Introduction

For the past few months I have been experimenting with Luxeon Power LEDs. My initial test platform was 12-18v flashlights. After creating a number of extreme flashlights with Luxeon K2s, I felt confident I had learned enough about working with Power LEDs to move on to other more interesting platforms.

Features: Three (3) surface mounted Luxeon Rebels.

Total Output: 500+ lumens at 1000ma drive current. This is the highest light density LED currently available on the market.

Power LEDs tend to generate a bit of heat.
Without a heatsink of some kind they will very quickly fail.

For LED cooling purposes I bought 29 salvaged server CPU heat sinks in bulk.

These sinks are a bit difficult to work with but are the best I've got for now.

1b. Two mini heat sinks ready for action!

2a. Now its time to modify the bulb housing from the car.

But before I pull it out, I want to test polarity and make sure I know what is Positive (+) and Negative (-) on the door plug. This way I will know how to get things wired later.

I also wanted to test fit the heat sink and make sure it would fit up inside the door all the way. And it very easily does!

NOTE: Red Wire WITH White Stripe is Negative (-). Solid Red Wire is Positive (+). I used a Sharpie marker and drew some black on the Negative (-) wire to eliminate any chance of confusion.

3a. I didn't just want to glue the heat sink in. I also wanted a more reliable mechanical fastener. One screw will do the trick.

3b. Glue time! After liberally applying high-temp silicone to the sides of the heat-sink I have it clamped down for about 2 hours.

NOTE: Make sure the heat sink is not too high in the plastic housing, the Endor Star requires a few millimeters of clearance to fit inside the factory lens cap. Make sure its not too low either otherwise the LED base won't contact the heat sink. You gotta Goldilocks it!

4a. While the silicone adhesive is still curing I will mount the LEDs. Arctic Alumina thermal adhesive makes this job quick and painless. I love this stuff!

NOTE: Since the Endor Star base is electrically neutral you can actually use any kind of thermal adhesive; Arctic Silver or any other type of thermal epoxy will work just fine.

5a. While the adhesives are curing... I decided I wanted to be able to plug and unplug the new LED housing just like I could with the original.

I used the plug terminals and other pieces from the plastic bulb housing to recreate the factory plug. Now I can just plug it right into the door.

5c. Its time to glue the LED driver onto the housing. Once again high-temp silicone does the trick.

5d. After the LED driver is secure, I need to solder the LED wires from the driver to the Endor Star.
After that it's time to test this bad boy!

After 10 minutes of testing it became clear that I should address the thermal stability of this luminous monstrosity. The heatsink was a bit warm to the touch, not nearly enough to endanger the LEDs. But a good friend of mine (NJW) always told me, "Better off excessive than sorry!". His philosophy is really the basis of this whole project. So let's stick with it!

I want to absolutely ensure that these LEDs will never overheat while stuck in the car door.

6a. Active cooling is going to require some small 40mm fans. These particular units are 5v fans from two video cards circa 2002, they are 10mm thick.

Due to the 5v nature of these fans I will need to limit the power they receive via a 100ohm resistor. This will supply the fans with ~4.75v while the car is running at 14v.

6b. After roughly placing the fan, I need to solder in the resistor, and attach it to power. Due to the proximity of the metal heat sink fins I protected the resistor and its leads with heat shrink. That makes it a bit difficult to see...

6c. Now for a quick test with power before attaching the fan securely. It works like a charm! This fan pushes roughly 3.5 CFM which is more than enough. The heat sink permanently remains cool to the touch.

These old fans have sleeve bearings that are a bit worn. That causes them to be a tad bit louder than I would like. Eventually I will be replacing them with new and quiet 12v ball bearing fans which will also eliminate the need for the resistor.

7c. Mission Status: Complete - Pathological Level of Brightness Attained






NOTE: Yes... I installed Blue Cold Cathode's in my climate control. Its much nicer than the nasty orange, like the radio, which will be torn out pretty soon anyway. You can read more about that here.