OK. The tail lights contain about 50 LEDs per lens. That would be approximately 100 per side. With 25 Low intensity wide angle LEDs and 25 High intensity narrow angle LEDs per lens the Total amperage per lens is still limited to 1 amp. This would total 2 amps on each side of the vehicle when all the LEDs are lit. Given the LED formula : Source Voltage - Forward Voltage over the Forward Current (Or MiliAmps in our Case) = The resistance needed to run the setup.
Our source voltage is obviously 12 Volts in our vehicles. The Forward Voltage for the 8000mcd 30 degree LEDs is 2.6 Volts, and they operate at 20 Ma. Soooooooo.....
12 - 2.6 / .020 = 470 Ohm resistor per LED.
I plan on running approximately 25 LEDs in the Tail lamps in parallel circuit. Meanin that the Ma will increase by the number of LEDs used. 25 X 20 = 500Ma. Given that.....
12 - 2.6 / .500 = 18.8 Ohm resistance for the whole set of LEDs for the Tail lights. The Brake lights would require it's own resistor, since they run at 2.5 Forward volts, and the resistor would have to be a slightly different size.
I have located a supplier that sells LEDs in Bulk and and a box of 100 would cost abbout $44.00, which I feel isn't bad at all for Red LEDs. It is the only thing the company des, so I know they are good quality.
The way this would have to be done.......... The lenses would need to be removed from the vehicle, and using a dremel or other similar tool, the backs of the housings would need to be shaved smooth. That would mean shaving the rough portions of the housing (obviously). From there, you would have to draw a grid on the back of the housing. Where the grids intersect is where the LEDs would be placed. Drill a whole in the housing where each LED is going to be placed, and wedge it it. Wire the LEDs in parallel circuit, solder the conections, and then spray the back of the housing with some kind of sealing adhesive to protect the circuits. I was thinking of something along the lines of undercarraige coating type spray can stuff. Once that's in place and all wired up, then you can hard wire the sytem to your vehicle wiring.
One fall back to this design is the fact that the LEDs would be pretty hard to replace when they burn out. The good thing is, that LEDs can burn up to 100,000 hrs continuously before going out. This equals roughly 11.41 years of continuous burn time. I don't know about you, but I don't plan on leaving my car running and the lights on for 11 and a half years solid.
Guys please tell me what you think about this idea, and tell me if I'm crazy for thinking about trying it.
David Warner
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