Author Topic: LED ceiling light fixture  (Read 4970 times)

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Offline Rover

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LED ceiling light fixture
« on: January 15, 2012, 12:40:50 pm »

How I built a 12V LED fixture for the shed.  The new shed (replacing the one Hurricane Irene crushed) needed a ceiling light. And since I like with these, and I had some around, figured I'd build  ceiling fixture that spanned two of the ceiling joists.

Stats: 2000 lumen, ~ 22W , 6 K color temp , 96 LEDs used

LEDS: SMD 5050 LED strips. These are 60 per meter, cuttable every 3

Although I had used PVC has an LED holder in the past, 96 of these were generating way too much heat. See picture below, noticed the discoloration. That idea , discarded.

152-0

Next thought process, is OK make it on aluminum, in this case .090" sheet that I had lying around. Problem, you can't just lay these strips down on aluminum. There are exposed contacts every 3 LED's, just placing it on sheet would produce quite a bit of magic smoke and sparkage when turned on. I still wanted to use the aluminum though, good heat sink. So what I did is drill holes anywhere where there would be a contact. Layed the strips down, then flipped the plate over and filled the holes with epoxy resin. See next pics


153-1


154-2

This is the backside, with the holes.
155-3

The full fixture
156-4

Backside of fixture
157-5

In the Shed
158-6

I would do this again, entire unit is a heatsink and casts a lot of light
Rover
Location: South East Virginia US

(Where did I bury that microcontroller?)

Offline oztules

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Re: LED ceiling light fixture
« Reply #1 on: January 15, 2012, 03:50:32 pm »
Good idea.
I didn't believe the heat leds put out until you bunch up a heap of then in very close proximity.... not as efficient as I first believed.

...............oztules
Flinders Island...... Australia

Offline Rover

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Re: LED ceiling light fixture
« Reply #2 on: January 15, 2012, 03:56:26 pm »
Thanks Oztules,

The 5050 SMD's put out 20-22 lumens each (based on datasheet). They are a 3 chip unit (3 LED), so 96 is like 3x96 LEDs. The have a 120 degree beam angle, which is good for larger area lighting, especialy if used overhead.

Rover
Rover
Location: South East Virginia US

(Where did I bury that microcontroller?)

Offline WooferHound

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Re: LED ceiling light fixture
« Reply #3 on: January 15, 2012, 06:53:13 pm »
What voltage do you run it on ?
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Offline Rover

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Re: LED ceiling light fixture
« Reply #4 on: January 15, 2012, 07:10:35 pm »
Hi Woof,

These are premade, come on a roll for 12V, so basically stuck at that voltage. Each SMD has a 101 Ohm resistor with it on the strip.

Rover 

Rover
Location: South East Virginia US

(Where did I bury that microcontroller?)