Dim/bright circuit for tail/stop light

[ecotack]

I need to make my stop/tail lights brighter. I replaced original light units with Lexus style smoked, but they are covered by another smoked lens as well (TVR Chimaera).

I was thinking of using a Cree XR-E. Driving them is really what I can't make my mind up on. I was thinking of a single 5W driver (DX SKU 26110) and a micro relay switching the LEDs between parallel for tail and series for stop. However this means the bulbs aren't self contained.

I came across these http://autolumination.com/led.html half way down the page, but they seam a little pricey.

Any suggestions?

 

[Foxx510]

Could you just run them direct drive with two different resistor values? I assume you've got heatsinking sorted, they might get hot in there with no airflow.

 

[ecotack]

I could, but when the tail light is on, braking would put the two resistors in parallel and either over drive the LED or give you a brighter brake light at night than in the day (reverse of what you want really).

I suppose if I use two identical resistors (e.g, 33ohm 5watt) and drove one through a diode for the tail and both through two diodes for the stop, it would work. Not very efficient though.

I can knock up a simple heat sink on my mini lathe.