# It's time for LED home lighting!



## Erasmus (Nov 22, 2006)

Hi folks!

The efficiency of the new Cree XR-E LEDs exceeds all those of common home lighting (incandescent, halogen, fluorescent lamps) so I think it's time for LEDs to make their entry in this world. Plus these new Cree LEDs have a beam angle of 75°, which is ideal for this kind of lighting. Last week I started thinking about a reading lamp with XR-E's and I started drawing. I found someone on this forum who could possibly make the heatsink I wanted, so I started drawing and calculating. Today I finished the sketches and I was satisfied of the result  

I have designed a reading lamp to mount on a Locline flexible stalk (http://www.locline.com/) the screw thread of the Locline connector can be directly screwed into the bottom of the heatsink, through which the wires come. The lamp contains 4 Cree XR-E LEDs which are directly mounted to the heatsink. There is also space for a 28.8mm lens (available from Flashlightlens.com). Diameter of the light is 38.8mm and the length is 70mm (needed for proper heatsinking of the LEDs). I will mount the XR-E's from my own sale (P4 flux bin, WH tint, very nice warm white tint and suitable for reading light). This lamp will consume around 4.4W and have a typical flux of 336 lumen which makes an efficiency of 76 lumen/W. Output will be comparable to a 30W incandescent lamp.

This afternoon I found the free 3D-drawing programme Sketchup (http://www.sketchup.com/) and I started experimenting with it. I just finished the drawing and it looks a lot better than my handmade sketches  

Here's the result :

Sideview compared to the Cree LED : 






Rounded edges on top : 





A look at the naked heatsink/lamp : 





Top view : 





Who's peeping out there?





4 Cree XR-E's! 





Top view of these little *******s : 





Small surface for the lens to sit on (I'll buy a 28.8mm diffused lens from flashlightlens.com for this) : 





Close-up inside the lamp : 





This is the first time in my life I used a 3D drawing software, so forgive me if everything isn't as smooth as it should be. Yet all dimensions are 100% correct.

Is anyone able to make this heatsink for me? Made from a solid piece of aluminium is fine  

Cheers,
Erasmus.


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## Manzerick (Nov 22, 2006)

but can you add one more to the center? :lolsign:


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## Erasmus (Nov 22, 2006)

The center is only 7mm x 7mm and the emitter is 7mm x 9mm. You can put 1, 2 (opposite each other), 3 (in an angle of 60°) or 4 (will fit right in) emitters in the lamp  In the center is a hole for the wires.

By the way, when designing the heatsink I have taken into account that there are a positive and negative path between the thermal path under the LED. The positive nor the negative path will touch the heatsink.


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## GHEN (Nov 22, 2006)

I'm very interested


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## Erasmus (Nov 22, 2006)

I found someone to make one for me  He just wants to make 1 prototype for me, so far no big production.

Anyone who's interested can download the Sketchup files from this site. Sketchup is free to download if you don't have it


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## TranquillityBase (Nov 23, 2006)

Pretty dang nice...drawings too.

TB


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## MorpheusT1 (Nov 23, 2006)

Very nice 





Benny


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## Erasmus (Nov 23, 2006)

Thanks for your nice comments  Here a picture of the lamp with a diffuse lens installed : 





Diameter of the light is 38.8mm or ~1.53".


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## jch79 (Nov 23, 2006)

McGizmo has a huge page _somewhere_ on his website :shrug: :thinking: about his home lighting setup... although I can't remember where it is now!
Nice work!
john


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## Erasmus (Nov 23, 2006)

jch79 said:


> McGizmo has a huge page _somewhere_ on his website :shrug: :thinking: about his home lighting setup... although I can't remember where it is now!
> Nice work!
> john


It's on http://dmcleish.com/tri-cluster/ but he uses 3mm 20mA LEDs which have a significant lower output than these Cree XR-E's.


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## AndyTiedye (Nov 23, 2006)

I'd like to see this! We have CF's all over the house, and would happily replace them
with something that was more reliable, more efficient, and puts out a better color of light!

Our electric rates here are high and go higher the more electricity we use,
so there is a strong incentive to conserve!


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## Brum (Nov 23, 2006)

Nice!

But a what current are you gonna drives those Cree's. It better not be any more then 20mA, otherwise you'd be blinded! Very, very nice!


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## chesterqw (Nov 23, 2006)

ROFL. 20ma and you will lose your night vision capabilities!

1A< and you are going to need some very good sunglasses.


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## Erasmus (Nov 23, 2006)

Cree's will be driven by a dimmer which goes from 0 to 350 mA


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## Amonra (Nov 24, 2006)

here's what you can expect out of 6pcs. XR-E's driven at various levels : https://www.candlepowerforums.com/threads/141499 the room is 12ft x 14ft x 10ft.


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## AndyTiedye (Jan 18, 2007)

Adding to LED Fixed Lighting Index


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## McGizmo (Jan 18, 2007)

Erasmus,
Here is my living room lit with Cree XR-E LED's:






Kitchen behind living room is lit with U bin Luxeon III's. I still use and believe in the small Nichia 3 mm LED's but I agree that the new high power LED's can step in and handle brighter lighting jobs. The fixture below the ceiling fan in the pic above has 28 XR-E LED's on it.


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## bombelman (Jan 18, 2007)

wow, cool !!


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## MikeSalt (Jan 18, 2007)

The only problem is that LEDs have a high colour temperature, which can make things look cold. Typically, incandescent light gives out a 'warmer' feel. If colour temperature could be adjusted, then it would be ideal.


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## Manzerick (Jan 18, 2007)

I can't wait for LED's to be commercial lighting!


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## Erasmus (Jan 18, 2007)

Mike, that's true. But I think Cree will also release the warm white LED with the EZ-1000 chip (that is the XR-E-chip). I think 60lm/W can be possible, that is still 5-6 times more efficient than incandescent bulbs. 

In the meantime I have designed several more LED-lamps but I still haven't found someone who can make them on a lathe for a decent price. Modamag promised me back then in November to make one for me when he had time around Christmas, but that's weeks ago now and I haven't heard anything from him.


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## matrixshaman (Jan 18, 2007)

Personally I like LED lighting as long as it's not too blue - it is a lot closer to natural sunlight than incandescent is. If you look at a photo taken indoors with incandescent versus sunlight (I've got 4 skylights in my house) and LED you'll see LED is generally a lot closer to natural light. I look forward to LED lighting for homes getting more available and common - good work Erasmus.


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## Weylan (Jan 21, 2007)

I was thinking of something that could speed up the development of this. Most of this stuff is more available then completely custom parts and would only take minor tweaking.

If you just used a 2D MAG head available anywhere.
4x PXT-CE that is currently available from modamag.

nflex driver available from taskled.com
loc line 1/8 NTP standard end connnector.
wall wart transformer of 12V-14V.

All of the above is available now.

The only piece missing is a screw in DISK that would sit flush in the 2D MAG head that has a 1/8NTP threaded hole for the loc line. This would be the only thing that needs to be machined.

Then the rest of this is just assembly.

I think we might be able to get a run of these plates for heads if we ask one of the machinests that have a lathe. I don't think it would be that difficult to have 1 piece made for you that has threads that matche the inside of a MAG head and a 1/8NTP hole in the middle of it.

I would be interested in a few of the disks for sure.


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## amyartisan (Mar 12, 2007)

How beautiful~~


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## KDOG3 (Mar 12, 2007)

How do they run off the A/C power? Converter board? They're not DD are they?


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