.

The location is not the problem with these. They were built to someone's specifications.

 

[made in china]

The location is not the problem with these. They were built to someone's specifications.

As being involved with Chinese manufacturing in the past, I can assure you that the "specifications" of a product are not usually adhered to by the time thousands of these units a packed into a shipping container. Yes, the specs may be OK, but look at what can happen:
poor assembly quality

swapping inferior sub components that appear the same as the specified components

plastics, paints and metals are very diverse products and can require extensive development and/or expensive components to manufacture to spec. Of course, shortcuts are to be had here.

Anyway, I could go on ALL day about how much imported stuff is inferior.

The main point is, any company acting as an LLC or the such and producing products in 3rd world countries or countries like China offer a poor product. There is no accountability on the manufacturer's end, and they know once they get that cargo container full, they get paid and they (the manufacturer) never need to be accountable for final product quality.

You can say it does not matter, as most Americans do. That's your right, even though you are wrong.