A funny Copper reading lamp build. Cree ML-E

foxtrot824

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The 02135!
I like making odd reading lamps, it combines my interest in machining things and my significant interest in solid state lighting. Because LED have such a slim profile I like to try and build lights that take advantage of that profile. I became inspired to make this lamp after I roughly machined a piece of black Delrin. It occurred to me it could make for a little lamp base because it was very easy to hollow out. I had originally intended to make the stem of the lamp from copper tubing seeing in the first pictures but after cutting some thick copper sheet to size I decided to go with it over the tubing. I like copper, it's aesthetically pleasing and it transfers heat very nicely. I went with the Cree ML-Es because I've used them in other projects and the 3K color temps turn out very nicely and diffused. The only drawback if you want to call it one is that they like to run at 150mA, most "off the shelf" drivers are in 350mA and up. A friend pointed me in the direction of an instructables that showed how to make a simple constant current driver. It can consist of as few as 4 components (if you have all the right resistors, I didn't so I put 3 in parallel) to regulate current to your liking. Looking at the components I thought it would be nice to see all of the guts since most drivers are potted and never seen. Again because the Delrin is so soft it was a treat to drill into and tap (a small 4-40 screw secures the larger transistor).

The MCPCBs came from the sandwich shoppe and were originally for the XP series family but the footprint is almost identical to the ML-E so they worked fine. A few drops of Arctic Silver secured the 3 LEDs to copper and carefully drilled 1/16th" holes guide the power wires to the LEDs in from the side of the material. It was not by any means necessary but I liked the idea of the power wires coming in from the sides. Because the setup is pretty low current and voltage I was able to get away with using tiny wire.

The base where the copper comes into the Delrin was semi secured with JB weld and still could use some polishing to look better. Maybe next time I'll even have the dimensions before I start machining :)

The end result is a small lamp that smoothly illuminates around it. I don't have an actual current reading to the LEDs but the over all consumption after the driver is 2.15 watts. Not too bad for a bright nightlight :)

























 

Ken_McE

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Jun 16, 2003
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Elegant and nicely done, but you've got to keep monkeys out of the workshop. They will get into everything.
 

Steve K

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I like the copper bar! Where do you buy that sort of copper stock?

The exposed circuit components are interesting, but I'd be worried about someone poking a piece of metal into it and buggering it up. You might just spray some lacquer over it to insulate it without changing the looks much. I also worry that the power transistor might need a bit of heatsinking. Does it get hot?

Steve K.
 

foxtrot824

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The 02135!
Elegant and nicely done, but you've got to keep monkeys out of the workshop. They will get into everything.

Thank you. And I only have the one monkey so I manage to keep things in order, but noted.

I like the copper bar! Where do you buy that sort of copper stock?

The exposed circuit components are interesting, but I'd be worried about someone poking a piece of metal into it and buggering it up. You might just spray some lacquer over it to insulate it without changing the looks much. I also worry that the power transistor might need a bit of heatsinking. Does it get hot?

Steve K.

The copper bar actually came from a copper sheet that was about 8" by 12". I cut it down to the desired/guessed size.

I did think about the possibility of the circuit being shorted, I don't have any kids or pets (except for the monkey pictured above and he only moves tools on me). I like the lacquer idea, I think if I were to make this light for some one I'd certainly do that. The power regulator goes not get too hot mostly because I have a small voltage drop from the power in to the LED power, they are also only running at 170ish mA.
 
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