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Sweeping LED spoiler brake lights


Prostheta

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The project idea is to create a functional yet "different" brake lighting effect to be mounted in the rear spoiler of a MK5b/6/7 Escort. Plus two bottle of red wine.

 

The proposition is to mount a row of 12 LEDs in the rear spoiler of my MK5b Escort and to add an animated "sweep" effect to the illumination/deluminate.

 

To explain the effect i'm aiming for, consider a row of twelve LEDs arranged as so:

spoiler_lights_1.jpg

 

The aim is for the central pair of lights to light up, and move out from the centre to the edge in sequence over the space of say, half a second like so:

spoiler_lights_2.jpg

 

...and when the brake lights extinguish, the lights to go out from the centre like so:

spoiler_lights_3.jpg

 

The circuit i've designed to achieve this uses a simple RC and Schmitt trigger circuit to sequentially illuminate the LEDs from the centre outwards and the reverse....

spoiler_lights_diagram.jpg

 

Yeah yeah yeah, so two bottles of red wine don't help my diagram stuff much, but hey.

 

Right, so what we have here is the LED array (notice the LEDs are grouped into pairs) and a cascade of RC/Schmitt triggers. The trigger feed from the brake light (Vbl) causes the first RC network to start charging using some good old 0.69RCms goodness. When the network achieves the triggering voltage for the Schmitt trigger, the first LED pair light up and the next RC/Schmitt pair starts charging up (on and on). Similarly, when the brake light feed voltage is removed, the RC/Schmitt combinations discharge and the LEDs extinguish from the centre outwards.

 

Right, geeksh1t over.

 

The problem herein lies in the spoiler itself. It's not easy mounting LEDs in the spoiler without the work showing. What i'm aiming to do with this project is to build the circuitry on breadboard, and test it from there before committing to mounting it into the boot frame. Secondly, the invasive Dremel work required to the spoiler is pretty damaging for the cosmetics.

 

All the work from start to finish will be photographed and documented in this thread. Hell, I wouldn't know how to make my car go much faster, but I sure can make some wacky electronic sh1t ;-)

 

To be continued.

 

Very slowly because i'm kind of lazy.

 

PS. Sorry about the crappy diagram. My reference only.

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The LED animation is intended to be more of a transitional thing, so the LEDs illuminate from the centre outwards and stay constant until the brake is released in which case they extinguish from the centre. Modifying the design to include a small logic function could make the lights cycle continuously like that...not sure what would happen if you tapped the brake light on and off mid-cycle though...i'll ponder on this today...
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