12-24-2008, 06:56 PM | #1 |
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LED Brake Light Conversion
I know there were a few threads on RL about this and a bit of scattered information. I eventually figured out what LED's I needed, but the big question always remained. What would it look like? Well I hope this post answers that question for others. First, the specs. I used 24 LEDs from superbrightleds.com. Then I used their series/parallel calculator here, http://led.linear1.org/led.wiz. The numbers I punched in are 14.8 for the Source Voltage, 2.2 for the Diode Forward Voltage, 29 for the Diode Forward Current (mA), and of course 24 for the number of LEDs. If you compare the diode forward voltage I put in compared to the specs of the LED itself you can see that I am above the recommended, but below the peak. My reasoning is that I really don't care if I shorten the life of an LED from a million hours of use to 100,000. That and my car is only putting out just over 14 volts when running. So I should be fine. [As a quick disclaimer: what works for me and my configuration may not work for others.]
The calculator told me to do four groups of six LEDs and use 56 ohms resistors. I got everything wired up and tucked back into the brake light for the pictures below. I may have went overboard on comparisons. However I was never satisfied with the end results people posted previously, if at all. FYI: The YouTube videos have the lights hooked up to a 12v bench power supply as opposed to the 14ish volts from a running car. http://www.youtube.com/watch?v=qPcbb_C5Yog http://www.youtube.com/watch?v=zssucLFLPMA The basket handle isn't attached for these shots and the wires were too short for the LED light I had so I had to rest it outside of the housing. Incandescent with 14v from running car. LED version with 14v from running car. Animated version And I know my drivers side brake light was burnt out! Anyway I hope some of this info will be helpful to others out there wanting to do the conversion. I'll probably do this conversion for a couple of buddies of mine 993s, but I'm kind of entertaining the thought of selling this as a completed brake light. (I'd have to get the old incandescent version back though, convert that, sell that one, repeat, etc.) The light itself can go in either the basket handle or roof/glass mount third brake light.
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-Steve '95 993 C2 '99 Explorer Eddie Bauer Kansas City Wrenching Society aka Raceit |
12-27-2008, 11:51 AM | #2 |
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Great work!
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Patrick Murphy 11 JK - 2.5 Frankenlift, WURX front and rear bumpers/tire carrier, Warn winch Gone, but not forgotten: 95 C4 Cab - Guards/Cashmere, M030/Bilstiens, HIDs, LPMM, MY02s 84 911 Targa - Black/Black 01 TJ - Anniversary Edition, 2" lift, 33" BFG ATKOs, Rhino-lined tub |
03-12-2009, 01:12 AM | #3 |
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That's awesome, nice work Steve. I'm putting this on my list of things to do the next time I have a bulb burn out in the 3rd brake light.
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08-17-2009, 11:48 AM | #4 |
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Steve,
Interested in doing this as well. I presume the first link points to the actual bulbs you purchased? Andreas |
08-17-2009, 02:54 PM | #5 |
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Yep those are the exact ones I bought.
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-Steve '95 993 C2 '99 Explorer Eddie Bauer Kansas City Wrenching Society aka Raceit |
08-17-2009, 03:41 PM | #6 |
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Steve,
Thank you! One more thing - are the resistors 56 ohm, or 560 Ohm? I found this site and am a bit confused.... If these are wrong, could you point me to a known source? Andreas |
08-17-2009, 07:38 PM | #7 | |
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Quote:
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